A novel marker of cardiovascular risk stratification: the role of total cardiovascular calcium score using cardiac CT

Abstract Introduction It is widely accepted that coronary and valve calcification measured by cardiac CT, individually, are associated with cardiovascular events and mortality. However, the role of an encompassing marker of cardiovascular atherosclerosis could be more representative of the real cardiovascular risk. Objectives To determine the prognostic value of a combined coronary, valvular and aortic calcium score to predict long-term major adverse cardiac and cerebrovascular events (MACCE). Methods We conducted a single center study on 316 consecutive patients who underwent cardiac CT scan between January 2018 and December 2019. We excluded patients with poor imaging quality, constrictive pericarditis, prosthetic valves and/or devices. The calcium score of coronary arteries (CA), mitral valve (MV), aortic valve (AoV), ascending aorta (AAo) and aortic arch (AAc) were calculated from non-contrast ECG-gated CT using the Agatston method and were combined to derive a valvular (VA=MV+AoV), total cardiac (TC=CA+VA) and total cardiovascular (TCV=TC+AAo+AAc) calcium scores (Fig.1A). The primary endpoint was a composite of MACCE, defined as all-cause death, stroke, myocardial infarction and hospital admission for heart failure. Results A total of 275 CT scans were suitable for analysis. Mean age was 59.6±12.3 years, 48.4% were female. A total of 183 (66.7%) patients presented calcification in at least one location. Patients with calcification on any of the prespecified locations had higher prevalence of hypertension, dyslipidemia and type 2 diabetes mellitus (DM) than those without any calcium (p<0.05). After a median follow-up of 3.18 [IQR 2.84-3.69] years, 40 (14.5%) patients had met the primary endpoint. Regression analyses demonstrated that all CA, VA, TC and TCV scores were independent predictors of MACCE (p<0.05 for all). The best prediction models included calcium score (all combinations), age, sex, type 2 DM and smoking status (Fig.1B). The model with TCV score was the most powerful predictor of MACCE (χ2 47.8), followed by TC score (χ2 43.1). Of interest, the model with CA score had the poorest performance (χ2 35.4). Conclusion Coronary calcium score is a quick way to stratify risk in clinical practice, but its performance is too focused on coronary events. Total cardiovascular calcium score, however, is more encompassing, also quick to measure, and a more truthful depiction of the patient’s cardiac and cerebrovascular risk, potentially allowing a more tailored and timely approach to risk factors in clinical practice.