After 30 days of follow-up, 92.7 percent of patients with atrial fibrillation at high-risk for stroke who were implanted with the Watchman device did not have any serious adverse events, according to an analysis of an international registry. In addition, 98.5 percent of patients had a successful implantation, which was defined as deployment and release of the device into the left atrial appendage.

Lead researcher Lucas Boersma, MD, PhD, of St. Antonius Hospital in the Netherlands, presented results of the study at the American Heart Association Scientific Sessions on Nov. 9.

“I’m absolutely pleased with these results,” Boersma told Cardiovascular Business. “For Europe, it is still very important that we gather more data outside of the randomized clinical trials because randomized clinical trials always have a very strict inclusion and exclusion criteria. What we encounter in daily practice never really fits with randomized clinical trials. That’s not only for Watchman, but that’s for any therapy. Once the therapy is approved, you have to incorporate it into real life, every day practice.”

In March, the FDA approved the Watchman device (Boston Scientific) to reduce the risk of stroke in patients with non-valvular atrial fibrillation who seek an alternative to warfarin or novel anticoagulants. The device received a CE mark in Europe in 2005. Boersma said reimbursement for the device varies throughout Europe. Patients typically spend one night in the hospital after implantation with the Watchman device.

In this study, Boersma and his colleagues evaluated 1,021 patients in 47 countries who enrolled between October 2013 and May 2015 in the EWOLUTION registry, a prospective, single-arm, multicenter registry sponsored by Boston Scientific. The patients were from Europe, Russia and the Middle East.

Of the patients, 61.8 percent were deemed unsuitable for anticoagulation based on their comorbidities and/or bleeding risk. They used antiplatelet medications or received no treatment. The remaining patients used warfarin or novel oral anticoagulants such as dabigatran (Pradaxa, Boehringer Ingelheim), rivaroxaban (Xarelto, Bayer/Johnson & Johnson) and apixaban (Eliquis, Bristol-Myers Squibb). After implantation with the Watchman device, 86 percent of patients used oral anticoagulants or dual antiplatelet therapy.

At baseline, the mean age was 73.4, while 34.2 percent had congestive heart failure, 45.4 percent had a history of hemorrhagic stroke, ischemic stroke or transient ischemic attack, 38.7 percent had prior major or predisposition bleeding and 86.3 percent had a history of hypertension.

Patients in the registry had a higher risk of stroke and bleeding compared with patients who enrolled in two previous randomized trials.

At 30 days, three of the 1,000 patients had a stroke. If these patients did not receive any anticoagulation, the annual stroke rate would be 7 to 8 percent, according to Boersma.

During the 30-day follow up period, seven patients died. Boersma said one patient died on the day of the procedure due to acute right ventricular failure, while another patient died as a result of a procedural complication with a cerebral air embolism at implant. He said the remaining five deaths were not related to the procedure, including two deaths due to major gastrointestinal bleeding, one death due to respiratory insufficiency, one death due to cardiac arrest and one death due to clostridium difficile.

There were also 19 major bleeding events that required transfusion, of which eight were procedure- or device-related.

The 98.5 percent successful implantation rate was significantly better than any previous Watchman trial, according to Boersma.

Boersma said the researchers plan on following the patients for up to two years to determine long-term outcomes such as mortality and the occurrence of stroke, embolism and bleeding.

“These procedural data and the longer-term follow up will be very, very important to convince healthcare authorities in several countries that this is actually a therapy that is here to stay and this is a therapy that can help patients that cannot take any form of anticoagulation and that these people now have a good alternative,” Boersma said. “I hope the EWOLUTION data in the coming two years will prove that this patient population is indeed helped and cured by this procedure, so that it will be reimbursed in all of the countries in Europe.”