Temporal Trends and Outcomes of Mechanical Complications in Patients With Acute Myocardial Infarction

Abstract

Objectives: The aim of this study was to examine the temporal trends and outcomes of mechanical complications after myocardial infarction in the contemporary era.

Background: Data regarding temporal trends and outcomes of mechanical complications after ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) are limited in the contemporary era.

Methods: The National Inpatient Sample database (2003 to September 2015) was queried to identify all STEMI and NSTEMI hospitalizations. Temporal trends and outcomes of mechanical complications after STEMI and NSTEMI, including papillary muscle rupture, ventricular septal defect, and free wall rupture, were described.

Results: The analysis included 3,951,861 STEMI and 5,114,270 NSTEMI hospitalizations. Mechanical complications occurred in 10,726 of STEMI hospitalizations (0.27%) and 3,041 of NSTEMI hospitalizations (0.06%), with no changes in trends (p = 0.13 and p = 0.83, respectively). The rates of in-hospital mortality in patients with mechanical complications were 42.4% after STEMI and 18.0% after NSTEMI, with no significant trend changes (p = 0.62 and p = 0.12, respectively). After multivariate adjustment, patients who had mechanical complications after myocardial infarction had higher in-hospital mortality, cardiogenic shock, acute kidney injury, hemodialysis, and respiratory complications compared with those without mechanical complications. Predictors of lower mortality in patients with mechanical complications who developed cardiogenic shock included surgical repair in the STEMI and NSTEMI cohorts and percutaneous coronary intervention in the STEMI cohort.

Conclusions: Contemporary data from a large national database show that the rates of mechanical complications are low in patients presenting with STEMI and NSTEMI. Post-myocardial infarction mechanical complications continue to be associated with high mortality rates, which did not improve during the study period.

Keywords: free wall rupture; myocardial infarction; papillary muscle; ventricular septal defect.