Pulsatility and the Risk of Nonsurgical Bleeding in Patients Supported With the Continuous-Flow Left Ventricular Assist Device HeartMate II

Abstract

Background— Bleeding is an important cause of morbidity and mortality in patients with continuous-flow left ventricular assist devices (LVADs). Reduced pulsatility has been implicated as a contributing cause. The aim of this study was to assess the effects of different degrees of pulsatility on the incidence of nonsurgical bleeding. Methods and Results— The Utah Transplantation Affiliated Hospitals (U.T.A.H.) heart failure and transplant program databases were queried for patients with end-stage heart failure who required support with the continuous-flow LVAD HeartMate II (Thoratec Corp, Pleasanton, CA) between 2004 and 2012. Pulsatility was evaluated by means of the LVAD parameter pulsatility index (PI) and by the echocardiographic assessment of aortic valve opening during the first 3 months of LVAD support. PI was analyzed as a continuous variable and also stratified according to tertiles of all the PI measurements during the study period (low PI: <4.6, intermediate PI: 4.6–5.2, and high PI: >5.2). Major nonsurgical bleeding associated with a decrease in hemoglobin ≥2 g/dL (in the absence of hemolysis) was the primary end point. A total of 134 patients (median age of 60 [interquartile range: 49–68] years, 78% men) were included. Major bleeding occurred in 33 (25%) patients (70% gastrointestinal, 21% epistaxis, 3% genitourinary, and 6% intracranial). In multivariable analysis, PI examined either as a categorical variable, low versus high PI (hazard ratio, 4.06; 95% confidence interval, 1.35–12.21; P =0.04), or as a continuous variable (hazard ratio, 0.60; 95% confidence interval, 0.40–0.92; P =0.02) was associated with an increased risk of bleeding. Conclusions— Reduced pulsatility in patients supported with the continuous-flow LVAD HeartMate II is associated with an increased risk of nonsurgical bleeding, as evaluated by PI.