Initial and long-term antithrombotic therapy after left atrial appendage closure with the WATCHMAN.

AIMS: Evidence regarding post-procedural antithrombotic regimen other than used in randomized trials assessing percutaneous left atrial appendage (LAA) closure is limited. The present work aimed to compare different antithrombotic strategies applied in the real-world EWOLUTION study. METHODS AND RESULTS: A total of 998 patients with successful WATCHMAN implantation were available for the present analysis. The composite ischaemic endpoint of stroke, transitory ischaemic attack, systemic embolism and device thrombus, and the bleeding endpoint defined as at least major bleeding were assessed during an initial period (from implant until first medication change) and long-term period (from first change up to 2 years). The antithrombotic medication chosen in the initial phase was dual antiplatelet therapy (DAPT) in 60%, oral anticoagulation (OAC) in 27%, single antiplatelet therapy (SAPT) in 7%, and no medication in 6%. In the second long-term phase, SAPT was used in 65%, DAPT in 23%, no therapy in 8%, and OAC in 4%. No significant differences were found between the groups regarding the ischaemic endpoint both in the initial period (Kaplan-Meier estimated rate 2.9% for DAPT vs. 4.3% for OAC vs. 3.9% for SAPT or no therapy) and in the second period (4.2% for SAPT vs. 1.8% for DAPT vs. 3.5% for no therapy). With respect to bleeding events, the only difference was found in the initial phase with a higher incidence in patients under SAPT or no therapy. CONCLUSIONS: Tailored antithrombotic treatment using even very reduced strategies such as SAPT or no therapy showed no significant differences regarding ischaemic complications after LAA closure.

True Efficacy of LAA Closure: Patient Outcomes on Long-term Single-Antiplatelet or No Therapy: Insights From the EWOLUTION Registry.

BACKGROUND: Left atrial appendage occlusion (LAAO) is recommended for patients with atrial fibrillation at increased stroke risk, where effective long-term oral anticoagulation (OAC) is not feasible. In order to assess long-term safety of LAAO with aspirin monotherapy or no therapy, we aimed to report on patients with the Watchman LAAO device (Boston Scientific) once postimplantation intensified antiplatelet or anticoagulation therapy is discontinued. METHODS: A total of 1025 patients scheduled for elective LAAO therapy prospectively consented for participation in the EWOLUTION registry; 1005 patients received a successful implant and were followed for 2 years. We identified 766 patients in EWOLUTION on single-antiplatelet therapy (SAPT; n = 639) or no therapy (n = 127) for ≥1 year following LAAO. RESULTS: Three to 6 months after LAAO, 766 patients were switched to SAPT or no therapy and were followed for at least 1 year until the study's conclusion or with events while on SAPT/ no therapy; mean time on SAPT/no therapy was 536.56 ± 177.59 days. Patients experienced 1.4 ischemic strokes per 100 patient years (PY) despite a CHA2DS2-VASC score of 4.3 ± 1.6. Major nonprocedural bleeding rates were low, with 1.3 major bleeds per 100 PY with a mean HAS-BLED score of 2.2 ± 1.2. Furthermore, the ischemic stroke rate in the SAPT/no-therapy subgroup was similar to the whole EWOLUTION collective and high-risk subgroups; the bleeding rate was even lower. When analyzed separately, strokes (2.1/100 PY) and bleedings (1.4/100 PY) of the no-therapy subgroup were similar to patients on SAPT (strokes 0.7/100 PY [P=.70]; bleedings 1.4/100 PY [P=.90]). CONCLUSIONS: Outcome data of patients on SAPT/no therapy for ≥1 year following Watchman implantation in the EWOLUTION registry suggest the efficacy and safety of LAAO.

Evaluating Real-World Clinical Outcomes in Atrial Fibrillation Patients Receiving the WATCHMAN Left Atrial Appendage Closure Technology: Final 2-Year Outcome Data of the EWOLUTION Trial Focusing on History of Stroke and Hemorrhage.

BACKGROUND: Left atrial appendage occlusion with WATCHMAN has emerged as viable alternative to vitamin K antagonists in randomized controlled trials. Evaluating real-life clinical outcomes in atrial fibrillation patients receiving the WATCHMAN left atrial appendage closure technology was designed to collect prospective multicenter outcomes of thromboembolic events, bleeding, and mortality for patients implanted with a WATCHMAN in routine daily practice. METHODS: One thousand twenty patients with a WATCHMAN implant procedure were prospectively followed in 47 centers. Left atrial appendage occlusion indication was based on the European Society of Cardiology guidelines. Follow-up and imaging were performed per local practice up to a median follow-up of 2 years. RESULTS: Included population was old (age 73.4±8.9 years), at high risk for stroke (311 prior ischemic stroke/transient ischemic attack and 153 prior hemorrhagic stroke) and bleeding (318 prior major bleeding), with CHA2DS2-VASc score ≥5 in 49%, hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, Labile international normalized ratio, elderly, drugs/alcohol concomitantly ≥3 in 40% and oral anticoagulation contraindication in 72%. During follow-up, 161 patients (16.4%) died, 22 strokes were observed (1.3/100 patient-years, 83% reduction versus historic data), and 47 major nonprocedural bleeding events (2.7/100 patient-years, 46% reduction versus historic data). Stroke and bleeding rates were consistently lower than historic data in those with prior ischemic (-76% and -41%) or hemorrhagic (-81% and 67%) stroke and prior bleeding (-85% and -30%). Lowest bleeding rates were seen in patients with early discontinuation of dual antiplatelet therapy. Patients with early discontinuation of antithrombotic therapy showed lower bleeding rates, while they were highest for those with prior bleeding. Device thrombus was observed in 34 patients (4.1%) and was not correlated to drug regimen during follow-up ( P=0.28). CONCLUSIONS: During the complete 2-year follow-up of Evaluating Real-Life Clinical Outcomes in Atrial Fibrillation Patients Receiving the WATCHMAN Left Atrial Appendage Closure Technology, patients with a WATCHMAN left atrial appendage occlusion device had consistently low rates of stroke and nonprocedural bleeding, although most were contraindicated to oral anticoagulation and used only single antiplatelet therapy or nothing. CLINICAL TRIAL REGISTRATION: URL: https://clinicaltrials.gov . Unique identifier: NCT01972282.

Efficacy and safety of left atrial appendage closure with WATCHMAN in patients with or without contraindication to oral anticoagulation: 1-Year follow-up outcome data of the EWOLUTION trial.

BACKGROUND: Left atrial appendage (LAA) occlusion with WATCHMAN has emerged as viable alternative to vitamin K antagonists in randomized controlled trials. OBJECTIVE: EWOLUTION was designed to provide data in routine practice from a prospective multicenter registry. METHODS: A total of 1025 patients scheduled for a WATCHMAN implant were prospectively and sequentially enrolled at 47 centers. Indication for LAA closure was based on European Society of Cardiology guidelines. Follow-up and transesophageal echocardiography (TEE) were performed per local practice. RESULTS: The baseline CHA2DS2-VASc score was 4.5 ± 1.6; the mean age was 73.4 ± 9 years; previous transient ischemic attack/ischemic stroke was present in 312 (30.5%), 155 (15.1%) had previous hemorrhagic stroke, and 320 (31.3%) had a history of major bleeding; and 750 (73%) were deemed unsuitable for oral anticoagulation therapy. WATCHMAN implant succeeded in 1005 (98.5%) of patients, without leaks >5 mm in 1002 (99.7%) with at least 1 TEE follow-up in 875 patients (87%). Antiplatelet therapy was used in 784 (83%), while vitamin K antagonists were used in only 75 (8%). At 1 year, mortality was 98 (9.8%), reflecting the advanced age and comorbidities in this population. Device thrombus was observed in 28 patients at routine TEE (3.7%) and was not correlated with the drug regimen (P = .14). Ischemic stroke rate was 1.1% (relative risk 84% vs estimated historical data); the major bleeding rate was 2.6% and was predominantly (2.3%) nonprocedure/device related. CONCLUSION: LAA closure with the WATCHMAN device has a high implant and sealing success. This method of stroke risk reduction appears to be safe and effective with an ischemic stroke rate as low as 1.1%, even though 73% of patients had a contraindication to and were not using oral anticoagulation.