Renal denervation – radiofrequency vs. ultrasound: insights from a mixed treatment comparison meta-analysis of randomized sham controlled trials

Background and aims: Multiple randomized trials have shown that renal denervation (RDN) reduces blood pressure (BP) when compared with sham control but the antihypertensive efficacy of radiofrequency vs. ultrasound-based RDN is uncertain. We aimed to compare the outcomes of radiofrequency RDN (rRDN) and ultrasound RDN (uRDN), when compared with sham in patients with hypertension. Methods: PubMed, EMBASE, and clinicaltrials.gov databases were searched for randomized sham-controlled trials (RCTs) of rRDN or uRDN or for trials of rRDN vs. uRDN. Primary efficacy outcome was 24-h ambulatory SBP. A mixed treatment comparison meta-analysis was performed comparing the efficacy and safety against sham and against each other. Results: Among 13 RCTs that enrolled 2285 hypertensive patients, rRDN reduced 24-h ambulatory SBP [(MD = 2.34 mmHg; 95% confidence interval (95% CI): 0.72–3.95], office SBP (MD = 5.04 mmHg; 95% CI: 2.68–7.40)], and office DBP (MD = 2.95 mmHg; 95% CI: 1.68–4.22) when compared with sham. Similarly, uRDN reduced 24-h ambulatory SBP (MD = 4.74 mmHg; 95% CI: 2.80–6.67), day-time ambulatory SBP (MD = 5.40 mmHg; 95% CI: 3.68–7.13), night-time ambulatory SBP (MD = 3.84 mmHg; 95% CI: 0.02–7.67), and office SBP (3.98 mmHg; 95% CI: 0.78–7.19) when compared with sham. There was significantly greater reduction in 24-h ambulatory SBP (MD = 2.40 mmHg; 95% CI: 0.09–4.71), day-time ambulatory SBP (MD = 4.09 mmHg; 95% CI: 1.61–6.56), and night-time ambulatory SBP (MD = 5.76 mmHg; 95% CI: 0.48–11.0) with uRDN when compared with rRDN. For primary efficacy outcome, uRDN ranked #1, followed by rRDN (#2), and sham (#3). Conclusion: In hypertensive patients, rRDN and uRDN significantly reduced 24-h ambulatory and office SBP when compared with sham control with significantly greater reduction in ambulatory BP with uRDN than with rRDN at 4 months (mean) of follow-up. A large-scale randomized head-to-head trial of rRDN or uRDN is warranted to evaluate if there are differences in efficacy.