Diagnostic performance of a novel coronary CT angiography algorithm : Prospective multicenter validation of an intracycle CT motion correction algorithm for diagnostic accuracy

OBJECTIVE. Motion artifact can reduce the diagnostic accuracy of coronary CT angiography (CCTA) for coronary artery disease (CAD). The purpose of this study was to compare the diagnostic performance of an algorithm dedicated to correcting coronary motion artifact with the performance of standard reconstruction methods in a prospective international multicenter study. SUBJECTS AND METHODS. Patients referred for clinically indicated invasive coronary angiography (ICA) for suspected CAD prospectively underwent an investigational CCTA examination free from heart rate–lowering medications before they underwent ICA. Blinded core laboratory interpretations of motion-corrected and standard reconstructions for obstructive CAD (= 50% stenosis) were compared with ICA findings. Segments unevaluable owing to artifact were considered obstructive. The primary endpoint was per-subject diagnostic accuracy of the intracycle motion correction algorithm for obstructive CAD found at ICA. RESULTS. Among 230 patients who underwent CCTA with the motion correction algorithm and standard reconstruction, 92 (40.0%) had obstructive CAD on the basis of ICA findings. At a mean heart rate of 68.0 ± 11.7 beats/min, the motion correction algorithm reduced the number of nondiagnostic scans compared with standard reconstruction (20.4% vs 34.8%; p < 0.001). Diagnostic accuracy for obstructive CAD with the motion correction algorithm (62%; 95% CI, 56–68%) was not significantly different from that of standard reconstruction on a per-subject basis (59%; 95% CI, 53–66%; p = 0.28) but was superior on a per-vessel basis: 77% (95% CI, 74–80%) versus 72% (95% CI, 69–75%) (p = 0.02). The motion correction algorithm was superior in subgroups of patients with severely obstructive (= 70%) stenosis, heart rate = 70 beats/min, and vessels in the atrioventricular groove. CONCLUSION. The motion correction algorithm studied reduces artifacts and improves diagnostic performance for obstructive CAD on a per-vessel basis and in selected subgroups on a per-subject basis.