Prognostic value of a new semiquantitative score system for adenosine stress myocardial perfusion by CMR

Cardiovascular magnetic resonance (CMR) provides information on myocardial ischemia through stress perfusion studies. In clinical practice, the grading of induced perfusion defects is performed by visual estimation of their extension. The aim of our study is to devise a score of the degree of ischemia and to test its prognostic value. Between 2009 and 2011, patients with diagnosed or suspected coronary artery disease underwent stress perfusion CMR. A score of ischemic burden was calculated on the basis of (1) stress-induced perfusion defect, (2) persistence, (3) transmurality, and (4) stress-induced contractile defect. Follow-up was censored after 4 years and primary end-point was defined by a composite of death, heart failure episode, acute coronary syndrome, and ventricular arrhythmias. Univariate and multivariate logistic regressions were used to assess the strength of the association between the CMR ischemic variables, and the composite outcome. Forty-four of the 128 patients (34%) presented with adverse events, while 84 (66%) did not. Sixty-one patients (48%) had negative perfusion studies while 67 (52%) showed perfusion defect. Patients with positive perfusion studies and adverse events (n = 39) had higher number of segments with persistent defect (3.3 vs 1.3, p = 0.001) and highest score (19.6 vs 13.3 p = 0.012) than patients with positive perfusion studies and absence of events (n = 28). The number of segments with persistent defect showed the strongest predictive value of adverse events (OR 1.54; CI 1.19–2.00; p < 0.001). The score of ischemic burden proposed herein has prognostic value. Persistence of a perfusion defect has the strongest impact on prognosis.