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.

Bleeding in continuous flow left ventricular assist device recipients: an acquired vasculopathy?

“…There is now strong evidence from multiple centers documenting the relationship between non-invasive measures of pulsatility and AVM GIB. This was first described by Wever-Pinzon et al who reviewed a single center experience of 134 patients and found that the HeartMate II Pulse Index (maximum flow-minimum flow/average flow over 15 seconds) was associated with the risk of non-surgical bleeding in the first 90 days after implantation (19). In a specific analysis of AVM-related GIB the investigators also found a significant association when the Pulse Index was examined as a continuous variable.…”

HeartMate 3—a “Step” in the right direction

“…This index reflects ventricular contractility and correlates with the pulse pressure on arterial pressure tracings. Newer reports indicate this measure of pulsatility is inversely related to GI bleeding, i.e., patients with a higher pulsatility demonstrate lower incidences of GI bleeding (16)(17)(18). Since the artificial pulse in the HM3 is not synchronized with patient heart rate, it may augment or diminish the native pulse.…”

Management of Pump Thrombosis in Patients with Left Ventricular Assist Devices

“…One further non-mechanical issue that has undergone some philosophical changes is the status of the aortic valve opening following LVAD implantation. After concerns arose surrounding progression of aortic regurgitation following LVAD implant, alterations in pump management toward lower speeds in an attempt to foster aortic valve opening were suggested [15]. The benefit of this strategy was felt not only to reduce progression of aortic regurgitation but also to reduce development of gastrointestinal arteriovenous malformations and gastrointestinal bleeding.…”