Abstract
Introduction
The use of intravascular imaging during percutaneous coronary intervention (PCI) has been shown to have a significant positive impact on clinical outcomes. The two most frequently used techniques of intravascular imaging for guiding decision-making and optimizing PCI are intravascular ultrasound (IVUS) and optical coherence tomography (OCT).
Aim
To investigate the impact of iodinated contrast agent administration on creatinine clearance and renal function in patients undergoing OCT and IVUS procedures.
Material and methods
An observational retrospective study was conducted at a tertiary institution involving a total of 336 consecutive patients who underwent intracoronary imaging (OCT/IVUS) and PCI procedures with stent implantation. The study included patients in whom intracoronary imaging was used to guide the procedure as well as those in whom it was used to verify the results of stent implantation.
Results
A significant increase in creatinine (greater than 25% from the initial creatinine value) was recorded in 12 patients (3.6%), with 7 patients from the OCT group (4.7%) and 5 patients from the IVUS group (2.7%), p > 0.01. The difference in mean values regarding the imaging groups was statistically significant for the variable amount of contrast medium used (p < 0.01), where the median contrast volume in the OCT group was 320.0 ml and in the IVUS group it was 270.0 ml.
Conclusions
Through retrospective analysis, we can conclude that adequate patient selection for OCT guidance led to increased contrast consumption but did not result in worsening of renal function with adequate patient preparation and parenteral and oral hydration.
Keywords: intravascular imaging, creatinine, iodine contrast
Summary
This study addresses the impact of iodinated contrast agent on renal function in patients undergoing percutaneous coronary intervention with optical coherence tomography (OCT) or intravascular ultrasound (IVUS), two widely used intravascular imaging techniques. While OCT requires more contrast, the study found no significant increase in contrast-induced nephropathy (CIN) risk compared to IVUS, filling a gap in understanding the renal safety of these methods. The major finding supports the safe use of OCT despite higher contrast volume, provided patients are adequately hydrated and selected. These results may influence clinical decision-making, suggesting that OCT can be safely employed, even in at-risk patients, and warrant further research on long-term outcomes and cost-effectiveness.
Introduction
In the past decade, the use of intravascular coronary imaging (ICI) during percutaneous coronary intervention (PCI) has been shown to have a significant positive impact on clinical outcomes [1, 2]. The two most used techniques of ICI for guiding decision making and optimizing PCI are intravascular ultrasound (IVUS) and optical coherence tomography (OCT). Providing key information such as vessel dimensions, suitable stent landing zones, plaque characteristics, detection of PCI complications and identification of stent malfunction mechanisms, intravascular imaging guidance improves the ultimate outcome of the intervention [3–7]. IVUS utilizes ultrasound waves while OCT utilizes near infrared light [3–5]. OCT provides a resolution that is 10 times higher than that provided by IVUS; however, to achieve this high resolution, OCT requires blood clearance, which is achieved by using contrast agents [8–10].
The use of contrast agents has significantly enhanced the sensitivity of medical imaging; however, the inherent toxicity of these agents can lead to a range of adverse effects, including contrast-induced nephropathy (CIN) [11].
Iodinated contrast agents are frequently employed for coronary angiography and angioplasty procedures, typically being well tolerated by patients without significant adverse effects [12]. The most common example of a significant adverse reaction of iodinated contrast is CIN, which is characterized by a rise in serum creatinine levels of over 25% or 44.2 µmol/l (0.5 mg/dl) within 72 h following intravascular administration of contrast medium, in the absence of another identifiable cause [13]. Some patients have a higher likelihood of developing CIN. Risk factors include reduced initial kidney function, characterized by an estimated glomerular filtration rate of 45 to 60 ml/min, and the presence of diabetes mellitus [14, 15].
The exact mechanisms of CIN are not fully understood. However, toxic effects from iodine and altered blood flow in the kidneys are known contributors. Contrast media increase blood flow in the cortex but decrease it in the medulla, making the already hypoxic medulla more susceptible to ischemic injury. Additionally, the osmolality and viscosity of contrast agents can exacerbate hypoxemia and tubular stress, leading to increased free radicals, reduced nitric oxide, and cell death [16, 17].
Volume expansion, either orally or intravenously, and the use of N-acetylcysteine have traditionally been recommended to reduce the risk of CIN. The primary preventive measure involves using isotonic solutions for volume expansion before administering intravenous contrast, especially during interventional procedures. This method is believed to work by increasing renal blood flow, enhancing diuresis, diluting the contrast in the kidney tubules, suppressing the renin-angiotensin-aldosterone system, and reducing the inhibition of endogenous vasodilator production [18–21].
Aim
The purpose of this study was to investigate the impact of iodinated contrast agent administration on creatinine clearance in patients undergoing OCT and IVUS procedures.
Material and methods
The observational retrospective study included consecutive patients who underwent intracoronary imaging (OCT/IVUS) and PCI procedures with stent implantation between May 1st, 2018, and May 1st, 2023, at a tertiary care center. Patients were divided into two groups: the first group, consisting of patients who underwent OCT, and the second group, consisting of patients who underwent IVUS.
Inclusion criteria
The study included patients with acute coronary syndrome (ST-segment-elevation myocardial infarction, non-ST-segment-elevation myocardial infarction and unstable angina) and chronic coronary syndrome (CCS), in whom intracoronary imaging was used to guide the PCI procedure as well as those in whom it was used to verify and if necessary guide optimization.
Exclusion criteria
Exclusion criteria were previous contrast application during index hospitalization and creatinine clearance (CrCl) < 15 ml/min.
Data were collected and analyzed for both groups regarding patient’s risk factors, comorbidities, and clinical findings at admission, length of hospitalization, major complications, echocardiographic findings, laboratory findings, and mortality.
Parameters monitored included serum creatinine values on admission and at discharge, estimated glomerular filtration rate (eGFR), CrCl, amount of contrast used during PCI procedures with IVUS/OCT considering age, gender, height, weight, left ventricular ejection fraction, risk factors for ischemic heart disease, the vessel on which the PCI procedure was performed, degree of vessel stenosis and urgency of the PCI procedure.
CrCl was calculated using the CKD-EPI formula (eGFRcr = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)–1.200 × 0.9938Age × 1.012 [if female] multiplied by 88.4 for conversion to µmol/l), where Scr = standardized serum creatinine in mg/dl, κ = 0.7 (females) or 0.9 (males), α = –0.241 (female) or –0.302 (male), min(Scr/κ, 1) is the minimum of Scr/κ or 1.0, max(Scr/κ, 1) is the maximum of Scr/κ or 1.0, age (years).
Primary PCI (pPCI) was performed on the infarct-related artery within 12 h after the onset of symptoms, without prior thrombolytic therapy in patients with acute coronary syndrome (ACS). Early PCI in ACS was defined as a procedure that was done at least 2 h after admission and after medicament stabilization of the patient.
Guiding PCI imaging was done during the procedure used for real-time guidance during the intervention while post-PCI imaging was done after the procedure used for assessing the outcome and ensuring the success of the procedure.
We defined multivessel disease as significant stenosis (> 70%) in two or more major coronary arteries of 2.5 mm diameter or more.
The criterion for CIN occurrence was the KDIGO definition of CIN (an increase in serum creatinine levels by more than 25% or ≥ 0.5 mg/dl (44 µmol/l) within 48 h of contrast application compared to its baseline value) [14]. The hydration protocol for patients with CrCl < 50 included 0.9% saline administration at 100 ml/h, beginning 6–12 h before and continuing for 4–12 h after contrast application.
Interventions were performed using the Ilumen optis console (Abbott, USA) and the Volcano integrated system (Philips, Netherlands).
In this study, we implemented several measures to address potential confounding factors and enhance the robustness of our findings on the effects of iodinated contrast agents on renal function during PCI guided by IVUS and OCT: control for confounding variables (use of nephrotoxic medications, medication records were reviewed, and patients on nephrotoxic drugs were identified and adjusted for in the analysis), PCI procedure duration (the length of the PCI procedures was recorded and considered as a variable influencing renal function outcomes), cardiogenic shock (patient hemodynamic data, including blood pressure and heart rate, were monitored throughout the procedures to ensure that any fluctuations were accounted for in relation to renal function impacts) and inclusion of long-term follow-up data (a follow-up period of 4 years was included to capture any long-term renal impairment and mortality, differentiating between cardiovascular and other causes of death, to assess the potential link between renal insufficiency and overall survival).
The study was approved by an appropriate institutional review board.
Statistical analysis
Statistical methods used included mean, standard deviation, median, quartiles, frequencies, and percentages. To compare the mean values of variables between two populations, the independent samples t-test and Mann-Whitney U test were used. The association of categorical variables was examined using the χ2 test for contingency tables or Fisher’s exact test. Multivariable logistic regression was used to control renal outcomes for potential confounding variables. Results are presented with odds ratio and 95% confidence intervals. Statistical data analysis was performed using the IBM SPSS Statistics 17 software package.
Results
A total of 336 patients who underwent PCI were analyzed. Patients were divided into two groups: the first group – patients who underwent optical coherence tomography (OCT) – consisted of 150 (44.5%) patients; and the second group – patients who underwent intravascular ultrasound (IVUS) – consisted of 186 (55.5%) patients.
Contrast consumption and kidney function
The study included 234 males (70%) and 102 females (30%) with the mean age of 63 (56–68) years. The mean iodinated contrast consumption volume was 290 ml per procedure (all demographic data are shown in Table I). There was no statistically significant difference in the amount of contrast with respect to the technique (post-PCI vs. PCI guiding) (p = 0.06).
Table I.
Baseline patient characteristics
| Patient characteristics | OCT (n = 150) n (%), median (Q1–Q3), mean ± SD |
IVUS (n = 186) n (%), median (Q1–Q3), mean ± SD |
P-value |
|---|---|---|---|
| Male | 96 (64) | 138 (74) | 0.04 |
| Age [years] | 60.3 ±11.7 | 62.1 ±9.5 | 0.22 |
| Weight [kg] | 81.0 (73–91) | 83 (73–95) | 0.45 |
| Height [cm] | 172 (167–180) | 174 (168–180) | 0.40 |
| BMI [kg/m2] | 27.7 (24.7–30.9) | 24.7 (24.8–30.9) | 0.90 |
| EF (%) | 52 (47–60) | 52 (45–59) | 0.37 |
| Family history | 43 (29) | 69 (37) | 0.10 |
| HTN | 98 (65) | 149 (80) | < 0.01 |
| Smoking | 46 (39.3) | 71 (60.7) | 0.18 |
| HLP | 52 (35) | 96 (64.9) | 0.02 |
| DM | 30 (20) | 57 (31) | 0.03 |
| ACS | 84 (56) | 65 (35) | < 0.01 |
| CCS | 66 (44) | 121 (65) | < 0.01 |
| Primary PCI | 58 (39) | 29 (16) | < 0.01 |
| Early PCI in ACS | 26 (17) | 36 (20) | 0.13 |
| Cardiogenic shock | 2 (1.3) | 3 (1.6) | > 0.99 |
| In-hospital mortality | 2 (0.74%) | 2 (0.59%) | > 0.99 |
HTN – hypertension, BMI – body mass index, EF – ejection fraction, HLP – hyperlipidemia, DM – diabetes mellitus, ACS – acute coronary syndrome, CCS – chronic coronary syndrome.
The median serum creatinine value for both groups on admission was 90 mmol/l (76–109), and the median creatinine value at discharge was 85 mmol/l (73–104). The median CrCl for both groups on admission was 79 ml/min (61–95) (p = 0.58), while at discharge the value was 81 ml/min (65–97) (p = 0.91).
Creatinine values on admission and at discharge were compared, and a significant increase in serum creatinine or a significant decrease in creatinine clearance values (greater than 25% from the initial creatinine value) was recorded in 12 (3.6%) patients, with 7 patients from the OCT group (4.7%) and 5 patients from the IVUS group (2.7%) (p = 0.33). There was a significant difference in median contrast volume consumption between the OCT group 320 (250–400) and IVUS group 270 (220–350) (p < 0.01). A non-significant decrease in serum creatinine values was observed in both groups (p = 0.41). Data are shown in Table II.
Table II.
Contrast consumption amount and change of serum creatinine values compared between OCT and IVUS groups of patients
| Variable | OCT n (%), mean (Q1–Q3) |
IVUS n (%), mean (Q1–Q3) |
P-value |
|---|---|---|---|
| Contrast amount [ml] | 320 (250–400) | 270 (220–350) | < 0.01 |
| PCI guidance contrast consumption [ml] | 285 (215–375) | 275 (210–365) | 0.06 |
| Post PCI contrast consumption [ml] | 315 (255–380) | 310 (250–390) | |
| Creatinine on admission [µmol/l] | 89 (74–106) | 91 (77–111) | 0.30 |
| Creatinine on discharge [µmol/l] | 84 (71–101) | 87 (74–104) | 0.41 |
| Creatinine change [µmol/l] | -1.0 (-9–6) | 0.0(-9–4) | 0.68 |
| eGFR – admission [ml/min] | 78 (62–97) | 79 (60–94) | 0.58 |
| eGFR – discharge [ml/min] | 80 (65–97) | 82 (65–98) | 0.91 |
| Change in creatinine clearance [µmol/l] | -1 (-9–4) | 0 (-8–3) | 0.69 |
| Significant increase in creatinine | 7 (4.7%) | 5 (2.7%) | 0.33 |
| Significant decrease in creatinine clearance | 7 (4.7%) | 5 (2.7%) | 0.33 |
| Creatinine change in ACS patients [µmol/l] | -1 (-11–6) | -5 (-16–4) | 0.92 |
| Creatinine change in CCS patients [µmol/l] | 0 (-7–6) | 0 (-6–3) | 0.85 |
eGFR – estimated glomerular filtration rate, ACS – acute coronary syndrome, CCS – chronic coronary syndrome, PCI – percutaneous coronary intervention.
The majority of patients had CrCl above 50 ml/min/1.73 m2, in the OCT group 139 (92.7%) and in the IVUS group 167 (89.3%) patients. There were 4 patients who had CrCl in the range 15–30 ml/min/1.73 m2(2 in the IVUS group and 2 in the OCT group).
There was no correlation between the amount of contrast consumption, initial creatinine clearance or presence of diabetes mellitus and hypertension with CIN occurrence within IVUS and OCT groups (characteristics of patients with CIN are shown in Table III).
Table III.
Characteristics of patients with CIN
| Variable | OCT n (%), median (Q1–Q3) |
IVUS n (%), median (Q1–Q3) |
P-value |
|---|---|---|---|
| CCS | 1 (14) | 3 (60) | 0.93 |
| ACS | 6 (86) | 2 (40) | 0.53 |
| Early PCI | 4 (57) | 1 (20) | 0.94 |
| Primary PCI | 3 (43) | 4 (80) | 0.92 |
| HTA | 4 (57) | 4 (80) | 0.58 |
| Smoking | 2 (29) | 4 (80) | 0.24 |
| HLP | 3 (43) | 5 (100) | 0.08 |
| Diabetes mellitus | 2 (29) | 3 (60) | 0.56 |
| Contrast consumption | 290 (250–490) | 240 (240–320) | 0.51 |
| eGFR – admission [ml/min] | 93 (82–120) | 85 (71–101) | 0.88 |
| Creatinine rise [µmol/l] | 25 (23–24) | 28 (25–43) | 0.46 |
CCS – chronic coronary syndrome, ACS – acute coronary syndrome, PCI – percutaneous coronary intervention, HTA – hypertension, HLP – hyperlipidemia, eGFR – estimated glomerular filtration rate.
The patient with the lowest CrCl recorded, which was 26 ml/min/1.73 m2, underwent OCT.
CCS and ACS
Overall, patients with ACS more often had OCT (56%) than IVUS (35%), with a statistically significant difference (p < 0.01). The percentage of primary PCI in the OCT group was 39%, and in the IVUS group it was 16%, while IVUS was more often performed in patients with CCS (p < 0.01). Data are shown in Tables I and II.
There was no statistically significant difference in the mean change in creatinine levels and CrCl between patients with ACS and CCS in relation to OCT and IVUS procedures (p = 0.85 and p = 0.92).
ICI and coronary vessels
The blood vessel that most commonly underwent these intravascular imaging methods was the left anterior descending artery (LAD), 233 (69%), followed by the left main stem (LMS), 181 (54%), circumflex artery (LCX), 111 (33%), and, least frequently, the right coronary artery (RCA), 65 (19%). IVUS was mostly used for lesions with between 70 and 90% stenosis, 103 (55%), while OCT was mostly used for 50–70% stenosis, 65 (43%) (p = 0.02). Both methods were less frequently used for subocclusive lesions, 48 (14%).
The percentage of patients with PCI on the LMS in the OCT group was 44%, and in the IVUS group it was 62%, p < 0.01. The percentage of patients with intervention on the LCX in the OCT group was 27%, and in the IVUS group it was 38% (p = 0.05).
The number of patients with a bifurcation lesion in the OCT group was 80 (40%), and in the IVUS group it was 118 (59.5%), p < 0.01. The median PCI duration was similar between the groups, with the OCT group having a median of 73 min and the IVUS group 75 min (p = 0.43). The data are presented in Table IV.
Table IV.
Target vessels, level of vessel stenosis, PCI duration and type of OCT and IVUS procedures
| Coronary artery vessel and type of procedure | OCT n (%), median (Q1–Q3) |
IVUS n (%), median (Q1–Q3) |
P-value |
|---|---|---|---|
| RCA | 31 (21) | 34 (18) | 0.58 |
| LMS | 66 (44) | 115 (62) | 0.01 |
| LAD | 98 (65) | 135 (73) | 0.15 |
| LCX | 41 (27) | 70 (38) | 0.05 |
| Bifurcation lesion | 80 (40) | 118 (59) | < 0.01 |
| PCI guidance | 88 (59) | 139 (75) | < 0.01 |
| Post-PCI | 62 (41) | 47 (25) | |
| Significance of coronary artery stenosis | |||
| 50–70% | 65 (43) | 53 (28) | 0.02 |
| 70–90% | 67 (45) | 103 (55) | |
| 90–99% | 18 (12) | 30 (16) | |
| PCI duration | 74 (51–100) | 73 (51–95) | 75 (51–100) |
RCA – right coronary artery, LAD – left anterior descending artery, LCX – left circumflex artery, LMS – left main stem, PCI – percutaneous coronary intervention.
Out of 337 patients, 4 patients in total died due to ST-segment-elevation myocardial infarction; 2 of those patients underwent OCT while IVUS was performed in 2 patients (p > 0.99).
Shock occurrence was similar across groups, with no significant difference observed (p > 0.99) (Table I).
The usage of nephrotoxic medications such as ACE inhibitors, diuretics, β-blockers, statins, and antibiotics showed no significant group differences, with p-values ranging from 0.31 to 0.77 (Table V).
Table V.
Outcomes and discharge medical therapy
| Characteristic | Overall (n = 336) n (%), median (Q1–Q3) |
OCT (n = 150) n (%), median (Q1–Q3) |
IVUS (n = 186) n (%), median (Q1–Q3) |
P-value |
|---|---|---|---|---|
| Death | 22 (6.5) | 9 (6.0) | 13 (7.0) | 0.71 |
| In-hospital death | 4 (1.2) | 2 (1.3) | 2 (1.1) | 0.91 |
| All-cause death | 26 (7.7) | 11 (7.3) | 15 (8.1) | 0.81 |
| Cardiac death | 18 (5.4) | 9 (6.0) | 9 (4.8) | 0.63 |
| Non-cardiac death | 8 (2.4) | 2 (1.3) | 6 (3.2) | 0.31 |
| ACE inhibitors | 150 (45) | 62 (42) | 88 (47) | 0.31 |
| Diuretics | 118 (35) | 49 (33) | 69 (37) | 0.42 |
| β-blockers | 169 (50) | 72 (48) | 97 (52) | 0.51 |
| Statins | 304 (91) | 138 (93) | 166 (89) | 0.31 |
| Antibiotics | 24 (7.2) | 10 (6.7) | 14 (7.5) | 0.74 |
Follow-up
No patients required dialysis in the 4-year follow-up. Overall mortality rates were similar between the OCT and IVUS groups, with 6.5% and 7.0% mortality, respectively (p = 0.71). For cardiac-related deaths, the rate was slightly higher in the OCT group (6%) compared to the IVUS group (4.8%), but this difference was not statistically significant (p = 0.63). Non-cardiac deaths occurred in 2.4% of the overall cohort, with a higher rate in the IVUS group (3.2%) compared to OCT (1.3%), though this was also not significant (p = 0.31). Data are shown in Table V.
Logistic regression was performed to control renal outcomes for important potentially confounding variables, such as the use of nephrotoxic medications, the duration of the PCI procedure and shock. The results are presented in Table VI. The use of diuretics, antibiotics and shock raises the likelihood of kidney injury.
Table VI.
Renal outcomes (CIN) controlled for potential confounding variables
| CIN | Odds ratio | Std. err. | z | P > z | 95% conf. interval | |
|---|---|---|---|---|---|---|
| Diuretics | 1.98 | 1.25 | 1.08 | 0.28 | 0.57 | 6.84 |
| ACE inhibitors | 1.04 | 0.67 | 0.07 | 0.95 | 0.30 | 3.64 |
| β-blockers | 0.43 | 0.30 | –1.20 | 0.23 | 0.11 | 1.69 |
| Statins | 0.56 | 0.51 | –0.63 | 0.53 | 0.09 | 3.33 |
| Antibiotics | 2.17 | 1.90 | 0.89 | 0.38 | 0.39 | 12.04 |
| PCI duration | 1.00 | 0.01 | –0.54 | 0.59 | 0.98 | 1.01 |
| Shock | 5.15 | 6.55 | 1.29 | 0.20 | 0.43 | 62.31 |
| _cons | 0.08 | 0.09 | –2.15 | 0.03 | 0.01 | 0.79 |
CIN – contrast-induced nephropathy, PCI – percutaneous coronary intervention.
Discussion
Our study revealed two key findings: 1) Neither method had an impact on the worsening of kidney function. 2) Patients in the OCT group had significantly higher iodine contrast consumption.
The study population comprised predominantly males (70%) compared to females (30%), with the mean age of 63 (56–68) years. The mean iodinated contrast consumption volume per procedure was 290 ml. The mean contrast volume used was significantly higher in the OCT group (320 ml) compared to the IVUS group (270 ml) (p < 0.01). This statistically significant difference highlights a potential concern regarding the higher contrast load with OCT procedures. There was no statistically significant difference in the amount of contrast used between the techniques for post-PCI vs. PCI guiding (p = 0.06).
Our results correspond with the OCTIVUS study, which found that a higher amount of contrast medium was used in OCT-guided PCI procedures (238.3 ±112.4 ml) compared to the IVUS group (199.8± 109.7 ml), which was not associated with an increased incidence of CIN; p < 0.01 [22]. The OCTOBER study had similar results: the average dose of contrast medium was 300 ml (250–375 ml) in the OCT-guided PCI group and 200 ml (160–278 ml) in the angiography guided PCI group; p > 0.01 [23].
Both groups showed a decrease in serum creatinine from admission to discharge: the OCT group admission mean was 89 mmol/l, and the discharge mean was 84 mmol/l, while the IVUS admission mean was 91 mmol/l, and discharge mean was 87 mmol/l (p = 0.91). A significant decline in renal function (defined as an increase in serum creatinine or decrease in CrCl > 25% from the baseline) was observed in 12 (3.6%) patients; 7 of those patients were from the OCT group and 5 patients from the IVUS group, a non-significant difference (p = 0.33). The higher contrast volume associated with OCT did not translate into a higher incidence of significant renal function decline compared to IVUS.
Several studies have identified a direct correlation between contrast volume and the development of CIN, which is particularly significant in complex PCI procedures involving a large amount of contrast agent [24–26]. This may be further complicated by the fact that such procedures often involve treating multiple lesions and employing aggressive plaque modification techniques, which can induce hemodynamic instability and renal hypoperfusion, known triggers for acute kidney injury (AKI) [24, 27].
Previous studies have shown that the total contrast volume in OCT-guided PCI is greater than that in IVUS-guided PCI. In the ILUMIEN III study, the contrast volume in OCT-guided PCI was significantly higher than in IVUS-guided PCI (222 ml vs. 190 ml, p = 0.004) [28]. A larger contrast volume in optical frequency domain imaging (OFDI)-guided PCI compared to IVUS-guided PCI (164 vs. 138 ml, p = 0.001) was also reported in the OPINION study [29].
The higher percentage of ACS patients in the OCT group suggests that OCT might be more frequently utilized in more acute settings compared to IVUS, which was more often used in patients with CCS (p < 0.01). The higher rate of primary PCI in the OCT group could indicate a preference for OCT in urgent situations requiring immediate intervention because OCT, due to its higher resolution, allows for easier identification of the etiology of ACS and easier recognition of plaque erosion and rupture.
IVUS was preferred for more severe stenosis (70–90%) and complex lesions, such as those in the LMS and other bifurcation lesions, while OCT was more frequently used in moderate stenosis (50–70%). These results suggest a preference for IVUS in more complex and significant lesions, while the use of OCT indicates a potential benefit for post-procedural assessment, ensuring optimal stent deployment and lesion coverage. The choice between OCT and IVUS should consider the lesion complexity, the urgency of the situation (ACS vs. CCS), and the specific anatomical challenges presented by the patient’s coronary artery disease. Both imaging modalities have their strengths, and selecting the appropriate one can optimize procedural success and patient outcomes.
In our study 4 patients died due to STEMI. Two of those patients underwent OCT and 2 patients underwent IVUS; both modalities showed similar outcomes in terms of mortality (p > 0.99).
These findings are crucial for clinical decision-making, particularly in selecting imaging modalities for patients undergoing procedures requiring iodinated contrast. The data support the safety of both OCT and IVUS in terms of renal function preservation, even with the higher contrast volume used in OCT procedures. However, caution should still be exercised in patients with significantly impaired renal function, and further studies are needed to evaluate the safety in those with CrCl < 15 ml/min/1.73 m2. Additional studies focusing on long-term outcomes and the cost-effectiveness of OCT vs. IVUS could provide more insights into their relative benefits and help refine guidelines for their use in different clinical scenarios.
The absence of any patients requiring dialysis during the four-year follow-up period underscores the effectiveness of the treatment protocols employed in this study. This result suggests that the interventions and management strategies utilized were successful in preventing AKI and its associated complications. These findings may indicate a favorable renal safety profile of the procedures undertaken. This lack of dialysis requirements reflects positively on both the patient selection criteria and the application of appropriate preventive measures against CIN. Additionally, it highlights the potential for improved long-term renal outcomes in similar patient populations when effective strategies are implemented.
In this 4-year follow-up study comparing outcomes between OCT and IVUS groups, our findings indicate similar mortality rates and medication usage between the two groups, with no statistically significant differences observed in most parameters. This similarity suggests that both imaging techniques offer comparable long-term prognostic outcomes in this patient population.
Good patient selection and adequate preparation and treatment, particularly in terms of hydration, are certainly necessary. Our study had several limitations. Since it was a retrospective study, there were no criteria for standardizing OCT and IVUS procedures, nor a clearly defined protocol for parenteral hydration. Instead, hydration was administered according to practice and the decision of the operator and attending physician.
Conclusions
Both imaging techniques appear to be viable for procedural guidance in similar patient populations, with no differences in long-term prognosis. Iodinated contrast did not negatively impact renal function in OCT-guided PCI compared to IVUS-guided PCI. As retrospective analysis shows, with proper patient selection and hydration, OCT’s increased contrast use results in minimal renal function decline.
Funding Statement
Funding No external funding.
Ethical approval
Written informed consent was obtained from all participants before enrollment.
Conflict of interest
The authors declare no conflict of interest.
References
- 1.Bruch L, Zadura M, Waliszewski J, et al. Results from the international drug-coated balloon registry for the treatment of bifurcations: Can a bifurcation be treated without stents? J Interv Cardiol 2016; 29: 348-56. [DOI] [PubMed] [Google Scholar]
- 2.Kobayashi N, Mintz GS, Witzenbichler B, et al. Prevalence, features, and prognostic importance of edge dissection after drug-eluting stent implantation. Circ Cardiovasc Interv 2016; 9: e004257. [DOI] [PubMed] [Google Scholar]
- 3.Tearney GJ, Regar E, Akasaka T, et al. Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies. J Am Coll Cardiol 2012; 59: 1058-72. [DOI] [PubMed] [Google Scholar]
- 4.Di Vito L, Yoon JH, Kato K, et al. Comprehensive overview of definitions for optical coherence tomography-based plaque and stent analyses. Coron Artery Dis 2014; 25: 172-85. [DOI] [PubMed] [Google Scholar]
- 5.Mintz GS, Nissen SE, Anderson WD, et al. Clinical expert consensus document on standards for the acquisition, measurement, and reporting of intravascular ultrasound studies: a report of the American College of Cardiology Task Force on Clinical Expert Consensus Documents. J Am Coll Cardiol 2001; 37: 1478-92. [DOI] [PubMed] [Google Scholar]
- 6.Hoffmann R. Treatment of calcified coronary lesions with Palmaz-Schatz stents: an intravascular ultrasound study. Eur Heart J 1998; 19: 1224-31. [DOI] [PubMed] [Google Scholar]
- 7.Lee MS, Shlofmitz E, Kong J, et al. Impact of the use of intravascular imaging on patients who underwent orbital atherectomy. J Invasive Cardiol 2018; 30: 77-80. [PubMed] [Google Scholar]
- 8.Chieffo A, Latib A, Caussin C, et al. A prospective, randomized trial of intravascular-ultrasound guided compared to angiography guided stent implantation in complex coronary lesions: the AVIO trial. Am Heart J 2013; 165: 65-72. [DOI] [PubMed] [Google Scholar]
- 9.Witzenbichler B, Maehara A, Weisz G, et al. Relationship between intravascular ultrasound guidance and clinical outcomes after drug-eluting stents. Circulation 2014; 129: 463-70. [DOI] [PubMed] [Google Scholar]
- 10.Buccheri S, Franchina G, Romano S, et al. Clinical outcomes following intravascular imaging-guided versus coronary angiography-guided percutaneous coronary intervention with stent implantation. JACC Cardiovasc Interv 2017; 10: 2488-98. [DOI] [PubMed] [Google Scholar]
- 11.Zhang F, Lu Z, Wang F. Advances in the pathogenesis and prevention of contrast-induced nephropathy. Life Sci 2020; 259: 118379. [DOI] [PubMed] [Google Scholar]
- 12.Meireles GCX, Kreimer S, Marchiori GGA, et al. Coronary angiography with gadolinium in patients with severe allergy to iodinated contrast media. Rev Bras Cardiol Inv 2012; 20: 329-32. [Google Scholar]
- 13.Kitajima K, Maeda T, Watanabe S, et al. Recent issues in contrast-induced nephropathy. Int J Urol 2011; 18: 686-90. [DOI] [PubMed] [Google Scholar]
- 14.KDIGO Acute Kidney Injury Work Group . KDIGO clinical practice guideline for acute kidney injury. Kidney Int Suppl 2012; 2: 1-138. [Google Scholar]
- 15.Bruce RJ, Djamali A, Shinki K, et al. Background fluctuation of kidney function versus contrast-induced nephrotoxicity. AJR Am J Roentgenol 2009; 192: 711-8. [DOI] [PubMed] [Google Scholar]
- 16.James MT, Ghali WA, Knudtson ML, et al. Associations between acute kidney injury and cardiovascular and renal outcomes after coronary angiography. Circulation 2011; 123: 409-16. [DOI] [PubMed] [Google Scholar]
- 17.James MT, Ghali WA, Tonelli M, et al. Acute kidney injury following coronary angiography is associated with a long-term decline in kidney function. Kidney Int 2010; 78: 803-9. [DOI] [PubMed] [Google Scholar]
- 18.McDonald JS, McDonald RJ, Comin J, et al. Frequency of acute kidney injury following intravenous contrast medium administration: a systematic review and meta-analysis. Radiology 2013; 267: 119-28. [DOI] [PubMed] [Google Scholar]
- 19.Langner S, Stumpe S, Kirsch M, et al. No increased risk for contrast-induced nephropathy after multiple CT perfusion studies of the brain with a nonionic, dimeric, iso-osmolal contrast medium. AJNR Am J Neuroradiol 2008; 29: 1525-29. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Barrett BJ, Parfrey PS. Preventing nephropathy induced by contrast medium. N Engl J Med 2006; 354: 379-86. [DOI] [PubMed] [Google Scholar]
- 21.Weisbord SD, Palevsky PM. Prevention of contrast-induced nephropathy with volume expansion. Clin J Am Soc Nephrol 2008; 3: 273-80. [DOI] [PubMed] [Google Scholar]
- 22.Kang DY, Ahn JM, Yun SC, et al. Optical coherence tomography-guided or intravascular ultrasound-guided percutaneous coronary intervention: the OCTIVUS randomized clinical trial. Circulation 2023; 148: 1195-206. [DOI] [PubMed] [Google Scholar]
- 23.Holm NR, Andreasen LN, Neghabat O, et al. OCT or angiography guidance for PCI in complex bifurcation lesions. N Engl J Med 2023; 389: 1477-87. [DOI] [PubMed] [Google Scholar]
- 24.Tsai TT, Patel UD, Chang TI, et al. Contemporary incidence, predictors, and outcomes of acute kidney injury in patients undergoing percutaneous coronary interventions. JACC Cardiovasc Interv 2014; 7: 1-9. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Rihal CS, Textor SC, Grill DE, et al. Incidence and prognostic importance of acute renal failure after percutaneous coronary intervention. Circulation 2002; 105: 2259-64. [DOI] [PubMed] [Google Scholar]
- 26.Azzalini L, Vilca LM, Lombardo F, et al. Incidence of contrast-induced acute kidney injury in a large cohort of all-comers undergoing percutaneous coronary intervention: comparison of five contrast media. Int J Cardiol 2018; 273: 69-73. [DOI] [PubMed] [Google Scholar]
- 27.Azzalini L, Spagnoli V, Ly HQ, et al. Contrast-induced nephropathy: from pathophysiology to preventive strategies. Can J Cardiol 2016; 32: 247-55. [DOI] [PubMed] [Google Scholar]
- 28.Ali ZA, Maehara A, Généreux P, et al. Optical coherence tomography compared with intravascular ultrasound and with angiography to guide coronary stent implantation (ILUMIEN III: OPTIMIZE PCI): a randomized controlled trial. Lancet 2016; 388: 2618-28. [DOI] [PubMed] [Google Scholar]
- 29.Kubo T, Shinke T, Okamura T, et al. Optical frequency domain imaging vs. intravascular ultrasound in percutaneous coronary intervention (OPINION trial): one-year angiographic and clinical results. Eur Heart J 2017; 38: 3139-47. [DOI] [PMC free article] [PubMed] [Google Scholar]