Higher Body Mass Index Increases Risk of HeartMate II Pump Thrombosis But Does Not Adversely Affect Long-Term Survival

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. Methods and Results: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/m 2 (n=99) and BMI >30 kg/m 2 (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.

Durable left ventricular assist device implantation in extremely obese heart failure patients

“…Our work confirms the results of several recent studies, which failed to detect a significant difference in short‐term and intermediate postoperative survival between obese and nonobese LVAD recipients . However, higher rates of hospital readmissions and complications such as AKI , infection , thromboembolism , and PT are often present in the obese cohort. We observed higher rates of stage 2/3 AKI and PT in the extremely obese cohort, which is in agreement with prior studies .…”

The impact of extreme obesity on outcomes after left ventricular assist device implantation

“…While LVADs are an effective long-term intervention for end-stage heart failure, expanding rates of obesity and extreme obesity increasingly complicate patient selection for this advanced surgical therapy (5,6,11). Though previous data and guidelines have suggested that LVAD implantation in patients with very low or very high BMI may confer excessive risk, several recent reports indicate no increased mortality in obese patients implanted with LVADs (5,(7)(8)(9)(10)(11)(12). This study evaluated outcomes in a group of patients with extreme obesity, including 25 patients with BMI greater than 40 kg/m 2 and 4 with BMI greater than 50 kg/m 2 .…”

“…Several studies have indicated that obese patients may have increased rates of LVAD thrombosis and infections, but have survival rates similar to normal and underweight patients. These reports have generated varied results, and as a result, selection and management of LVAD patients with high BMIs remains challenging (7)(8)(9). At present there is only one other published study which investigated outcomes in patients with BMI ≥35 kg/m 2 (10).…”

Surgical device exchange provides improved clinical outcomes compared to medical therapy in treating continuous‐flow left ventricular assist device thrombosis

“…Recently, obesity was reported to be a risk factor of device thrombosis. While the mechanism is unclear, Han et al proposed that obese patients have a higher risk of developing blood clots and that obesity may interfere with optimal device placement or remodeling …”