Left Atrial Appendage Closure: Is the Strategy Enough to Lower Long-Term Stroke Risk?

Purpose of Review: Left atrial appendage closure (LAAC) emerged as a promising site-directed therapy to mitigate stroke risk in patients ineligible for long-term oral anticoagulation. We sought to summarize the current evidence regarding the role of LAAC on long-term risk of ischemic stroke and systemic thromboembolism. Recent Findings: Data from EWOLUTION registry provides real world evidence on the 1-year outcomes of LAAC by WATCHMAN device. The annual ischemic stroke rate was 1.1 per 100 patient-years, as opposed to the CHADS2VASC score-predicted stroke rate of 7.2% (84% relative risk reduction). No differences in death, stroke, or bleeding rates were observed between patients with or without a contraindication for anticoagulation or based on type of anticoagulant used. Pooled registry data in patients who underwent Amplatzer Cardiac Plug (ACP) demonstrate an observed stroke rate of 2.0–2.7% as opposed to CHADS2VASC score-predicted stroke rate of 5.6–8.3% over a median follow-up ~ 5 years. Recent studies evaluating efficacy of LARIAT over a median follow of ~3 years demonstrate that the observed ischemic stroke rate was 1% as opposed to the expected stroke rate of 6.2%. A recent propensity score matched observational study by Melduni RM et al. demonstrated that patients with AF who underwent routine LAAC during elective cardiac surgery (CABG/valvular surgery) were found to have higher risk (OR = 2.83) of postoperative AF with no effect on long-term stroke risk (OR 0.80, 95% CI 0.53–1.22) or mortality (OR 0.99, 95% CI 0.80–1.22). Summary: LAAC device studies have shown promising results in patients ineligible for long-term oral anticoagulation (OAC). Patients who develop stroke while being on OAC should also be considered for LAAC. But, caution must be executed while interpreting the current evidence as these devices may only offer benefit in decreasing LAA-dependent cardio-embolic stroke and non-LAA-dependent thrombi contribute to a small but significant portion of stroke risk. Currently, WATCHMAN device and ACP are being used extensively, and other LAA closure devices are being studied in clinical trials (Amulet IDE, WaveCrest II, Amaze, LAAOS III) which will be available for clinical use in near future. Further studies with long-term follow-up data utilizing prospective registries (LAAO registry, ACP registry) are needed to determine their safety/efficacy profile in comparison with newer oral anticoagulants that are currently available for stroke prevention.