Pooled Trial, Registry Data Support Watchman for Stroke Prevention in A-fib

AMSTERDAM, The Netherlands—A new combination of long-term data affirms that left atrial appendage (LAA) closure with the Watchman device is becoming an increasingly efficacious and safe alternative to warfarin in patients with nonvalvular atrial fibrillation (A-fib), according to results presented on September 2, 2013, at the European Society of Cardiology Congress.

Saibal Kar, MD, of Cedars-Sinai Medical Center (Los Angeles, CA), and colleagues pooled 5-year data from the PROTECT AF trial and the Continued Access Protocol (CAP) registry on 1,122 patients (3,503 patient years) who underwent LAA closure with the Watchman device (Boston Scientific, Natick, MA).

Learning Curve Overcome

Procedure/device related safety events decreased from PROTECT AF and stroke dropped to zero in the CAP registry, with significant gains in safety over time between the early and late phases of PROTECT AF (table 1).

Table 1. Safety Event Rates: PROTECT AF vs. CAP

According to Dr. Kar, the above findings show that such concerns were “not related to the device but the actual procedure itself.”

When data from the 2 studies were combined, rates of both the composite of stroke, systemic embolism, and CV/unknown death (primary efficacy endpoint) and of ischemic stroke decreased compared with PROTECT AF alone (table 2).

Table 2. Combined Clinical Outcomes

Once Approved, How Will it Compare?

“The efficacy of ischemic events of the Watchman device is equivalent to warfarin therapy,” Dr. Kar observed. “If you add the fact that you decrease hemorrhagic events significantly, you get a net benefit of the device itself. This translates into a mortality reduction.”

Since Watchman’s efficacy and associated rates of ischemic events are comparable to warfarin historical controls, and safety and efficacy have improved over time,  “we’ve overcome the learning curve,” he commented. Four-year results of PROTECT AF, presented in May 2013 at the Heart Rhythm Society 34th Annual Scientific Sessions in Denver, CO, found Watchman superior to warfarin alone with regard to avoiding stroke and mortality. Altogether, the findings confirm the superiority of the Watchman, Dr. Kar added.

But the important question of whether or not Watchman can compete with the benefits of newer anticoagulants like dabigatran, rivaroxaban, and apixaban has yet to be answered. Dr. Kar said his team plans on addressing this issue at the annual Transcatheter Cardiovascular Therapeutics symposium this October in San Francisco, CA. “We’re going to show it’s almost equivalent,” he said, adding that “the hemorrhagic events will definitely be lower” with LAA closure.

Looking toward the future of Watchman, Dr. Kar predicted that the US Food and Drug Administration will convene a new panel to “finally” approve the device. Once approved, “it should be recommended to all patients with atrial fibrillation who require long-term anticoagulation,” he added.

Source:

Kar S. Long term efficacy of left atrial appendage closure with WATCHMAN device. Presented at: European Society of Cardiology Congress; September 2, 2013; Amsterdam, The Netherlands.

Related Stories:

• LAA Occlusion More Cost-effective Than Both Warfarin and Dabigatran for A-fib Patients
• PROTECT AF: 4-Year Results Show Superiority of Watchman Over Warfarin for A-fib
• ASAP Published: Watchman a Safe Option for A-fib Patients Ineligible for Warfarin