The two-drug strategy offers both benefits and risks after coronary artery bypass graft surgery

A new analysis shows that a combination of two antiplatelet drugs may benefit patients after the most common type of heart surgery – while increasing the risk of potentially dangerous bleeding. This double-edged finding by Weill Cornell Medicine and New York-Presbyterian investigators suggests that physicians should carefully evaluate the use of these drugs after this procedure.

In an analysis reported Aug. 9 JAMA, a team led by Dr. Mario Gaudino, a coronary artery bypass surgeon, examined data from 1,668 grafts, in which surgeons use a piece of vein from the leg to bypass blocked coronary arteries. However, sometimes blood clots form in the transplanted vein, restricting blood flow. Typically, patients are given aspirin; However, some evidence suggests that aspirin, along with a prescription antiplatelet drug such as ticagrelor, may be more effective at preventing this clotting.

“We have found that this dual therapy significantly reduces the risk of graft failure. However, we have shown for the first time that this approach also carries a significant risk of clinically meaningful bleeding,” said Dr. Gaudino, the Stephen and Suzanne Weiss Professor of Cardiothoracic Surgery at Weill Cornell Medicine and Cardiothoracic Surgeon at NewYork-Presbyterian/Weill Cornell Medical Center. “So the advantage comes at a price.”

Taken together, these results indicate that physicians should base their decisions on patients’ individual circumstances and should not use this approach in patients with medical conditions that put them at risk of bleeding, he said.

Each year, approximately 300,000 patients undergo coronary artery bypass graft surgery to treat narrowed or blocked arteries that deprive the heart muscle of oxygen-rich blood. In more than 90 percent of these procedures, the surgeon harvests a graft from one of the patient’s saphenous veins, which carry blood up the inside of the leg. However, within a year, up to a quarter of these grafts become clogged.

A few studies have examined the benefit of giving patients both aspirin and ticagrelor, an approach known as dual antiplatelet therapy (DAPT). However, these studies were small and came to conflicting conclusions. The team, including first author Dr. Sigrid Sandner, a masters student in clinical epidemiology at the Weill Cornell Graduate School of Medical Sciences, reached out to researchers from four such studies for access to their raw data. The team then compiled this data, creating a much larger study that could draw more robust conclusions.

They found a failure rate of about 11 percent in patients who received a combination of aspirin and ticagrelor, while blockages occurred in 20 percent of grafts when patients received aspirin alone. However, compared to aspirin alone, DAPT resulted in more bleeding events that, while not generally life-threatening, required medical attention.

In these earlier studies, patients received DAPT for a full year. However, most graft failures occur in the first few months after surgery. Next, Dr. Gaudino, who is also director of the Joint Clinical Trials Office at Weill Cornell Medicine and New York-Presbyterian, to test aspirin and ticagrelor over a period of one to three months to see if a shortened course offers the same benefit with less risk bleeding.