Who Might Benefit from Long-Term DAPT? Risk Score May Help

By Kelly Young

Edited by David G. Fairchild, MD, MPH, and Lorenzo Di Francesco, MD, FACP, FHM

Researchers have developed a risk score to determine which percutaneous coronary intervention (PCI) patients would benefit most from continuing dual antiplatelet therapy (DAPT) beyond 12 months, according to results presented at the American Heart Association's annual meeting.

In the DAPT study, nearly 12,000 patients who'd undergone PCI and finished 12 months of DAPT were randomized to continued thienopyridine plus aspirin or aspirin alone. For the risk score, points were added or subtracted based on numerous factors, including age, diabetes, prior PCI, and MI at initial presentation (total scores could range from -2 to 10).

Among patients with DAPT scores of 2 or more, those who continued thienopyridine had significantly lower rates of MI or stent thrombosis at 12–30 months after PCI compared with placebo recipients (2.7% vs. 5.7%); rates of moderate-to-severe bleeding did not differ between the groups. Patients with lower DAPT scores who continued thienopyridine didn't see a significant benefit in ischemia prevention and did have an increased bleeding risk (3.0% vs. 1.4% for placebo).

For DAPT scores of 2 or more, 34 patients would need to be treated to prevent one ischemic event, and 272 treated to see one additional case of bleeding.

Dr. James de Lemos, who was not involved in the study, said that the risk score "offers a simple and practical solution to a daily clinical problem seen for practicing cardiologists and physicians. This completely revises my interpretation of the DAPT results. I had considered the trial essentially null based on the tradeoff of risk and benefit and the importance of the bleeding complications, but we see now a much more clearly favorable benefit-to-risk profile for a substantial subset of post-PCI patients."