The Mid-term Mortality and Mode of Death in Survivors with ST-elevation Myocardial Infarction

Objective The popularity of primary percutaneous coronary intervention (p-PCI) for ST-elevation myocardial infarction (STEMI) has increased over the past decades. Despite improvements in in-hospital mortality rates, it is clinically important to investigate the prognoses after discharge. However, data on the mode of death and prognostic factors are limited. We analyzed these factors in a Japanese cohort in the modern p-PCI era. Methods Between January 2004 and December 2017, a total of 1,222 patients who underwent p-PCI within 24 hours from the onset of STEMI and were alive at discharge (mean age, 67.7 years old; men, 75.5%), were evaluated. The two-year mortality was analyzed using a Cox regression model, and the mode of death was evaluated. Results The rate of mortality at 2 years was 5.7%. Non-cardiac death was more frequent than cardiac death (62.6% vs. 37.4%). A Cox multivariate analysis identified the following as independent predictors of the 2-year mortality: hemoglobin (log-transformed) [adjusted hazard ratio (HR), 0.048; 95% confidence interval (CI), 0.008-0.29; p<0.001], age above 80 years old (adjusted HR, 2.26; 95% CI, 1.30-3.91; p=0.004), Killip class ≥II (adjusted HR, 1.99; 95% CI, 1.17-3.39; p=0.011), brain natriuretic peptide level (log-transformed) (adjusted HR, 1.47; 95% CI, 1.09-2.01; p=0.013), and body mass index (log-transformed) (adjusted HR, 0.16; 95% CI, 0.030-0.84; p=0.030). Conclusion This study demonstrated that the 2-year mortality was 5.7% in STEMI survivors after p-PCI. Non-cardiac death was more frequent than cardiac death. Compared to well-known clinical variables, angiographic findings did not have a significant influence on the mid-term mortality.