Long-term effectiveness of renal denervation in patients with resistant hypertension: results of 5-year follow-up

Aim . To evaluate the long-term effectiveness of renal denervation (RDN) in reducing blood pressure (BP) and cardio- and nephroprotection in patients with resistant hypertension based on five-year follow-up. Material and methods . A total of 53 patients who completed a five-year follow-up period after RDN were examined (mean age 56,3±9,2 years, 23 men (43%), mean 24-hour BP (BP-24) — 168/94 mm Hg). Office and mean 24-hour BP were assessed. Left ventricular mass (LVM) were measured using echocardiography data. Renal function was evaluated using the estimated glomerular filtration rate (eGFR) (CKD-EPI), 24-hour urine volume, 24-hour urine protein and albumin excretion, daily K- and Na-cut. The primary endpoint of RDN efficacy was considered to be a decrease in systolic BP (SBP)-24. There were following secondary endpoints: achievement of target BP, proportion of responders (individuals with decrease in SBP-24 by 5 mm Hg or more), decrease in LVM, slowing of eGFR decline rate (change in eGFR <3 ml/min/1,73 m 2 per year). Results . Five years after RDN, significant SBP-24 decrease was registered on average in the group (p=0,01). Target clinical SBP was achieved by 15 patients (28,3%). There were 28 responders (52,8%). According to echocardiography, significant decrease in interventricular septal thickness was noted (p=0,01) in the absence of significant decrease in LVM (p=0,2). Annual decline rate in eGFR was 2,56 ml/min/1,73 m 2 . An increase in 24-hore urine volume (p=0,02) and sodium excretion (p=0,01) was documented. The degree of reduction in SBP-24 had a direct quantitative relationship with the increase in 24-hour natriuresis (r=-0,63; p=0,017). According to the ROC analysis, the predictors of response to RDN were the initial level of SBP-24 (>155,5 mm Hg), variability of SBP-24 (>5,5 mm Hg) and kaliuresis level (>27,2 mmol/l). Conclusion . RDN in patients with resistant HTN is accompanied by a stable 5-year antihypertensive effect without accelerating the renal function decline rate, as well as myocardial structural improvement in the form of a decrease in interventricular septal thickness. One of the pathophysiological mechanisms for BP reduction may be an increase in natriuresis, and its predictors are the initial levels of SBP-24, its variability, and 24-hour kaliuresis.