Background: The predictive value of coronary computed tomographic angiography (cCTA) in subjects without chest pain syndrome (CPS) has not been established. We investigated the prognostic value of coronary artery disease (CAD) detection by cCTA, and determined the incremental risk classification of cCTA findings as compared to clinical risk factor scoring and coronary artery calcium scoring (CACS) for individuals without CPS.
Methods and Results: An open-label, 12-center, 6-country observational registry of 27,125 consecutive patients undergoing cCTA and CACS was queried, and 7,590 individuals without CPS or history of CAD met the inclusion criteria. All-cause mortality and composite outcome of all-cause mortality and non-fatal MI were measured.
During a mean follow-up of 26 짹 11 months, all-cause mortality occurred in 136 individuals. After risk adjustment, compared to individuals without cCTA evidence of CAD, individuals with obstructive 2-vessel disease (VD) and 3-VD or left main CAD experienced a increased risk of death and composite outcome (P<.05 for all) (Figure1). The C statistics of Framingham risk score (FRS) plus cCTA extent of obstructive CAD was significantly increased compared to FRS alone (0.699 vs. 0.609, respectively, P<.001), but not significantly different from FRS plus CACS (0.709, P=.395). Further, compared to FRS plus CACS, FRS plus cCTA extent of obstructive CAD did not demonstrate significant net reclassification improvement (0.063, P=.748) or integrated discrimination improvement (-0.006, P<.001).
Conclusion: While risk stratification for individuals without CPS is observed by cCTA measures of obstructive CAD, cCTA does not improve the classification of risk when compared to risk model based upon CACS. Based upon the present findings, use of cCTA for risk assessment of individuals without CPS is not justified.