Chadi Ayoub1,2, Yeung Yam1, Li Chen3, Punitha Arasaratnam1, Clara K Chow2, Graham S Hillis2,4, Leonard Kritharides2,5, Benjamin J W Chow1,6. 1. 1 Department of Medicine (Cardiology), University of Ottawa Heart Institute, ON, Canada. 2. 2 University of Sydney, New South Wales, Australia. 3. 3 Cardiovascular Research Methods Centre, University of Ottawa Heart Institute, ON, Canada. 4. 4 Department of Cardiology, Royal Perth Hospital, University of Western Australia. 5. 5 Department of Cardiology, Concord Hospital, Sydney Local Health District, New South Wales, Australia. 6. 6 Department of Radiology, University of Ottawa, ON, Canada.
Abstract
BACKGROUND: Total plaque score (TPS) on coronary computed tomography angiography (CCTA) has been validated as a surrogate measure of coronary artery disease (CAD) burden and is prognostic. We propose a novel measure, percentage TPS adjusted to age (%TPS/age), that may reflect vascular age and potentially more rapidly progressive atherosclerosis and evaluate its potential prognostic value. METHODS: %TPS/age was calculated for consecutive patients prospectively enrolled into our institutional CCTA registry and evaluated for primary composite outcome of cardiac death, nonfatal myocardial infarction, and late revascularization. RESULTS: Of 1896 patients identified (mean age 57.7 ± 11.4 years, 50.1% male, median follow-up 18.6 months [interquartile range: 15.3, 32.4]), 552 (29%) had %TPS/age = 0 (no atherosclerosis), with 1 (0.2%) primary outcome observed (annual event rate [AER] = 0.1%). Two events (0.4%, AER = 0.3%) were observed in %TPS/age < 0.314 category, 22 (5.0%, AER = 2.2%) in %TPS/age 0.314 to 0.699 category, and 54 (12.0%, AER = 5.7%) in %TPS/age ≥ 0.700 category. After adjusting for clinical predictors and obstructive CAD, higher %TPS/age category was associated with hazard ratio 1.95 (1.31-2.88, P < .001) for primary outcome on multivariable analysis, Harrell-C-Statistic 0.87 (confidence interval 95%: 0.84-0.90), and net reclassification improvement of 0.71 ( P < .001). CONCLUSION: %TPS/Age has incremental prognostic value to traditional risk factors and CCTA measures of CAD and improves evaluation of burden of coronary atherosclerosis and clinical risk.
BACKGROUND: Total plaque score (TPS) on coronary computed tomography angiography (CCTA) has been validated as a surrogate measure of coronary artery disease (CAD) burden and is prognostic. We propose a novel measure, percentage TPS adjusted to age (%TPS/age), that may reflect vascular age and potentially more rapidly progressive atherosclerosis and evaluate its potential prognostic value. METHODS: %TPS/age was calculated for consecutive patients prospectively enrolled into our institutional CCTA registry and evaluated for primary composite outcome of cardiac death, nonfatal myocardial infarction, and late revascularization. RESULTS: Of 1896 patients identified (mean age 57.7 ± 11.4 years, 50.1% male, median follow-up 18.6 months [interquartile range: 15.3, 32.4]), 552 (29%) had %TPS/age = 0 (no atherosclerosis), with 1 (0.2%) primary outcome observed (annual event rate [AER] = 0.1%). Two events (0.4%, AER = 0.3%) were observed in %TPS/age < 0.314 category, 22 (5.0%, AER = 2.2%) in %TPS/age 0.314 to 0.699 category, and 54 (12.0%, AER = 5.7%) in %TPS/age ≥ 0.700 category. After adjusting for clinical predictors and obstructive CAD, higher %TPS/age category was associated with hazard ratio 1.95 (1.31-2.88, P < .001) for primary outcome on multivariable analysis, Harrell-C-Statistic 0.87 (confidence interval 95%: 0.84-0.90), and net reclassification improvement of 0.71 ( P < .001). CONCLUSION: %TPS/Age has incremental prognostic value to traditional risk factors and CCTA measures of CAD and improves evaluation of burden of coronary atherosclerosis and clinical risk.
Entities:
Keywords:
atherosclerosis; cardiac CT; prognosis; total plaque score; vascular age