The results of a four-year study that included Providence Saint John’s Health Center cardiologists and compared a tiny implant in the heart to oral blood-thinning medication to treat irregular heartbeats were published last week in the prestigious Journal of the American Medical Association.
The JAMA report concluded that after an average of 3.8 years of follow-up among patients with nonvalvular atrial fibrillation and at elevated risk for stroke, the WATCHMAN device compared favorably to warfarin in preventing stroke, blood clots and cardiovascular death.
The study was to determine if the device would prove as effective as warfarin, which may have serious side effects and which also can be difficult to dose. The study can be found at the Journal of the American Medical Association.
Fifty-nine hospitals across the nation took part in the trial. Providence Saint John’s enrolled the largest number of patients, said cardiologist Shephal Doshi, M.D., who led the trial at Providence Saint John’s. Dr. Doshi is the director of cardiac electrophysiology and is one of the world’s most experienced in this procedure.
“I am extremely proud of our achievement, and elated that we may have this innovative option to warfarin for a serious condition that currently affects nearly 5 million people in the United States.” Dr. Doshi said. “This speaks highly not just of Saint John’s, but also of the Providence system, which is dedicated to new ideas in patient care, all aimed at providing the best possible outcomes.”
The randomized clinical trial, known as PROTECT AF, included 707 patients and compared the WATCHMAN device to warfarin, commonly marketed as Coumadin, over the four years. The study was funded by the device manufacturer Boston Scientific. The results show WATCHMAN (compared to long-term warfarin therapy) resulted in:
— A 40 percent relative risk reduction for stroke, cardiovascular/unexplained death and embolism
— A 32 percent relative risk reduction in stroke
— A 63 percent relative risk reduction in fatal or disabling stroke
— A 60 percent relative risk reduction in cardiovascular death
— One drawback to the mainstay treatment warfarin, which reduces blood clotting in patients with atrial fibrillation and other cardiovascular conditions, is the need for lifelong monitoring, frequently resulting in dosage changes.
Trials have shown that patients’ levels of warfarin typically are not the therapeutic dose more than one-third of the time. Diet, particularly consumption of Vitamin K, can counteract the effect of warfarin and lead to unstable levels.
The use of warfarin also can result in severe bleeding (sometimes spontaneous and catastrophic) because the blood does not easily coagulate.
Utilizing a minimally invasive procedure, the WATCHMAN is inserted via a thin tube into the left atrial appendage, the major source of blood clots in patients with atrial fibrillation, clots that can be deadly if they break loose and enter the blood stream.
Just 21 to 33 millimeters in diameter, the WATCHMAN is a self-expanding device with a metal frame and permeable polyester fabric cover that allows blood to flow.
The device continues to be under review by the Food and Drug Administration, and three advisory committees have recommended its approval, most recently last month. Dr. Doshi was one of three physician experts who presented findings in October at the FDA panel meeting in Washington, D.C.
Successful implantation of the WATCHMAN continues Providence Saint John’s stance as a leader in cardiology and electrophysiology, with expertise in historic cardiac firsts, including the world’s first open heart surgery and the country’s first use of a laser balloon in an electrophysiological procedure known as atrial fibrillation ablation.