Novel Score May Help Clinicians Determine Suitable Candidates for Extended DAPT

ORLANDO, Fla. — Results of the DAPT (dual antiplatelet therapy) study suggest that the new DAPT Score can accurately identify patients who have the greatest anticipated benefit and harm from an extended duration of therapy .

In the DAPT trial, Robert W. Yeh, MD, MSc, MBA, of Harvard Medical School, Boston, and colleagues randomly assigned patients (n=11,648) who received percutaneous coronary intervention (PCI) and completed 12 months of DAPT to either continued thienopyridine therapy plus aspirin or aspirin alone.

Compared with placebo, those who received extended therapy experienced reductions in ischemic complications but increases in moderate or severe bleeding events.

Using data from the trial, Dr Yeh and colleagues created a clinical risk score, called the DAPT Score, with the goal of identifying patients who derive the greatest benefit and risk from continuation of DAPT after 1 year.

During a press conference at the American Heart Association Scientific Sessions, Dr Yeh said that while individual risk scores for bleeding and ischemia have been produced previously, “Our goal here was to simultaneously account for the risk of ischemia and bleeding to inform overall treatment benefit.”

For the analysis, Dr Yeh and colleagues developed 2 prediction models within the DAPT trial population: the ischemic model, which identified predictors of myocardial infarction (MI) or stent thrombosis, including fatal events; and the bleeding model, which identified predictors of GUSTO moderate or severe bleeding, including fatal bleeds. Both models predicted events that occurred between 12 months and 30 months after index PCI.

After analyzing trial data, the following patient and index procedure characteristics were incorporated into the DAPT Score, with a point value (in parentheses) ascribed to each characteristic: age ≥75 years (–2), 65 to 75 years (–1), and < 65 years (0); diabetes (1); cigarette smoking (1); prior PCI or MI (1); chronic heart failure or left ventricular ejection fraction <30% (2); MI at presentation (1); vein graft PCI (2); and stent diameter <3 mm (1).

“As you go up in increasing DAPT score, there is a clear greater reduction in stent thrombosis and MI; simultaneously, moving in that same direction, you get less of an adverse impact on bleeding with continued thienopyridine vs placebo,” said Dr Yeh.

For example, Dr Yeh explained that among patients with a low DAPT score (<2), extended DAPT would be 2.5 times more likely to cause a bleed than to prevent stent thrombosis or MI. However, extended therapy for those in the high-risk group (≥2) would be more than 8 times more likely to prevent an MI than to cause a bleeding event. 

“The DAPT Score may help clinicians decide who should and who should not be treated with extended duration dual antiplatelet therapy,” Dr Yeh concluded.

For more information on the DAPT Score and to access the web-based calculator, visit The DAPT Study website.

Disclosures: Dr Yeh has received personal fees from Abbott Vascular, Boston Scientific, and Merck. The study received funding from Abbott, Boston Scientific, Bristol-Myers Squibb, Cordis, Daiichi Sankyo, Eli Lilly, Medtronic and Sanofi.

Reference

1. Yeh RW, et al. LBCT 03. ACS and PCI: The Continuum of Care. Individualizing Treatment Duration of Dual Antiplatelet Therapy after Percutaneous Coronary Intervention:  An Analysis from the DAPT Study.  Presented at: American Heart Association Scientific Sessions; November 7-11, 2015; Orlando, FL.