Scientists from the Netherlands indicate that individuals with a transcatheter aortic-valve implant (TAVI) may face an increased bleeding risk when given a combination of aspirin and Plavix, even though aspirin alone appears to be just as effective at preventing blood clots.
In findings published in the New England Journal of Medicine on October 8, researchers revealed that patients given a combo of Plavix and aspirin faced nearly twice the rate of bleeding events than patients given aspirin alone.
At issue is whether single drug therapy or dual drug therapy is more appropriate for individuals undergoing transcatheter aortic valve replacement (TAVR); a type of heart procedure which allows the surgeon to replace the heart valve by threading it through an artery in the leg instead of via open chest surgery. The procedure, which places the valve over the damaged aortic valve in a less invasive procedure, requires the patient be placed on blood thinners for some time, to avoid blood clot complications like deep vein thrombosis or pulmonary embolism.
Initially, TAVR was approved only in high risk patients who were frail or could not undergo open heart surgery because the procedure carried such high risks. However, it has gained popularity in recent years, despite questions about the durability of the heart valves, particularly among younger patients who could live another 30 years or more.
In this latest study, researchers conducted a randomized, controlled trial involving 331 patients assigned to receive aspirin alone, and 334 patients given aspirin plus Plavix.
Plavix (clopidogrel) is a blood thinner that prevents blood platelets from sticking together to form clots. It is prescribed to prevent heart attacks, strokes and blood clotting when drug coated stents are used in patients with arteriosclerosis and in other at-risk patients. It is a blockbuster medication, generating annual sales of over $9 billion for Bristol Myers Squibb Co. and Sanofi-Aventis.
According to the findings of this study, 50, or 15.1% of aspirin-only patients suffered a bleeding event over the course of a year. But there were 89 such incidents, or 26.6%, among patients given aspirin and Plavix.
Rates of deaths among those patients due to bleeding, strokes and heart attacks were far more similar.
“Among patients undergoing TAVI who did not have an indication for oral anticoagulation, the incidence of bleeding and the composite of bleeding or thromboembolic events at 1 year were significantly less frequent with aspirin than with aspirin plus clopidogrel administered for 3 months,” the researchers concluded.
In 2018, researchers from the University of Texas also warned that the drug combination could increase bleeding risks, but that study indicated they also lowered the risk of stroke when used together.
A study earlier that same year found that the combination of the two drugs could also increase the risk of heart attacks. In March 2018, South Korean researchers published a study in the medical journal The Lancet, which found little benefit in giving the two drugs to patients who had recently been implanted with a coronary stent.