Correlations Between Regional Accumulation of Calcium in the Culprit Arteries and Plaque Burden in Acute Coronary Syndromes

Introduction: The association between a high calcium score at the level of the unstable coronary lesions and the different characteristic of culprit lesions which result in an acute coronary syndrome (ACS) has not been described yet. We aimed to study the correlation between the accumulation of calcium within the vessel wall of a coronary artery and the plaque burden of culprit lesions that develop an acute coronary event.
Material and methods: A total of 45 patients with ACS (22 unstable angina, 23 nonST elevation myocardial infarction) underwent 64-slice CCTA. In all patients a complex CT analysis of the culprit plaques was performed and the calcium score for each coronary artery was computed.
Results: We found a significant correlation between a calcium score higher than 100 and the plaque volume (r = 0.85. p = 0.01). Selecting a cut-off value of 100 HU for regional calcium score at the level of the coronary artery, we found that those arteries with Ca score higher than 100 presented significantly larger plaque volumes than the ones with calcium score below 100 (110.8 ml vs 82.4 ml, p <0.0001 for left anterior descending artery, 111.09 ml vs 82.5 ml, p = 0.0005 for circumflex artery, and 132.78 ml vs 76.23 ml for right coronary artery).
Conclusion: Our data shows that in ACS, the severity of the culprit lesions correlates with regional accumulation of calcium within the vessel wall.