Poststenting ischemic events occur despite dual-antiplatelet therapy, suggesting that a “one size fits all” antithrombotic strategy has significant limitations. Ex vivo platelet function measurements may facilitate risk stratification and personalized antiplatelet therapy.

We investigated the prognostic utility of the strength of adenosine diphosphate (ADP)–induced (MA_ADP) and thrombin-induced (MA_THROMBIN) platelet-fibrin clots measured by thrombelastography and ADP-induced light transmittance aggregation (LTA_ADP) in 225 serial patients after elective stenting treated with aspirin and clopidogrel. Ischemic and bleeding events were assessed over 3 years.

Overall, 59 (26%) first ischemic events occurred. Patients with ischemic events had higher MA_ADP, MA_THROMBIN, and LTA_ADP (P < .0001 for all comparisons). By receiver operating characteristic curve analysis, MA_ADP >47 mm had the best predictive value of long-term ischemic events compared with other measurements (P < .0001), with an area under the curve = 0.84 (95% CI 0.78-0.89, P < .0001). The univariate Cox proportional hazards model identified MA_ADP >47 mm, MA_THROMBIN >69 mm, and LTA_ADP >34% as significant independent predictors of first ischemic events at the 3-year time point, with hazard ratios of 10.3 (P < .0001), 3.8 (P < .0001), and 4.8 (P < .0001), respectively. Fifteen bleeding events occurred. Receiver operating characteristic curve and quartile analysis suggests MA_ADP ≤31 as a predictive value for bleeding.

This study is the first demonstration of the prognostic utility of MA_ADP in predicting long-term event occurrence after stenting. The quantitative assessment of ADP-stimulated platelet-fibrin clot strength measured by thrombelastography can serve as a future tool in investigations of personalized antiplatelet treatment designed to reduce ischemic events and bleeding.