Sixty-four-slice multidetector computed tomography: an accurate imaging modality for the evaluation of coronary arteries in dilated cardiomyopathy of unknown etiology.

BACKGROUND The goal of this study was to assess the safety, feasibility, and diagnostic accuracy of 64-slice multidetector computed tomography (MDCT) for the evaluation of coronary arteries in dilated cardiomyopathy (DCM) of unknown etiology. Sixteen-slice MDCT is useful in patients affected by DCM. However, technical limitations, such as cardiac arrhythmias, an inability of patients to sustain a long breath-hold, and the need of a high dose of contrast agent may limit its accuracy and widespread use. METHODS AND RESULTS Invasive coronary angiography (ICA) and MDCT coronary angiography were performed on 132 consecutive patients (82 men; age 63+/-11 years) affected by DCM (ejection fraction, 34+/-10%) of unknown etiology. In 2 patients (1.5%), MDCT was not feasible because of atrial fibrillation. Of the remaining 130 patients, 88 exhibited normal and 42 exhibited diseased coronary arteries in both MDCT and ICA. All patients with coronary artery disease except for 1 were correctly classified by MDCT as 1-vessel (11 cases), 2-vessel (13 cases), and 3-vessel (18 cases) disease. In the segment-based analyses, the overall feasibility for MDCT was 98.5% (1902 of 1930 segments). Segment-based and patient-based analyses for the detection of luminal stenosis of >50% and >70% were performed. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >50% stenosis were 98.1%, 99.9%, 98.7%, 99.8%, and 99.7%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MDCT for the detection of >70% stenosis were 99.5%, 98.6%, 94.1%, 99.9%, and 99.4%, respectively. CONCLUSIONS Excellent feasibility and diagnostic accuracy, combined with low invasiveness, make 64-slice MDCT an ideal imaging modality for the anatomic evaluation of coronary circulation in patients with DCM of unknown etiology.