Remote ischemic preconditioning of the heart: Combining lower limb ischemia and electronic stimulation of the gastrocnemius muscle

BACKGROUND: Remote ischemic preconditioning (RIPC) has been demonstrated to induce potent cardioprotection in individuals experiencing coronary ischemia. A protocol combining limb ischemia and electronic muscle stimulation of the ischemic skeletal muscle (RIPC+), performed in advance of coronary artery occlusion, was superior in terms of infarct size reduction when compared to RIPC alone. METHODS: This study was performed to evaluate the benefit of RIPC + in humans compared to a standard RIPC protocol and a control group. Patients with a single vessel coronary artery disease undergoing elective PCI were eligible to participate in this study. ST-segment elevations from an intracoronary ECG during 3 brief episodes of coronary artery balloon occlusions/dilatation were used as the primary endpoint. RESULTS: ST-elevations significantly declined from the first to the third angioplasty in the control but remained at the same level in the RIPC and RIPC+groups. The RIPC group was characterized by the lowest ST-segment shift during coronary ischemia, which was comparable to coronary balloon occlusion number 3 in the control group, indicating successful preconditioning by the conventional RIPC method. In contrast, ST segment elevations were significantly higher in the RIPC + group. Troponin levels taken 24 h after the study procedure were significantly lower in the RIPC when compared to the control and the RIPC + group. CONCLUSION: Our results again confirm the feasibility of remote ischemic preconditioning in patients undergoing coronary angioplasty. According to our results ischemia combined with electronic skeletal muscle stimulation was not superior to conventional RIPC cycles (skeletal muscle ischemia alone).