Clinical Characteristics and Outcomes of Patients Presenting With Acute Myocardial Infarction Without Cardiogenic Shock

BACKGROUND: Most patients with acute myocardial infarction (AMI) present in the emergency department in a hemodynamically stable condition (i.e., non-cardiogenic shock) (AMI-NCS). However, few studies specifically focused on the clinical characteristics and outcomes of AMI-NCS patients. Temporal trends in clinical characteristics, in-hospital occurrence of in-hospital adverse outcomes, and the effect of primary percutaneous coronary intervention (PPCI) were examined. METHODS AND RESULTS: Between April 2012 and March 2018, 176,275 AMI-NCS patients (67.7% of the total AMI population; 25.4% female; mean age 68.6±13.1 years) were identified in a nationwide Japanese administrative database. During the 6-year study period, AMI-NCS patients have been getting older and had an increasing burden of comorbidities. The rates of 30-day all-cause mortality and in-hospital complications were 2.6% and 30.5%, respectively. Thirty-day all-cause mortality did not change significantly over time, whereas in-hospital complications, especially major non-cardiac events, increased progressively. On multivariable analyses, higher age, higher Killip class, atrial fibrillation, chronic renal failure, and malignancy were independently associated with both increased 30-day mortality and in-hospital complications. PPCI was independently associated with lower mortality and in-hospital complications. CONCLUSIONS: The clinical background of AMI-NCS patients has been becoming more complex with increasing age and the burden of comorbidities, with increased in-hospital complications. More active and appropriate application of PPCI may further decrease adverse events and improve survival of AMI-NCS patients.