Renal denervation, adjusted drugs, or combined therapy for resistant hypertension: A meta-regression

The objective of this study is to systematically evaluate the efficacy of renal denervation (RD), adjusted drugs, or combined therapy for resistant hypertension (RH) through a systematic review and meta-analysis of controlled studies. Publications were comprehensively searched. Studies that investigated the effects of RD and/or adjusted drugs in lowering blood pressure (BP) were included. After quality assessment and data extraction, subgroup analyzes were first performed according to blinding method. Meta-regression and inverted funnel plots were also conducted. A total of 13 studies containing 1604 RH patients were included. Compared with control, the meta-analysis showed that RD significantly reduced office-based BP and ambulatory BP in 6 months in the unblinded studies, while no significant difference was found in the blinded studies. Meta-regression demonstrated the significant influence of blinding method on BP reduction, and further analysis revealed a significant BP reduction compared with baseline even in the control arm of blinded studies. RD had similar effects compared with adjusted drugs, and combined therapy seemed to further reduce the level of BP. The efficacy of RD was different between blinded and unblinded studies, and our data revealed a significant BP-lowering effect in the control arm of blinded studies, which was helpful to explain this finding. Furthermore, RD seemed to be equivalent to adjusted drugs, and also we suggested a potential advantage of combined therapy of RD and adjusted drugs compared with monotherapy for RH. However, more studies are warranted to better address the issue.