Abstract
BACKGROUND: Inadequately controlled hypertension is a major global public health challenge. This study aimed to explore whether remote ischemic conditioning (RIC), a type of heart- and brain-protection treatment, could be used as an adjunctive therapy for people with poor blood pressure (BP) control. METHODS: This was a randomised, single-blinded, parallel-controlled trial conducted at a single centre in Changchun, China. Patients with clinically diagnosed essential hypertension and systolic blood pressure (SBP) ≥140 mm Hg, including those with SBP ≥140 mm Hg even after treatment or those who do not receive any treatment, were enrolled. Enrolled participants were randomly allocated (1:1) to either RIC or sham RIC for 7 days. Sitting BP was measured twice daily (morning: between 6:00 and 9:00; evening: between 18:00 and 21:00) from the day before treatment to the last day (8 days, 16 measurements). Blood pressure variability (BPV) was also calculated. The primary endpoint was the difference in average SBP during treatment (7 days, 14 measurements). Adverse events were recorded during the study period. The intention-to-treat analysis included all participants who were randomly assigned to a study group. This trial is registered with ClinicalTrials.gov, NCT05910242. FINDINGS: Between June 20, 2023, and March 6, 2024, 102 patients completed the study (n = 51 per group). In the intention-to-treat analysis, the average SBP during treatment was lower in the RIC group than the sham RIC group (143·3 ± 10·0 vs. 147·6 ± 6·3 mm Hg; baseline adjusted between-group difference: -4·8 mm Hg [95% CI, -6·9, -2·7 mm Hg]; P < 0·001). The trend of overall SBP (the daily average of morning and evening SBP) over time was significantly different between the two groups (F = 4·316, P < 0·001, group-by-time-interaction). The reduction degree of overall SBP at day 7 was larger in the RIC group than in the sham RIC group (-5·1 ± 8·1 vs. 2·0 ± 7·8 mm Hg; between-group difference: -7·2 mm Hg [95% CI, -10·3, -4·0 mm Hg]; P < 0·001). Additionally, no significant differences were observed in the number of adverse events between the two groups, and no major adverse events occurred. INTERPRETATION: Our findings suggest that RIC treatment can safely and effectively reduce BP in patients with essential hypertension who have SBP ≥140 mm Hg, regardless of whether antihypertensive drugs are applied or not. This finding provides a safe and effective antihypertensive strategy for treating essential hypertension in patients with poor BP control. However, further research is warranted to explore the mechanisms underlying the BP-lowering effects of RIC deeply. FUNDING: National Natural Science Foundation of China, Science and Technology Department of Jilin Province, Jilin Provincial Key Laboratory, the Norman Bethune Health Science Center of Jilin University, the Talent Reserve Program of the First Hospital of Jilin University, and the Science and Technology Research Program of the Education Department of Jilin Province.