Sex Differences in the Risk of Pump Thrombosis in Patients Supported with Left Ventricular Assist Devices

Background There is increasing recognition that female patients supported by continuous flow left ventricular assist devices (CF-LVADs) have worse outcome in terms of overall survival and adverse events. However, reports on sex differences in risk of pump thrombosis have been inconclusive. Objective Our aim was to evaluate the association between sex and the risk of pump thrombosis. Methods We included patients receiving a CF-LVAD at our institution from 2007 to 2017. The primary endpoint was time to first pump thrombosis during 3 years of follow up. The Kaplan-Meier method was used to analyze survival free of pump thrombosis based on sex and Cox regression was used to determine the predictors of pump thrombosis. Results Our cohort included 301 patients (median age 59), of which 49 (16.3%) were female. During a median follow up time of 846 (interquartile range 313-1096) days, 31 (10.3%) patients developed pump thrombosis. Survival free of pump thrombosis was lower in female patients ( figure 1 ). After adjusting for covariates (including age, race, body mass index, heart failure etiology, LVAD types, LVAD designations and medical comorbidities), the risk of pump thrombosis was higher for female patients than male patients (hazard ratio 2.64, 95% confidence interval 1.22-5.69, p= 0.01). Conclusion The risk of pump thrombosis following LVAD varies based on sex, with female patients at higher risk. Further research is warranted to fully understand these differences, and whether device management strategies should be tailored based on sex.