Characteristics and long-term mortality of patients with ST-elevation or non-ST-elevation myocardial infarction after orthopaedic surgery

Objective To investigate the clinical characteristics and long-term mortality of patients with ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) after orthopaedic surgery. Methods This retrospective, single-centre study enrolled patients that underwent inpatient orthopaedic surgery from 2009 to 2017 in Beijing Jishuitan Hospital. The patients were screened for a cardiac troponin I elevation and fulfilled the Fourth Universal Definition of Myocardial Infarction within 30 days of surgery. Results A total of 180 patients that developed perioperative myocardial infarction (MI) were included in the study. Among them, 14 patients (7.8%) were classified as STEMI, and 166 (92.2%) had NSTEMI. Compared with those with NSTEMI, STEMI patients had significantly higher 30-day and long-term mortality rates (50.0% versus 5.4%; 71.4% versus 22.3%; respectively). Multivariate Cox regression model analysis among the entire cohort demonstrated that STEMI (hazard ratio [HR] 5.78, 95% confidence interval [CI] 2.50, 13.38) and prior MI (HR 2.35, 95% CI 1.02, 5.38) were the most significant independent predictors of long-term mortality. Conclusion Perioperative MI after orthopaedic surgery was associated with a high mortality rate. STEMI was independently associated with a significant increase in short- and long-term mortality.