Prevalence, Predictors, and Clinical Presentation of a Calcified Nodule as Assessed by Optical Coherence Tomography

Abstract Objectives This study sought to determine the anatomic characteristics and clinical presentation associated with a calcified nodule (CN) as assessed by optical coherence tomography. Background CN is an unusual but demonstrable cause of acute coronary syndromes (ACS). Methods We studied 889 de novo culprit lesions in 889 patients (48% ACS) who underwent optical coherence tomography before intervention. CN was defined as an eruptive accumulation of nodular calcification (small fractured calcifications). Using quantitative coronary angiography, the change in the angle of the lesion between diastole and systole was measured (angiographic Δ angle). Results CN was seen in 4.2% of all lesions and was located more frequently in the ostial or mid right coronary artery. Hemodialysis (odds ratio: 4.0; 95% confidence interval: 1.1 to 13.4; p = 0.04), in-lesion angiographic Δ angle (odds ratio: 1.09; 95% confidence interval: 1.05 to 1.14; p  2 [first quartile, third quartile: 0.69, 1.26] vs. 1.61 [first quartile, third quartile: 1.03, 2.06] mm 2 ; p = 0.02) accompanied by more thrombus (82.4% vs. 20.0%; p  180°), 30% of ACS culprit lesions contained a CN, and the presence of a CN was associated with ACS presentation independent of other vulnerable plaque morphologies. Conclusions The presence of a CN was associated with severe calcification and larger hinge movement of the coronary artery (especially ostial and mid right coronary artery). One-third of the underlying plaque morphology of severely calcified culprit lesions in patients with ACS was caused by a CN.