Sex differences and in-hospital outcomes in patients undergoing mechanical circulatory support implantation

Abstract

Background: Mechanical circulatory support (MCS) is a widely available management strategy. No studies have described sex differences in both extracorporeal and durable MCS. We analyzed sex-related differences of in-hospital outcomes for extracorporeal and durable MCS using administrative hospital data.

Methods: In total, 134.5 million hospital records between 1994 and 2012 were screened for placement of MCS using procedure codes of the International Classification of Diseases-9, Clinical Modification. Major adverse events (MAEs) were defined as death, major bleeding, stroke, device infection or mechanical complication. Participation in the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry was determined on an annual basis using quarterly reports of the INTERMACS. Associations between characteristics and outcomes were determined using multivariable logistic regression.

Results: Sex was reported in 3,523 of 4,337 patients undergoing MCS placement from 45 INTERMACS sites (n = 1,383) and 246 non-INTERMACS sites (n = 2,954). Twenty-two percent were female. Baseline characteristics were significantly different with women being slightly younger (33.5% vs 27.4% age <50 years, p < 0.001; mean 55.7 ± 17.3 vs 56.1 ± 14.6 years) with fewer comorbidities. Women had higher rates of in-hospital mortality (52.3% vs 40.8%, p < 0.001) and MAEs (64.8% vs 52.5%, p < 0.001). Women had an 89% higher likelihood of MAEs when corrected for multivariate predictors (p < 0.001). In-hospital mortality decreased over time for both men and women (10% relative risk reduction/year, p < 0.001), but mortality in women was higher than in men throughout the study period.

Conclusion: There are significant sex differences in characteristics and outcomes of patients receiving MCS. Women had higher in-hospital mortality and were at increased risk of MAEs, which could not be explained by age or comorbid conditions. Further research on the causes of these disproportionate outcomes is needed.

Keywords: cardiac surgery; cardiomyopathies; heart assist device; heart failure; sex.