New insights into spotty calcification and plaque rupture in acute coronary syndrome: an optical coherence tomography study

Although recent optical coherence tomography (OCT) studies have focused on spotty calcification, whether there were any characteristics in the concomitant existence of calcification and plaque rupture remains unknown. The aim of the present study was to investigate the characteristics of spotty calcification in acute coronary syndrome (ACS) patients with or without plaque rupture, using OCT. This study enrolled 98 consecutive patients with ACS. OCT image acquisitions were performed in the culprit lesions, and patients were divided into the plaque rupture group (n = 38) and the non-rupture group (n = 60). The frequency of spotty calcification (p = 0.006), thin-capped fibroatheroma (p = 0.012), macrophage infiltration (p = 0.022), and the number of spotty calcification per patient (p < 0.001) were significantly higher and the largest arc and the minimum depth of spotty calcification from the luminal surface were significantly smaller in the rupture group. Moreover, in the rupture group, most of the spotty calcifications in the site nearest to the minimum lumen area were observed in the proximal portion of that site, and tended to be located near the plaque rupture. Multivariate analysis revealed that the presence of spotty calcification (OR 3.19, 95 % CI 1.12–9.76, p = 0.030) and age (OR 1.08, 95 % CI 1.02–1.14, p = 0.008) were independent predictive factors for plaque rupture. This study demonstrates the characteristics of spotty calcification in ACS patients with plaque rupture and the positional relationship between spotty calcification and plaque rupture. These detailed observations could impact on treatment strategies for the prevention of ACS.