Predictors, Outcomes and Impact of Mechanical Circulatory Support of Patients With Mechanical Complications After Acute Myocardial Infarction

Background: Despite early and currently effective epicardial coronary recanalization, the mortality rate after mechanical complication (MC) remains high, especially in cardiogenic shock. There is an increase in the use of mechanical circulatory support in patients with cardiogenic shock and MC, however, evidence is still scarce and most studies exclude patients with mechanical complications.

Methods: Using the National Inpatient Sample database from 2015 to 2018 to identify patients with AMI, we aimed to determine the predictors and outcomes of patients with MC, subtypes and the use of MCS.

Results: We identified 2,427,315 patients with AMI; 2345 (0.1 %) developed MC and of them 1320 (56.3 %) received MCS. Regarding subtypes, 960 (40.9 %) had ventricular septal rupture (VSR), 540 (23.0 %) papillary muscle rupture (PMR), 530 (22.6 %) pseudoaneurysm, and 315 (13.4 %) free wall rupture (FWR). Mortality was 12 times higher (OR: 11.663, CI: 10.582-12.855, p < 0.001) in patients with MC compared to patients without MC (49.7 % vs. 4.6 %, p < 0.001) and all subtypes of MC showed a significant increase in mortality. The use of MCS was associated with decreased mortality in PMR (46.2 % to 34.8 %, p = 0.009) and pseudoaneurysm (64.7 % to 42.1 %, p < 0.001), however, with higher mortality in VSR.

Conclusions: The incidence of MC after an AMI is very low, nonetheless the in-hospital mortality rate remains very high. It tends to occur more in older patients and with fewer comorbidities. The subtype with the highest frequency and highest mortality was VSR. The use of mechanical circulatory support was associated with better survival in PMR and pseudoaneurysm, but not overall survival.