P94 LOWER RATE OF MAJOR BLEEDING IN HIGH–RISK PATIENTS UNDERGOING LEFT ATRIAL APPENDAGE OCCLUSION: A PROPENSITY MATCHED COMPARISON WITH DIRECT ORAL ANTICOAGULATION

Background

Stroke prophylaxis in very high risk (CHA2DS2–VASc ≥ 5) patients with atrial fibrillation (AF) is one of the major challenges faced by physicians. Specifically, initiating direct oral anticoagulants (DOACs) in these patients poses a therapeutic conundrum due to the concomitant high risk of bleeding. Left atrial appendage occlusion (LAAO) might be a potential alternative for thromboembolic (TE) prevention; however, there are no studies comparing these two strategies in very high–risk patients.

Objective

To evaluate the efficacy of LAAO versus DOACs in AF patients at very high TE risk.

Methods

Data were extracted from two prospective databases including 1053 Watchman and 1328 DOAC patients. Watchman patients with a CHA2DS2–VASc ≥ 5 accounted for 26.3% (n = 277). In order to attenuate the imbalance in covariates, a 1:1 propensity score matching technique was used (co–variates: age, sex, CHA2DS2–VASc and HAS–BLED scores). This method resulted in 554 matched patients (277 patients per group; mean age: 79±7y; 57.4% F; CHA2DS2–VASc: 5.8±0.9). The primary endpoint was a composite of cardiovascular (CV) death, TE events (Stroke/TIA/peripheral embolism) and clinically significant bleeding. The annual TE and major bleeding risks were estimated based on the CHA2DS2–VASc score and compared with the annualized observed risk.

Results

After a mean follow–up of 26±7 months, total events were 55 (9.4 event rates per 100 patient–years) in LAAO group vs. 78 (14.9 event rates per 100 patient–years) in DOAC group. DOACs had a significantly higher risk of the primary endpoint (hazard ratio [HR]: 1.30; 95% confidence interval [CI]: 1.08 to 1.56; p = 0.03). TE events (HR: 1.15; 95% CI: 0.84 to 1.57; p = 0.63) and CV death (HR: 1.13; 95% CI: 0.84 to 1.54; p = 0.63) did not differ between groups. Major bleeding events were significantly lower in LAAO patients (HR: 0.75; 95% CI: 0.51 to 0.82; p = 0.04). The unadjusted estimated risk of TE events was 12.3% with LAAO and 12.4% with DOACs. The annualized incidence of TE was 3.2% with LAAO and 4.1% with DOACs, which led to a risk reduction of 74% and 67%, respectively.

Conclusion

In a large cohort of AF patients at very high TE risk (CHA2DS2–VASc ≥ 5), LAAO showed similar stroke prevention but a significantly lower risk of major bleeding than DOACs during a > 2year follow–up.

C32 TRANSCATHETER LEAK OCCLUSION WITH ENDOVASCULAR COILS FOLLOWING LEFT ATRIAL APPENDAGE CLOSURE: PROCEDURAL SUCCESS AND OUTCOMES BEFORE AND AFTER LEAK CLOSURE

Background

Whether residual peri–device leaks after left atrial appendage occlusion (LAAO) portend a higher risk of thromboembolism (TE), it is still a matter of debate.

Objectives

We report the TE risk in patients with incomplete LAA closure before and after leak closure with endovascular coils.

Methods

One hundred twenty–four Watchman patients with a significant (≥3mm) leak (mean age: 74 ± 9 years; 66.9% males; CHA2DS2–VASc: 4.4 ± 1.7; HAS–BLED: 3.1 ± 1) underwent LAA leak coiling. The expected annual TE risk was estimated based on the patients’ CHA2DS2–VASc and compared with the annualized incidence observed before and after coiling (Fig.1B).

Results

The time between LAAO and leak coiling was 8±6 months [83 patients–year (PY)]; before leak closure, 6 (4.8%) patients had a TE event (annualized rate: 7.2%). Coil deployment was successful in all cases [median n. of coils deployed: 5 (IQR: 2–10)]. Procedure time was 79 ± 40 min; the mean volume of iodinated contrast medium used was 80 ± 43mL. The overall complication rate was 2.4% (1 pericardial tamponade, 2 pericardial effusion). Follow–up TEE after 61±14 days revealed complete LAA sealing or a negligible leak in 117 cases (94.4%); the remaining 7 patients had a moderate leak. During 14±6 months post–coiling (145 PY), 1 (0.8%) patient suffered from stroke. The incidence of TE events was significantly lower after leak closure than before coiling (0.8% vs 4.8%; log–rank p = 0.02; Fig.1A). The annualized TE rates were 7.2% before and 0.7% after leak closure (Fig. 1A). According to the expected rate estimated from the patients’ CHA2DS2–VASc (9.8%), LAAO with and without significant leaks yielded to a risk reduction of 26.5% and 92.9% (Fig. 1B).

Conclusions

Transcatheter leak occlusion via endovascular coils was safe. LAA closure led to a significant reduction in TE events.

P4 LEFT ATRIAL APPENDAGE ANATOMICAL CHANGES FOLLOWING RADIOFREQUENCY–BASED OSTIAL ISOLATION

Background

Left atrial appendage (LAA) electrical isolation (ei) may be achieved via radiofrequency (RF) energy applications at the level of the appendage ostium targeting the sites of earliest activation recorded by a mapping catheter. Notably, RF has long been used in vascular, orthopedic, and aesthetic surgery to promote thermal–induced collagen matrix contraction, fibrosis, and tissue retraction. LAA anatomical changes associated to RF–induced tissue retraction have never been reported.

Objective

To quantify the anatomical changes of the LAA ostium following RF–based LAAei.

Methods

Thirty–four consecutive patients requiring AF ablation with LAAei underwent transesophageal echocardiography (TEE) within 7 days before (baseline TEE) and >6 months after (follow–up TEE) ablation. The diameter of LAA orifice and landing zone were measured at 4 different views (0°, 45°, 90°, 135°). Measurements were performed by two independent reviewers blinded to the patient’s identity.

Results

Among 34 AF patients (68±7yrs, 73.5% males), the LAA morphology was classified as chicken wing in 15 (44%) patients, windsock in 10 (29%), cactus in 6 (18%), and cauliflower in 3 (9%). At baseline TEE, the mean maximum and mean minimum ostial diameters were 25±4mm and 22±4mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 26±4mm and 23±3mm, respectively. On average, LAAei was achieved after 16±7 minutes of RF at a power of 45–47W. Follow–up TEE was performed 257±148 days after LAAei. The median LAA contraction velocity was 0.1 m/s (IQR: 0.04–0.18) and was significantly impaired in all patients. At follow–up TEE, the mean maximum and mean minimum ostial diameters were 19±4mm and 17±3mm, respectively. The mean maximum and mean minimum diameters of the landing zone were 20±4mm and 18±4mm, respectively. The mean relative reduction of the ostium and the landing zone were –24.4% and –22.5%, respectively. Box–Whisker plots of the maximum and minimum ostial diameters before and after LAAei are reported in Fig. 1.

Conclusion

RF led to a > 20% reduction of the diameters of the ostium and the landing zone. These changes may have important implications for a successful percutaneous occlusion procedure and justify a staged approach of isolation and occlusion.

Extended Pulmonary Vein Isolation: is it sufficient to achieve long-term sinus rhythm in octogenarian women with atrial fibrillation?

Background

Atrial fibrillation (AF) is a disease of the elderly and women typically present with AF at an older age than men do. Moreover, they tend to experience more symptoms and post-ablation recurrences, have worse quality of life and increased risk of stroke and mortality.

Objective

We evaluated long-term efficacy of our standard ablation approach of extended pulmonary vein isolation (PVI) in octogenarian women undergoing their first AF ablation.

Methods

Consecutive female AF patients aged ≥80 years receiving their first catheter ablation at our center were included in the analysis. Our standard ablation approach at the first procedure includes PVI + empirical isolation of left atrial posterior wall (LAPW) and superior vena cava (SVC). Complete abolition of all potentials rather than decrease in amplitudes was the procedural end point. Patients were prospectively monitored at regular intervals for 3 years after the index procedure with event recorders, 12-lead ECG, cardiology evaluation at office visits and 7-day Holter monitoring.

Results

A total of 194 patients with mean age of 84.2±1.4 years were included in the analysis. Of the 194, 120 (61.8%) had non-paroxysmal AF. All received PVI+ isolation of LAPW and SVC. Acute procedural success was achieved in 100% of cases.

At 3 years of follow-up, 24 (12.4%) patients remained in sinus rhythm; 22 on- and 2 off-antiarrhythmic drugs (AAD). All of the 23 patients had paroxysmal AF as their initial diagnosis.

Of the 170 patients experiencing recurrence, 147 underwent repeat ablation. PV/PW/SVC reconnection was noted in only 6 (4.1%) patients at redo. Triggers originating from non-PV sites were targeted for ablation in all. At 1.5 years after the repeat procedure, 136 (92.5%) patients were in sinus rhythm; 131 off-AAD and 5 patients on-AAD.

Conclusion

Extended PVI including isolation of posterior wall and SVC was not sufficient to maintain long-term sinus rhythm in majority of octogenarian women, regardless of AF type. Moreover, non-PV triggers rather than PV reconnection was the major cause of recurrence in this subset of AF population.

Funding Acknowledgement

Type of funding source: None