Abstract 1727: Acute Coronary Thrombosis Leading To Sudden Death In The Young: Calcium Score Does Not Predict Atherosclerotic Plaque Instability
Purpose. The coronary calcium score (CCS) assessed by multislice computed tomography (MCST) has been demonstrated to predict coronary artery disease events beyond standard risk factors. The aim of the present study was to assess CCS in young people (aged <35 yrs) who died suddenly due to acute coronary artery thrombosis.
Methods. Among 77 consecutive cases of coronary sudden death in young people, 26 (34%) aged 22–35 (mean 32±2.3, M/F=23/3) were due to acute coronary artery thrombosis. Formalin fixed hearts underwent ex-vivo 16 slice MSCT (LightSpeed Plus, General Electric Company, Milwakee, WI, USA). Twenty consecutive older coronary sudden death victims (age range 44–76, mean 59±12, M/F=17/3) were used for comparison. CCS was evaluated both by Agatston and volume scoring methods. Serial sections investigation of all major epicardial coronary arteries was performed and slides routinely processed with H&E, Heidenhain trichrome and von Kossa stains.
Results. Coronary calcium was detected by ex vivo MSCT in 9 (35%) young and in 13 (65%) older patients (P=0.04), with a mean CCS of 21 Agatston (volume score 21.5) and 269 Agatston (volume score 316), respectively. By comparing the morphopathologic findings in young vs older sudden death victims, a multivessel coronary artery disease was detected in 10 (38%) vs 16 (80%, p=0.003), fibroatheromasic plaques with abundant lipid core in 9 (35%) vs 20 (100%), fibrous cap rupture in 8 (31%) vs 20 (100%) and endothelial erosion in 18 (69%) vs none (0%) (all p<0.0001). In the young, a positive CCS was detected in 9 (90%) with multivessel disease vs none (0%) with single vessel disease; and in 2 (11%) with endothelial erosion vs 7 (87%) with fibrous cap rupture (all p<0.001).
Conclusions. In the young CCS is a strong predictor of coronary artery disease extent but not of unstable atherosclerotic plaques prone to acute luminal thrombosis. Moreover, a negative CCS does not exclude the presence of coronary atherosclerosis which mostly consists of a single vessel disease with exhuberant intimal fibrocellular proliferation devoid of lipids.