## 2 Materials and Methods  
The study was approved by the local ethics committees and was performed in accordance with the Declaration of Helsinki. Following screening and RSD, clinical follow-ups were scheduled at one and/or three months. All patients provided written informed consent for their participation in the trial and further laboratory testing. Study subjects: In this study, we included 54 consecutive RH patients with available sST-2 measurements at baseline and/or during follow-up at one and/or three months following RSD. Baseline sST-2 measurement was performed before RSD at the time of hospital admission. As eligible patients were confined to those with RH in accordance with previous RSD studies and current hypertension guidelines, the patient collective enrolled was pre-selected and limited in scope. All eligible patients were older than 18 years and presented with a systolic office BP greater than 160 mmHg despite treatment with three or more antihypertensive drugs. No changes in medication were made for the last three months prior to intervention. A preceding 24 h BP measurement was performed to rule out white coat hypertension. Secondary causes of hypertension, as well as renal insufficiency with a glomerular filtration rate <45 mL/min/1.73 m\({}^{2}\) were excluded before RSD. Furtherexclusion criteria were pregnancy, type 1 diabetes mellitus, significant valvular heart diseases, myocardial infarction, or stroke within the last six months. Unfavorable anatomical conditions, such as a renal artery diameter of less than 4 mm, length below 20 mm, and an existing or treated renal artery stenosis, were contraindications for the procedure [7]. BP measurements: Before BP measurements, the adherence of the patients to their antihypertensive medication regimen was checked. Office BP was measured in sitting posture using an automatic oscillometric monitor (Omron HEM-705, Omron Healthcare, Vernon Hills, IL, USA), recording BP and heart rate after 10 min of rest on the brachial artery. Three measurements for 1 min intervals were recorded and averaged for statistical analysis. Throughout the study, measurements were performed on the same arm after initial measurements on both sides had ruled out BP differences of more than 10 mmHg. Transthoracic echocardiography: Transthoracic echocardiography (TTE) was performed with a Philips IE33 ultrasound system (Philips Inc., Amsterdam, The Netherlands) in accordance with the American Society of Echocardiography [11] to assess LVM (\(n=45\)), which was extrapolated from LV linear dimensions by using the Devereux formula [7]. RSD procedure: In 54 consecutive hypertensive patients, renal angiograms were performed via femoral access to conform anatomic eligibility as previously defined [7]. In the same session, RSD was performed using either the Symplicity Flex catheter (Medtronic Inc., Minneapolis, MN, USA) or the Vessix V2 catheter (Vessix Vascular/Boston Scientific, Marlborough, MA, USA). Up to six ablations at 8 W for two minutes each were performed in both renal arteries. In 46 Patients, the intervention was performed with the Symplicity Flex catheter and in 8 patients with the Vessix/Boston Scientific V2 catheter. Biomarker analysis: In a subgroup of patients, serum levels of sST-2 were analyzed at baseline, at one month (\(n=24\)) and three months (\(n=20\)). Serum levels of sST-2 were measured by using commercially available enzyme linked immunosorbent assay (ELISA) kits (DuoSet ELISA, DY523B, R&D Systems, Minneapolis, MN, USA). Statistical analysis was performed using SPSS (22.0, SPSS Inc., Chicago, IL, USA). All values were provided as mean \(\pm\) standard deviation (SD). The Kolmogorov-Smirnov test was used to assess a normal distribution of data in the study population. As all parameters and biomarker concentrations were normally distributed, mean values between groups were compared using Student's \(t\)-test. Correlation analysis was performed using Pearson's correlation analysis.