Nonprocedural bleeding after left atrial appendage closure versus direct oral anticoagulants: A subanalysis of the randomized PRAGUE-17 trial

INTRODUCTION

Observational studies have shown low bleeding rates in patients with atrial fibrillation (AF) treated by left atrial appendage closure (LAAC); however, data from randomized studies are lacking. This study compared bleeding events among patients with AF treated by LAAC and nonvitamin K anticoagulants (NOAC).

METHODS

The Prague-17 trial was a prospective, multicenter, randomized trial that compared LAAC to NOAC in high-risk AF patients. The primary endpoint was a composite of a cardioembolic event, cardiovascular death, and major and clinically relevant nonmajor bleeding (CRNMB) defined according to the International Society on Thrombosis and Hemostasis (ISTH).

RESULTS

The trial enrolled 402 patients (201 per arm), and the median follow-up was 3.5 (IQR 2.6-4.2) years. Bleeding occurred in 24 patients (29 events) and 32 patients (40 events) in the LAAC and NOAC groups, respectively. Six of the LAAC bleeding events were procedure/device-related. In the primary intention-to-treat analysis, LAAC was associated with similar rates of ISTH major or CRNMB (sHR 0.75, 95% CI 0.44-1.27, p = 0.28), but with a reduction in nonprocedural major or CRNMB (sHR 0.55, 95% CI 0.31-0.97, p = 0.039). This reduction for nonprocedural bleeding with LAAC was mainly driven by a reduced rate of CRNMB (sHR for major bleeding 0.69, 95% CI 0.34-1.39, p = .30; sHR for CRNMB 0.43, 95% CI 0.18-1.03, p = 0.059). History of bleeding was a predictor of bleeding during follow-up. Gastrointestinal bleeding was the most common bleeding site in both groups.

CONCLUSION

During the 4-year follow-up, LAAC was associated with less nonprocedural bleeding. The reduction is mainly driven by a decrease in CRNMB.

Left Atrial Appendage Closure versus Non-Warfarin Oral Anticoagulation in Atrial Fibrillation: 4-Year Outcomes of PRAGUE-17

BACKGROUND

The PRAGUE-17 trial demonstrated that left atrial appendage closure (LAAC) was non-inferior to non-warfarin oral anticoagulants (NOAC) for preventing major neurological, cardiovascular or bleeding events in high-risk patients with atrial fibrillation (AF).

OBJECTIVE

To assess the pre-specified long-term (4-year) outcomes in PRAGUE-17.

METHODS

PRAGUE-17 was a randomized non-inferiority trial comparing percutaneous LAAC (Watchman or Amulet) with NOACs (95% apixaban) in non-valvular AF patients with a history of cardioembolism, clinically-relevant bleeding, or both CHA₂DS₂-VASc > 3 and HASBLED > 2. The primary endpoint was a composite of cardioembolic events (stroke, transient ischemic attack, or systemic embolism), cardiovascular death, clinically-relevant bleeding, or procedure/device-related complications (LAAC group only). The primary analysis was modified intention-to-treat (mITT).

RESULTS

We randomized 402 AF patients (201 per group, age 73.3±7.0 years, 65.7% male, CHA₂DS₂-VASc 4.7+1.5, HASBLED 3.1+0.9). After 3.5 years median follow-up (1,354 patients-years), LAAC was non-inferior to NOAC for the primary endpoint by mITT (subdistribution hazard ratio[sHR] 0.81, 95% CI 0.56-1.18; p=0.27; p for non-inferiority=0.006). For the components of the composite endpoint, the corresponding sHRs (and 95% CIs) were 0.68 (0.39-1.20; p=0.19) for cardiovascular death, 1.14 (0.56-2.30; p=0.72) for all-stroke/TIA, 0.75 (0.44-1.27; p=0.28) for clinically-relevant bleeding, and 0.55 (0.31-0.97; p=0.039) for non-procedural clinically-relevant bleeding. The primary endpoint outcomes were similar in the per-protocol [sHR 0.80 (95% CI 0.54-1.18), p=0.25] and on-treatment [sHR 0.82 (95% CI 0.56-1.20), p=0.30] analyses.

CONCLUSION

In long-term follow-up of PRAGUE-17, LAAC remains non-inferior to NOACs for preventing major cardiovascular, neurological or bleeding events. Furthermore, non-procedural bleeding was significantly reduced with LAAC.

The effect of left atrial appendage closure on heart failure biomarkers: A PRAGUE-17 trial subanalysis

INTRODUCTION

The randomized PRAGUE-17 trial demonstrated noninferiority of left atrial appendage closure (LAAC) to non-vitamin K anticoagulants (NOACs) for the prevention of major cardiovascular or cerebrovascular events. However, the left atrial appendage is an important source of natriuretic peptides and plays a role in left atrial reservoir function. Changes of heart failure (HF) biomarkers after LAAC compared to NOAC has not been studied. The aim of the study was to compare the changes in concentrations of HF biomarkers between LAAC and NOAC patients.

METHODS

Of 402 patients randomized in the PRAGUE-17 trial, biomarkers were analyzed in 144 patients (73 in the NOAC and 71 in the LAAC group). Both groups had similar baseline characteristics. Serum concentration of NT-proBNP, NT-proANP, Galectin-3, and GDF-15 were measured at baseline (before the procedure in the LAAC group), at the 6-month (and at 24-month for NT-proBNP) follow-up timepoint.

RESULTS

There were no significant differences in baseline, 6 month, and delta (δ = baseline - 6 month) concentrations of NT-proANP between the groups (NOAC: baseline 2.6 [0.5; 4.9], 6-month 3.1 [1.8; 4.8], p = .068; LAAC: baseline 3.3 [1.1; 4.6], 6-month 2.6 [0.9; 5.3], p = .51; p value for δ in concentrations between groups = 0.42). Similarly, there were no significant differences in baseline, 6, 24 months, and delta concentrations of NT-proBNP between the groups (NOAC: baseline 461.0 [113.5; 1342.0], 6 month 440.0 [120.5; 1291.5], 24 month 798 [274; 2236], p = .39; LAAC: baseline 421.0 [100.0; 1320.0], 6 month 601.0 [145.0; 1230.0], 24 month 855 [410; 1367], p = .28; p value for δ in concentrations between groups = 0.73 at 6 months, and 0.58 at 24 months). Finally, no significant differences were present in baseline, 6 month, and δ concentrations of Galectin-3 and GDF-15 between the two groups.

CONCLUSION

LAAC did not significantly influence the levels of HF biomarkers 6 months after the procedure.

Intracardiac echocardiography-guided implantation of the Watchman FLX left atrial appendage closure device

BACKGROUND

The next-generation Watchman FLX left atrial appendage closure (LAAC) device has: (1) an atraumatic closed distal end, (2) reduced height, (3) a recessed screw hub to decrease device-related thrombus (DRT), (4) two rows of J-shape anchors so redeployment is possible after full recapture, and (5) ability to treat a greater size range of LAA ostia.

OBJECTIVE

To report, for the first time, the feasibility and safety of intracardiac echocardiography (ICE)-guided Watchman FLX implantation.

METHODS

A single-center prospective registry of atrial fibrillation patients planned for LAAC with the FLX device underwent ICE-guided implantation with conscious sedation. Transesophageal echocardiography (TEE) imaging was done preprocedure (to assess LAA size and exclude thrombus) and at clinical follow-up at 6-12 weeks. Clinical outcomes were LAA closure success, complications, leak, or DRT on follow-up TEE and major safety events.

RESULTS

The study included 30 patients: age 75 ± 8 years, 53% men, CHA₂ DS₂ -VASc 4.6 ± 1.6, and HAS-BLED 3.4 ± 1.1. The primary indication was prior bleeding in 60% (72% GI bleeding). The LAA orifice width and length were 22.7 ± 3.1 and 25.7 ± 5.7 mm, respectively. Technical success was 100% (the first-choice device was used in 28 of 30). Procedure time was less than 30 min in 27 of 30 cases, with 36 ± 15 ml contrast used. The final device size was 29.2 ± 4.7 mm with 21.6 ± 4.5% compression. There were no procedure-related complications. Follow-up TEE at a median 47 days follow-up showed 100% device success with no DRT or peridevice leak ≥5 mm. Major safety events occurred in 6.6% (2/30).

CONCLUSION

The Watchman FLX device can be safely implanted with intraprocedural ICE imaging instead of TEE.

P998Left atrial appendage closure device thrombosis is associated with systemic embolization

Introduction

Atrial fibrillation, in one of its forms, is the most frequent sustained tachyarrhythmia and increases the risk of stroke more than 5 times. Cardioembolic stroke and systemic embolism (CS/SE) represents the most severe complication of this arrhythmia. Approximately 92% of intracardiac thrombosis originates from the left atrial appendage (LAA) and, although its mechanical occlusion is proved method to prevent cardioembolism, thrombosis of all types of LAA occlusion devices and their associations with CS/SE were observed.

The purpose of this study is to evaluate the rate of LAA occlusion device thrombosis, its predictors and the risk for cardioembolism.

Methods

We analyzed a group of 359 patients (65% male, mean age 72 years) with high risk for thromboembolism (mean CHADSVASc = 4.0) after LAA catheter occlusion using any of 9 different occluder types since 2005. During clinical follow-up 819 patientyears were collected and an intracardiac thrombus was found on 22 devices. Total of 17 patients suffered CS/SE.

Results

Thrombosis was found in 11 men and 11 women, mean age 76 years, average CHADSVASc = 4.5 and HASBLED = 2.0. The thrombus was discovered on average 4.0 months after the LAA occlusion. In that time patients were receiving dual antiplatelet therapy (11x), acetysalicic acid (4x), or interrupted anticoagulation (6x). In 3 cases the thrombosis was associated with CS/SE which represented risk of 6.6% per year. In patients with no thrombosis annual risk of CS/SE was only 1.7% (P<0.001).

Figure 1

Conclusion

In our single center register thrombosis was found in total of 6.3% patients after LAA device implantation. In these patients, risk of CS/SE is 3.9-fold higher compared to patients without thrombus formation. Elderly patients and patients with more risk factors in general were affected more frequently.