Diabetes mellitus and platelet reactivity in patients under prasugrel or ticagrelor treatment: an observational study.

Background: The influence of diabetes mellitus (DM) on platelet reactivity (PR) in prasugrel or ticagrelor treated patients is not well studied.
Methods: In an observational study involving 777 patients with acute coronary syndrome undergoing percutaneous coronary intervention treated by either prasugrel 10 mg od (n = 315) or ticagrelor 90 mg bid (n = 462), platelet function was assessed using the VerifyNow P2Y12 function assay (in PRU) at one month post intrvention.
Results: In the overall population, ticagrelor and insulin-treated DM affected PR, with a decrease in log by 0.88 (corresponding to a 58 % decrease in PR) compared to prasugrel-treated patients (p < 0.001), and an increase in log by 0.26 (corresponding to a 30 % increase in PR) compared to non-diabetic patients (p = 0.01), respectively. PR in prasugrel-treated patients differed significantly by DM status: 70.0 (36.3-113.0) in non-diabetic vs 69.0 (44.5-115.3) in non insulin-treated diabetic vs 122.0 (69.0-161.0) in insulin-treated diabetic patients, p for trend = 0.01. No differences were observed in ticagrelor-treated patients. By multivariate analysis, in prasugrel-treated patients insulin-treated DM was the only factor predicting PR, with log of PR increased by 0.42 (corresponding to a 52 % increase in PR) compared to non-diabetic patients (p = 0.001). No factor was found to affect PR in ticagrelor-treated patients.
Conclusions: Patients with insulin-treated DM treated with prasugrel post PCI have higher PR, than patients without DM or non insulin-treated diabetic patients treated with this drug. Ticagrelor treated patients have overall lower PR than patients on prasugrel, independent of DM status or insulin treatment.
Trial Registration: Clinical Trials Gov. NCT01774955.