SYMPLICITY HTN-Japan – First randomized controlled trial of catheter-based renal denervation in Asian patients

Background: SYMPLICITY HTN-Japan is a prospective, randomized, controlled trial comparing renal artery denervation (RDN) with standard pharmacotherapy for treatment of resistant hypertension (systolic blood pressure [SBP] ≥160 mmHg on ≥3 anti-hypertensive drugs including a diuretic for ≥6 weeks). When SYMPLICITY HTN-3 failed to meet the primary efficacy endpoint, the HTN-Japan enrollment was discontinued before completion. Methods and Results: The 6-month change in office and 24-h ambulatory SBP were compared between RDN (n=22) and control (n=19) subjects. Mean baseline office SBP was 181.0±18.0 mmHg and 178.7±17.8 mmHg for the RDN and control groups, respectively. The 6-month office SBP change was –16.6±18.5 mmHg for RDN subjects (P<0.001) and –7.9±21.0 mmHg for control subjects (P=0.117); the difference between the 6-month change in RDN and control subjects was –8.64 (95% CI: –21.12 to 3.84, P=0.169). Mean 24-h SBP was 164.7±18.3 (RDN group) and 163.3±17.2 mmHg (control group). The 24-h 6-month SBP change for the RDN group was –7.52±11.98 mmHg (P=0.008) and –1.38±10.2 mmHg (P=0.563) for control subjects; the between-group difference in SBP change was –6.15 (95% CI: –13.23 to 0.94, P=0.087). No major adverse events were reported. Conclusions: SYMPLICITY HTN-Japan, the first randomized controlled trial of RDN in an Asian population, was underpowered for the primary endpoint analysis and did not demonstrate a significant difference in 6-month BP change between RDN and control subjects.