Abstract
Despite the availability of a numerous antihypertensive agents, hypertension treatment and control rates remain low in many countries. The role of the sympathetic nervous system has long been recognized, but recent sham control renal denervation studies demonstrated conflicting results. In this reviewe paper, the authors performed a systematic review and meta-analysis to examine outcomes of sham-controlled studies utilizing new technologies and procedures. Six published randomized, sham-controlled studies were included in this meta-analysis. Of those, three trials used the first-generation radiofrequency renal denervation device and technique and the other three used second-generation devices and techniques. In total, 981 patients with hypertension were randomized in all 6 trials to undergo renal denervation (n = 585) or sham procedure (n = 396). Overall, renal denervation resulted in a decrease of 24-hours systolic ambulatory blood pressure (ABP) by 3.62 mm Hg (95% CI: -5.28--1.96; I(2) = 0%), compared to sham procedure (GRADE: low). Renal denervation also reduced daytime systolic ABP by 5.51 mm Hg (95% CI: -7.79--3.23; I(2) = 0%), compared to sham procedure but not nighttime systolic ABP. Office systolic blood pressure was reduced by 5.47 mm Hg (95% CI -8.10--2.84; I(2) = 0%), compared to sham control. Further analysis demonstrated that second-generation devices were effective in reducing blood pressure, whereas the first-generation devices were not. These results indicate that effective renal denervation can result in significant and clinically meaningful blood pressure reduction. The second-generation devices provide better renal nerve ablation.