Coronary Revascularization of Ischemic Territories Improves Myocardial Perfusion, Increases Submaximal Aerobic Capacity and Reduces Exercise-Induced Angina in Patients with Chronic Coronary Syndrome.

Abstract

Chronic coronary syndrome (CCS) is associated with reduced stress perfusion, a predictor of adverse cardiovascular outcome. To what extent myocardial perfusion is related to cardiorespiratory fitness is not completely known. The aim was to investigate if change in myocardial perfusion correlates to change in aerobic capacity after revascularization. Sixty-two patients with suspected or established CCS underwent cardiopulmonary exercise testing (CPET) and [¹³N]NH₃ positron emission tomography (PET) before and after elective invasive coronary angiography. Thirty-six patients were revascularized and 26 were not. The angiographer was blinded to the results from CPET and PET. Myocardial perfusion was defined as decreased when below 2 ml/min/g and as myocardial perfusion reserve (MPR) < 2. Change in oxygen uptake at submaximal effort (VO₂ at AT) correlated positively to change in MPR in revascularized patients (r=0.36, p=0.04), but not in conservatively treated patients (r=0.03, p=0.90). Change in VO₂peak, however, did not correlate to change in myocardial perfusion in any of the groups. Myocardial perfusion at stress and MPR increased significantly after revascularization, when baseline perfusion was decreased (P=0.01 stress and P=0.001 MPR, respectively). Furthermore, the number of patients with exercise-induced angina decreased significantly for the revascularized patients (42% (14/33) at baseline vs 3% (1/33) at follow-up, p<0.001) whereas half of the conservatively treated patients still had exercise-induced angina at follow-up (42% (10/24) at baseline vs 21% (5/24) at follow-up, p=0.12). In conclusion, change in myocardial perfusion correlates with change in submaximal aerobic capacity after revascularization and revascularization reduces exercise-induced angina.