A shortened, three-month course of dual antiplatelet therapy (DAPT) might be a safer bet than 12-month treatment for patients at a high risk of bleeding after percutaneous coronary intervention (PCI) and implantation of a drug-eluting stent, according to research presented at TCT 2019 in San Francisco.
Lead investigator Ajay J. Kirtane, MD, SM, of Columbia University Irving Medical Center, and colleagues’ study centered around the efficacy of three-month DAPT in protecting patients from MI and stent thrombosis after PCI and implantation with a contemporary drug-eluting stent. The stent, Boston Scientific’s thin-strut platinum-chromium Synergy stent, elutes everolimus from an abluminal layer of bioabsorbable polymer.
Because the design of the Synergy stent is favorable and could facilitate endothelialization—both the drug and polymer and absorbed and degraded within four months of implantation—it might also pair well with shorter-duration DAPT, the authors said. They recruited 2,009 patients from 110 international sites for the study, all of whom were experiencing a high bleeding risk that prevented them from going on DAPT longer than three months. Patients with acute MI or complex lesions were excluded from the study.
After PCI with implantation of the Synergy stent, patients were required to take DAPT (aspirin plus a P2Y12 inhibitor) for three months, except those on chronic anticoagulation for whom aspirin was optional. Event-free patients who discontinued the P2Y12 inhibitor at three months but continued taking aspirin for up to 15 months were included in the team’s analysis.
At three months, 77% of patients were eligible to discontinue the P2Y12 inhibitor. One co-primary endpoint that assessed death or MI between three and 15 months post-PCI compared to a propensity-adjusted historical limus-eluting stent control group receiving 12-month DAPT revealed a 5.6% event rate in three-month DAPT patients compared to a 5.7% event rate in those undergoing more traditional DAPT. The second co-primary endpoint—ARC definite/probable stent thrombosis in patients with three-month DAPT between three and 15 months—achieved an incidence of 0.3% compared to the 1% performance goal.
The researchers’ secondary endpoint of BARC 2/3/5 bleeding in patients undergoing three-month DAPT was met in 6.26% of patients compared to 4.17% in the historical 12-month DAPT cohort.
“These data prospectively demonstrate a low rate of adverse events for patients who are at high risk for bleeding and who then stop DAPT at three months,” Kirtane said in a release from the Cardiovascular Research Foundation. “This is critically important information because the required duration of DAPT following implantation of current generation drug-eluting stent platforms was previously unknown. These data better inform physicians on how best to tailor the recommended duration of DAPT to the bleeding risk of the patients they treat.”