13.7 Renal Denervation in Treatment Resistant Hypertension: Effects on Coronary Flow Reserve and Forearm Dilation Capacity. A Randomized, Double-Blinded, Sham-Controlled Clinical Trial

Background: Microvascular impairment is well documented in hypertension.In this ReSET 1 sub-study we investigated the effects of renal sympathetic denervation (RDN) on coronary flow reserve (CFR) and coronary-and forearm minimum vascular resistance (C-Rmin and F-Rmin) in patients with resistant hypertension.Methods: A randomised, single centre, double-blind, sham-controlled clinical trial in 58 patients with resistant hypertension randomised to RDN or SHAM.Inclusion criteria: ASBP-day > 145 mmHg following stable antihypertensive treatment and 2 weeks of compliance registration.RDN was performed with the unipolar Medtronic Flex catheter (Medtronic, California, USA).CFR and C-Rmin were determined with transthoracic Doppler echocardiography and F-Rmin with venous occlusion plethysmography at baseline and six-months follow-up.Results: Baseline mean 24-h ambulatory BP was 111AE1 mmHg (RDN, nZ29) and 111AE2 mmHg (SHAM, nZ29).Similar reductions in MAP were seen at sixmonths follow up (-3.5AE2.0vs -3.2AE1.8,pZ0.92).Baseline CFR was 2.9AE0.1 (RDN) and 2.4AE0.1 (SHAM) with no significant change at follow-up (0.2AE0.2 vs. -0.1AE0.2,PZ0.57).C-Rmin was 1.9AE0.3(RDN) and 2.7AE0.6 (SHAM) (mmHg min/ml pr. 100 g LVM) and unchanged (0.3AE0.5 vs. -0.4AE0.8,PZ0.48).F-Rmin was 3.6AE0.2(RDN) and 3.6AE0.3(SHAM) (mmHg min/ml pr. 100 ml tissue) and unchanged at follow-up (0.6AE0.3 vs. 0.1AE0.2,PZ0.17).There was a tendency toward increased baseline LVMI in the SHAM-group (121AE7 (SHAM) vs. 108AE3 (RDN) g/m 2 , PZ0.08), but with proportional change at follow-up (-4AE7 vs. 3AE5, PZ0.38).Conclusion: RDN had no significant effect on CFR, C-Rmin and F-Rmin.Thus, data does not support microvascular improvement following RDN in resistant hypertension.