Results from a clinical study evaluating the use of the Watchman left atrial appendage closure device (Boston Scientific) in patients with atrial fibrillation who have a contraindication to oral anticoagulants such as warfarin were presented at the EuroPCR congress in Paris. Data were presented by Martin Bergmann, Department of Cardiology at the Asklepios Klinik St. Georg in Hamburg, Germany, and principal investigator of the study.
“Patients with atrial fibrillation who cannot take oral anticoagulants have limited options to reduce their stroke risk,” said Bergmann. “Early study results are promising of the Watchman device as an alternative for stroke prevention in this high-risk patient population with patients using dual antiplatelet therapy in place of warfarin after left atrial appendage closure.”
In the study, 24 patients with contraindications to warfarin were successfully implanted with the Watchman device at a single centre in Germany. Following the procedure, they received dual antiplatelet therapy for at least three months. Results showed that after a mean follow-up of 4.2 months, no cerebrovascular events or device dislodgements occurred. In a single case, a thrombus was observed and resolved after two weeks of treatment with heparin.
These results are consistent with clinical data from the multicentre ASA Plavix (ASAP) Registry recently presented at the 2011 American College of Cardiology by Vivek Reddy, Mount Sinai Medical Center in New York. This study evaluated 113 patients with contraindications to warfarin implanted with the Watchman device and treated with dual antiplatelet therapy for six months post-procedure.
In the multicentre, randomised PROTECT AF trial, the Watchman device demonstrated a 38% relative risk reduction for stroke, cardiovascular death and systemic embolism compared to long-term warfarin therapy in 800 patients. Boston Scientific is currently enrolling patients in the PREVAIL study, a confirmatory study designed to gain FDA approval.
The CE-marked Watchman device was commercialised outside the United States in 2009. In the USA, it is an investigational device, limited by applicable law to investigational use and not available for sale. The device was developed by Atritech, which was acquired by Boston Scientific in March, for left atrial appendage closure in patients with atrial fibrillation. For more information, visit www.Atritech.net.