Central venous pressure, rather than cardiac output, is associated with peripheral chemoreceptor sensitivity in heart failure patients with left ventricular assist device

BACKGROUND: Heart failure (HF) patients experience elevated sympathetic tone and abnormal peripheral chemoreceptor (PChR) function (elevated sensitivity [PChS] and tonicity [PChT]), which can be attributed to a reduction in cardiac output (CO) and resultant hypoperfusion of the carotid bodies. Left ventricular assist devices (LVADs) are known to increase CO, and can be used as a unique model to examine the impact of acute hemodynamic changes on PChR. METHODS AND RESULTS: Fourteen HF patients with LVADs underwent assessment of PChS (using the transient hypoxia test) and PChT (using low-dose dopamine infusion) under different LVAD flow parameters, previously determined using right heart catheterization to achieve significantly distinct CO levels. PChS did not differ between the low- vs high-flow conditions (0.61 [0.49;0.74] vs. 0.67 [0.33;0.9] L/min/SpO2%, p = 0.36) as well as PChT (0.97 [-0.36;1.96] vs. 0.81 [-1.67;2.2] L/min-1, p = 0.81).). In 9 patients, central venous pressure (CVP) decreased in response to higher pump speeds. In this group, PChS more frequently increased and was significantly higher than in the remaining patients. ΔCVP was also inversely related to ΔHVR (R = 0.75, p = 0.002). CONCLUSIONS: Acute changes in CO, as well as pulse pressure, did not affect PChS or PChT. Surprisingly, we observed a strong correlation between a decrease in CVP in response to higher LVAD speed and an increase in PChS, which can be explained by the function of low-pressure baroreceptors. These findings provide unique data on PChR function under different hemodynamic conditions in the LVAD population.