The time-dependent prognostic value of coronary computed tomography angiography in symptomatic patients

Abstract Funding Acknowledgements Type of funding sources: Public grant(s) – National budget only. Main funding source(s): State Research Funding for Turku University Hospital. Background Coronary computed tomography angiography (CCTA) is recommended for diagnostic workup of coronary artery disease (CAD) and is known to provide prognostic information. However, it is unknown whether there is time-dependent variation in the prognostic strength of CCTA. Purpose To study the time-varying prognostic value of CCTA in patients with suspected CAD. Methods From two academic medical centers, we identified symptomatic patients who underwent CCTA for suspected CAD. A composite endpoint of all-cause mortality and myocardial infarction was recorded. The prognostic value of non-obstructive or obstructive (≥50%) CAD was assessed by Cox proportional hazard model. The prognostic power of the model according to the cumulative length of follow-up was evaluated by measuring area under the receiver operating characteristic (ROC) curve (AUC) as a function of follow-up time (time-dependent AUC). Results A total of 2662 patients (age 61 ± 10 years, 45% male) were included, with 247 adverse events (9%) during a median follow-up time of 6.9 years (25th–75th percentile 4.9–8.8 years; maximum 13.3 years). Based on CCTA, 804 (30%) patients had no CAD, 963 (36%) had non-obstructive CAD, and 895 (34%) had obstructive CAD. The presence of non-obstructive CAD (adjusted HR 2.24; p = 0.002) or obstructive CAD (adjusted HR 4.42; p<0.001) were independent predictors of adverse outcome. The predictive power of CCTA findings was relatively stable until 10 years of follow-up time, as demonstrated in the Figure showing time-dependent AUC of the adjusted model (solid line) with 95% confidence intervals (dashed lines). A model including only clinical variables is shown for comparison. Conclusion Coronary CTA findings retain their prognostic value in at least 10-year follow-up of symptomatic patients evaluated for suspected CAD.