Korean Society of Interventional Cardiology Expert Consensus for the Management of Chronic Coronary Syndrome: Part 2

Author's summary

Chronic coronary syndrome management includes risk-based use of revascularization, particularly for high-risk coronary anatomy, left ventricular dysfunction, or persistent symptoms despite guideline-directed medical therapy. Revascularization improves prognosis in selected patients and relieves angina in others, while the choice between percutaneous coronary intervention and coronary artery bypass grafting should be individualized based on coronary anatomy and clinical risk. Long-term care requires tailored follow-up to detect disease progression, revascularization failure, and cardiovascular complications, along with multidisciplinary management for heart failure, arrhythmias, and valvular disease.

Abstract

Revascularization remains an important component of chronic coronary syndrome (CCS) management, particularly in patients with high-risk coronary anatomy, impaired left ventricular (LV) function, or persistent symptoms despite guideline-directed medical therapy. Evidence indicates that prognostic benefit is most pronounced in patients with left main disease, multivessel disease, proximal left anterior descending artery involvement, and severe LV systolic dysfunction. In other patients, revascularization primarily improves angina symptoms and quality of life. The choice between percutaneous coronary intervention (PCI) and coronary artery bypass grafting should be individualized according to coronary anatomy, clinical risk, comorbidities, and the likelihood of complete revascularization. Contemporary PCI increasingly incorporates coronary physiology and intravascular imaging to refine lesion selection and improve procedural outcomes. Long-term CCS management requires structured follow-up to detect disease progression, recurrent ischemia, revascularization failure, and cardiovascular complications. Routine surveillance testing is not recommended in asymptomatic patients after PCI. Instead, follow-up should be tailored to patient risk and clinical status. When complete revascularization fails, mechanisms such as stent thrombosis, in-stent restenosis, graft failure, and progression of untreated coronary disease should be identified; intravascular imaging has an important role in guiding repeat revascularization. Comprehensive CCS management should also address complications, including heart failure, ventricular arrhythmias, and secondary valvular disease, through a multidisciplinary, patient-centered approach.

GUIDELINE-DIRECTED THERAPY

Revascularization

Invasive treatment for chronic coronary syndrome (CCS) includes percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The role of revascularization in CCS is to relieve inducible myocardial ischemia rather than to treat the underlying atherosclerotic process.¹⁾,²⁾,³⁾ Evidence from meta-analyses suggests that revascularization improves selected cardiovascular (CV) outcomes, primarily by preventing future myocardial infarction (MI), especially in patients with left main (LM) disease,⁴⁾,⁵⁾ 3-vessel disease,⁶⁾ and left ventricular (LV) dysfunction.⁵⁾,⁷⁾,⁸⁾ Recent advances in PCI techniques and pharmacotherapy have expanded the role of PCI in the management of complex coronary artery disease (CAD). In contemporary practice, PCI for patients with CCS should be considered within an integrated decision-making framework that includes (i) appropriate patient selection, (ii) selection of the optimal revascularization modality for complex CAD (PCI vs. CABG), and (iii) interpretation of inducible myocardial ischemia testing together with clinical, anatomical, and physiological determinants.

Evidence regarding revascularization for chronic coronary syndrome

In patients without LM disease or severe LV systolic dysfunction, the ISCHEMIA trial showed that an initial invasive approach in patients with stable CAD and moderate or severe inducible ischemia did not significantly improve the primary outcomes over 5 years compared with an initial conservative approach.⁹⁾ However, the invasive-strategy group had fewer spontaneous MIs and reported better angina control and health status. The ORBITA-2 trial found that PCI reduced angina compared with a placebo procedure in patients with inducible myocardial ischemia.²⁾ Meta-analyses published after the ISCHEMIA trial have consistently reported similar overall survival with routine revascularization and guideline-directed medical therapy (GDMT) alone, but routine revascularization was associated with more procedural MIs, fewer spontaneous MIs and unstable angina episodes, and greater reductions in angina symptoms.¹⁰⁾,¹¹⁾ Extended follow-up of the ISCHEMIA trial (ISCHEMIA-EXTEND) showed a 2.2% absolute reduction in CV mortality (adjusted hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.63–0.96), suggesting a potential benefit of an invasive strategy, particularly in patients with multivessel CAD (≥70% stenosis on coronary computed tomography angiography [CCTA]).¹²⁾ In a post hoc analysis of the ISCHEMIA trial, CAD severity was correlated with higher risks of all-cause death, MI, and the primary endpoint, defined as a composite of death from CV causes, MI, or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest.¹³⁾

The STICH trial randomly assigned 1,212 patients with CAD without LM disease who were eligible for CABG and had an left ventricular ejection fraction (LVEF) ≤35% to receive CABG plus GDMT or GDMT alone. The trial did not meet its primary endpoint of reduced all-cause mortality at a median follow-up of 4 years (HR with CABG, 0.86; 95% CI, 0.72–1.04; p=0.12).¹⁴⁾ However, at a median follow-up of 9.8 years, CABG significantly reduced both all-cause and CV mortality compared with GDMT alone (all-cause mortality: 58.9% vs. 66.1%; HR, 0.84; 95% CI, 0.73–0.97; p=0.02; CV mortality: 40.5% vs. 49.3%; HR, 0.79; 95% CI, 0.66–0.93; p=0.006).¹⁵⁾ Myocardial viability was assessed by single-photon emission computed tomography (SPECT) and/or dobutamine echocardiography in 50% of patients in the STICH trial; 298 patients were randomized to CABG and 303 to GDMT alone.¹⁶⁾ No significant interactions were observed between the presence or absence of myocardial viability and improvement in LV function or the long-term survival benefit of CABG over GDMT.¹⁶⁾,¹⁷⁾,¹⁸⁾ The REVIVED-BCIS2 trial randomized 700 patients with impaired LV function (LVEF ≤35%), extensive CAD amenable to PCI, and evidence of myocardial viability in at least 4 dysfunctional myocardial segments to PCI plus GDMT or GDMT alone.¹⁹⁾ After 3.4 years of follow-up, PCI did not significantly reduce the composite primary endpoint of all-cause death or heart failure rehospitalization (HR, 0.99; 95% CI, 0.78–1.27; p=0.96). Patients treated with PCI had slight and transient symptom improvement, without incremental improvement in overall LV function compared with GDMT. However, the PCI group had significantly lower risks of spontaneous MI and implantation of an implantable cardioverter-defibrillator (ICD) or cardiac resynchronization therapy device than the GDMT group.

The heterogeneous designs of these studies, combined with the limited statistical power of subgroup analyses, variation in viability-assessment methods, and inconsistent quantification of viability, leave important questions about how viability should be defined and how revascularization should be selected for patients with CCS.²⁰⁾ Additional randomized controlled trials are needed to clarify the potential benefit of PCI in this population.

When to revascularize for prognostic benefit

The following indications refer specifically to revascularization performed for prognostic benefit, including reductions in CV mortality and/or spontaneous MI, rather than for symptom control.

For patients with LVEF >35%, revascularization in addition to GDMT is recommended for (i) functionally significant LM stenosis, to improve survival⁴⁾,⁵⁾,²¹⁾; (ii) 3-vessel disease, to improve long-term survival and reduce CV mortality and the risk of spontaneous MI¹⁰⁾,¹¹⁾,¹²⁾,¹³⁾,²²⁾; and (iii) single- or 2-vessel disease involving the proximal left anterior descending (LAD), to reduce CV mortality and spontaneous MI.⁵⁾,¹⁰⁾,¹¹⁾,¹²⁾,¹³⁾,²²⁾

For patients with LVEF ≤35%, the choice between revascularization and medical therapy should follow Heart Team evaluation of coronary anatomy, the possible contribution of CAD to LV dysfunction, comorbidities, life expectancy, and patient preferences.²³⁾ In surgically eligible patients with multivessel disease, CABG is recommended over medical therapy to improve survival¹⁴⁾,¹⁵⁾,²⁴⁾,²⁵⁾; PCI may be considered when surgical risk exceeds the expected benefit or when surgery is not feasible.¹⁹⁾,²⁶⁾

When to revascularize for symptom relief

Independent of the prognostic indications outlined above, revascularization is also recommended for symptom relief in patients with persistent angina or anginal-equivalent symptoms despite GDMT and functionally significant obstructive CAD. This recommendation is consistent with sham-controlled and randomized controlled data showing improved angina and health status after ischemia-guided PCI.¹⁰⁾,²⁷⁾,²⁸⁾,²⁹⁾,³⁰⁾

Selecting the modality: percutaneous coronary intervention vs. coronary artery bypass grafting

Heart Team–based, individualized decision-making is particularly important in patients with LM disease, multivessel disease, diabetes mellitus, reduced LVEF, or high anatomical complexity, such as a high SYNTAX score, because the choice of revascularization modality can have substantial prognostic implications.

Meta-analyses of randomized clinical trials (RCTs) have shown that the risk of death is similar after CABG and PCI for LM CAD up to 5–10 years after intervention, even among patients with a high SYNTAX score. However, CABG is associated with a higher risk of stroke, whereas PCI is associated with a higher risk of spontaneous MI.³¹⁾,³²⁾,³³⁾,³⁴⁾,³⁵⁾ Subgroup analyses based on SYNTAX score and the number of additionally involved coronary vessels showed no difference in all-cause mortality between CABG and PCI among patients with a SYNTAX score ≤32 or LM stenosis with 0 or 1 additional diseased vessel. However, a trend toward higher all-cause mortality was observed with PCI among patients with a SYNTAX score ≥33 (HR, 1.30; 95% CI, 0.92–1.84) and/or LM stenosis with 2 or 3 additional diseased vessels (HR, 1.25; 95% CI, 0.97–1.60).³⁶⁾ Despite excellent angiographic results after LM bifurcation stenting, 13% of patients still had residual ischemia, which was associated with higher long-term CV mortality.³⁷⁾ Intracoronary imaging guidance to optimize stent expansion and prevent side-branch jailing may improve outcomes after PCI for bifurcation LM lesions.³⁸⁾,³⁹⁾

The SYNTAX trial and its 5-year follow-up, which compared PCI and CABG for multivessel CAD with or without unprotected LM CAD, reported differences in survival and freedom from CV events according to SYNTAX score.⁴⁰⁾,⁴¹⁾ The 10-year follow-up reported similar all-cause mortality with the 2 revascularization modalities overall,⁴²⁾ but mortality was significantly higher among patients with SYNTAX scores ≥33 who were randomized to PCI (HR, 1.41; 95% CI, 1.05–1.89). In the FREEDOM trial, 1,900 patients with diabetes and multivessel disease without LM CAD were randomized to CABG or PCI with first-generation drug-eluting stents (DESs).⁴³⁾ At a median follow-up of 3.8 years, all-cause mortality was higher in the PCI group than in the CABG group (24.3% vs. 18.3%; p=0.01).

1. Left main disease

In low-surgical-risk patients, CABG is recommended over medical therapy and is generally preferred over PCI because it is associated with lower rates of spontaneous MI and repeat revascularization. PCI is recommended as an alternative when a SYNTAX score ≤22 and suitable anatomy allow equivalent completeness of revascularization; PCI should be considered for SYNTAX scores of 23–32 when similar completeness is achievable. These recommendations reflect the 2022 European Society of Cardiology (ESC)/European Association for Cardio-Thoracic Surgery (EACTS) joint review and individual-patient-data meta-analysis of LM CAD.³²⁾,³⁶⁾

2. Left main and multivessel disease

In suitable low-risk candidates with LM and multivessel disease, CABG is recommended over medical therapy.⁴⁾,⁵⁾ PCI may be considered over medical therapy when surgical risk is high.³¹⁾,⁴⁴⁾

3. Multivessel disease with diabetes

In patients with multivessel disease and diabetes, CABG is recommended to improve symptoms and clinical outcomes.⁴³⁾,⁴⁵⁾,⁴⁶⁾,⁴⁷⁾,⁴⁸⁾,⁴⁹⁾ PCI should be considered in patients at very high surgical risk.²²⁾,⁴⁹⁾

4. Three-vessel disease without diabetes, preserved left ventricular ejection fraction

In patients with 3-vessel disease without diabetes and with preserved LVEF, CABG is recommended over medical therapy.⁵⁾,⁶⁾,⁵⁰⁾ PCI is recommended when anatomical complexity is low to intermediate and completeness of revascularization equivalent to CABG is feasible, recognizing that trials such as FAME 3 have shown generally noninferior survival and lower invasiveness but higher rates of repeat revascularization.³¹⁾,⁴⁰⁾,⁴²⁾,⁵¹⁾,⁵²⁾

5. Single/2-vessel with proximal left anterior descending

In patients with single- or 2-vessel disease involving the proximal LAD, CABG or PCI is recommended over medical therapy.²⁾,⁵⁾,²⁸⁾,⁵³⁾,⁵⁴⁾ CABG is recommended when lesion complexity makes PCI less suitable, particularly to reduce the need for repeat revascularization.⁵⁵⁾,⁵⁶⁾,⁵⁷⁾

6. Single/2-vessel without proximal left anterior descending

In patients with single- or 2-vessel disease without proximal LAD involvement, PCI is recommended for symptom relief. CABG may be considered when PCI is not feasible.¹⁰⁾,²⁷⁾,²⁸⁾

Complete or partial revascularization

Coronary revascularization should aim to achieve complete revascularization of ischemia-causing vessels or lesions when feasible. Unintended incomplete revascularization is associated with worse outcomes and often reflects greater anatomical complexity or comorbidity.⁵⁸⁾,⁵⁹⁾,⁶⁰⁾ Among patients with high-risk multivessel CAD, incomplete anatomical revascularization has been reported more frequently after PCI than after CABG, with rates of more than 50% after PCI and approximately 30% after CABG.⁵⁹⁾,⁶¹⁾,⁶²⁾ However, whether complete revascularization should be defined anatomically or functionally remains unclear. In the PCI group of the SYNTAX trial, a higher residual SYNTAX score, indicating incomplete anatomical revascularization, was associated with higher mortality.⁵⁸⁾ Conversely, outcomes after anatomically incomplete but functionally complete revascularization with PCI were superior to those after anatomically complete revascularization.⁶³⁾,⁶⁴⁾ Therefore, the distinction between “complete” and “partial” revascularization should not be the sole determinant of treatment strategy; instead, decisions should balance patient-centered goals, procedural risk, and expected clinical benefit.

Recommendations

• • In patients with LM disease, complex multivessel disease, diabetes mellitus, reduced LVEF, or a high SYNTAX score, an individualized decision regarding revascularization modality by a multidisciplinary Heart Team is recommended.

• • In patients with CCS and LVEF >35%, myocardial revascularization, in addition to GDMT, is recommended for those with functionally significant LM stem stenosis, functionally significant 3-vessel disease, or functionally significant single- or 2-vessel disease involving the proximal LAD to improve survival and reduce the risk of spontaneous MI.

• • In patients with CCS and LVEF ≤35%, the choice between revascularization and medical therapy alone should be made after careful evaluation, preferably by the Heart Team, of coronary anatomy, the correlation between CAD and LV dysfunction, comorbidities, life expectancy, the individual benefit–risk balance, and patient perspectives.

• • In surgically eligible patients with CCS, multivessel CAD, and LVEF ≤35%, myocardial revascularization with CABG is recommended over medical therapy alone to improve long-term survival.

• • In selected patients with CCS, functionally significant multivessel disease, and LVEF ≤35% who are at high surgical risk or are not operable, PCI may be considered as an alternative to CABG.

• • In patients with CCS and persistent angina or anginal-equivalent symptoms despite GDMT, myocardial revascularization of functionally significant obstructive CAD is recommended to improve symptoms.

• • In patients with multivessel obstructive CAD, calculation of the SYNTAX score is recommended to assess anatomical disease complexity.

• • Physicians should select the most appropriate revascularization modality according to patient profile, coronary anatomy, procedural factors, LVEF, patient preferences, and expected outcomes.

Percutaneous coronary intervention planning & optimization

1. Coronary physiology

In patients with multivessel disease, intracoronary pressure measurement using fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR), or computational assessment using quantitative flow ratio (QFR), is recommended to guide target-lesion selection.²⁸⁾,⁶³⁾,⁶⁴⁾,⁶⁵⁾,⁶⁶⁾,⁶⁷⁾ Although FAVOR III China supported the use of QFR to guide PCI,⁶⁷⁾ subsequent trials evaluating angiography-derived physiological indices have produced more heterogeneous results across systems and populations.⁶⁸⁾ More recently, 2 large randomized noninferiority trials, FAST-3 and ALL-RISE, demonstrated the noninferiority of wire-free, angiography-based physiological assessment to wire-based FFR for 1-year clinical outcomes, with shorter procedural times in the wire-free arms.⁶⁹⁾,⁷⁰⁾ These findings support angiography-derived physiology as a clinically validated alternative to wire-based FFR in selected patients.

Nevertheless, angiographically guided PCI does not guarantee functionally optimized PCI.⁷¹⁾,⁷²⁾,⁷³⁾,⁷⁴⁾ Multiple studies have shown that a substantial proportion of patients with angiographically successful PCI have residual ischemia, reflected by suboptimal post-PCI FFR²⁷⁾,⁷⁵⁾,⁷⁶⁾ or iFR values,⁷⁷⁾ and that these findings are associated with worse clinical outcomes.²⁷⁾,⁷²⁾,⁷⁵⁾,⁷⁶⁾,⁷⁸⁾,⁷⁹⁾,⁸⁰⁾,⁸¹⁾,⁸²⁾ The TARGET-FFR trial showed that adjunctive therapy can improve physiological results in some patients, although residual ischemia may persist. Approximately 25% of patients have residual ischemia despite angiographically “good” results, often because of focal lesions not evident on angiography. After adjunctive therapy, the percentage increase in FFR had a modest but significant correlation with angina score, and a larger percentage increase in FFR was associated with a lower burden of patient-reported angina⁸³⁾ and better prognosis after PCI.⁷²⁾ On the basis of this evidence, the ESC guidelines recommend considering intracoronary pressure measurement using FFR or iFR, or computational assessment using QFR, at the end of the procedure to identify patients at high risk for persistent angina and future clinical events.²³⁾

2. Intravascular imaging

Intravascular ultrasound (IVUS)- or optical coherence tomography (OCT)-guided PCI is recommended for anatomically complex lesions, including LM lesions, true bifurcations, and long lesions. Recent RCTs, including RENOVATE-COMPLEX-PCI, OCTOBER, ILUMIEN IV, and OCCUPI, have shown that intravascular imaging-guided PCI reduces major vessel- or lesion-related events compared with angiography-guided PCI, although ILUMIEN IV was neutral for its primary composite endpoint but showed less stent thrombosis with OCT.³⁸⁾,³⁹⁾,⁸⁴⁾,⁸⁵⁾ In the RENOVATE-COMPLEX-PCI trial (n=1,639; IVUS, 75%; OCT, 25%), imaging guidance significantly reduced target-vessel failure (7.7% vs. 12.3%; HR, 0.64; 95% CI, 0.45–0.89) and cardiac death (1.7% vs. 3.8%) at a median follow-up of 2.1 years.³⁹⁾ The OCTOBER trial confirmed the superiority of OCT guidance specifically in bifurcation lesions, with a lower 2-year target-lesion failure rate (10.1% vs. 14.1%; HR, 0.70; 95% CI, 0.50–0.98).³⁸⁾ The ILUMIEN IV trial was neutral for its primary composite clinical endpoint but demonstrated a larger final minimal stent area and a markedly lower rate of definite or probable stent thrombosis (0.5% vs. 1.4%) with OCT guidance.⁸⁴⁾ Most recently, the Korean OCCUPI trial reported a 38% reduction in the composite of cardiac death, MI, stent thrombosis, and target-vessel revascularization at 1 year (4.6% vs. 7.4%) with OCT guidance in complex lesions.⁸⁵⁾ Regarding the choice between OCT and IVUS, the Korean OCTIVUS trial demonstrated the noninferiority of OCT compared with IVUS for clinical outcomes, supporting flexible modality selection based on lesion characteristics, operator experience, and institutional resources.⁸⁶⁾

The superior outcomes observed with intravascular imaging guidance are primarily attributed to improved stent optimization. OCT and IVUS help operators achieve larger stent expansion, and studies have shown that minimal stent area remains the strongest predictor of clinical outcomes.⁸⁷⁾ In ILUMIEN IV, OCT guidance led to more frequent advanced lesion preparation, larger stent selection, higher balloon pressures during post-dilation, and ultimately better stent expansion.⁸⁴⁾ Intravascular imaging also significantly reduces acute procedural complications that predispose patients to stent thrombosis. OCT-guided PCI was associated with fewer major edge dissections, major malapposition, major tissue protrusion, and untreated focal reference-segment disease.⁸⁴⁾ These factors have been directly linked to subsequent adverse events, particularly stent thrombosis. In addition, preprocedural imaging allows optimal selection of stent landing zones, avoiding areas with a high plaque burden (>50%) or lipid-rich tissue that may predispose patients to edge dissection and restenosis. This is particularly important in complex lesions, for which angiography provides limited information about vessel-wall characteristics. When intravascular imaging is not available, quantitative coronary angiography-guided PCI may be considered as a procedural optimization tool.⁸⁸⁾

Recommendations

• • Intracoronary pressure measurement using FFR or iFR is recommended to guide lesion selection for intervention in patients with multivessel disease.

• • Intracoronary pressure measurement using FFR or iFR should be considered at the end of the procedure to identify patients at high risk for persistent angina and subsequent clinical events.

• • Intracoronary imaging guidance using IVUS or OCT is recommended when PCI is performed for anatomically complex lesions, particularly LM stem lesions, true bifurcations, and long lesions.

LONG-TERM FOLLOW-UP AND CARE

Diagnosis of disease progression

Long-term follow-up of patients with CCS, including those with prior acute MI, prior revascularization, or known CAD, should focus on surveillance for disease progression and recurrent cardiac events. Current evidence remains limited regarding the optimal mode, frequency, and duration of follow-up. Therefore, clinical assessment should be individualized according to each patient’s risk profile, residual symptoms, cardiac complications, such as LV remodeling or dysfunction, functional mitral regurgitation, heart failure, or significant arrhythmia, and extracardiac comorbidities, such as peripheral artery disease, stroke, or renal dysfunction.

The main objectives of follow-up are to stratify future risk for adverse CV events, detect symptoms suggestive of CAD progression, and diagnose and manage extracoronary complications such as heart failure, arrhythmia, or valvular dysfunction. Antianginal and disease-modifying therapies should be optimized during follow-up, taking into account new comorbidities and tolerability issues. The benefit–risk balance of long-term antithrombotic therapy should also be periodically reevaluated. Although angina assessment has traditionally been central to follow-up, symptoms resolve within 1 year in approximately 40% of patients with CCS, often without revascularization or major medication changes.⁸⁹⁾ Conversely, persistent or recurrent angina indicates a higher risk of CV death or MI, particularly among patients with a history of MI.⁹⁰⁾

Risk factors for recurrent coronary events

Patients with established atherosclerotic cardiovascular disease are at high risk for recurrent events. Large registries such as REACH have shown that, in addition to conventional risk factors, disease burden, lack of treatment, and geographic factors are associated with increased CV morbidity and mortality, leading to the development of a validated risk score for major adverse cardiovascular events (MACE).⁹¹⁾

Recent European cohort data from EUROASPIRE IV and V, together with external validation from the SWEDEHEART registry, established an online model to estimate recurrent CV risk in patients younger than 75 years.⁹²⁾ Comorbidities, including diabetes, renal insufficiency, dyslipidemia, and psychological distress, such as depression or anxiety, were major determinants of recurrent MACE. Findings from the UK Biobank confirmed that traditional risk factors, lifestyle and sociodemographic variables, genetic predisposition to CAD, low high-density lipoprotein cholesterol, and younger age at the first acute coronary syndrome (ACS) event significantly predict recurrence risk.⁹³⁾ Adding a polygenic risk score to conventional tools such as the Framingham score modestly improved predictive accuracy.⁹⁴⁾

Despite these refinements, the overall predictive performance of current risk models remains limited, and a substantial proportion of recurrent MACE events remains unexplained. Existing models also do not incorporate LV function, heart failure, valvular disease, atherosclerotic burden in other vascular territories, or anatomical CAD severity.

Organization of long-term follow-up

The frequency and intensity of follow-up should be determined by patient characteristics, CV risk factors, diagnostic-test availability, and healthcare resources. Different CCS phenotypes may evolve or recur over time, requiring adjustment of follow-up intervals and methods. A stepwise, risk-based approach similar to that used in the diagnostic pathway is appropriate.

1. Step 1: Annual clinical evaluation

Annual review by a cardiologist or general practitioner should include symptom assessment, medication review, physical examination, resting 12-lead electrocardiography (ECG), and laboratory testing, including lipid profile, renal function, glycemic status, and complete blood count. The ECG should be reviewed for rhythm, evidence of silent ischemia or prior infarction, and conduction intervals, including PR, QRS, and QT intervals. More frequent follow-up, such as every 3–6 months, should be considered in patients with reduced LVEF, recent revascularization of complex anatomy, such as LM or multivessel PCI, incomplete revascularization, recurrent or unstable symptoms, recent dose changes in antianginal or antithrombotic therapy, or significant comorbidities such as diabetes mellitus, chronic kidney disease, or heart failure.²³⁾

2. Step 2: New or worsening symptoms

The 2024 ESC guidelines recommend further cardiac evaluation when patients develop new or worsening angina, heart failure symptoms, arrhythmias, or ischemic ECG changes, particularly when symptoms persist despite optimized GDMT.²³⁾ Echocardiography should be performed to assess LV function and valvular structure. Exercise ECG testing may be considered to confirm symptoms and evaluate exercise tolerance when clinically relevant. Notably, in the POST-PCI trial of 1,706 high-risk post-PCI patients (mean age, 64.7 years), routine functional testing at 12 months did not reduce the 2-year composite of death, MI, or hospitalization for unstable angina (5.5% in the testing group vs. 6.0% in the standard-care group; HR, 0.90; 95% CI, 0.61–1.35; p=0.62).⁹⁵⁾ On the basis of these findings, routine functional testing is not recommended for asymptomatic post-PCI patients in the 2023 American Heart Association (AHA)/American College of Cardiology (ACC) guidelines.⁹⁶⁾

3. Step 3: Persistent symptoms or left ventricular dysfunction

The 2024 ESC guidelines recommend further cardiac imaging to assess CAD progression in patients with persistent symptoms despite optimized GDMT, particularly those with reduced LV function or regional wall-motion abnormalities.²³⁾ In patients with nonobstructive CAD, CCTA is useful for detecting new obstructive lesions, evaluating atherosclerotic progression, and identifying high-risk plaque features. According to the 2024 ESC guidelines, noninvasive functional imaging, such as stress echocardiography, SPECT, positron emission tomography (PET), or stress cardiac magnetic resonance (CMR), is preferred in patients with obstructive CAD or a history of cardiac events to detect and quantify ischemia or myocardial scar. In patients with severe angina or extensive ischemia on testing, direct referral for invasive coronary angiography (ICA) for potential revascularization is appropriate. However, the 2023 AHA/ACC guidelines note that routine periodic ICA may be harmful in patients without a change in clinical or functional status.⁴⁾ Although CCTA can assess bypass-graft patency and rule out in-stent restenosis (ISR) in large vessels, functional imaging remains the preferred modality in post-revascularization patients because of their diffuse disease burden.⁹⁷⁾,⁹⁸⁾

4. Step 4: Management optimization and revascularization

Before further interventions are considered, lifestyle modification, risk-factor control, and GDMT should be intensified. In patients with significant inducible ischemia or high-risk CAD and persistent angina despite optimized therapy, repeat revascularization may be indicated for symptom relief and prognostic improvement. In patients with prior CABG, GDMT should be optimized first. If frequent angina persists, ICA or CCTA may guide treatment decisions. When symptoms are uncertain, functional testing can clarify the presence and extent of myocardial ischemia.⁹⁹⁾

Non-invasive diagnostic testing

Noninvasive imaging modalities, including CCTA, stress SPECT or PET myocardial perfusion imaging, stress echocardiography, and stress CMR, provide prognostic information in patients with established CAD.¹⁰⁰⁾ CCTA is useful for assessing LM disease and graft patency, whereas stress imaging quantifies ischemic burden to guide management decisions. For example, symptomatic patients with moderate-to-severe ischemia despite GDMT generally benefit from further revascularization.

For patients with angina with non-obstructive coronary arteries (ANOCA) or ischemia with non-obstructive coronary arteries (INOCA), invasive coronary functional testing remains the current reference standard for confirming coronary vasomotor dysfunction. In the ILIAS registry, among 287 patients with nonobstructive coronary stenoses, 38.2% were diagnosed with INOCA and 45.3% had coronary microvascular dysfunction (CMD), defined as a coronary flow reserve ≤2.5. CMD was independently associated with a higher 5-year risk of MACE (adjusted HR, 2.88; 95% CI, 1.52–7.19; p=0.024), and concomitant CMD and INOCA conferred the highest risk (adjusted HR, 4.00; 95% CI, 1.41–11.35; p=0.009).¹⁰¹⁾ Stress SPECT, PET, stress CMR, or stress echocardiography remain first-line investigations, although their diagnostic yield may be modest.

Evidence from Korea

In the POST-PCI randomized trial, which included 1,706 high-risk patients who had undergone PCI, routine functional testing at 1 year, including nuclear stress testing, exercise ECG, or stress echocardiography, did not reduce the 2-year composite outcome of all-cause death, MI, or hospitalization for unstable angina compared with standard care (5.5% vs. 6.0%; HR, 0.90; 95% CI, 0.61–1.35; p=0.62).⁹⁵⁾ A detailed assessment showed no difference in any component of the primary outcome between the 2 groups.

Compared with standard care, routine functional testing was associated with greater use of ICA at 2 years (12.3% vs. 9.3%) and higher rates of repeat revascularization (8.1% vs. 5.8%), without improvement in clinical outcomes. These findings indicate that routine surveillance testing after PCI does not provide clinical benefit in high-risk patients, despite increasing downstream invasive procedures.

Recommendations

• • Follow-up should be individualized according to risk, symptoms, comorbidities, and cardiac structural and functional status. A risk-based, stepwise follow-up strategy is recommended.

• • Annual clinical evaluation with ECG and laboratory testing is recommended.

• • Routine functional testing is not recommended in asymptomatic post-PCI patients.

• • New or persistent symptoms warrant targeted cardiac evaluation, including echocardiography, functional testing, CCTA, or ICA, as clinically appropriate.

• • Stress imaging is recommended to evaluate ischemia when symptoms persist despite GDMT.

• • In patients with suspected ANOCA or INOCA, invasive coronary functional testing may be considered if noninvasive testing is inconclusive. Patients with CMD or combined CMD and INOCA should be recognized as high risk and monitored closely.

Treatment of revascularization failure

Except in cases of procedural failure, revascularization failure refers to recurrent vessel occlusion or restenosis after initially successful revascularization. Revascularization failure frequently requires repeat revascularization, with a cumulative incidence of approximately 10% within the first 5 years after the index procedure.¹⁰²⁾

This consensus document focuses on the management of revascularization failure that creates a clinical need for repeat revascularization, based on the following underlying mechanisms: (i) PCI failure, (ii) CABG failure, and (iii) progression of residual CAD that was previously left untreated.

Failure of percutaneous coronary intervention

In contemporary practice, DESs are predominantly used for PCI. Accordingly, stent thrombosis and ISR are the major mechanisms of PCI failure requiring repeat revascularization.

1. Stent thrombosis

Stent thrombosis is defined as thrombus formation within or adjacent to a previously implanted stent, usually resulting in occlusion of the stented segment. According to the Academic Research Consortium criteria, stent thrombosis is classified by timing of onset (early, late, or very late) and level of diagnostic certainty (definite, probable, or possible).¹⁰³⁾ The incidence of definite stent thrombosis is approximately 1.0% within the first year, with an annual incidence of 0.2–0.5% thereafter.¹⁰⁴⁾,¹⁰⁵⁾ Stent thrombosis usually presents as acute MI and carries a high mortality rate of approximately 30%.¹⁰⁶⁾,¹⁰⁷⁾ Therefore, management should follow current guideline recommendations for ACS.¹⁰⁸⁾,¹⁰⁹⁾,¹¹⁰⁾

ICA is mandatory for both diagnosis and treatment in patients with suspected stent thrombosis. If thrombotic occlusion has impaired coronary flow, Thrombolysis in Myocardial Infarction 3 flow should be restored promptly. Intravascular imaging with IVUS or OCT is strongly recommended to elucidate the underlying mechanisms of stent failure.¹⁰⁹⁾,¹¹⁰⁾,¹¹¹⁾,¹¹²⁾ Adjunctive therapies, such as thrombus aspiration or glycoprotein IIb/IIIa inhibitors, may be considered in patients with a large thrombus burden.¹¹³⁾,¹¹⁴⁾ Contributing factors should be identified and corrected. Mechanical causes include stent underexpansion or malapposition, significant stent-edge dissection, geographic miss, and deficits in stent integrity, such as stent gap, stent fracture, or longitudinal deformation.¹¹⁵⁾ Underexpansion or malapposition requires correction with noncompliant (NC) balloons, potentially including very-high-pressure NC balloons, or intravascular lithotripsy (IVL).¹¹⁶⁾,¹¹⁷⁾ Routine repeat stenting should be avoided, especially in the presence of an underexpanded stent or multiple stent layers. If significant residual disease is present in the stented segment, or if edge dissection or a deficit in stent integrity is present, repeat stenting with DES is generally recommended. Nonmechanical causes include nonadherence to antiplatelet therapy or hyporesponsiveness to antiplatelet agents.¹¹⁸⁾,¹¹⁹⁾ Assessment of antiplatelet adherence is mandatory, and potent P2Y12 inhibitors such as prasugrel or ticagrelor are preferred over clopidogrel after stent thrombosis.¹²⁰⁾ Prolonged dual antiplatelet therapy beyond 12 months may be considered in patients with high ischemic risk but without high bleeding risk.¹²¹⁾

2. In-stent restenosis

ISR is an angiographic diagnosis, defined as >50% diameter stenosis within the stented segment, and is the most common cause of PCI failure. It may lead to target-lesion revascularization in up to 10% of patients within 10 years after DES implantation.¹⁰²⁾,¹²²⁾ Neointimal hyperplasia, representing an exaggerated healing response to vessel-wall injury, and neoatherosclerosis are the primary biological etiologies.¹⁰²⁾,¹²³⁾ Clinically, ISR most commonly presents as CCS; approximately 20% of patients present with ACS, whereas others remain asymptomatic. Revascularization should be considered only in the presence of symptoms or objective evidence of myocardial ischemia.¹²⁴⁾,¹²⁵⁾

Because the underlying mechanical causes of ISR often overlap with those of stent thrombosis, the management principles are similar. Stent underexpansion is the principal mechanical determinant of ISR, whereas stent malapposition and tissue prolapse have limited prognostic impact.¹²⁶⁾,¹²⁷⁾ If revascularization is indicated, treatment should target the stenotic segment rather than the entire stented segment.¹⁰²⁾ The critical procedural principle is to achieve maximal acute luminal gain through meticulous lesion preparation. The mechanism of ISR should be identified and corrected accordingly. Intravascular imaging is strongly recommended to identify the underlying mechanism and correct contributing mechanical factors.²³⁾,¹²⁸⁾,¹²⁹⁾ If significant neointimal hyperplasia or neoatherosclerosis is present, cutting or scoring balloons may yield better acute angiographic outcomes than semi-compliant balloons.¹³⁰⁾,¹³¹⁾ If underexpansion or stent collapse is identified, aggressive dilation with NC balloons, very-high-pressure NC balloons, or IVL may be necessary.¹¹⁶⁾,¹¹⁷⁾ After optimal lesion preparation, repeat DES implantation is generally preferred over drug-coated balloon (DCB) angioplasty, particularly for DES-ISR, based on recent evidence suggesting greater efficacy in preventing repeat revascularization (ESC Class I recommendation).¹³²⁾ However, DCB remains a valuable option (ESC Class I),¹³³⁾,¹³⁴⁾ especially to avoid multiple metallic layers, because ≥3 layers are associated with persistent underexpansion and worse outcomes.¹²⁶⁾,¹³⁵⁾ Therefore, the choice between these strategies should be individualized according to patient and lesion characteristics.¹⁰²⁾

In summary, repeat DES implantation is generally favored for DES-ISR with a single metallic layer, focal lesions, significant residual disease, edge dissection, or stent-integrity defects. DCB is preferred when ≥2 metallic layers are already present, in long diffuse ISR where additional stent layers are undesirable, or when bifurcation anatomy makes repeat stenting technically unfavorable.¹⁰²⁾ In all cases, underlying mechanical issues, such as underexpansion, must be corrected before the final treatment strategy is selected.

Recommendations

• • In patients with suspected stent thrombosis, coronary angiography is mandatory for both diagnosis and treatment.

• • In patients with ISR, revascularization should be considered only in the presence of symptoms or objective evidence of myocardial ischemia.

• • Intravascular imaging (IVUS/OCT) is strongly recommended to clarify the underlying mechanisms of stent failure.

• • Stent underexpansion or malapposition should be corrected using NC balloons or IVL.

• • Repeat DES implantation is generally recommended in cases of residual disease in the stented segment, edge dissection, or a deficit of stent integrity.

• • Routine repeat stenting should be avoided, especially in the presence of an underexpanded stent or multiple stent layers.

• • DCB is preferred in cases of ISR with multiple metallic layers.

• • In patients with stent thrombosis, assessment of antiplatelet adherence is necessary, and potent P2Y₁₂ inhibitors are preferred after stent thrombosis.

Failure of coronary artery bypass grafting

CABG failure is defined as angiographic occlusion or significant stenosis of a bypass graft. Despite guideline recommendations favoring arterial grafting because of superior long-term patency, saphenous vein grafts (SVGs) remain more widely used than arterial grafts in contemporary practice.¹³⁶⁾,¹³⁷⁾ The cumulative incidence of SVG failure is up to 50% at 10 years after surgery, with graft occlusion rates reaching up to 27% within the first year.¹³⁸⁾,¹³⁹⁾ Graft failure can be categorized as acute or late according to time of onset, reflecting distinct underlying mechanisms.

1. Acute graft failure

Acute graft failure, occurring within the first month after CABG, is observed in up to approximately 12% of grafts.¹⁴⁰⁾ The predominant causes are surgical technical errors and competitive flow from the native coronary artery. Because acute graft failure frequently results in MI and carries a substantial mortality risk, coronary angiography is recommended in patients with sudden clinical deterioration or new evidence of myocardial ischemia after CABG. Treatment decisions should be guided by multidisciplinary Heart Team discussion.¹⁴¹⁾,¹⁴²⁾ PCI of the native coronary vessel is preferred when anatomically suitable (ESC/ACC Class I). Redo CABG may be considered when PCI is not feasible because of anatomical constraints or when multiple critical grafts, including the left internal mammary artery graft to the LAD, are occluded. If diagnosis is delayed and myocardial viability is expected to be limited, conservative management should be considered.¹²⁸⁾,¹²⁹⁾

2. Late graft failure

Late graft failure, occurring more than 1 month after surgery, is characterized by neointimal hyperplasia and accelerated atherosclerosis, leading to degenerative graft changes.¹³⁸⁾,¹⁴³⁾ Clinically relevant late graft failure most commonly presents as CCS or unstable angina. Because redo CABG is associated with higher periprocedural mortality than PCI, PCI is generally preferred as the initial revascularization strategy for late graft failure.¹⁴⁴⁾ Redo CABG should be considered when PCI is anatomically unsuitable, particularly in the absence of patent arterial grafts. PCI of SVGs carries higher risks of periprocedural distal embolization and future adverse CV events than PCI of native coronary vessels in observational data, forming the basis for current ESC/ACC guideline recommendations that favor native-vessel PCI whenever feasible (Class IIa).¹²⁸⁾,¹²⁹⁾,¹⁴⁵⁾ However, the randomized PROCTOR trial reported a lower 1-year rate of major adverse cardiac events after PCI of relatively simple SVG lesions than after PCI of native coronary vessels, providing conflicting evidence that may refine contemporary practice.¹⁴⁶⁾

Recommendations

• • Coronary angiography is recommended for both diagnosis and treatment of acute graft failure in patients with sudden clinical deterioration or new evidence of myocardial ischemia after CABG.

• • In patients with graft failure, treatment decisions should be guided by multidisciplinary Heart Team discussion.

• • PCI is generally recommended over redo CABG as the initial revascularization strategy when anatomically feasible.

• • Redo CABG should be considered when PCI is not technically or anatomically feasible.

• • In patients with acute graft failure, conservative management may be considered if the diagnosis is delayed and myocardial viability is expected to be limited.

• • PCI of the native coronary vessel is generally preferred over PCI of the graft.

Progression of residual coronary artery disease previously left untreated

After PCI, disease progression in untreated native coronary segments contributes to repeat revascularization to an extent similar to that of target-lesion failure.¹⁴⁷⁾ After CABG, accelerated progression of previously nonobstructive coronary lesions is observed more frequently in bypassed coronary vessels than in similar lesions in nonbypassed vessels.¹⁴⁸⁾ One analysis of contemporary surgical techniques reported that new chronic total occlusions developed in native coronary arteries in more than 40% of patients within 1 year after CABG.¹⁴⁹⁾ Patients with progression of previously untreated native coronary disease after PCI should receive optimal GDMT, and the revascularization strategy in such cases should follow the same principles used for patients with de novo CAD, including consideration of anatomical suitability, ischemic burden, and patient comorbidities.²³⁾,⁹⁶⁾

Management of recurrent or refractory angina/ischemia

The management of recurrent or refractory angina remains a substantial challenge in contemporary cardiology. This condition, characterized by persistent symptoms despite optimal medical therapy and revascularization efforts, substantially impairs quality of life and increases healthcare utilization.²³⁾

Guideline summary, evidence, and future perspectives

Refractory angina is defined as a chronic condition, with symptoms lasting >3 months, characterized by debilitating symptoms caused by established reversible myocardial ischemia that cannot be controlled with a combination of optimal medical therapy, PCI, or CABG. This definition primarily applies to patients with obstructive CAD in whom escalation of therapy has failed.²³⁾ Although patients with ANOCA or INOCA are also included, refractory angina should be diagnosed in this group only after invasive functional testing has defined the endotype and appropriate mechanism-based therapies have failed to alleviate symptoms.²³⁾

A central update in the 2024 ESC guidelines is the Class I recommendation for invasive coronary functional testing in patients with refractory angina and suspected ANOCA or INOCA.²³⁾ This approach identifies specific endotypes, such as CMD or vasospastic angina (VSA), and allows mechanism-based therapy. This recommendation is consistent with the 2021 AHA/ACC guidelines, which also support invasive functional testing to diagnose CMD or vasospasm in patients with persistent symptoms and no obstructive CAD.¹⁵⁰⁾ This diagnostic approach is particularly relevant in Korea, where VSA is highly prevalent. A previous comprehensive review identified provocation testing as an essential diagnostic tool in Korea, underscoring the regional clinical importance of VSA. Recent Korean registry data further support this approach: acetylcholine provocation testing showed that more than half of patients with chest pain and nonobstructive arteries had evidence of coronary spasm, supporting coronary spasm as a key etiology in this population.¹⁵¹⁾ The clinical utility of stratified management was demonstrated in the CorMicA trial, in which endotype-guided therapy significantly improved angina symptoms and quality of life compared with standard care.¹⁵²⁾

For patients in whom all conventional options have been exhausted, guidelines acknowledge a role for advanced therapies. The ESC guidelines give a Class IIb recommendation for the coronary sinus reducer.²³⁾ This position is supported by a comprehensive meta-analysis reporting that approximately 76% of patients had significant improvement in angina after reducer implantation.¹⁵³⁾ Additional evidence comes from the sham-controlled ORBITA-COSMIC trial, which showed symptomatic benefit, with a significant reduction in daily angina episodes, although the primary perfusion outcome was not met.¹⁵⁴⁾ Similarly, enhanced external counterpulsation (EECP) is recognized as a reasonable noninvasive therapy for symptom improvement in patients with no further conventional treatment options.²³⁾,¹⁵⁵⁾

The therapeutic landscape for refractory angina continues to evolve. Several ongoing randomized controlled trials are evaluating the coronary sinus reducer specifically in ANOCA/INOCA populations, including COSIMA (NCT04606459) and COSIRA-II (NCT05102019).²³⁾ Beyond device-based therapies, several pharmacological and biological approaches are under investigation, including angiogenic therapies and stem cell therapy. Meta-analyses of RCTs evaluating intramyocardial delivery of autologous CD34+ cells have shown promising results, including improvements in exercise capacity and reductions in angina frequency.¹⁵⁶⁾,¹⁵⁷⁾ However, current evidence for these novel options is limited by small patient numbers and short follow-up. Larger sham-controlled RCTs are needed to define the role of each treatment modality and its long-term effects on CV outcomes. Ultimately, treatment algorithms should be based on etiological stratification and stepwise escalation of available therapies.²³⁾

Recommendations

• • Integrating the 2024 ESC and 2021 AHA/ACC guidelines with the Korean clinical context, the following expert consensus recommendations are proposed for managing recurrent or refractory angina/ischemia.

• • Systematic optimization of GDMT: Before refractory angina is diagnosed, GDMT should be rigorously and systematically optimized. This includes confirming patient adherence, titrating antianginal agents to the maximum tolerated doses, and using rational, evidence-based combination therapy.

• • Proactive investigation of ischemic mechanisms: In patients with persistent symptoms despite optimized GDMT, particularly those with nonobstructive CAD, the underlying pathophysiology should be definitively evaluated with invasive coronary functional testing. Given the high pretest probability of vasospastic disorders in the Korean population, this protocol should include spasm provocation testing to diagnose or exclude coronary artery spasm accurately.

• • Endotype-guided pharmacotherapy: Pharmacotherapy should be tailored to the invasively defined endotype. Confirmed VSA requires intensive treatment with high-dose and/or combination calcium channel blockers and nitrates. In contrast, documented CMD requires prioritization of therapies known to improve microvascular function, such as beta-blockers, angiotensin-converting enzyme inhibitors, statins, and ranolazine.

• • Advanced therapeutic modalities: In a highly selected cohort of patients with truly refractory angina, defined as persistent Canadian Cardiovascular Society Class III–IV symptoms when further revascularization is not feasible, a Heart Team should consider advanced therapeutic modalities. The coronary sinus reducer may be an option to improve quality of life in patients with obstructive CAD, whereas EECP can be offered as a noninvasive alternative to improve symptoms.

• • Multidisciplinary team approach: A comprehensive, patient-centered approach coordinated by a multidisciplinary refractory angina team is essential for managing these complex cases. This collaborative team should address both the physical symptoms and the substantial psychosocial burden of this chronic condition.

Treatment of disease complications

Patients with CCS are often affected by complications such as LV dysfunction, malignant ventricular arrhythmias, and secondary valvular disease.

Left ventricular dysfunction

Ischemic heart disease can lead to LV dysfunction through recurrent MI, repeated myocardial stunning, and myocardial hibernation,¹⁵⁸⁾,¹⁵⁹⁾ and patients with CCS who develop LV dysfunction may eventually progress to advanced heart failure.¹⁶⁰⁾ Along with optimal medical therapy, including renin–angiotensin system inhibitors, beta-blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors, specific therapeutic strategies are needed in patients with advanced heart failure regardless of the underlying heart failure etiology.²⁶⁾,¹⁶¹⁾ Inotropes may improve hemodynamics, reduce congestive symptoms, and support peripheral perfusion. Escalating loop diuretic doses, often with adjunctive agents, is frequently necessary because kidney dysfunction and diuretic resistance are typical features of advanced heart failure. In patients with an inadequate response to diuretics, renal replacement therapy should be considered. In selected patients, mechanical circulatory support (MCS) can improve the prognosis of advanced heart failure. Short-term MCS, including percutaneous and extracorporeal ventricular assist devices, is indicated when critical end-organ hypoperfusion and hypoxia occur in cardiogenic shock, as a bridge to recovery or bridge to decision. Long-term MCS should be considered in patients with advanced heart failure and New York Heart Association (NYHA) Class IV symptoms who are dependent on inotropes or temporary MCS and are unlikely to recover. Finally, heart transplantation may be the last option for patients with advanced heart failure in the absence of contraindications. Recently, early evaluation for MCS or transplantation has also been recommended even in mildly symptomatic individuals, such as those with NYHA Class II symptoms, who have a high-risk profile, including LVEF <20%, recurrent hospitalizations, hypotension, poor tolerance of medical therapy, progressive end-organ dysfunction, or recurrent ventricular arrhythmias or ICD shocks.²⁶⁾

Ventricular arrhythmias

Along with LV dysfunction, life-threatening ventricular arrhythmias may occur. An ICD is indicated to reduce mortality in patients with ischemic cardiomyopathy and an LVEF <35% despite optimal medical therapy and in patients who have recovered from a ventricular arrhythmia causing hemodynamic instability.¹⁶²⁾,¹⁶³⁾ In patients with LVEF ≤35%, sinus rhythm, left bundle branch block with a QRS duration ≥150 ms, and NYHA Class II, III, or ambulatory IV symptoms despite optimal medical therapy, cardiac resynchronization therapy with defibrillation is indicated to reduce mortality, reduce hospitalization, and improve symptoms.¹⁶⁴⁾,¹⁶⁵⁾ In patients with symptomatic or frequent ventricular arrhythmias, with or without device implantation, antiarrhythmic medication such as a beta-blocker or amiodarone should be used.¹⁶⁶⁾ In patients with CCS who experience recurrent sustained monomorphic ventricular tachycardia despite amiodarone, catheter ablation is preferred over further escalation of antiarrhythmic therapy.¹⁶⁶⁾ In addition to controlling ventricular arrhythmias, ongoing myocardial ischemia should be reassessed in patients with recurrent ventricular fibrillation or polymorphic ventricular tachycardia.

Secondary valvular disease

In advanced heart failure due to ischemic etiologies, secondary mitral regurgitation and tricuspid regurgitation can occur as ventricular geometry changes, worsening symptoms. Transcatheter edge-to-edge repair (TEER), a percutaneous treatment for secondary mitral regurgitation, reduced the risk of hospitalization for heart failure or CV death and improved health status.¹⁶⁷⁾,¹⁶⁸⁾ In addition, one trial demonstrated the noninferiority of percutaneous TEER compared with surgical repair or replacement.¹⁶⁹⁾ For secondary tricuspid regurgitation, evidence has historically been limited; however, recent data show that TEER can substantially reduce severe regurgitation and produce significant improvements in quality of life.¹⁷⁰⁾ In addition to TEER, transcatheter tricuspid valve replacement may be a future treatment option, typically in the absence of severe right ventricular dysfunction or pulmonary hypertension.¹⁷¹⁾