Trends and Outcomes of ST-Segment-Elevation MI in Hospitalized Patients Without Standard Modifiable Cardiovascular Risk Factors

Abstract

Mixed results were seen in hospital outcomes comparing the first episode of ST-elevation myocardial infarction (STEMI) without standard modifiable cardiovascular risk factors (SMuRFs) than with risk factors. To understand whether the first episode of STEMI SMuRFs has worse in-hospital outcomes than patients with risk factors and to identify confounders that contribute towards worse results. We queried the Nationwide Inpatient Sample for hospitalizations with a primary diagnosis of STEMI but no prior coronary disease from 2016 to 2019. Our study population was divided into 2 comparative cohorts, SMuRFs and SMuRFless STEMI, based on cardiovascular risks. We assessed demographics, in-hospital mortality, complications of the 2 groups. SMuRFless patients were statistically more likely than those with SMuRFs to be younger, white, male, and underweight (BMI < 20) and were significantly less likely to receive percutaneous coronary intervention (85.8 vs 90.7%, P < 0.001) or cardiac bypass (3.8 vs 5.9%, P < 0.001). SMURFless patients were more likely to have in-hospital mortality (15.7 vs 7.1%, unadjusted odds ratio: 2.41, 95% confidence interval: 2.27-2.56, P < 0.001), a finding that persisted when adjusted for all factors found significant in univariate analysis (adjusted odds ratio: 2.48; 95% confidence interval: 2.30-2.67, P < 0.001). Incidence of cardiac complications, including cardiogenic shock, ventricular arrhythmia, cardiac arrest, were significantly higher in the SMuRFless patients, even after statistical adjustment and sensitivity analysis. SMuRFless patients represent a sizable minority of patients presenting with STEMI and have higher mortality, complications and receive fewer invasive procedures. Patient-level studies may be necessary to understand better how to treat this subset of myocardial infarction patients. SMuRFless STEMI were statistically more likely than those with SMuRFs to be younger, white, male, and underweight (BMI < 20) and were significantly less likely to receive percutaneous coronary intervention. SMURFless patients were more likely to have in-hospital mortality, a finding that persisted when adjusted for all factors found significant in univariate analysis. Incidence of cardiac complications, including cardiogenic shock, ventricular arrhythmia, cardiac arrest, were significantly higher in the SMuRFless patients, even after statistical adjustment and sensitivity analysis. SMuRFless patients represent a sizable minority of patients presenting with STEMI and have higher mortality, complications and receive fewer invasive procedures.