Left ventricular assist devices (LVADs) are pumps that are used to circulate blood in patients with weakened hearts due to advanced heart failure. Mechanical stress on these implants can make patients susceptible to blood clots, and patients are required to take anti-clotting medications including vitamin-k antagonists (VKA) and aspirin. Modern heart pump models are designed to reduce malfunction, with frictionless motors and fewer mechanical parts. For decades, aspirin has been thought to be necessary in addition to VKA therapy to prevent clotting in patients with these heart pumps.
A team led by investigators at Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, conducted an international clinical trial to determine the impact of removing aspirin, while continuing VKA, in patients supported with modern LVADs. The study found that patients who did not receive aspirin were not at increased clotting-related risk of stroke or pump malfunction and fared comparably to those who were prescribed the drug. In addition, the researchers found that aspirin avoidance was associated with a reduction in bleeding events, reduced hospital days and decreased cost of care for such events.
The study involved a randomized, double-blind, placebo-controlled trial involving 628 patients with advanced heart failure and a specific type of LVAD, the HeartMate 3 pump. The enrolled population comprised a diverse population from nine countries across the globe, including the United States, Canada, France, Italy, Austria, Czech Republic, United Kingdom, Kazakhstan, and Australia.
After exclusions, 296 patients who received a placebo and 293 patients who received aspirin in addition to VKA therapy were assessed for major adverse events at the end of 12 months. The researchers found no difference in clotting-related risks between the two groups, and noted that for every 100 patients, 14.5 major bleeding events were prevented per year in the placebo group.
"Our findings suggest that avoidance of aspirin meaningfully improves clinical outcomes in patients with advanced heart failure supported with a heart pump," said corresponding author Mandeep R. Mehra, MD, the executive director of the Center for Advanced Heart Disease in the Brigham's Division of Cardiovascular Medicine. "A reduction in bleeding events translates to lower hospitalization rates, fewer days spent in the hospital, and reduced cost of care for patients."
