Calcified Plaques in Patients With Acute Coronary Syndromes.

Objectives: This study conducted detailed analysis of calcified culprit plaques in patients with acute coronary syndromes (ACS).

Background: Calcified plaques as an underlying pathology in patients with ACS have not been systematically studied.

Methods: From 1,241 patients presenting with ACS who had undergone pre-intervention optical coherence tomography imaging, 157 (12.7%) patients were found to have a calcified plaque at the culprit lesion. Calcified plaque was defined as a plaque with superficial calcification at the culprit site without evidence of ruptured lipid plaque.

Results: Three distinct types were identified: eruptive calcified nodules, superficial calcific sheet, and calcified protrusion (prevalence of 25.5%, 67.4%, and 7.1%, respectively). Eruptive calcified nodules were frequently located in the right coronary arteries (44.4%), whereas superficial calcific sheet was most frequently found in the left anterior descending coronary arteries (68.4%) (p = 0.012). Calcification index (mean calcification arc × calcification length) was greatest in eruptive calcified nodules, followed by superficial calcific sheet, and smallest in calcified protrusion (median 3,284.9 [interquartile range (IQR): 2,113.3 to 5,385.3] vs. 1,644.3 [IQR: 1,012.4 to 3,058.7] vs. 472.5 [IQR: 176.7 to 865.2]; p < 0.001). The superficial calcific sheet group had the highest peak post-intervention creatine kinase values among the groups (eruptive calcified nodules vs. superficial calcific sheet vs. calcified protrusion: 241 [IQR: 116 to 612] IU/l vs. 834 [IQR: 141 to 3,394] IU/l vs. 745 [IQR: 69 to 1,984] IU/l; p = 0.032).

Conclusions: Three distinct types of calcified culprit plaques are identified in patients with ACS. Superficial calcific sheet, which is frequently located in the left anterior descending coronary artery, is the most prevalent type and is also associated with greatest post-intervention myocardial damage. (Identification of Predictors for Coronary Plaque Erosion in Patients With Acute Coronary Syndrome; NCT03479723).