Causes and Temporal Patterns of Hospital Readmissions after Implantation of the HeartMate 3 Left Ventricular Assist Device: A Comparison with HeartMate II

Abstract

<h3>Purpose</h3> We sought to determine the temporal patterns, causes, and predictors of readmission after HeartMate 3 (HM3) implantation and compare them with those of HeartMate II (HMII). <h3>Methods</h3> We retrospectively reviewed hospital readmission data for HM3 recipients at our institution between 2014 and 2019. As a historical control, HMII recipients between 2010 and 2014 were used for comparison. The Fine-Gray method was used to generate cumulative incidence functions for readmissions with death as a competing risk and the Nelson non-parametric method was used to generate mean cumulative functions for readmissions. A total time restricted multivariable Fine-Gray competing risk regression with a robust sandwich covariance estimator was used to determine risk factors for readmission while accounting for repeated events within patients. <h3>Results</h3> There were 207 HMII and 182 HM3 patients. The average number of readmissions per patient was 2.14 and 1.73 for HMII and HM3 (p=0.09), respectively. Leading causes of readmission for HMII were bleeding (21%), infection (20%), and device malfunction (12%), while those for HM3 were infection (22%), bleeding (11%), and arrhythmia (10%). The mean cumulative number of readmissions and temporal pattern of readmissions in patients receiving HMII and HM3 did not differ significantly (Figure 1a and b). Risk factors for readmission in patients implanted with HM3 included age (HR = 1.011, 95% CI = 1.001-1.021, p = 0.03) and postoperative urinary tract infection (HR = 1.453, CI = 1.094-1.928, p = 0.01). <h3>Conclusion</h3> Overall readmission burden was similar for patients implanted with HMII and HM3. Postoperative urinary tract infection may be a risk factor for readmissions, but further studies are needed to determine additional risk factors.