DAPT Score Performance in a Nationwide Population

Study Questions:

What is the performance of the dual antiplatelet therapy (DAPT) score in a nationwide real-world population?

Methods:

The investigators used registry data in Sweden (from 2006-2014) and followed 41,101 patients who had undergone 12 months of event-free DAPT, from months 12-30 after stenting. Risk of myocardial infarction (MI) or stent thrombosis, major adverse cardiovascular and cerebrovascular events (MACCE) (MI, stroke, and all-cause death), and fatal or major bleeding were compared according to DAPT score.

Results:

The DAPT score had a discrimination of 0.58 (95% confidence interval [CI], 0.56-0.60) for MI or stent thrombosis, 0.54 (95% CI, 0.53-0.55) for MACCE, and 0.49 (95% CI, 0.45-0.53) for fatal or major bleeding. Risk of MI or stent thrombosis was significantly increased at scores of ≥3, while MACCE risk followed a J-shaped pattern and increased at scores of ≥4. Absolute differences in fatal or major bleeding risk were small between scores. Event rates of ischemic and bleeding outcomes in patients with high (≥2) and low (<2) scores differed compared to the DAPT Study from which the score was derived; fatal or major bleeding rates were approximately one-half of those in the placebo arm of the DAPT Study.

Conclusions:

The authors concluded that in a nationwide population, the DAPT score did not adequately discriminate ischemic and bleeding risk.

Perspective:

This study reports that in a real-world population, the DAPT score did not adequately discriminate ischemic and bleeding risk. Furthermore, the relationship between DAPT score and ischemic risk did not correspond to the suggested decision rule for extended DAPT, and the risk of bleeding was lower compared with the DAPT Study. It appears the score and its decision rule may not be generalizable to real-world populations. This careful analysis highlights the fact that mathematical models and prediction rules cannot replace clinical judgment and reasoning and the uncertain utility of the DAPT score in patient management. Whether a better/optimized tool may identify patients most likely to benefit from extended DAPT after coronary stenting will need prospective assessment.

Keywords: ESC Congress, ESC18, Coronary Stenosis, Hemorrhage, Myocardial Infarction, Myocardial Ischemia, Platelet Aggregation Inhibitors, Primary Prevention, Risk Assessment, Stents, Stroke, Vascular Diseases


< Back to Listings