Abstract 18687: Obesity is Associated With Increased Mortality and Hospitalization in Patients Supported With a Continuous-Flow Left Ventricular Assist Device
Background: Greater body mass index (BMI) is associated with poor prognosis following cardiac transplantation, but little is known about the influence of BMI on outcomes after mechanical circulatory support (MCS). In particular, no data exists describing either serial changes in BMI or the impact of baseline obesity on morbidity or mortality in “real-world” patients supported with a continuous-flow LVAD (CF-LVAD).
Methods: We reviewed records for all consecutive patients implanted with a CF-LVAD at our institution from 2008-2012. BMI was recorded prior to surgery, and at 1, 3, 6, and 12-months post-implant. Obesity was defined as a BMI ≥ 30 kg/m2. Serial BMI measurements were analyzed for significance, and Cox proportional hazards analysis was used to identify any associations between pre-implant BMI, or BMI changes, and survival or all-cause hospitalization.
Results: Ninety-eight patients were included - 79 as bridge-to-transplant (BTT) and 19 as destination therapy (DT). Median follow-up was 256d, during which 24 patients died, 31 were transplanted, and 43 remained on MCS. At baseline, median BMI was 27.1 kg/m2 (IQR 23.6, 30.9) and 27% were obese. Obesity rates were similar in BTT and DT cohorts. Non-obese patients exhibited a mean weight gain from pre-implant to 12 months of 11.7 ± 1.4 kg (p<0.001), while obese patients showed no significant changes in weight. Pre-implant obesity was associated with increased mortality at 90d (31% vs 6% non-obese, HR 6.0, p=0.002) and with decreased hospitalization-free survival (HR 1.7, p=0.04). Neither absolute nor relative changes in BMI after CF-LVAD were significantly associated with the evaluated outcomes.
Conclusions: Obese patients have a significantly increased risk of death and hospitalization within the first 90d after the implantation of a durable CF-LVAD. This is the first study to demonstrate a mortality liability associated with obesity in patients implanted with these contemporary devices. Similar to clinical trial cohorts, non-obese patients gained a significant amount of weight during LVAD support, while obese patients neither gained nor lost weight. Serial changes in BMI did not influence outcomes. Future analysis will focus on mode of death and causes of morbidity for these obese patients.
- © 2013 by American Heart Association, Inc.