Background: Remote ischemic conditioning (RIC) confers protection against myocardial ischemia-reperfusion injury and may modulate coronary blood flow. We investigated whether RIC affects resting myocardial perfusion (MP) in patients with suspected ischemic coronary artery disease by quantitative MP imaging.
Methods and results: We included 49 patients with suspected ischemic coronary artery disease. Resting MP was quantified by 82Rubidium positron emission tomography/computed tomography (82Rb-PET/CT) imaging before and after RIC, performed as four cycles of 5 minutes upper arm ischemia and reperfusion. Subsequent adenosine 82Rb-PET/CT stress-imaging identified non-ischemic and reversibly ischemic myocardial segments. MicroRNA-144 plasma levels were measured before and after RIC. Normalized for rate pressure product, RIC did not affect MP globally (P = .64) or in non-ischemic myocardial segments (P = .58) but decreased MP in reversibly ischemic myocardial segments (-0.11 mL/min/g decrease in MP following RIC; 95% CI -0.17 to -0.06, P < .001). However, we found no effect of RIC when MP was normalized for cardiac work. MicroRNA-144 plasma levels increased following RIC (P = .006) but did not correlate with a change in global MP in response to RIC (P = .40).
Conclusions: RIC did not substantially affect resting MP globally or in non-ischemic and reversibly ischemic myocardial territories in patients with suspected ischemic coronary artery disease.
Keywords: 82Rb-PET/CT; ischemic heart disease; ischemic preconditioning; microRNA-144; myocardial perfusion; positron emission tomography/computed tomography; remote ischemic conditioning.