P2242Prognostic impact of CT derived quantified coronary artery plaque volume: A 10 year follow-up study

Abstract

Abstract Background Automated plaque quantification derived from coronary CT angiogragphy (CCTA) datasets provides exact and reliable assessment of coronary atherosclerosis burden. Purpose To investigate the long-term predictive value of quantified coronary plaque volume (PV) in comparison to Calcium Score (CACS). Methods Dedicated software was used to quantify PV in 1577 patients. A combination of cardiac death and acute coronary syndrome was used as endpoint. Incremental prognostic value was tested with c-statistics and continuous net reclassification improvement (NRI). The Morise Score was used to summarize patients clinical risk profile. Results Patients were followed for 10.4 years. The combined endpoint occurred in 59 patients, of whom 36 suffered from cardiac death, 18 had non-fatal myocardial infarction and 5 presented with unstable angina requiring revascularisation. The additive predictive value of PV and CACS was tested against a baseline model (c-index 0.741) including clinical risk and the number of diseased coronary segments (segment-Involvement score). While PV provided additive prognostic value (rise in c-index to 0.763, p=0.01 and NRI 0.247, p=0.03), CACS did not (c-index 0.749, p=0.2 and NRI 0.162, p=0.12). A threshold of 110.5 mm3, which was established by a previous analysis of our group, provided excellent separation of patients into low (no PV), intermediate (PV <110.5 mm3) and high (PV >110.5 mm3) risk categories based upon quantified PV (see attached Figure). Conclusion Quantification of PV from CCTA datasets provides excellent prognostic information on long-term follow-up.