Cardiac fibrosis and cellular hypertrophy decrease the degree of reverse remodeling and improvement in cardiac function during left ventricular assist

Abstract

This study investigated if the degree of cardiac fibrosis and myocyte size at the time of left ventricular assist device (LVAD) implantation predicts the degree of improvement in cardiac function and sustained recovery after LVAD explantation. The study included 34 patients who underwent LVAD-off test. LV end-diastolic (LVEDD) and end-systolic diameter (LVESD), LV ejection fraction (LVEF), mean pulmonary artery pressure (mPAP), pulmonary capillary wedge pressure (PCWP), and cardiac index (CI) were measured before LVAD implantation and during LVAD-off test. Myocardial tissue was obtained from the apical core at LVAD implantation. The degree of cardiac fibrosis had significant correlations with changes in LVEDD (r = -0.725, p < 0.0001), LVESD (r = -0.800, p < 0.0001), LVEF (r = -0.637, p < 0.0001), mPAP (r = -0.569, p = 0.0010), PCWP (r = -0.463, p = 0.0123), and CI (r = -0.544, p = 0.0015). Myocyte size also had significant correlations with changes in LVEDD (r = -0.386, p = 0.0235), LVESD (r = -0.414, p = 0.0141), and LVEF (r = -0.528, p = 0.0015). The LVAD was successfully removed in 9 patients. The degree of cardiac fibrosis and myocyte size in these patients was significantly smaller compared with the patients who did not undergo LVAD removal. Cardiac fibrosis and myocyte size at the time of LVAD implantation were significant predictors of degree of improvement of cardiac function and the sustained recovery after the LVAD explantation.