Chronic Remote Ischemic Conditioning on Mild Hypertension in the Absence of Antihypertensive Medication: a Multicenter, Randomized, Double-Blind, Proof-of-Concept Clinical Trial

Background: Exploratory studies have shown that remote ischemic conditioning (RIC) has the potential to lower blood pressure (BP). We investigated whether chronic RIC reduces BP for hypertension. Methods: This is a multicenter, randomized, double-blind, parallel-controlled trial. Patients with an office BP of 130/80 to 160/100 mm Hg and a 24-hour average BP ≥125/75 mm Hg not on antihypertensive medications were recruited. After a 1-week compliance screening phase, they were randomly assigned in a 1:1 ratio to receive RIC or sham RIC twice daily for 4 weeks. The primary efficacy outcome was the change in 24-hour average systolic BP from baseline to 4 weeks. Safety events were assessed over the study period. Results: Ninety-five participants were randomly allocated to the RIC (n=49) and sham RIC (n=46) groups. In the intention-to-treat analysis, the reduction in 24-hour average systolic BP was greater in the RIC group than the sham RIC group (−4.6±9.5 versus −0.9±6.8 mm Hg; baseline-adjusted between-group mean difference: −3.6 mm Hg [95% CI, −6.9 to −0.3 mm Hg]; adjusted P =0.035). The per-protocol analysis showed that 24-hour average systolic BP reduced −5.9±8.6 mm Hg in the RIC group and −0.7±6.7 mm Hg in the sham RIC group (baseline-adjusted between-group mean difference: −5.2 mm Hg [95% CI, −8.5 to −1.9 mm Hg]; adjusted P =0.002). No major adverse events were reported in both groups. Conclusions: RIC is safe in patients with mild hypertension and may lower BP in the absence of antihypertensive medications. However, the effects of RIC on clinical outcomes in these patients require further investigation. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04915313.