One-Year Cardiovascular Outcome in Patients on Clopidogrel Anti-Platelet Therapy After Acute Myocardial Infarction

The aim of this study was to determine the risk factors in patients on clopidogrel anti-platelet therapy after acute myocardial infarction, for cardiovascular mortality, re-hospitalization and admission to emergency care unit. We followed 175 patients on dual antiplatelet therapy, with clopidogrel and acetylsalicylic acid, for 1 year after acute myocardial infarction, both STEMI and NSTEMI. Beside demographic and clinical characteristics, genetic ABCB1, CYP2C19 and CYP2C9 profile was analyzed using Cox-regression analysis. End-points used were: mortality, re-hospitalization and emergency care visits, all related to cardiovascular system. During the accrual and follow-up period, 8 patients (4.6%) died, mostly as a direct consequence of an acute myocardial infarction. Re-hospitalization was needed in 27 patients (15.4%), in nine patients (33.3%) with the diagnosis of re-infarction. Thirty-two patients (18.3%) were admitted to emergency care unit due to cardiovascular causes, up to 15 times during the follow-up. NSTEMI was an independent predictor of all three events registered (mortality OR=7.4, p<0.05; re-hospitalization OR=2.8, p<0.05); emergency care visit OR=2.4, p<0.05). Other significant predictors were related to kidney function (urea and creatinine level, creatinine clearance), co-morbidities such as arterial hypertension and decreased left ventricular ejection fraction, as well as clopidogrel dosing regimen. As a conclusion, it may be suggested that one of the most significant predictors of cardiovascular events (mortality, re-hospitalization and emergency care visits) is NSTEMI. Besides, clopidogrel administration according to up-to-date guidelines, with high loading doses and initial doubled maintenance doses, improves 1-year prognosis in patients with AMI.