The aim of this study was to evaluate platelet reactivity and 30-day
bleeding events in patients treated with
prasugrel 10 mg after
acute coronary syndromes. A total of 444 patients with
acute coronary syndromes treated with
percutaneous coronary intervention and
prasugrel 10 mg/day were monitored by measurement of the
vasodilator-stimulated phosphoprotein (VASP) index 2 to 4 weeks after hospital discharge. Platelet reactivity was also assessed using the VerifyNow P2Y(12) assay and light transmission aggregometry.
Bleeding events (per the
Bleeding Academic Research Consortium [BARC] definition) and ischemic events (death,
myocardial infarction, and definite
stent thrombosis) were collected over 30 days of follow-up. Two thirds of the patients presented with ST-segment elevation
myocardial infarctions, 28.8% had diabetes, and 12.4% were aged >75 years. High on-treatment platelet reactivity according to 3 prespecified definitions (VASP index ≥ 50%, platelet reactivity ≥ 235 P2Y(12) reaction units, and residual platelet reactivity ≥ 46.2%) was found in 6.8%, 3.4%, and 3.2% of patients, respectively.
Obesity (body mass index >30 kg/m(2)) and multivessel disease were the only independent factors associated with high on-treatment platelet reactivity (p = 0.006 and p = 0.045, respectively). At 30 days, there was no major
bleeding complication (BARC grade 3 or 5), and 1.6% of patients had recurrent ischemic events. Nuisance
bleeding (BARC grade 1) and minor
bleeding (BARC grade 2) occurred in 14.2% (n = 63) and 2.5% (n = 11) of patients, respectively, but were not predicted by VASP index. In conclusion, patients with
acute coronary syndromes receiving maintenance doses of
prasugrel have low rates of HPR and ischemic events within the first month. Minor or minimal
bleeding is frequent, but not major
bleeding. VASP was poorly correlated with the risk for minor or minimal
bleeding.