In heart failure, can renal denervation attenuate the increased cardiac sympathetic drive?

Abstract

Currently renal denervation (RD) is being investigated as a possible treatment for heart failure (HF) patients. We tested the hypotheses that RD is cardioprotective in HF and that, in HF, RD lowers basal levels of cardiac SNA. In Wistar rats, myocardial infarction (MI) or sham surgery was performed 4 weeks prior to RD surgery. 3 weeks post RD or sham surgery and 7 weeks post-MI or sham surgery arterial pressure (AP), heart rate (HR) and left ventricular (LV) pressure-volume were recorded in chloralose-urethane anesthetized animals. At 1, 4, and 7 weeks post-MI echocardiography was performed to determine LV function and at 3 and 6 weeks post-MI the animals were placed in metabolic cages. RD improved LV function in HF rats and abolished the increased heart weight/body weight and lung weight/body weight ratios that were observed in HF rats without RD. No effects of MI and/or RD on fluid, sodium or potassium balance were observed. Resting AP was significantly lower in both RD groups when compared to sham-RD groups irrespective of HF. HF with RD animals demonstrated a significantly attenuated fall in arterial pressure in response to metoprolol (β1AR specific antagonist) compared to HF without RD thereby abolishing the differences in resting AP between animals in HF. The results suggest that renal denervation in heart failure attenuates the actions of cardiac SNA via the β1AR and that this may be a cardioprotective action of RD independent of actions on fluid regulation.