05:15am Tuesday 12 December 2017

Implanted Device Shows Potential as Alternative to Warfarin for Stroke Prevention in Patients with Atrial Fibrillation

Icahn School of Medicine at Mount Sinai’s Vivek Y. Reddy, MD, and colleagues examined the long-term efficacy and safety, compared to warfarin, of a device to achieve left atrial appendage (LAA) closure in patients with atrial fibrillation (AF). The study appears in the November 19 issue of JAMA.

The LAA is a pouch-like appendix located in the upper left chamber of the heart. The LAA is the major source of clots that block blood vessels in patients with AF. Oral anticoagulation with the blood-thinner medication warfarin has been the mainstay of treatment for prevention of cardioembolic stroke in AF. Although effective, warfarin is limited by a need for lifelong coagulation monitoring and multiple medication and food interactions.

Warfarin’s side effects have led to the development of minimally invasive surgical approaches to close the LAA such as the use of the implantable WATCHMAN device to close the LAA during a catheter-based procedure performed by cardiologists.

“Our large, international study results show that the WATCHMAN device is a promising alternative option to warfarin for atrial fibrillation patients with a left atrial appendage that puts them at high risk for a stroke,” says Dr. Vivek Reddy, Director of Arrhythmia Services for the Mount Sinai Health System. “Our findings show the device offers an advantageous reduced risk of hemorrhagic stroke and death when compared to Coumadin which has several debilitating side-effects affecting the quality of life of patients living with AF.”

This study included 707 patients with nonvalvular AF and at least 1 additional stroke risk factor who were randomly assigned to LAA closure with a WATCHMAN device made by Boston Scientific (n = 463) or warfarin (n = 244). The study was conducted at 59 hospitals in the United States and Europe.

At an average follow-up of 3.8 years, there were 39 events (stroke, systemic embolism or blood clot, and cardiovascular death) among 463 patients (8.4 percent) in the device group, compared with 34 events among 244 patients (13.9 percent) in the warfarin group, with the difference in the event rate indicating that LAA closure met prespecified criteria for both noninferiority and superiority compared with warfarin. LAA closure reduced the relative risk of a composite of these events by 40 percent (1.5 percent absolute reduction) compared with warfarin anticoagulation.

Additionally, patients in the device group demonstrated lower rates of both cardiovascular death (3.7 percent vs. 9.0 percent) and all-cause death (12.3 percent vs. 18.0 percent), with the device-based strategy. This translated to a 60 percent relative risk reduction (1.4 percent absolute reduction) of cardiovascular death and 34 percent reduction (5.7 percent absolute reduction) in all-cause death.

Also, although the device implantation procedure was associated with early complications, the accumulation of complications related to chronic anticoagulation resulted in similar safety profiles for the two groups.

This study was funded by the manufacturer of the device, Atritech (now owned by Boston Scientific) which provided the LAA closure device used in this trial.

Dr. Reddy has served as a consultant to Boston Scientific, Inc., the manufacturer of the WATCHMAN device.

About the Mount Sinai Health System
The Mount Sinai Health System is an integrated health system committed to providing distinguished care, conducting transformative research, and advancing biomedical education. Structured around seven member hospital campuses and a single medical school, the Health System has an extensive ambulatory network and a range of inpatient and outpatient services—from community‐based facilities to tertiary and quaternary care.

The System includes approximately 6,600 primary and specialty care physicians, 12‐minority‐owned free‐standing ambulatory surgery centers, over 45 ambulatory practices throughout the five boroughs of New York City, Westchester, and Long Island, as well as 31 affiliated community health centers. Physicians are affiliated with the Icahn School of Medicine at Mount Sinai, which is ranked among the top 20 medical schools both in National Institutes of Health funding and by U.S. News & World Report.


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