Abstract 20698: Renal Denervation Lowers the Slope of the Pressure-Diuresis Relation and Blunts the Diuretic Response to Acute Volume Load in Heart Failure
Background: Previous animal studies have shown that renal denervation (RDN) was beneficial in chronic heart failure (CHF) by increasing the sodium excretion and inhibiting the renin release. However, we recently demonstrated that sympathoinhibition via baroreflex steepens the pressure-diuresis (PD) relation. This is to say that renal neural regulation plays a crucial role in buffering volume overload and thereby RDN, which loses baroreflex dependent renal neural regulation, could flatten the PD relation and thus blunt the buffering function against volume overload.
Purpose: We examined the impact of RDN on the PD relation and the diuretic response to acute volume overload in CHF.
Methods: We used 12 CHF rats induced by myocardial infarction (MI) (LVEF 18-33%). Four weeks after the surgery, we performed RDN by stripping the adventitia of bilateral renal arteries and veins, and painting 10% phenol in ethanol in 6 rats and sham operation in 6 other rats. After the 1-2 weeks recovery period, we performed the acute volume overload experiment. We re-anesthetized animals, infused hydroxyethyl starch at a rate of 4 ml/kg/min to a total of 20 ml/kg, while measuring arterial pressure (AP) and urine flow (UF) every 5 minutes before and after volume overload for 2 hours. Plotting the AP-UF relation every 5 minutes in response to volume overload yielded the acute PD relation.
Results: Before volume overload, AP and UF did not differ between the two groups (AP: sham vs RDN, 81.6±9.8 vs 79.3±14.9 mmHg, p=NS, UF: 73.3±13.3 vs 73.3±5.0 μl/kg/min, p=NS). Volume overload increased the cumulative urine volume more in sham than in RDN at 60 and 120 minutes after the initiation of volume overload (60 min: 10.5±1.4 vs 8.1±0.7 ml/kg, p<0.05, 120 min: 17.2±2.2 vs 13.3±1.3 ml/kg, p<0.05). The slope of the acute PD relation of RDN was significantly lower than that of sham (16.1±9.3 vs 5.5±3.0 μL/kg/min/mmHg, p<0.05). The correlation coefficients of the slope were 0.84±0.18 in sham and 0.83±0.08 in RDN indicating the accuracy of the estimation.
Conclusions: RDN lowers the slope of the PD relation and consequently blunts the diuretic response to acute volume overload. These results suggest that RDN may induce volume overload intolerance and increase the risk of pulmonary edema in patients with CHF.
Author Disclosures: K. Abe: None. T. Sakamoto: None. Y. Oga: None. K. Saku: None. S. Hoka: None. H. Tsutsui: None. K. Sunagawa: None.
- © 2016 by American Heart Association, Inc.