Differences in the mode of presentation for acute coronary syndrome by pre-hospitalization medication, in relation to coronary risk factors, East-Osaka acute coronary syndrome (EACS) registry

Background Pre-hospitalization medication such as aspirin and nitrates has been shown to affect the mode of presentation in acute coronary syndrome (ACS). However, it is not formally assessed whether other cardiovascular medications may be contributed to the differences in the mode of presentation, especially in relation to coronary risk factors. Methods and results We conducted a registration study of patients (M/F 850/323) with either ST-segment elevation myocardial infarction (STEMI), non-ST-segment elevation myocardial infarction (NSTEMI) or unstable angina (UA), and examined the differences in the mode of presentation, pre-hospitalization medication, and coronary risk factors. The ratio of the incidence of STEMI and NSTEMI/UA was significantly reduced in patients having pre-hospitalization medication with aspirin, nitrates or statins, but not with other medications such as beta-blockers in multivariate analysis. Pre-hospitalization medication with aspirin and nitrates was significantly associated with the same reduction of the ratio in patients with male gender, hypertension, diabetes mellitus and a history of coronary artery disease. However, in patients who smoked, were obese and hypercholesterolemic, pre-hospitalization medication with nitrates was significantly associated with the reduced ratio. The ratio was significantly low in patients with males and hypercholesterolemia treated with statins before admission. Conclusion Depending on their coronary risk factors, pre-hospitalization medication with aspirin, nitrates or statins was associated with a different presentation and evolution of ACS.