Vascular Reactivity Analysis in Patients with Continuous Flow Left Ventricular Assist Devices (CF-LVADs) – The Role of Endothelial Function in Continuous Flow Physiology
A.S. Cruz-Solbes , C. Uribe, K.A. Youker, B.H. Trachtenberg, G. Ashrith, J.D. Estep, G. Torre-Amione, B.A. Bruckner, J.P. Cooke, A. Bhimaraj. Methodist DeBakey Heart Center, Houston Methodist Hospital, Houston, TX.
Endothelial dysfunction associated with CF-LVAD placement and a loss of pulsatility could result in complications such as GI bleeding. Reports using both brachial reactivity and EndoPAT® machines have shown mixed results of endothelial dysfunction when compared to pulsatile LVAD. Both tests rely on physical pulse volume and might be impacted by the mere loss of pulsatility. Hence, we set out to analyze endothelial function utilizing thermal digital monitoring (VENDYS) in patients with CF-LVADs.
Stable patients were recruited and we performed the VENDYS and determined aortic valve opening with a portable echo. Patients were classified based on parameters of vascular reactivity index (VRI) described in normal populations: poor (<1) intermediate (1 - 2) and good VRI (2 - 3) with higher VRI correlated with better endothelial function, hence better outcomes. Pearsons correlation and T-test were performed, P-values < 0.05 were considered significant.
81% of the patients had aortic valve opening at the time of endothelial function assessment. Only 19% had a poor VRI, while majority had an intermediate VRI. Older patients had worse endothelial function. Correlation between VRI and VAD flow (r= -0.2766 P value= 0.08) and high Doppler blood pressure (r= -0.2656 P value=0.09) showed no significance. However, 50% of the patients with a poor VRI had adverse events while only 23% of those with good endothelial function. The 2 patients with poor VRI who had a GI bleed had 5 episodes while the 3 patients with good VRI had 4 episodes.
In a cohort of CF-LVAD patients where the majority had open aortic valves, endothelial function was poor in only a few. It is not clear if endothelial dysfunction contributes to any of the adverse events for CF-LVAD patients but there seems to be a higher recurrence of GI bleeding in patients who had a poor endothelial function.
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