Objective: The blood pressure (BP)-lowering effect of renal sympathetic nervous denervation (RDN) in resistant hypertension (rHT) shows large variation among studies.
Methods: We meta-analyzed summary statistics of randomized clinical trials on RDN in rHT. For continuous outcomes, we assessed heterogeneity by Cochran's Q test and used random-effect models weighted for the inverse of the variance. We assessed safety by assessing the risk of major adverse events from stratified contingency tables.
Results: Of 5652 patients screened in seven trials, 985 (17.4%) qualified and were randomized to control (n = 397) or RDN with SYMPLICITY(™) catheters (n = 588). Follow-up was 6 months. In both control and RDN patients, antihypertensive treatment was continued or optimized. At enrolment, age averaged 58.1 years, systolic/diastolic office and 24 h BP 168.5/93.3 mmHg and 151.8/86.1 mmHg, respectively, and estimated glomerular filtration rate (eGFR) 79.3 ml/min/1.73 m². For BP outcomes, there was heterogeneity among trials. Pooled effects (control minus RDN) were -4.9/-3.5 mmHg (95% confidence interval, -20.9 to 11.1/-8.9 to 1.9) for office BP, -2.8/-1.5 mmHg (-6.5 to 0.8/-3.3 to 0.4) for 24 h BP and 0.81 ml/min/1.73 m² (-1.69 to 3.30) for eGFR. Removing one trial at a time produced confirmatory results. Adverse events occurred in 7.4% and 9.9% of control and RDN patients, respectively (p = 0.24).
Conclusion: In selected rHT patients maintained on antihypertensive drugs, RDN with the SYMPLICITY systems does not significantly decrease BP but is safe. Future trials with next-generation catheters should aim at identifying responders in patients with evidence of sympathetic nervous overactivity.
Keywords: Blood pressure-lowering treatment; meta-analysis; randomized clinical trial; renal sympathetic nervous denervation; resistant hypertension.