Four-year data from PROTECT AF trial: Watchman device superior to Warfarin for mortality and primary efficacy in patients with atrial fibrillation
The four-year follow-up data from the PROTECT AF clinical trial demonstrated the Watchman Left Atrial Appendage ( LAA ) Closure device was statistically superior to Warfarin ( Coumadin ) for preventing cardiovascular death, all-cause stroke and systemic embolization. The data demonstrated significant reductions in both cardiovascular and all death compared to Warfarin.
The data were presented at Heart Rhythm 2013, the Heart Rhythm Society's 34th Annual Scientific Sessions in Denver.
Atrial fibrillation ( AF ) is an irregular heartbeat that can lead to blood clots, stroke, heart failure and other heart-related complications. The condition affects approximately 2.7 million Americans and 15 million people worldwide, and is the most common cause of disabling stroke.
A primary treatment goal for AF patients is to reduce the risk of blood clots causing stroke. Patients with AF and additional risk factors for stroke are commonly prescribed anticoagulants, like Warfarin, to prevent blood clots from forming in the heart. However, due to blood monitoring requirements, dietary restrictions, side effects and an increased risk of serious bleeding, many patients are unable or unwilling to take these medications for long periods of time. In contrast, the Watchman device is designed to close off the left atrial appendage, a major source of clots in patients with atrial fibrillation, and reduce the risk of stroke, potentially eliminating the need for long term use of blood-thinning medications.
The PROTECT AF clinical trial is a multicenter, prospective randomized clinical trial designed to demonstrate the safety and effectiveness of the Watchman device in patients with non-valvular atrial fibrillation who are eligible for Warfarin therapy and meet certain stroke risk factors. A total of 707 patients from 59 Centers were randomized 2:1 to device or warfarin control.
The PROTECT AF trial has achieved superiority for the combined endpoint of all stroke, cardiovascular or unexplained death and systemic embolism.
The observed primary efficacy event rate was 2.3% and 3.8% in the Watchman and control groups, respectively, demonstrating a 40% relative risk reduction in primary efficacy in the Watchman group ( RR=0.60, posterior probability of superiority = 96% ). Secondary analysis also showed a relative risk reduction and superiority to control for all-cause mortality and cardiovascular mortality.
The Watchman group was superior to the control group 3.2% to 4.8% respectively, representing a 34% relative risk reduction in all-cause mortality in the Watchman group ( HR= 0.66, p=0.0379 ).
The Watchman group was superior to the control group, 1.0% and 2.4% respectively, representing a 60% relative risk reduction in cardiovascular death in the Watchman group ( HR=0.40, p=0.0045 ). ( Xagena )
Source: Boston Scientific, 2013