Effects of renal denervation on coronary flow reserve and forearm dilation capacity in patients with treatment-resistant hypertension. A randomized, double-blinded, sham-controlled clinical trial

Background: Microvascular impairment is well documented in hypertension. We investigated the effect of renal sympathetic denervation (RDN) on cardiac and peripheral microvasculature in patients with treatment-resistant essential hypertension (TRH). Methods: A randomized, single centre, double-blinded, sham-controlled clinical trial. Fifty-eight patients with TRH (ambulatory systolic BP (ASBP) >= 145 mm Hg) despite stable treatment were randomized to RDN or SHAM. RDN was performed with the unipolar Medtronic Flex catheter. Coronary flow reserve (CFR) and coronary-and forearm minimum vascular resistance (C-Rmin and F-Rmin) were determined using transthoracic Doppler echocardiography and F-Rmin with venous occlusion plethysmography at baseline and at six-months follow-up. Results: RDN was performed with 5.3 +/- 0.2 lesions in the right renal artery and 5.4 +/- 0.2 lesions in the left. Baseline ASBP was 152 +/- 2mmHg (RDN, n=29) and 154 +/- 2mmHg (SHAM, n=29). Similar reductions in MAP were seen at follow up (-3.5 +/- 2.0 vs. -3.2 +/- 1.8, P = 0.92). Baseline CFR was 2.9 +/- 0.1 (RDN) and 2.4 +/- 0.1 (SHAM), with no significant change at follow-up (0.2 +/- 0.2 vs. -0.1 +/- 0.2, P = 0.57). C-Rmin was 1.9 +/- 0.3 (RDN) and 2.7 +/- 0.6 (SHAM) (mm Hg min/ml pr. 100 g) and did not change significantly (0.3 +/- 0.5 vs. -0.4 +/- 0.8, P = 0.48). F-Rmin was 3.6 +/- 0.2 (RDN) and 3.6 +/- 0.3 (SHAM) (mm Hg min/ml pr. 100 ml tissue) and unchanged at follow-up (4.2 +/- 0.4 vs. 3.8 +/- 0.2, P = 0.17). Left ventricular mass index was unchanged following RDN (-4 +/- 7 (RDN) vs. 3 +/- 5 (SHAM) (g/m(2)) P = 0.38). Conclusion: The current study does not support positive effects of RDN on microvascular impairment in TRH. (C) 2017 Elsevier B.V. All rights reserved.