(696) Cerebral Autoregulation Changes After Left Ventricular Device Implantation: A Pilot Study

Introduction: End-stage heart failure (HF) has been associated with neurologic damage and reduced cerebral blood flow (CBF). Studies have reported a 13% to 19% decrease in CBF in HF patients, along with disrupted cerebral autoregulation (CA). Left ventricular assist devices (LVADs) are commonly used to improve systemic perfusion pressure. Although some research suggests intact CA in LVAD patients, neurologic complications post-implantation raise concerns about possible CA impairment. This study aims to assess changes in CA before and after LVAD implantation in HF patients.

Methods: We conducted a prospective cohort study comparing CA pre- and post- implantation. Near-infrared spectroscopy (NIRS) was used to calculate cerebral oximetry, which was then used to calculate a measure of CA: cerebral oximetry index (COx) via a Pearson correlation coefficient between regional cerebral oximetry and blood pressure. Impaired COx is defined as ≥ 0.3. A linear mixed effects model was created using pre/post LVAD status as fixed effects and individual subjects as random effects to predict COx. A second linear model was run to compare differences between CoxL and COxR with the same fixed and random effects.

Results: The study included 65 hours of continuous monitoring across 4 HF patients with three patients having ischemic cardiomyopathy and one with hypertensive cardiomyopathy. Two patients were implanted for destination therapy and two as a bridge to transplant. All patients had periods of disrupted CA prior to implantation with 5% (9minutes) of the recorded time prior implantation having disrupted CA. The linear mixed model revealed that the mean value for COx after LVAD implantation was -0.0019. On average, COx values were significantly 0.0106 higher before LVAD implantation compared to after (p < 0.001). There was minimal variability between subjects (variance= 5.761e-05). Both COxL and CoxR decreased after LVAD implantation, with a larger decrease observed for COxR [0.0138 (SE 0.0037)] compared to COxL [0.0076 (SE 0.0043)].

Conclusions: The linear mixed model provides evidence that both COxL and CoxR significantly decreased after LVAD implantation, while accounting for the clustered data. Future studies are needed to understand the clinical significance of the changes in CA following LVAD implantation.