LONG-TERM OUTCOME OF THE RANDOMIZED OSLO-RDN STUDY

Abstract

Objective: The blood pressure (BP) lowering effect of renal sympathetic denervation (RDN) in treatment resistant hypertension (TRH) shows variation among the few randomized studies. The duration of antihypertensive effect and long-term effect and safety of RDN requires further follow-up. We aimed to report the office, ambulatory blood pressure changes as well as long-term safety at 3 years follow-up in our Oslo-RDN study.Design and method: Patients with apparent TRH (n = 65) were referred specifically for RDN and those with secondary and spurious hypertension (n = 26) were excluded. TRH was defined as office systolic BP > 140 mmHg despite maximally tolerated doses of at least 3 antihypertensive drugs including a diuretic. Furthermore, ambulatory daytime systolic BP > 135 mmHg following witnessed intake of antihypertensive drugs was required. This procedure revealed that 20 patients had normalized BP, indicating poor adherence, and these patients were excluded. Patients with true TRH were randomized and underwent RDN with Symplicity catheter (n = 9) versus adjusted drug treatment (n = 10). Patients came for follow-up 3–4 years after baseline. Results: 24-hour ambulatory systolic and diastolic BPs in the drug adjustment group changed from 151 ± 13/84 ± 7 mmHg at baseline to 132 ± 15/77 ± 6 mmHg at 3-years, and in the RDN group from 149 ± 9/89 ± 7 mmHg at baseline to 137 ± 13/81 ± 10 mmHg at 3-years follow-up. Office, daytime and nighttime ambulatory BPs changed in parallel to the 24-hour ambulatory BPs. The absolute differences in systolic or diastolic BPs between the groups were consistent with earlier follow up points with a tendency toward a smaller difference between the groups. The difference in systolic BP at long-term follow up was not significant (p = 0.34). There were no significant changes in renal arteries assessed by MRI or CT scans at long-term follow-up. No deterioration of renal function was observed. Conclusions: The results at the three-year follow-up are consistent with earlier time points, with a tendency toward a smaller difference in BPs between the TRH and RDN groups. Our data support that RDN is a safe procedure on long-term follow-up and this allows further research to identify characteristics of patients who might respond to RDN.