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.