Hypertensive status is associated with renoprotection by remote ischemic conditioning for acute myocardial infarction—a meta-regression and trial sequential analysis of randomized clinical trials

The potential modifiable factors for remote ischemic conditioning (RIC) in reducing contrast-associated acute kidney injury (CA-AKI) in patients with acute myocardial infarction (AMI) have not been investigated. The aim of this meta-regression was to address these issues.We searched Pubmed, Embase and the Cochrane Library database for published randomized controlled trials (RCTs) with registration number CRD42020155532. Nine RCTs comprising of 1540 subjects were included in our meta-analysis. Compared with control group, RIC was associated with reduced incidence of CA-AKI [(9 studies, 1540 subjects, relative risk (RR) 0.51, 95% confidence intervals (CI) 0.35 to 0.76, p = 0.000, I2 = 52%, p for heterogeneity 0.04)] and major adverse cardiovascular events (MACE) (5 studies, 1078 subjects, RR 0.52, 95% CI 0.38 to 0.73, p = 0.000, I2 = 9%, p for heterogeneity 0.36) for AMI. In addition, both meta-regression and subgroup analyses have shown that RIC was more effective in the hypertensive patients in reducing CA-AKI for AMI (regression coefficient = –0.05, p = 0.021; for subgroup with more hypertensive patients: RR 0.36, 95% CI 0.25 to 0.52 vs the one with less hypertensive patients: RR 0.72, 95% CI (0.40 to 1.30, p for subgroup difference 0.008). Subsequent trial sequential analysis confirmed the effect of RIC in both CA-AKI and MACE. RIC is an effective strategy in reducing CA-AKI and MACE in patients with AMI, especially for patients with hypertension.