Nicotinamide Riboside in LVAD Recipients

This Pilot Study will examine the following Aims: Aim 1: Enroll 5 participants scheduled for elective left ventricular assist device (LVAD) placement into an open-label study of nicotinamide riboside (NR). a. Participants will have labs (including safety panels) drawn at baseline (Day 1), then receive escalating doses of NR to a maximum dose of 1000mg twice daily by Day 3. Participants will be continued on NR at 1000mg twice daily until LVAD implantation surgery. On the morning of LVAD implantation Surgery (Day 5 or later), participants will have final labs drawn. Samples of fresh cardiac tissue removed from the left ventricular apex during LVAD implantation surgery will be collected in the operating room. The primary analyses will be performed on NR-treated participants who were on the maximum NR dose of 1000mg twice daily for at least 2 days prior to LVAD implantation surgery. The maximum duration of NR administration will be capped at 14 days. If the surgery doesn't happen by then, the participant will be withdrawn from the study. Aim 2: Determine the effect of NR (as compared to historical controls) on levels of the oxidized and reduced forms of nicotine-adenine dinucleotide (NAD+ and NADH, respectively), mitochondrial function and its regulation through modifications of the epigenome in the failing myocardium. 1. Measure NAD+ and NADH levels in the blood and myocardium of the participants. 2. Assess mitochondrial morphology and function in cardiac tissue using, respectively, electron microscopy (EM) and isolated mitochondria. 3. Determine protein acetylation in the mitochondrial and non-mitochondrial compartments and changes in nuclear gene regulation. Aim 3: Test the hypothesis that NR improves mitochondrial function and reduces inflammatory response in heart failure (HF) patients receiving NR (as compared to historical controls). 1. Measure mitochondrial function in peripheral blood mononucleated cells (PBMC). 2. Determine the inflammatory response in PBMC. 3. Compare effects on the circulating inflammasome vs. myocardial inflammation.