Ten Year Follow-Up of Patients With Resistant Hypertension Randomized to Renal Denervation or Antihypertensive Drug Treatment

Objective: Renal denervation (RDN) is a treatment option in resistant hypertension. The procedure is considered safe, although randomized trials only demonstrate a moderate blood pressure (BP) lowering effect, when considering medication adherence. Some observational studies describe reduction in BP several years after the procedure. The aim of the study was to describe long-term safety and potential benefits of RDN after ten years, compared to optimized drug treatment, measuring serum concentration of antihypertensive drugs to ensure adherence. Design and method: We report data from ten year follow-up of patients randomized to RDN (n=9) or drug adjustment (n=10). Initially the patients had treatment-resistant hypertension, defined as daytime systolic ambulatory BP >= 135 mmHg after witnessed intake (directly observed therapy, DOT) of >= 3 antihypertensive drugs including a diuretic and therefore considered as adherent. One year after RDN or drug adjustment, we optimized antihypertensive medication for all patients. Thereafter, patients received appropriate antihypertensive treatment in primary or secondary care, according to their BPs. Patients were informed of serum concentration measurements performed at the 7-year visit. At the 10-year visit, serum drug measurements before DOT and ambulatory BP measurement (ABPM) were used for evaluation of adherence. Antihypertensive agents were registered, glomerular filtration rate (eGFR) was estimated by the CKD-EPI formula using creatinine and Cystatin C, and renal arteries were examined by CT or MRI. Results: All living patients (n=18) attended the 10-year visit, now mean age 69 years, using 4±2 antihypertensive agents, with no difference between groups. Serum concentrations confirmed that all patients were adherent to reported medication. There were significant and similar BP reductions in both groups compared to baseline; daytime ABPM -22±15/9±8 mmHg in the RDN group, and -20±15/13±7 mmHg in the control group (figure). No patients developed renal artery stenosis. The decrease in eGFR was similar in both groups. Conclusions: To our knowledge this is the RCT with the longest follow-up supporting long-term safety of RDN in patients with resistant hypertension. Daytime ABPM improved during 10 years of follow-up, not explained by RDN, but due to adjustments in antihypertensive regimens and probably better adherence to medication.