Among Medicare beneficiaries, short- and long-term mortality rates after implantation with ventricular assist devices have improved since 2006, but rates of hospital readmission remain high, according to recent results.
In a population-based, retrospective cohort study, researchers reviewed the Medicare inpatient claims and denominator files of 2,507 patients diagnosed with HF who were implanted with ventricular assist devices between 2006 and 2011. Incidences of heart transplant and all-cause and CV-related rehospitalization were assessed among patients who were discharged. Inpatient and post-discharge costs, as well as possible associations between the volume of ventricular assist devices implanted at a hospital and outcome, also were investigated.
During the study, the overall volume of device implantations performed increased from 192 in 2006 to 622 in 2011. In-hospital mortality associated with ventricular assist device procedures decreased from 30% of patients in 2006 to 10% in 2011 (P<.001), whereas 1-year mortality decreased from 42% to 26% (P<.001). Both total length of hospital stay (46 days to 33 days) and the length of stay post-procedure (33 days to 24 days) also decreased between 2006 and 2011 (P<.001 for both).
However, the rates of all-cause and CV-related readmission did not change significantly during the study period. Although adjustment for covariates further decreased the rates of in-hospital and 1-year mortality (P<.001 for both), all-cause readmission remained unchanged.
Multivariate analysis indicated a higher risk of both in-hospital (RR=1.72; 95% CI, 1.28-2.33) and 1-year mortality (HR=1.55; 95% CI, 1.24-1.93) in hospitals with a lower device procedure volume compared with high-volume centers. Surgery volume did not, however, significantly affect rehospitalization risk.
Across the cohort, the mean Medicare cost for initial hospitalization was $210,021, and the mean inpatient care cost was $38,469 at 1 year. Neither amount changed significantly during the study.
The researchers wrote that high readmission rates among patients with ventricular assist devices appear to be largely precipitated by postoperative infection, bleeding, thrombosis, HF and arrhythmias. Such complications could be related to the distinct physiological challenges created by nonpulsatile blood flow, they hypothesized.
“We are now in a state of transition in the longitudinal care path of patients receiving [ventricular assist device] therapy,” the researchers wrote. “Although early survival has improved markedly, the transition from the operating room to the post-discharge environment demands attention.”
Disclosure: Two researchers reported serving as consultants for Thoratec. Another researcher also reported serving as a principal investigator in the HeartWare ENDURANCE trial.