Songling Xuemaikang capsule for grade 1 hypertension at low-to-moderate risk: a multicenter randomized placebo-controlled trial

BACKGROUND: Songling Xuemaikang Capsule (SXC), a Chinese herbal medicine, has shown promise in decreasing blood pressure (BP), but its efficacy in grade 1 hypertension patients at low-to-moderate cardiovascular (CV) risk remains uncertain. PURPOSE: This study investigated the efficacy of SXC in grade 1 hypertension patients at low-to-moderate CV risk. STUDY DESIGN: This study was designed as a multicenter, randomized, double-blind, placebo-controlled clinical trial. METHODS: Eligible patients from 9 centers were randomized to receive SXC or placebo for consecutive 8 weeks. The primary outcome was the changes of 24-h ambulatory BP. The secondary outcomes were the changes of daytime/nighttime BP, office BP, and control rate of hypertension. The adverse events were reported. RESULTS: Of 508 patients who underwent screening, 393 were randomized after a 2-week run-in phase, and 356 were included in final analysis. Intention-to-treat analysis revealed a greater reduction in 24-h systolic/diastolic blood pressure (SBP/DBP) in SXC group compared to placebo group (-5.91±11.32/-4.66±9.33 mm Hg vs -2.26±10.47/-2.56±8.76 mm Hg, p < 0.001/p < 0.001). The patients in SXC group also showed a greater reduction in daytime SBP/DBP, nighttime SBP/DBP and office SBP/DBP than placebo group (p = 0.002/p = 0.004, p = 0.005/p = 0.046 and p < 0.001/p = 0.001, respectively). The control rate of 24-h BP (defined as SBP/DBP <130/80 mm Hg) was higher in SXC group than in placebo group (38.04 % vs 24.42 %, p = 0.002). There was no statistical difference in adverse events between two groups. CONCLUSION: Treatment with SXC for 8-week demonstrated a superiority in reducing 24-h average SBP/DBP over placebo, without increasing adverse events. The confirmed net efficacy suggested that SXC may provide an alternative therapy for grade 1 hypertension patients at low-to-moderate CV risk.