Long-Term Effects of Renal Denervation on Blood Pressure Burden in Patients with Resistant Arterial Hypertension

Abstract

Background: Catheter based ablation of nerves in the adventitia of renal arteries (renal denervation) by the use of radiofrequency energy can reduce blood pressure levels in patients with resistant arterial hypertension. Blood pressure burden (BPB), defined by the proportion of elevated blood pressure values during day and night time is associated with increased cardiovascular morbidity and mortality. We investigated the long-term effects of renal denervation on blood pressure burden out to 12 months. Methods: Patients suffering from drug-resistant arterial hypertension (mean systolic office BP>160 mmHg) were treated by renal denervation after exclusion of secondary causes of hypertension. Additionally, ambulatory blood pressure measurement was performed at baseline and after 6 and 12 months, respectively. Patients were classified as responders, if the 24 hours average systolic blood pressure dropped by ≥ 5 mmHg at the 6 months-follow-up. BPB was defined by the proportion of systolic/diastolic BP values ≥ 135/85 mmHg during day time and ≥ 120/70 mmHg during nighttime. Results: Six months after renal denervation, 41 patients (51.9%) were classified as responders. In these patients, mean systolic/diastolic 24 hours BP reductions were -17.2 ± 15.9/-9.0 ± 11.6 mmHg (p<0.0001/p<0.0001) after 12 months. The mean systolic/diastolic Blood pressure-burden BPB at baseline was 75.6%/57.1% during day time and 100%/62.5% during night time and decreased to 38.9%/ 26.8% (p<0.001/p<0.001) at day time and 57.1%/20.0% (p<0.001/p<0.001) at nighttime 12 months after renal denervation. Conclusion: The pronounced improvement of BPB in responders to renal denervation may be an important clinical component of this interventional treatment for arterial hypertension.