ABSTRACT
BACKGROUND: Obesity has been correlated with various adverse events in patients who receive left ventricular assist devices (LVAD). In this study, we sought to further characterize the role of obesity in this patient population.MethodsâandâResults:We performed a retrospective analysis of 164 patients implanted with a HeartMate II from August 2008 to December 2014. Patients were categorized into 2 BMI groups based on WHO guidelines: BMI 18.5-30 kg/m2(n=99) and BMI >30 kg/m2(n=65). Patient demographics, adverse outcome and long-term survival were compared between the 2 groups. For any outcome associated with BMI groups, we performed a Cox regression to identify confounding comorbidities. Preoperative demographics and comorbidities were similar. Patients with BMI >30 were younger (P=0.01) and had a higher incidence of type 2 diabetes (P=0.01). While rate of pump thrombosis was higher among patients with BMI >30 (P=0.02), overall survival at 2 years did not differ. The most common cause of death was hemorrhagic stroke in the obese group. On multivariable cox regression analysis, BMI was an independent risk factor of pump thrombosis. CONCLUSIONS: Higher BMI does not reduce survival after VAD implantation but it does appear to increase the risk of pump thrombosis. Further studies to characterize the role of BMI in survival and thrombosis rates are warranted.
Subject(s)
Body Mass Index , Heart-Assist Devices/adverse effects , Obesity/complications , Thrombosis/etiology , Aged , Cohort Studies , Female , Humans , Male , Middle Aged , Obesity/mortality , Retrospective Studies , Risk Factors , Stroke/etiology , Survival Rate , Thrombosis/mortality , Ventricular Dysfunction, Left/therapyABSTRACT
BACKGROUND: Orthotopic heart transplantation (OHT) remains the gold standard for end-stage heart failure. However, donor availability is severely limited. With a median wait time of 6.6 months and more than 12% of patients waiting 5 or more years, the decision is often made to implant a left ventricular assist device (LVAD) as a bridge to transplantation for medical stabilization. Furthermore, the number of patients who have had at least one prior sternotomy while awaiting transplantation is increasing. Previous studies have indicated reoperative sternotomy as a risk factor for compromised survival. Concerns are specifically focused on perioperative, short-term, and long-term outcomes after LVAD explantation or redo sternotomy before OHT because of increasing operative complexity. We hypothesize that despite the greater technical difficulty caused by LVAD explantation or redo sternotomy, outcomes would not be compromised. METHODS: We retrospectively analyzed patients who underwent OHT at the University of Pennsylvania during a 5-year period (2008-2013; n = 253). All patients who underwent a bridge to transplantation LVAD (n = 72) or prior sternotomy (n = 65) were compared with those undergoing OHT with a virgin chest (n = 116). Preoperative, intraoperative, and postoperative variables were analyzed. Short- and long-term survival were studied (minimum follow-up, 6 months). RESULTS: Comorbidities were similar among the groups. There was no difference in donor allograft ischemic time (p = 0.6). However, cardiopulmonary bypass time was longer in both bridge to transplantation and prior sternotomy cohorts (p < 0.00001). The blood transfusion requirement was higher in bridge to transplantation (12.5 ± 13.7 units; p = 0.0007) and prior sternotomy groups (11.7 ± 12.9 units; p = 0.02) as compared with the virgin chest cohort (7.1 ± 10.7 units). For bridge to transplantation, both time to extubation (1.0 ± 1.6 versus 0.9 ± 1.0 days; p = 0.03) and intensive care unit length of stay (7.0 ± 7.0 versus 6.0 ± 7.0 days; p = 0.06) were longer compared with the virgin chest cohort. The same was true for prior sternotomy (extubation time, 1.9 ± 4.4 days; p = 0.005; intensive care unit length of stay, 8.0 ± 12.0 days; p = 0.06). There was no difference in hospital length of stay (p = 0.2). Overall, there was no difference in short- or long-term survival. CONCLUSIONS: Implantation of an LVAD as a bridge to transplantation or prior sternotomy does not adversely impact allograft function, hospital length of stay, or long-term outcomes after OHT. The decision to manage a patient medically while awaiting transplantation versus an LVAD bridge strategy should not be limited by concerns of subsequent poor outcomes after transplantation.
