Trends, Predictors, and Outcomes of Temporary Mechanical Circulatory Support for Postcardiac Surgery Cardiogenic Shock

Abstract

Postcardiac surgery cardiogenic shock (PCCS) is seen in 2% to 6% of patients who undergo cardiac surgery. There are limited large-scale data on the use of mechanical circulatory support (MCS) in these patients. This study sought to evaluate the in-hospital mortality, trends, and resource utilization for PCCS admissions with and without MCS. A retrospective cohort of PCCS between 2005 and 2014 with and without the use of temporary MCS was identified from the National Inpatient Sample. Admissions for permanent MCS and heart transplant were excluded. Propensity-matching for baseline characteristics was performed. The primary outcome was in-hospital mortality and secondary outcomes included trends in use, hospital costs and lengths of stay. In the period between 2005 and 2014, there were 132,485 admissions with PCCS, with 51.3% requiring MCS. The intra-aortic balloon pump was the predominant device used with a steady increase in other devices. MCS use for more frequent in younger patients, males and those with higher co-morbidity. There was a decrease in MCS use across all demographic categories and hospital characteristics over time. Older age, female sex, previous cardiovascular morbidity and MCS use were independently predictive of higher in-hospital mortality. In 6,830 propensity-matched pairs, PCCS admissions that required MCS use, had higher in-hospital mortality (odds ratio 2.4; p<0.001), higher hospital costs ($98,759 ± 907 vs $81,099 ± 698; p<0.001) but not a longer length of stay compared with those without MCS use. In conclusion, in patients with PCCS, this study noted a steady decrease in MCS use. Use of MCS identified PCCS patients at higher risk for in-hospital mortality and greater resource utilization.