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Stroke rate low with LAA closure at 4 years
Rates of stroke at 4 years were low for patients with nonvalvular atrial fibrillation who underwent left atrial appendage, or LAA, closure with an FDA-approved device, according to new registry data.
The researchers evaluated patients treated with the device (Watchman, Boston Scientific) in the CAP and CAP2 registries, which accompanied the PROTECT-AF and PREVAIL randomized controlled trials, respectively.
The CAP registry included 566 patients followed for a mean of 50.1 months (2,293 patient-years) and the CAP2 registry included 578 patients followed for a mean of 50.3 months (2,227 patient-years). The primary efficacy endpoint for both was a composite of stroke, systemic embolism and CV/unexplained death. The researchers also evaluated rates of stroke types.
Low event rates
The primary composite endpoint occurred at a rate of 3.05 per 100 patient-years in CAP and 4.8 per 100 patient-years in CAP2, Cardiology Today Editorial Board Member David R. Holmes Jr., MD, the Scripps Professor in Cardiovascular Medicine at the Mayo Clinic in honor of Dr. George Gura, and colleagues wrote.
The most commonly occurring component of the primary endpoint was CV/unexplained death (CAP, 1.69 per 100 patient-years; CAP2, 2.92 per 100 patient-years), according to the researchers.
Strokes occurred at rates of 1.48 per 100 patient-years in CAP and 2.25 per 100 patient-years in CAP2, most of which were ischemic strokes (CAP, 1.3 per 100 patient-years; CAP2, 2.2 per 100 patient-years), the researchers wrote, noting the rates of hemorrhagic strokes were very low (CAP, 0.17 per 100 patient-years; CAP2, 0.09 per 100 patient-years).
Total stroke rates were 78% lower in CAP and 69% lower in CAP2 than those predicted by CHA2DS2-VASc score, Holmes and colleagues wrote.
Procedural success was 94% in both registries. Compared with patients in CAP, patients in CAP2 were older (75 years vs. 74 years; P = .0065) and had higher CHA2DS2-VASc scores (4.5 vs. 3.88; P < .0001), according to the researchers.
In addition, they wrote, 95% of patients were able to discontinue anticoagulation at 1 year.
The findings add “to increasing information that local site therapy is an effective and safe alternative to long-term anticoagulation in patients with nonvalvular AF who are at increased risk for stroke,” Holmes and colleagues wrote. “The current data documents the lowest rate of hemorrhagic stroke yet documented in this patient population.”
Worthwhile therapy
In a related editorial, A. John Camm, MD, FRCP, professor of clinical cardiology at St. Georges University of London, wrote: “Despite the accumulation of very substantial registry data, guideline writers will understandably remain cautious about their recommendations for use of LAA closure implantation as an alternative to oral anticoagulation, but it is increasingly clear that, for those who have no alternative because they cannot take long-term oral anticoagulation, this therapy is well worthwhile. But do these new data really help? Are they enough to confirm the value of LAA closure? Yes, but ‘tis not enough to help the feeble up, but to support him after’ (William Shakespeare). They do only a little to ‘help up’ a too thinly researched therapy, but they do much more to support what has so far been achieved.” – by Erik Swain
Disclosures: The registries were funded by Boston Scientific. Holmes reports he is an unpaid member of an advisory board for Boston Scientific. Please see the study for the other authors’ relevant financial disclosures. Camm reports he received institutional grants and personal fees from Bayer, Boehringer Ingelheim, Bristol-Myers Squibb/Pfizer and Daiichi Sankyo and has received personal fees from Abbott, Boston Scientific and Medtronic.