Abstract 13930: Improvements in Systolic Function and Myocardial Mechanics with Left Ventricular Assist Device Support are Attenuated with Prolonged Unloading
Introduction: Improvements in left ventricular (LV) function may occur in patients with a LV assist device (LVAD); however, recovery with LVAD explant is rare. It is unknown whether prolonged unloading regresses hypertrophy, induces atrophy, or both. The goal of this study was to longitudinally investigate the effect of prolonged LVAD support on LV function as assessed by ejection fraction (EF) and myocardial mechanics (strain and strain rate) from speckle tracking echocardiography.
Methods: Serial echocardiograms were retrospectively reviewed from 8 patients (mean age 48±19 years) with nonischemic cardiomyopathy with continuous-flow LVADs from before LVAD implant to a mean follow-up of 366 days. A 2D tissue tracking software (VVI, Siemens) was used to calculate EF, average peak circumferential strain and systolic strain rate, average peak longitudinal strain and systolic strain rate, and LV mass.
Results: The mean EF improved from 20.8±5.4% before LVAD to 35.3±10.8% after a mean of 175 days of LVAD support; however, at 1 year EF returned to near baseline (Table). Similar initial improvements were noted for circumferential strain (-5.7±3.1 to -16.0±9.1%) and longitudinal strain (-6.7±3.6 to -14.2±5.8%) with subsequent reductions in both at maximal follow-up. Improvements for circumferential and longitudinal strain rate were partially preserved with prolonged unloading. The mean LV mass adjusted for body surface area decreased from 153±87 g/m2 before LVAD implant to 60±52 g/m2 at maximal follow-up (p<0.01).
Conclusions: There are initial improvements in EF, strain, and strain rate with LVAD support, suggesting that LV recovery may be possible. However, prolonged unloading attenuates such improvements and is accompanied by a decline in LV mass. This suggests that the initial benefit of unloading (regression of hypertrophy) may compete with the long-term negative effects of unloading (atrophy), contributing to low rates of LV recovery for patients with LVADs.
- Ventricular assist devices
- Heart failure
- Artificial heart/Cardiac support devices
- © 2011 by American Heart Association, Inc.