STOPDAPT-2 Data Show Improved Outcomes for Stent Patients on a P2Y12 Inhibitor Who Stop Taking Aspirin After 1 Month

March 18, 2019—Data from the STOPDAPT-2 trial show that patients who stopped taking aspirin 1 month after undergoing coronary stenting but continued taking a P2Y12 inhibitor fared significantly better after 1 year compared with those who followed the standard practice of continuing both medications. These data were presented by Hirotoshi Watanabe, MD, at the American College of Cardiology’s (ACC) 68th Annual Scientific Session, being held March 16–18 in New Orleans, Louisiana.

According to ACC’s announcement, for the trial’s primary endpoint—a composite of death from cardiovascular causes, heart attack, clotting near the stent, stroke, and major bleeding—stopping aspirin at 1 month but continuing with a P2Y12 inhibitor was found to be superior to dual antiplatelet therapy (DAPT) for 1 year.

Current guidelines recommend DAPT (a combination of aspirin and a P2Y12 inhibitor such as clopidogrel) for at least 12 months after undergoing a stenting procedure. However, according to the ACC announcement, there was a need to determine whether this is the best combination of drugs to use with newer drug-eluting stents. STOPDAPT-2 was therefore designed to assess whether stopping aspirin after 1 month but continuing clopidogrel alone for 12 months might be a better approach.

STOPDAPT-2 enrolled 3,009 patients who received a drug-eluting stent at 89 medical centers in Japan. Half of the patients were randomly assigned to receive standard DAPT. The other half took aspirin plus clopidogrel or prasugrel for the first month and took clopidogrel only after that, with patients who took prasugrel initially switching to clopidogrel after the first month, according to the ACC announcement.

“One-month DAPT followed by clopidogrel monotherapy as compared with standard 12-month DAPT reduced the bleeding events and did not increase the ischemic events,” said Dr. Watanabe, Research Associate at Kyoto University Graduate School of Medicine and the study’s lead author in the ACC announcement. “That led to a net clinical benefit for both ischemic and bleeding outcomes.”

After 12 months, the patients who stopped aspirin were instructed to continue taking clopidogrel, while the patients in the DAPT arm were instructed to discontinue clopidogrel but continue taking aspirin. In the 1-month DAPT group, aspirin was stopped in 96% of patients at 1 month, while DAPT was continued up to 1 year in 88% of patients in the standard 12-month DAPT group.

Overall, stopping aspirin after 1 month reduced the risk of adverse events by 36%. After 1 year, only 2.4% of patients who stopped aspirin after 1 month experienced the composite primary endpoint compared with 3.7% among those following standard DAPT.

In the ACC announcement, it was reported that an analysis of secondary endpoints revealed that stopping aspirin after 1 month significantly reduced the rate of bleeding. Overall, those stopping aspirin experienced fewer major bleeding incidences compared with those who followed standard DAPT (0.4% vs 1.5%). Furthermore, stopping aspirin after 1 month did not increase the events related to ischemic events, in a secondary endpoint that included a composite of death from cardiovascular causes, heart attack, clotting around the stent, or stroke.

The ACC’s announcement noted that researchers plan to continue to track outcomes until 5 years poststenting.