The build-up of high-density calcified 1K plaque (more than 350 HU) is one of the leading predictors of heart attack and other cardiovascular diseases. This study aims to assess the association of the risk of acute coronary syndrome (ACS) with the increasing density of calcified coronary plaque.

This is a multicenter, case-control cohort study that included a total of 378 individuals, 189 with a core laboratory-verified ACS, and 189 control individuals with no ACS. The whole-heart atherosclerotic plaque volume from all coronary vessels and branches was quantified. The primary outcome of the study was the risk of ACS associated with calcium density.

The mean (SD) calcified plaque volume was similar between ACS patients and controls, but patients with ACS showed less 1K plaque compared with controls (3.9 vs. 9.4). The participants with the highest quartile of 1K plaque showed less low-density plaque when compared with patients with lower three quartiles (12.6% vs. 24.9%). When restricted to myocardial infarction cases, the per-lesion and per-patient results were also similar in the two groups.

The findings concluded that 1K plage, when quantified on a per-lesion and per-patient basis, was associated with a lower risk of the future acute coronary syndrome.