Cardiovascular Magnetic Resonance May Avoid Unnecessary Coronary Angiography in Patients with Unexplained Left Ventricular Systolic Dysfunction: A Retrospective Diagnostic Pilot Study.

Background: Coronary angiography (CA) is usually performed in patients with reduced left ventricular ejection fraction (LVEF) to search ischemic cardiomyopathy. Our aim was to examine the agreement between CA and cardiovascular magnetic resonance (CMR) imaging among a cohort of patients with unexplained reduced LVEF, and estimate what would have been the consequences of using CMR imaging as the first-line examination. Methods: Three hundred five patients with unexplained reduced LVEF of <45% who underwent both CA and CMR imaging were retrospectively registered. Patients were classified as CMR+ or CMR according to presence or absence of myocardial ischemic scar, and classified CA(+) or CA according to presence or absence of significant coronary artery disease. Results: CMR+ (n = 89) included all 54 CA(+) patients, except 2 with distal coronary artery disease in whom no revascularization was proposed. Among the 247 CApatients, 15% were CMR+. CMR imaging had 96% sensitivity, 85% specificity, 99% negative predictive value, and 58% positive predictive value for detecting CA(+) patients. Revascularization was performed in 6.5% of the patients (all CMR+). Performing CA only for CMR+ patients would have decreased the number of CAs by 71%. Conclusions: In reduced LVEF, performing CA only in CMR+ patients may significantly decrease the number of unnecessary CAs performed, without missing any patients requiring revascularization.