Intrinsic Myocardial Function and Relationship with Left Ventricular Unloading in Patients Supported on CF-LVAD Therapy

Abstract

Despite strong interest in left ventricular recovery, no clinical data exist on the relationship between intrinsic myocardial function and reverse remodeling or LVAD unloading. We sought to evaluate this interaction. Patients implanted with continuous flow LVADs between 2015 and 2018 who underwent combined LHC/RHC ramp protocol at a single institution were enrolled. Exclusion criteria were significant valve disease, inability to optimize hemodynamically during ramp study, or inotropic therapy. Hemodynamic data including peak LV dP/dt and tau were obtained. Among a cohort of 62 patients undergoing LHC/RHC study, 25 patients were included (12 with LVEF ≥25%, augLV, and 13 with LVEF <25%, impLV). Important hemodynamic differences between augLV and impLV included aortic pulse width, tau, and peak LV dP/dt. On linear regression, aortic pulse width was associated with each of LV systolic pressure, peak LV dP/dt, and LVEF% (r = 0.58, 0.59, and 0.40 with p < 0.05 for all). Both adjusted tau and LV dP/dt were associated with PCWP values (r = 0.41, p < 0.0001 and r = -0.52, p <0.0001, respectively); however, an inverse relationship between LVAD speed and strength of association with PCWP was noted. Significant correlations between intrinsic myocardial function and reverse remodeling as well as aortic pulsatility were noted. A greater reliance on LVAD for unloading is noted at higher speeds, suggesting excessive LVAD unloading may be detrimental. Future work should focus on defining the optimal level of LVAD support, particularly in relation to LV recovery and functional outcomes.