An international multicenter case-control cohort study suggested that high density 1K plaque (the volume of plaque with more than 1000 Hounsfield unit) detected by coronary computed tomography angiography (CCTA) is associated with lower risk of future occurrence of acute coronary syndrome (ACS). The study included 189 patients who experienced vs 189 control individuals who did not experience an ACS matched 1:1 by propensity scores (mean age 59.9; 65.3% male). During a mean follow-up period of 3.9 years, the overall mean calcified plaque volume (>350 HU) was similar between patients and controls (76.4 mm3 vs 99.0 mm3), but patients who experienced ACS exhibited less 1K plaque (>1000 HU) compared with controls (3.9 mm3 vs 9.4 mm3). Individuals within the highest quartile of 1K plaque exhibited less low-density plaque, as a percentage of total plaque, when compared with patients within the lower 3 quartiles (12.6% vs 24.9%). For 93 culprit precursor lesions detected by CCTA, the volume of 1K plaque was lower compared with the maximally stenotic lesion in controls (2.6 mm3 vs 7.6 mm3). The per-patient and per-lesion results were similar between the 2 groups when restricted to myocardial infarction cases. The findings suggest that measurement of 1K plaque and considering separately the volume and density of calcium may improve risk stratification beyond plaque burden. However, patients with known coronary artery disease should receive optimal preventive therapy in any case. Source: https://jamanetwork.com/
