Abstract 2005: Coronary Calcium Score by Multislice Computer Tomography Does Not Predict Atherosclerotic Plaques at Risk of Sudden Death in the Young
Purpose- Coronary calcium score (CCS) assessed by multislice computed tomography (MSCT) has been demonstrated to predict coronary events beyond standard risk factors. Our aim was to assess CCS as screening tool to detect atherosclerotic coronary artery disease at risk of sudden death (SD) in young people.
Methods- Among 80 consecutive young victims of coronary SD, formalin fixed hearts were available for ex vivo 16 slice MSCT (LightSpeed Plus, GE Company, Milwakee, WI, USA) in 60 patients (M/F=54/6), age range 19 –39 (mean 31±4.7). Twenty older patients with coronary SD (age range 44 –76, mean 59±12, M/F=17/3 ) were used for comparison. CCS was evaluated by Agatston and volume scoring methods. Serial sections investigation of major coronary arteries and staining with H&E, trichrome and von Kossa was performed.
Results-In young coronary SD victims, single vessel disease was found in 42 (70%), the left anterior descending branch was the most frequently involved vessel (56, 93%) and plaques mostly consisted of fibrocellular intimal hyperplasia (35, 42%). Acute thrombosis did occur in 27 (45%) -either by rupture (8, 30%) or erosion (19, 70%)-, whereas 33 patients (55%) showed fibrocellular intimal proliferation in the absence of thrombosis. By comparing young and older SD victims, a multivessel disease was detected in 18 (30%) vs 16 (80%), fibroatheromasic plaques with lipid core in 25 (42%) vs 20 (100%), luminal thrombosis was due to cap rupture in 8 (30%) vs 20 (100%) (all P<0.0001). Coronary calcium was detected by MSCT in 20% of young and in 65% of older patients (P<0.0001), with a mean CCS of 15 Agatston (volume score 13) and 269 Agatston (volume score 316), respectively. In the young, a positive CCS was exceptional under the age of 30 (4% vs 32% >30 yrs) and its was present in 67% with multivessel vs none with single vessel disease; and in 10% with erosion vs 87% with rupture (all P<0.001).
Conclusions- While CCS is a strong predictor of coronary artery disease extent and increases with age, a negative CCS in the young does not exclude the presence of atherosclerotic plaques at risk of SD which mostly consists of a single vessel disease due to fibrocellular intimal proliferation. Moreover, CCS it is not a marker of unstable atherosclerotic plaques prone to luminal thrombosis.