Remote Ischemic Conditioning in Patients with Acute Coronary Syndromes: A Systematic Review with Meta-Analysis and Trial Sequential Analysis.

OBJECTIVE

To evaluate the efficacy of remote ischemic conditioning (RIC) as compared to no conditioning on clinical endpoints in acute coronary syndromes (ACS) patients undergoing percutaneous coronary intervention (PCI).

DESIGN

Systematic review of randomized clinical trials (RCTs).

MATERIAL AND METHODS

Literature was searched up to September 13, 2019, and we identified a total of 13 RCTs. The efficacy of RIC on incidence of clinical events during follow-up was quantified by the rate ratio (RR) with its 95% confidence interval (CI), and we used fixed and random effects models to synthetize the results. Small-study effect was evaluated, and controlled for by the trim-and-fill method. Heterogeneity between studies was examined by subgroup and meta-regression analyses. The risk of false-positive results in meta-analysis was evaluated by trial sequential analysis (TSA).

RESULTS

Pooled analysis of 13 trials (7183 patients) showed that RIC compared to no conditioning revealed a non-significant risk reduction on endpoint mortality (RR=0.81, 95% CI: 0.56-1.17) during a median follow-up time of 1 year (range: 0.08-3.8) with low heterogeneity (I=16%). Controlling for small-study effect showed no efficacy of RIC (adjusted RR: 1.03, 95% CI: 0.66-1.59). Pooled effect of RIC on the incidence of myocardial infarction (MI) from 11 trials (6996 patients) was non-significant too (RR=0.85, 95% CI: 0.62-1.18), with no observed heterogeneity (I=0%) or small-study effect. A similar lack of efficacy was found in endpoint congestive heart failure (CHF) from 6 trials including 6098 patients (RR=0.71, 95% CI: 0.44-1.15), with moderate heterogeneity (I=30%). TSAs showed that the pooled estimates from the cumulative meta-analyses were true negative with adequate power.

CONCLUSION

Evidence from this updated systematic review demonstrates no beneficial effect of RIC on the incidence of clinical endpoint mortality, MI and CHF during a median follow-up of 1 year in ACS patients undergoing PCI.