Impact of symptom presentation on in-hospital outcomes in patients with acute myocardial infarction

Background Limited data exist regarding the association between symptom presentation of acute myocardial infarction (AMI) and in-hospital outcomes. Methods We analyzed data of the Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET). This was a prospective and multicenter registry consisting of 3085 AMI patients with available data of symptoms, who were hospitalized within 48 h from onset during July 2012 to March 2014. We defined typical symptoms as any of chest pain or pressure due to myocardial ischemia. Results Of this study population, 642 patients (20.8%) had atypical symptoms (atypical group) and the remaining 2443 patients (79.2%) showed typical symptoms (typical group). Compared to the typical group, the atypical group was associated with higher age, more females, hypertension, diabetes, chronic kidney disease, history of cardiovascular disease, non-ST elevation MI, and Killip class ≥2. In the atypical group, urgent percutaneous coronary intervention was less frequently performed than in the typical group, and in STEMI patients door-to-balloon time was longer in the atypical than typical group. Atypical group had larger infarct size than typical group. Furthermore, in-hospital mortality was significantly higher in atypical than in typical group (19.5% vs. 3.3%, p < 0.001). In multivariable analysis, presence of atypical symptoms was an independent predictor of in-hospital mortality (odds ratio 3.12, 95% confidence interval 2.19 to 4.47, p < 0.001). Moreover, the association between atypical symptoms and mortality was consistent across each subgroup. Conclusions Atypical symptoms of AMI were associated with less invasive therapy and poor outcome. Attention should be directed to these high-risk patients.