Long-term clinical outcomes of Remote Ischemic Preconditioning and Postconditioning Outcome (RISPO) trial in patients undergoing cardiac surgery

Abstract

Background: Remote ischemic conditioning has been shown to confer myocardial protection. However, there is still no sufficient data on its long-term clinical outcomes. We analyzed the long-term results of the Remote Ischemic Preconditioning and Postconditioning Outcome (RISPO) trial in cardiac surgery patients.

Methods: In the RISPO trial, 1280 patients were randomized to receive remote ischemic preconditioning (RIPC) with postconditioning (RIPostC, upper arm ischemia by four cycles of 5-min inflation followed by 5-min deflation of a pneumatic cuff, N=644) or sham (N=636) during cardiac surgery. Patient follow-up data were collected by review of medical records, telephone interviews, and from the National Statistical Office. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE; a composite of all-cause mortality, myocardial infarction (MI), stroke, and revascularization), and the secondary endpoints were the individual components of the primary endpoint.

Results: At completion of follow-up (mean 44months), there was no difference in MACCE between the groups (90 [14.0%] versus 101 [15.9%] in the RIPC with RIPostC versus control groups; hazard ratio [HR], 0.893; 95% confidence interval [CI], 0.672-1.187; P=0.435). However, MI was reduced to half in the RIPC with RIPostC group (10 [1.6%] versus 23 [3.6%]; HR, 0.468; 95% CI, 0.222-0.984; P=0.045).

Conclusions: Remote ischemic preconditioning with RIPostC did not improve long-term MACCE after cardiac surgery. However, MI was reduced in the RIPC with RIPostC group compared with the control group during the follow-up period.

Clinical trial registration: ClinicalTrials.gov identifier, NCT00997217.

Keywords: Cardiac surgery; Cardioprotection; Clinical outcome; Remote ischemic conditioning.