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

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