Abstract
Aims
Preprocedural transoesophageal echocardiography (TEE) screening for left atrial (LA) thrombi is the standard of care in many centres performing atrial fibrillation (AF) ablation. However, TEE imposes procedural risks for patients and is often challenging to implement in daily practice, besides causing patient discomfort. At our centre, a novel standard operating procedure (SOP) was implemented, aiming to identify patients that can be exempt from TEE screening. We aimed to assess whether this screening approach may reduce preprocedural TEEs without imposing patients of higher risks for cerebrovascular events (CVEs).
Methods and results
Data of 1874 consecutive patients treated by catheter ablation of LA arrhythmias between 2018 and 2022 were retrospectively analysed. A cohort of 937 patients, where decision to perform TEE screening was based on a new SOP (considering rhythm at admission, CHA2DS2-VASc score, and sufficient anticoagulation), was compared to a matched cohort receiving TEE before every procedure. Number of performed TEEs and incidences of CVEs were compared. Implementation of the new SOP led to a 67% reduction in TEEs performed (old SOP: 933 vs. new SOP: 305). No significant differences between the groups were detected regarding transitory ischaemic attack (old SOP: 5 vs. new SOP: 3; P = 0.48) and stroke (no events). No solid thrombi were detected during TEE screening.
Conclusion
The number of preprocedural screening TEEs before AF ablation procedures can be safely reduced by applying risk stratification based on rhythm at admission and CHA2DS2-VASc score, if anticoagulation was performed properly.
Keywords: Atrial fibrillation, Catheter ablation, Transoesophageal echocardiography, LAA thrombus, Stroke
Graphical Abstract
Graphical Abstract.
What’s new?
We report a simple and easy-to-practice screening algorithm that can be implemented into clinical practice, reducing the number of transoesophageal echocardiographies by 67% without raising patient risk for cerebrovascular events.
The investigated cohort is the first reported to include a large number of patients with persistent atrial fibrillation, a subgroup of patients where clinicians are hesitant to omit TEE screening.
The proposed screening algorithm was applied to patients treated with novel oral anticoagulants as well as vitamin K antagonists, without seeing an increase in the rates of cerebrovascular events.
Introduction
Catheter ablation has become the cornerstone of atrial fibrillation (AF) treatment.1 While the number of procedures has risen annually during recent years, likely even more patients will be treated in the future due to demographics and the rising prevalence of AF in the general population.2,3 Patients suffering from AF are at a high risk to develop thromboembolic complications due to impaired blood flow in the left atrial appendage (LAA) during AF, ultimately bearing the risk for development of an LAA thrombus. Prevalence of LAA thrombus as well as sludge in the LAA has been associated with an increased stroke risk.4
As with any rhythm control attempt, rule out of LAA thrombus or safe therapeutic anticoagulation needs to be assured before catheter ablation.5 Initially endorsed by the Assessment of Cardioversion Using Transoesophageal Echocardiography (ACUTE) trial, transoesophageal echocardiography (TEE) has become the gold standard for detection of LAA thrombi and has been used for thrombus rule out before electrical cardioversions as well as ablation procedures.6,7 However, with minimally interrupted anticoagulation strategies becoming the standard of care in the setting of catheter ablation, the necessity of TEE screening before every procedure has come into question.8–11 Furthermore, several studies performed during the last years have demonstrated that the risk for an LAA thrombus is low, with incidences being reported below 1% in cohorts of patients receiving catheter ablation for AF lately.4,9,12–16
Although current guidelines recommend 3 weeks of uninterrupted anticoagulation therapy in therapeutic range before every ablation procedure with a class I recommendation and TEE as an alternative with a class IIa recommendation, TEE screening is still performed in a lot of centres before AF procedures.5 Often, no standards are in place that guide the decision to screen or not based on the identification of risk populations. In this study, we present the outcomes of the application of a novel standard operating procedure (SOP, Figure 1) during routine clinical practice that aims to identify patients at a low risk for periprocedural cerebrovascular events (CVEs) that are exempt from TEE screening. We report data regarding CVEs including stroke and transitory ischaemic attack (TIA), major TEE-related complications, and TEEs needed according to the new SOP.
Figure 1.
Schematic of the new SOP. TEE, transoesophageal echocardiography.
Methods
Patient selection
The study design is displayed in Figure 2. All LA ablation procedures performed at our hospital between January 2018 and November 2022 were included in the analysis. In this time frame, 963 patients were treated according to the old SOP (TEE before every ablation procedure), while 1374 patients were treated according to the new SOP. We performed case control matching to gender, rhythm at admission, and CHA2DS2-VASc score, excluding 26 patients in the old SOP cohort and 437 patients in the new SOP cohort. Accordingly, we compared 937 patients who were treated according to the old SOP with 937 patients who were treated according to the new SOP.
Figure 2.
Illustration of the study design. AT, atrial tachycardia; CTI, cavotricuspid isthmus; PersAF, persistent atrial fibrillation; PVI, pulmonary vein isolation; ReDo, repeat procedure; SOP, standard operating procedure.
Transoesophageal echocardiography screening
In all procedures performed until March 2020, TEE screening was performed in every patient. In all patients being treated beginning from March 2020, a new SOP (Figure 1) was in place performing risk stratification for LAA thrombi based on the rhythm at the time of admission, CHA2DS2-VASc score, and anticoagulation treatment: All patients who did not present in sinus rhythm still received TEE before every procedure. Patients who presented in sinus rhythm were exempt from TEE if any of the following conditions were present: CHA2DS2-VASc score < 2 and/or patients had been sufficiently anticoagulated for at least 3 weeks before the procedure. In the case of vitamin K antagonists, patients had to provide documentation of International Normalized Ratio (INR) values for the last 3 weeks. In the case of novel oral anticoagulants (NOACs), compliance was evaluated by patient report, and last dose had to be taken no longer than 24 h before admission in the case of once-daily administered types and 12 h before admission in the case of twice-daily administered types. Screening TEEs were performed either in the echocardiography laboratory or in course of the ablation procedure by an electrophysiologist. In both cases, a sedation with propofol and midazolam was used for TEE procedures. In TEEs performed in the electrophysiology (EP) lab, fentanyl was used additionally.
Ablation procedures
In the case of NOACs, oral anticoagulation was paused for a single dose in the morning of the ablation procedure. In patients on vitamin K antagonists, the procedure was performed within a therapeutic international normalized ratio range of 2.0–3.5 with an INR measurement performed in the morning of the procedure. All ablation procedures were performed during sedation using propofol, midazolam, and fentanyl.
Triple femoral venous access through the right femoral vein was performed, and a decapolar catheter was positioned in the coronary sinus. Afterwards, a fluoroscopy-guided single transseptal puncture was performed. Immediately after successful transseptal puncture, a weight-adjusted heparin bolus (160 IU/kg body weight) was administered. Every 30 min, activated clotting times (ACTs) were measured while administering repeat heparin boluses targeting an activated clotting time of >300 s. For oesophageal temperature monitoring, a temperature probe (S-Cath, Esophageal Temperature Probe, Circa Scientific Inc., Englewood, CO, USA) was orally placed in the oesophagus. The ablation procedures were carried out using cryoablation, radiofrequency ablation (RFA) or pulsed field ablation (PFA) according to operators’ discretion. In the case of RFA procedures, a 3D electroanatomical mapping was performed before the ablation procedures.
Postprocedural care
Transthoracic echocardiography was performed directly after the procedure, after 2 h, and 1 day after the procedure to rule out pericardial effusion. Patients were monitored by telemetry for 48 h to detect early recurrences of AF, and a 12-lead electrocardiogram (ECG) was performed the day after the procedure. Oral anticoagulation was continued in the evening of the procedure. In the case of NOAC therapy with apixaban or edoxaban, the regular dose was applied in the evening. In the case of rivaroxaban, a dose of 10 mg was applied in the evening, and in the case of edoxaban, a dose of 30 mg was applied in the evening. In patients using vitamin K antagonists, routine dosage was taken in the evening of the procedure. In patients with a pacemaker or implantable cardioverter defibrillator (ICD), a device interrogation was performed on the first day after the procedure. Neurological assessments were performed according to standard clinical care.
Data analysis
We performed a retrospective analysis in the previously described patient cohort, comparing the old SOP group with the new SOP group. We analysed the results of TEE screening, incidence of CVEs (stroke, TIA), major TEE-related complications, and pneumonia. A TIA was defined as a temporary neurological impairment that resolved without any residues within 24 h without a therapeutic intervention. A stroke was defined as a neurological impairment that did not dissolve within 24 h and was accompanied by an ischaemic lesion in a cerebral magnetic resonance imaging (MRI) imaging. Furthermore, we analysed how many TEEs were performed in both cohorts and what findings were reported.
Statistical analysis
Continuous data are displayed as mean and standard deviation and categorical variables as counts and percentages. For skewed data, median and interquartile range were used. Statistical significance was evaluated by Student’s t-test. In the case of categorical variables, Fisher’s exact test was used. A P < 0.05 was considered statistically significant. All analyses were performed using SPSS Statistics Version 29 (IBM, Armonk, NY, USA).
Results
Baseline characteristics
Among both groups, 1874 patients were included in the analysis. Baseline characteristics are displayed in Table 1. Overall, 1178 (62.9%) were male, and the average age was 65.6 (±11.7) years. The average body mass index (BMI) in our study cohort was 27.4 (±4.6) kg/m2. Among all patients, 903 (48.6%) were treated for paroxysmal AF (PAF) and 954 (51.4%) for persistent AF. There were 1412 (75.3%) patients who presented with sinus rhythm on admission, and 1605 (85.7%) patients had been on anticoagulation for AF at the timepoint of admission. The median CHA2DS2-VASc score was 2 (0–7), whereas 137 (7.3%) patients had a history of stroke. A history of coronary artery disease (CAD) was known in 354 (18.9%) patients, and 283 (15.1%) patients suffered from cardiomyopathy (CMP). A history of congestive heart failure was documented in 283 (15.2%) patients. In total, 268 (28.6%) patients showed impairment in left ventricular ejection fraction (LVEF) with no statistically significant differences between both groups.
Table 1.
Baseline parameters
| All patients | Old SOP | New SOP | P-value (old SOP vs. new SOP) | |
|---|---|---|---|---|
| Patients (n) | 1874 | 937 | 937 | |
| Male (n) | 1178 (62.9%) | 589 (62.9%) | 589 (62.9%) | 1.0 |
| Age (years) | 65.6 (±11.7) | 65.9 (±11.3) | 65.3 (±12.2) | 0.24 |
| EHRA I–II (n) | 865 (46.1%) | 435 (46.4%) | 430 (45.9%) | 0.85 |
| EHRA III–IV (n) | 1007 (53.7%) | 502 (53.6%) | 505 (53.9%) | 0.85 |
| History of valve repair (n) | 123 (6.6%) | 57 (6.1%) | 66 (7.1%) | 0.39 |
| History of CAD (n) | 354 (18.9%) | 186 (19.9%) | 168 (18%) | <0.01 |
| History of CMP (n) | 283 (15.1%) | 120 (12.8%) | 163 (17.4%) | <0.01 |
| Hypertension (n) | 1251 (66.8%) | 640 (68.3%) | 611 (65.3%) | 0.37 |
| Diabetes (n) | 199 (10.6%) | 96 (10.2%) | 103 (11%) | 0.036 |
| Hypercholesterolaemia (n) | 554 (29.6%) | 237 (25.3%) | 317 (33.9%) | <0.01 |
| History of stroke (n) | 137 (7.3%) | 66 (7%) | 71 (7.6%) | 0.65 |
| Arterial thromboembolism (n) | 22 (1.2%) | 11 (1.2%) | 11 (1.2%) | 1.0 |
| COPD (n) | 96 (5.1%) | 33 (3.5%) | 63 (6.7%) | <0.01 |
| OSA (n) | 169 (9%) | 66 (7%) | 103 (11%) | <0.01 |
| History of smoking (n) | 167 (8.9%) | 74 (7.9%) | 93 (9.9%) | 0.12 |
| Anticoagulation at time of procedure (n) | 1605 (85.7%) | 799 (85.3%) | 806 (86.2%) | 0.57 |
| Device carrier (n) | 218 (11.6%) | 111 (11.8%) | 107 (11.4%) | 0.77 |
| Sinus rhythm at start of the procedure (n) | 1412 (75.3%) | 706 (75.3%) | 706 (75.3%) | 1.0 |
| Congestive heart failure (n) | 283 (15.2%) | 118 (12.6%) | 165 (17.7%) | <0.01 |
| LVEF | ||||
| Normal (n) | 1514 (80.9%) | 756 (80.7%) | 758 (81.1%) | 0.6 |
| Mildly reduced (n) | 121 (6.5%) | 61 (6.5%) | 60 (6.4%) | 0.93 |
| Moderately reduced (n) | 88 (4.7%) | 43 (4.6%) | 45 (4.8%) | 0.91 |
| Severely reduced (n) | 59 (3.2%) | 26 (2.8%) | 33 (3.5%) | 0.43 |
| CHA2DS2-VASc score | 2 [0–7] | 2 [0–7] | 2 [0–7] | 1.0 |
| GFR (mL/min) | 71.9 (±21.2) | 70.4 (±22) | 73.4 (±20.4) | <0.01 |
| BMI (kg/m2) | 27.4 (±4.6) | 27.6 (±4.6) | 27.1 (±4.6) | 0.03 |
| Paroxysmal AF (n) | 903 (48.6%) | 489 (52.8%) | 414 (44.5%) | <0.01 |
| Persistent AF (n) | 954 (51.4%) | 438 (47.2%) | 516 (55.5%) | <0.01 |
Continuous data are summarized as means ± standard deviation or median (interquartile range), and categorical data are presented as number (per cent).
AF, atrial fibrillation; BMI, body mass index; CAD, coronary artery disease; CMP, cardiomyopathy; GFR, glomerular filtration rate; LVEF, left ventricular ejection fraction; n, number; OSA, obstructive sleep apnoea.
Ablation procedures
The types of ablation procedures performed in both groups are displayed in Table 2. Overall, pulmonary vein isolation (PVI) was performed in 1265 (67.5%) patients, re-PVI in 346 (18.5%) patients, and ablation of the cavotricuspid isthmus (CTI) in 181 (9.7%) patients. Non–CTI-dependent atrial flutter (AT) ablation was performed in 187 (10%) patients, while 174 (9.3%) patients were treated with a substrate-based ablation approach. Between both groups, substrate-based ablation approaches were carried out significantly more often in the new SOP group vs. the old SOP group (108, 11.5% vs. 66, 7%; P < 0.01).
Table 2.
Performed ablation procedures
| All patients (1874) | Old SOP (937) | New SOP (937) | P-value | |
|---|---|---|---|---|
| PVI | 1265 (67.5%) | 651 (69.5%) | 614 (65.5%) | 0.68 |
| Re-PVI | 346 (18.5%) | 173 (9.2%) | 173 (9.2%) | 1.0 |
| Substrate-based ablation | 174 (9.3%) | 66 (7%) | 108 (11.5%) | <0.01 |
| Non–CTI-dependent flutter | 187 (10%) | 101 (10.8%) | 86 (9.2%) | 0.25 |
| CTI ablation | 181 (9.7%) | 90 (9.6%) | 91 (9.7%) | 0.94 |
CTI, cavotricuspid isthmus; PVI, pulmonary vein isolation; SOP, standard operating procedure.
Anticoagulation regime
Anticoagulation regimes in both groups are displayed in Table 3. Overall, anticoagulation was performed with vitamin K antagonists in 191 (10.2%) patients, with NOACs in a full-dose regimen in 1285 (68.7%) patients and NOACs in a reduced dose scheme in 125 (6.7%) patients. Anticoagulation regimes differed significantly between both groups: Vitamin K antagonists were less frequently used in the new SOP cohort compared to the old SOP cohort (66, 7.1% vs. 125, 13.4%; P < 0.01), while full-dose NOAC therapy was used more frequently in the new SOP cohort compared to the old SOP cohort (693, 74% vs. 592, 63.4%; P < 0.01). Reduced dose NOACs were also significantly less frequent in the new SOP cohort than in the old SOP cohort (46, 4.9% vs. 79, 8.5%; P < 0.01). Data concerning intraprocedural ACT levels and heparin applications for the whole cohort are displayed in Table 4 and Figure 3. During repeated measurements, average ACTs were within the predefined target of >300 s after the first reapplication bolus.
Table 3.
Anticoagulation regime at the time of the procedure
| All patients | Old SOP | New SOP | P-value | |
|---|---|---|---|---|
| Vitamin K antagonists (n) | 191 (10.2%) | 125 (13.4%) | 66 (7.1%) | <0.01 |
| NOAC full dose (n) | 1285 (68.7%) | 592 (63.4%) | 693 (74%) | <0.01 |
| NOAC reduced dose (n) | 125 (6.7%) | 79 (8.5%) | 46 (4.9%) | <0.01 |
NOAC, novel oral anticoagulant; SOP, standard operating procedure.
Table 4.
The ACT measurements during procedures
| Old SOP | New SOP | |
|---|---|---|
| ACT 1 (s) | 299.3 ± 59.7 (n = 907) | 283.3 ± 48.4 (n = 897) |
| ACT 2 (s) | 313.4 ± 48.9 (n = 576) | 300.2 ± 39.6 (n = 583) |
| ACT 3 (s) | 321.8 ± 46.8 (n = 281) | 312.9 ± 43.7 (n = 265) |
| ACT 4 (s) | 319.6 ± 40.1 (n = 129) | 319 ± 36.6 (n = 102) |
ACT, activated clotting time; SOP, standard operating procedure.
Figure 3.
The ACT measurements performed during the ablation procedures. Line graphs displaying the results of repeated ACT measurements during ablation procedures for the whole cohort (A) and for all individual patients who suffered a TIA, (B). The ACT measurements are numbered chronologically, with #1 being the first measurement performed 30 min after the first bolus application. ACT, activated clotting time; TIA, transitoric ischemic attack.
Results of transoesophageal echocardiography screening
The results of TEE screening in both groups are displayed in Table 5. While 933 (99.6%) patients received a screening TEE in the old SOP cohort, 306 (32.6%) TEEs were performed in the cohort treated according to the new SOP, representing a 67% relative reduction in performed TEEs. During TEE screening, no solid thrombus was discovered in any patient. While 37 (4% of TEEs) patients presented with spontaneous echos in the old SOP group, they could be observed in two patients (0.6%) during screening in the new SOP cohort. A low flow in the LAA (defined by <40 cm/s in pulsed-wave Doppler) could be observed in 51 (5.5%) and 9 (3%) patients, respectively. Among incidental findings during TEE screening are three non-haemodynamically relevant pericardial effusions, 12 persistent foramen ovales (PFO), one thrombus on the right ventricle (RV) lead of an implanted pacemaker, and one bicuspid aortic valve that was not known before.
Table 5.
Results of TEE screening
| Old SOP | New SOP | |
|---|---|---|
| Total TEEs performed (n, % of total) | 933 (99.6%) | 305 (32.6%) |
| Solid thrombus (n, % of TEEs) | 0 (0%) | 0 (0%) |
| Spontaneous echos (n, % of TEEs) | 37 (4%) | 2 (0.6%) |
| Low LAA flow <40 cm/s (n, % of TEEs) | 51 (5.5%) | 9 (3%) |
| Incidental findings | ||
| Pericardial effusion (n, % of TEEs) | 3 (0.3%) | 0 (0%) |
| PFO (n, % of TEEs) | 11 (1.2%) | 1 (0.3%) |
| Thrombus on RV lead of PM (n, % of TEEs) | 1 (0.1%) | 0 (0% |
| Bicuspid aortic valve (n, % of TEEs) | 1 (0.1%) | 0 (0%) |
LAA, left anterior appendage; PFO, persistent foramen ovale; PM, pacemaker; RV, right ventricle; SOP, standard operating procedure; TEE, transoesophageal echocardiography.
Outcomes
Outcome data are displayed in Tables 6 and 7. Overall, a periprocedural CVE was observed in eight (0.4%) patients, all those patients suffering from TIA. No significant differences could be observed between both groups: While five (0.5%) patients suffered a TIA in the old SOP cohort, three (0.3%) patients suffered a TIA in the cohort treated according to the new SOP (P = 0.48). No major TEE-related complications occurred in any of the patients in both cohorts. No significant differences could be observed in the incidence of pneumonia, with 17 (1.8%) observed in the old SOP cohort and 11 (1.2%) observed in the new SOP cohort (P = 0.25). Detailed baseline data of the eight patients who suffered a TIA are displayed in Table 7. Out of those eight patients, seven had received a TEE before the procedure without any abnormalities. The single patient that had suffered from TIA without preprocedural TEE had a CHA2DS2-VASc score of 0 and had presented in sinus rhythm without prior anticoagulation therapy, as per guidelines. In seven out of eight patients, an MRI has been performed according to a consulting neurologist’s discretion. These showed acute or subacute brain lesions in four patients. Detailed information on the results of the performed MRI scans is provided in Supplementary material online, S1. Data on ACTs and heparin applications during the procedures are displayed in Table 8 and Figure 3. All patients could be discharged from the hospital without any residues.
Table 6.
Periprocedural events
| All patients | Old SOP | New SOP | P-value | |
|---|---|---|---|---|
| Stroke (n) | 0 (0%) | 0 (0%) | 0 (0%) | 1.0 |
| Transitory ischaemic attack (n) | 8 (0.4%) | 5 (0.5%) | 3 (0.3%) | 0.48 |
| Major TEE-related complications (n) | 0 | 0 | 0 | 1.0 |
| Pneumonia (n) | 28 (1.5%) | 17 (1.8%) | 11 (1.2%) | 0.25 |
SOP, standard operating procedure; TEE, transoesophageal echocardiography.
Table 7.
Patient characteristics of CVE cases
| Patient no. | ||||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Age (years) | 39 | 82 | 58 | 70 | 65 | 59 | 71 | 79 |
| Sex | M | F | M | M | M | M | M | F |
| BMI (kg/m²) | 22 | 32.7 | 26.9 | 32.4 | 26.1 | 27.5 | 29.6 | 32.4 |
| AF type | PAF | PersAF | PersAF | PersAF | PersAF | PersAF | PAF | PersAF |
| OAC | None | Apixaban 2.5mg | Rivaroxaban 20 mg | Apixaban 5mg | Edoxaban 60 mg | Rivaroxaban 20 mg | Rivaroxaban 20 mg | Rivaroxaban 20 mg |
| CHA2DS-VASc score | 0 | 5 | 1 | 2 | 2 | 3 | 1 | 7 |
| Hypertension | No | Yes | Yes | Yes | Yes | Yes | No | Yes |
| Diabetes | No | No | No | No | No | No | No | No |
| CAD | No | Yes | No | No | No | No | No | No |
| Previous CVE | No | No | No | No | No | Yes | No | Yes |
| Rhythm | SR | AF | SR | SR | SR | AT | SR | AF |
| LV-EF impaired | No | No | No | No | No | No | No | No |
| Group | New SOP | New SOP | Old SOP | Old SOP | Old SOP | New SOP | Old SOP | Old SOP |
| TEE performed | No | Yes | Yes | Yes | Yes | Yes | Yes | Yes |
| Thrombus | n/a | No | No | No | No | No | No | No |
| Spontaneous echo | n/a | No | No | No | No | No | No | No |
| Other incidental findings | n/a | No | No | No | No | No | No | No |
| Type of CVE | TIA | TIA | TIA | TIA | TIA | TIA | TIA | TIA |
| MRI performed | Yes | Yes | Yes | Yes | Yes | Yes | Yes | No |
| Acute or subacute ischaemic lesions visible | Yes | No | Yes | Yes | No | Yes | No | n/a |
AF, atrial fibrillation; BMI, body mass index; CAD, coronary artery disease; CVE, cerebrovascular event; LV-EF, left ventricular ejection fraction; MRI, magnetic resonance imaging; OAC, oral anticoagulation; PAF, paroxysmal AF; PersAF, persistent AF; SOP, standard operating procedure; TEE, transoesophageal echocardiography; TIA transitoric ischemic attack.
Table 8.
Heparin treatment and ACT measurements during the procedures in TIA cases
| Patient no. | ||||||||
|---|---|---|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
| Heparin administered after TSP (IU) | 16,000 | 15,000 | 14,000 | 13,000 | 12,000 | 14,000 | 16,000 | 10,000 |
| ACT 1 (s) | 272 | 340 | 335 | 354 | 204 | 390 | 320 | 400 |
| Heparin administered (IU) | 5000 | 0 | 2000 | 2000 | 6000 | 0 | 0 | 0 |
| ACT 2 (s) | n/a | 261 | 352 | n/a | n/a | 354 | 244 | n/a |
| Heparin administered (IU) | n/a | 3000 | 1000 | n/a | n/a | 0 | 3000 | n/a |
| ACT 3 (s) | n/a | 320 | 372 | n/a | n/a | 331 | n/a | n/a |
| Heparin administered (IU) | n/a | 1000 | 0 | n/a | n/a | 0 | n/a | n/a |
| ACT 4 (s) | n/a | 305 | 355 | n/a | n/a | n/a | n/a | n/a |
| Heparin administered (IU) | n/a | 0 | 1000 | n/a | n/a | n/a | n/a | n/a |
ACT, activated clotting time; IU, international units; n/a, not applicable; TSP, transseptal puncture.
Discussion
In this retrospective study, we report outcomes of the implementation of a novel SOP for preprocedural TEE screening before AF ablation procedures. We compared a cohort of patients that had undergone TEE according to risk stratification with the new SOP with a matched cohort of patients that received TEE before every ablation procedure. Implementation of the new SOP led to a 63% reduction in TEEs performed with no significant differences in the incidence of CVEs.
In current guidelines, therapeutic anticoagulation for at least 3 weeks before ablation or the use of TEE for rule out of LAA thrombus is recommended.5 In clinical practice, many centres still routinely perform preprocedural TEE screening. Apart from our data, very few studies have investigated the outcomes of more liberal screening strategies in the relevant patient cohort: A previous study by Diab et al.17 investigated periprocedural CVE rates in patients presenting in AF at the day of the procedure with no TEE performed before the ablation. In this study, event rates were low with CVE incidence being 0.3%. Notably, only patients on NOACs were included, and no comparison was made with a cohort that received TEE. Our study indicates that omitting TEE screening might be equally safe in patients anticoagulated with vitamin K antagonists, if INR values inside therapeutic range have been properly documented. Another study performed by Balouch et al.9 has reported no rise in CVE rates across a time frame of 5 years, while TEE screening rates declined from 86 to 42% in the same time frame. In this study, no standardized criteria were applied for the decision to perform TEE or omit TEE. The authors also show that persistent AF was a risk factor for development of LAA thrombus and discuss persistent AF as a precondition that should prompt preprocedural TEE. In our study collective that represents the patient collective we routinely treat with AF ablation, 51.4% were treated for persistent AF, which indicates that risk stratification as performed in this study might be equally safe for these patients.
It is important to note that our cohorts show significant differences in the kind of anticoagulation used for stroke prevention: Patients in the new SOP cohort are significantly more often anticoagulated with NOACs on reduced and full dose. This is to be expected as the retrospective nature of our study compares two cohorts that were treated in different time frames, and guidelines regarding anticoagulation therapy have changed significantly in the last years. Those differences in anticoagulation strategies may influence the results of the study as to where the incidences in CVEs might not only be influenced by the screening strategy but also by differences in anticoagulation. However, performing ablation procedures in a setting of minimally interrupted NOAC treatment, as performed in large parts of the new SOP cohort, is standard of care according to current recommendations.18
Interestingly, in those patients that suffered a periprocedural TIA, TEE screening for LAA thrombus had been performed before the procedures in seven out of eight patients, and no abnormalities had been detected. Those results are in line with previous data reported in the previously mentioned study by Balouch et al.,9 where TEE had been performed in three out of four patients that suffered a periprocedural CVE. These results emphasize that—most likely due to modern minimally interrupted anticoagulation strategies—there are other possibly more relevant mechanisms leading to periprocedural CVEs in the respective cohort of patients presenting for AF ablation. Those mechanisms are likely not related to thrombus formation in the LAA and thus may not be addressable by TEE screening, lowering the significance of preprocedural TEE and pointing towards other aspects, such as strict sheath irrigation during the procedures. Furthermore, the aetiology of the neurological symptoms observed in those patients classified as a TIA might also originate from other causes than a CVE. Other factors leading to symptoms mimicking those of a CVE might include the sedation used during the index procedures, a periprocedural orthostatic reaction, or a migraine with aura. While brain lesions were observed in four out of seven patients who received an MRI, the correlation of these lesions with the clinical symptoms of those patients remains unclear. Silent brain lesions have been reported to occur frequently in LA procedures, as reported before.19
In our proposed SOP, we still perform TEE screening in all patients that do not present in sinus rhythm. However, some centres have switched to omitting TEE in any patients on NOACs.17 We believe that this practice is supported by our study results, as we could not identify any thrombus in the cohort of patients presenting in sinus rhythm. Also considering the results of the previously mentioned studies by Goldi et al.,4 a viable adaptation of our proposed SOP would be to exclude patients in AF from screening, as long as proper NOAC therapy is in place or CHA2DS2-VASc-Score is < 2. Another aspect to consider is the fact that many centres—apart from using it for exclusion of thrombi—have completely excluded TEE or intracardiac echocardiography from their regular workflow during EP procedures, as transseptal punctures are performed guided by fluoroscopy or 3D mapping.20,21 Omitting TEE for screening might thus bring further organizational benefits and reduce procedure times, although not investigated in this study.
Our data indicate that preprocedural TEE screening might be safely omitted before AF ablation in patients suffering from persistent AF or PAF and regardless of the type of anticoagulation therapy used, if administered in therapeutic range per recommendations. Ideally, these results need to be confirmed in prospective randomized trials that investigate certain screening strategies. However, with event rates for periprocedural CVE and LAA thrombi being low, designing adequately sized trials for a prospective randomized investigation remains challenging. Considering this, reports from clinical practice with easy-to-implement screening criteria can be of great value to reduce the number of unnecessary TEE procedures.
Limitations
Limitations of the reported study include its retrospective nature. The data used for this investigation were derived from a prospectively maintained database of ablation procedures and were retrospectively analysed for the endpoints. The TEE procedures were performed in different settings (echocardiography lab, EP lab), and thus, different study protocols were in place. No standardized definition for sludge was present; thus, spontaneous echos are reported. Furthermore, as an oesophageal temperature probe was used in all patients, it is impossible to differentiate between the oesophageal temperature probe or the TEE as a reason for pneumonia.
Conclusions
The number of preprocedural screening TEEs before AF ablation procedures can be safely reduced by applying risk stratification based on the rhythm at admission and CHA2DS2-VASc score, if anticoagulation therapy has been performed based on current recommendations.
Supplementary Material
Contributor Information
Sebastian Dittrich, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Fehmi Kece, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Cornelia Scheurlen, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Jan-Hendrik van den Bruck, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Karlo Filipovic, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Jonas Wörmann, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Susanne Erlhöfer, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Friederike Pavel, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Jan-Hendrik Schipper, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Arian Sultan, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Jakob Lüker, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Daniel Steven, Department of Electrophysiology, Heart Center, University of Cologne, Kerpener Str. 62, 50937 Cologne, Germany.
Supplementary material
Supplementary material is available at Europace online.
Funding
None declared.
Data availability
All data and material are available upon contacting the corresponding author.
Consent
Consent to participate was acquired from every patient who participated in this study.
References
- 1. Hindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomstrom-Lundqvist Cet al. 2020 ESC guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association of Cardio-Thoracic Surgery (EACTS). Eur Heart J 2021;42:373–478. [DOI] [PubMed] [Google Scholar]
- 2. Di Carlo A, Bellino L, Consoli D, Mori F, Zaninelli A, Baldereschi Met al. Prevalence of atrial fibrillation in the Italian elderly population and projections from 2020 to 2060 for Italy and the European Union: the FAI Project. Europace 2019;21:1468–75. [DOI] [PubMed] [Google Scholar]
- 3. Benjamin EJ, Muntner P, Alonso A, Bittencourt MS, Callaway CW, Carson APet al. Heart disease and stroke statistics-2019 update: a report from the American Heart Association. Circulation 2019;139:e56–e528. [DOI] [PubMed] [Google Scholar]
- 4. Goldi T, Krisai P, Knecht S, Aeschbacher S, Spies F, Zeljkovic Iet al. Prevalence and management of atrial thrombi in patients with atrial fibrillation before pulmonary vein isolation. JACC Clin Electrophysiol 2019;5:1406–14. [DOI] [PubMed] [Google Scholar]
- 5. Hindricks G, Potpara T, Dagres N, Arbelo E, Bax JJ, Blomstrom-Lundqvist Cet al. 2020 ESC guidelines for the diagnosis and management of atrial fibrillation developed in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS): the Task Force for the diagnosis and management of atrial fibrillation of the European Society of Cardiology (ESC) developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC. Eur Heart J 2021;42:373–498. [DOI] [PubMed] [Google Scholar]
- 6. Klein AL, Grimm RA, Murray RD, Apperson-Hansen C, Asinger RW, Black IWet al. Use of transesophageal echocardiography to guide cardioversion in patients with atrial fibrillation. N Engl J Med 2001;344:1411–20. [DOI] [PubMed] [Google Scholar]
- 7. Anic A, Bakovic D, Jurisic Z, Farkowski M, Lisica L, Breskovic Tet al. Diagnostic and therapeutic pathways for the malignant left atrial appendage: European Heart Rhythm Association physician survey. Europace 2023;25:1–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8. Di Biase L, Briceno DF, Trivedi C, Mohanty S, Gianni C, Burkhardt JDet al. Is transesophageal echocardiogram mandatory in patients undergoing ablation of atrial fibrillation with uninterrupted novel oral anticoagulants? Results from a prospective multicenter registry. Heart Rhythm 2016;13:1197–202. [DOI] [PubMed] [Google Scholar]
- 9. Balouch M, Gucuk Ipek E, Chrispin J, Bajwa RJ, Zghaib T, Berger RDet al. Trends in transesophageal echocardiography use, findings, and clinical outcomes in the era of minimally interrupted anticoagulation for atrial fibrillation ablation. JACC Clin Electrophysiol 2017;3:329–36. [DOI] [PubMed] [Google Scholar]
- 10. Alyeshmerni D, Pirmohamed A, Barac A, Smirniotopoulos J, Xue E, Goldstein Set al. Transesophageal echocardiographic screening before atrial flutter ablation: is it necessary for patient safety? J Am Soc Echocardiogr 2013;26:1099–105. [DOI] [PubMed] [Google Scholar]
- 11. Ellis CR. To TEE, or not to TEE, that is the question. JACC Clin Electrophysiol 2019;5:1415–7. [DOI] [PubMed] [Google Scholar]
- 12. Alqarawi W, Birnie DH, Spence S, Ramirez FD, Redpath CJ, Lemery Ret al. Prevalence of left atrial appendage thrombus detected by transoesophageal echocardiography before catheter ablation of atrial fibrillation in patients anticoagulated with non-vitamin K antagonist oral anticoagulants. Europace 2019;21:48–53. [DOI] [PubMed] [Google Scholar]
- 13. Frenkel D, D'Amato SA, Al-Kazaz M, Markowitz SM, Liu CF, Thomas Get al. Prevalence of left atrial thrombus detection by transesophageal echocardiography: a comparison of continuous non-vitamin K antagonist oral anticoagulant versus warfarin therapy in patients undergoing catheter ablation for atrial fibrillation. JACC Clin Electrophysiol 2016;2:295–303. [DOI] [PubMed] [Google Scholar]
- 14. Khan MN, Usmani A, Noor S, Elayi S, Ching CK, Di Biase Let al. Low incidence of left atrial or left atrial appendage thrombus in patients with paroxysmal atrial fibrillation and normal EF who present for pulmonary vein antrum isolation procedure. J Cardiovasc Electrophysiol 2008;19:356–8. [DOI] [PubMed] [Google Scholar]
- 15. McCready JW, Nunn L, Lambiase PD, Ahsan SY, Segal OR, Rowland Eet al. Incidence of left atrial thrombus prior to atrial fibrillation ablation: is pre-procedural transoesophageal echocardiography mandatory? Europace 2010;12:927–32. [DOI] [PubMed] [Google Scholar]
- 16. Scherr D, Dalal D, Chilukuri K, Dong J, Spragg D, Henrikson CAet al. Incidence and predictors of left atrial thrombus prior to catheter ablation of atrial fibrillation. J Cardiovasc Electrophysiol 2009;20:379–84. [DOI] [PubMed] [Google Scholar]
- 17. Diab M, Wazni OM, Saliba WI, Tarakji KG, Ballout JA, Hutt Eet al. Ablation of atrial fibrillation without left atrial appendage imaging in patients treated with direct oral anticoagulants. Circ Arrhythm Electrophysiol 2020;13:e008301. [DOI] [PubMed] [Google Scholar]
- 18. Calkins H, Hindricks G, Cappato R, Kim YH, Saad EB, Aguinaga Let al. 2017 HRS/EHRA/ECAS/APHRS/SOLAECE expert consensus statement on catheter and surgical ablation of atrial fibrillation. Europace 2018;20:e1–e160. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19. Calvert P, Kollias G, Purerfellner H, Narasimhan C, Osorio J, Lip GYHet al. Silent cerebral lesions following catheter ablation for atrial fibrillation: a state-of-the-art review. Europace 2023;25:1–8. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20. Matoshvili Z, Bastani H, Bourke T, Braunschweig F, Drca N, Gudmundsson Ket al. Safety of fluoroscopy-guided transseptal approach for ablation of left-sided arrhythmias. Europace 2017;19:2023–6. [DOI] [PubMed] [Google Scholar]
- 21. Bohnen M, Minners J, Eichenlaub M, Weber R, Allgeier HJ, Jadidi Aet al. Feasibility and safety of a three-dimensional anatomic map-guided transseptal puncture for left-sided catheter ablation procedures. Europace 2023;25:1126–34. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Supplementary Materials
Data Availability Statement
All data and material are available upon contacting the corresponding author.