Sildenafil to Reduce Vascular Remodeling During Left Ventricular Assist Device Support

Over 6.5 million individuals in the United States suffer from heart failure (HF), with the burden of this disease expected to grow over the next decade. Approximately 300,000 of these patients have advanced HF and may benefit from durable left ventricular assist device (LVAD) therapy, which can improve outcomes during advanced HF. However, despite advancements in device design that have increased survival rates, large registries of real- world cases reveal that nearly half of patients experience severe vascular adverse events, including stroke and bleeding, during prolonged contemporary LVAD support. This elevated adverse-event rate remains a major barrier to safely expanding the use and durability of LVAD therapy. Vascular remodeling or aging of the large and small blood vessels is known to promote stroke and bleeding within the general population. Critically, such remodeling is rapidly accelerated under conditions of reduced pulsatility produced by LVADs, evidenced by large vessel stiffening and fibrosis, small vessel angiodysplasia, and endothelial dysfunction. Phosphodiesterase-5 inhibitors (PDE5i), such as sildenafil, are prescribed to select LVAD patients with pulmonary hypertension and right heart failure. However, given that these agents enhance nitric oxide-cGMP signaling in platelets and vascular smooth muscle cells, leading to anti-thrombotic and anti-fibrotic effects, they may also reduce vascular remodeling and related adverse events. Here, based on preliminary findings, a double-blind, randomized, placebo-controlled trial will be conducted to determine the effects of chronic sildenafil administration on vascular remodeling during LVAD support.