Cardioprotective Role of Remote Ischemic Periconditioning in Primary Percutaneous Coronary Intervention: Enhancement by Opioid Action

ObjectivesWe sought to determine the potential of remote ischemic periconditioning (RIPC), and its combination with morphine, to reduce reperfusion injury in primary percutaneous coronary interventions.BackgroundRemote ischemic post-conditioning is implemented by applying cycles of ischemia and reperfusion on a remote organ, which result in release of circulating factors inducing the effects of post-conditioning on the myocardium.MethodsA total of 96 patients (59 men) were enrolled. The patients were randomized to groups as follows: 33 to each treatment group (Group A: RIPC; Group B: RIPC and morphine) and 30 to the control group (Group C). Measures of efficacy were achievement of full ST-segment resolution (primary), and reduction of ST-segment deviation score and peak troponin I during hospitalization.ResultsA higher proportion of patients in Groups A (73%) and B (82%) achieved full ST-segment resolution after percutaneous coronary intervention, compared with control patients (53%) (p = 0.045). Peak troponin I was lowest in Group B, 103.3 ± 13.3 ng/ml, in comparison to peak levels in Group A, 166.0 ± 28.0 ng/ml, and the control group, 255.5 ± 35.5 ng/ml (p = 0.0006). ST-segment deviation resolution was 87.3 ± 2.7% in Group B, compared with 69.9 ± 5.1% in Group A and 53.2 ± 6.4% in the control group (p = 0.00002). In paired comparisons between groups, Group B did better than the control group in terms of both ST-segment reduction (p = 0.0001) and peak troponin I (p = 0.004), whereas Group A differences from the control group did not achieve statistical significance (p = 0.054 and p = 0.062, respectively).ConclusionsThese findings demonstrate a cardioprotective effect of RIPC and morphine during primary percutaneous coronary intervention for the prevention of reperfusion injury. This is in agreement with observations that the beneficial effect of RIPC is inhibited by the opioid receptor blocker naloxone.