Association of Sex and Age with Mortality in Stemi Patients Without Standard Modifiable Risk Factors: Analysis from Nationwide Readmission Database

Introduction: The proportion of STEMI patients without standard modifiable cardiovascular risk factors (SMuRFs: hypertension, diabetes mellitus, hypercholesterolemia and smoking) has increased over time. However, outcomes of STEMI patients without SMuRFs are not well known. Hypothesis: To test the hypothesis that age and sex would have a significant impact on mortality after STEMI in the absence of SMURFs. Methods: Patients who underwent primary PCI after STEMI were identified from the Nationwide Readmission Database. Clinical characteristics, in-hospital and 30-day mortality in STEMI patients with or without SMuRFs were compared in men and women stratified into 5 age groups (<50, 50 to 59, 60 to 69, 70 to 79 and ≥80 years of age). Results: Between January 2010 and November 2014, 54,665 (11.3%) of 482,947 patients, who underwent primary PCI for STEMI, did not have pre-existing SMuRFs. Absence of SMuRFs was more common in men than women (11.4% vs 9.8%, p<0.001) across all age groups, and patients without SMuRFs had higher in-hospital mortality rates than those with SMuRFs . Among those without SMuRFs, in-hospital mortality rate was significantly higher in women than men (13.5% vs 9.3%, p<0.001) accross all age groups and was increased with advanced age groups. In addition, absence of SMuRFs was associated with higher 30-day mortality rates than those with SMuRFs (0.5% vs 0.3%, p<0.001). Among patients without SMuRFs, women had higher 30-day mortality than men (0.7% vs 0.5%, p<0.001). The increased risk of in-hospital (Odds Ratio [OR] 2.02, 95% CI 1.87 to 2.20) and 30-day mortality (OR 1.40, 95% CI 1.11 to 1.78) in patients without SMuRFs remained significant after multivariate adjustment. Conclusions: Patients presenting with STEMI without SMuRFs have a significantly higher risk of in-hospital mortality and 30-day mortality compared with those with SMuRFs. Women and older age group without SMuRFs experienced more frequent in-hospital mortality and 30-day mortality.