Left atrial appendage closure with the Watchman device appears associated with reduced stroke risk long-term for atrial fibrillation patients unable to take warfarin (Coumadin) even in the early period afterward, 5-year follow-up from the observational ASAP study showed.
The annual rate of ischemic stroke or systemic embolism was 1.8%, representing a 75% cut from the expected odds of 7.3% for these oral anticoagulant-contraindicated patients, Vivek Y. Reddy, MD, of New York’s Icahn School of Medicine at Mount Sinai, and colleagues reported in the Journal of the American College of Cardiology.
While the device is an alternative to long-term anticoagulation for stroke risk reduction in nonvalvular atrial fibrillation for patients able to take the medication but with “an appropriate rationale” not to do so, the pivotal trials continued oral anticoagulants for at least 6 weeks. No randomized trials have been done in oral anticoagulant-contraindicated patients.
ASAP was a prospective, nonrandomized trial to fill that gap. It included 150 patients contraindicated for oral anticoagulation, who instead got dual antiplatelet therapy with aspirin and clopidogrel (Plavix) for 6 months, followed by aspirin alone.
The mean CHADS2 and CHA2DS2-VASc scores were 2.8 and 4.4, respectively.
Hemorrhagic strokes occurred at an annual rate of 0.54%, all-strokes at 2.4%, cardiovascular or unexplained deaths at 2.3%, all-cause mortality at 4.6%, transient ischemic attacks at 0.9%, and major bleeding events at 1.8%.
ASAP had previously shown a promising stroke rate of only 1.7% 1 year after Watchman implantation. The 5-year annual frequency of 1.8% is “not appreciably different,” the authors wrote, and is “in line with that observed with the trials of warfarin-tolerant patients (PROTECT-AF and PREVAIL): 1.7% versus 1.6%, respectively.”
“The hemorrhagic stroke rate was higher than in PROTECT-AF/PREVAIL (0.54% versus 0.15%, respectively), but the lower 95% confidence interval for the hemorrhagic stroke rate was 0.1%, likely related to the smaller size of the ASAP cohort,” the authors noted.
Reddy’s group added that the present investigation shared similar rates of major bleeding with the ACTIVE A (1.3%) and AVERROES (1.2%) trials on patients ill-suited for oral anticoagulants.
Reddy disclosed receiving grant support and speakers honoraria from Boston Scientific.
Journal of the American College of Cardiology
Sharma D, et al “Left atrial appendage closure in patients with contraindications to oral anticoagulation” J Am Coll Cardiol 2016; DOI: 10.1016/j.jacc.2016.02.053.