Objectives
To evaluate the diagnostic performance and predictive value of coronary computed tomography angiography (CCTA) on subsequent cardiac outcomes.
Background
CCTA has been suggested as an alternative method to invasive coronary angiography for detection of and ruling out coronary artery disease (CAD). However, the usefulness of CCTA findings in predicting patient outcome in routine clinical practice is still uncertain.
Materials and methods
A prospective, multicenter registry study of CCTA with a Visipaque injection 320 mg I/ml was carried out in symptomatic patients suspected of having CAD as part of their medical care. CCTA findings were used to guide patient management decisions. Patient cardiac outcomes were followed at 1, 6, and 12 months after the CCTA procedure for the occurrence of major adverse cardiac event (MACE) (cardiac death, nonfatal myocardial infarction, or unstable angina requiring hospitalization). All cardiac outcome events or deaths were adjudicated independently.
Results
Of 874 patients (mean age=59 years; 51% men) who received Visipaque, 857 were included in the efficacy analysis. Using cardiac outcomes as the endpoint, the sensitivity of CCTA was 96.1, 95.8, and 94.7%, specificity was 84.5, 86.6, and 87.0%, and negative predictive value more than 99.0% at 1, 6, and 12 months, respectively. At 12 months, the rate of MACE was 5.7% (10/174) in patients with a positive CCTA (one or more ≥50% stenosis) and 0.1% (1/683) in patients with a negative CCTA (99.9% MACE-free survival rate). The Cox proportional hazards analysis with CCTA outcome, age, sex, reasons for CCTA, and cardiac risk factors as covariates showed a hazard ratio of 87.6 for positive versus negative CCTA (P=0.0001).
Conclusion
CCTA is a highly accurate, noninvasive tool to detect or rule out subsequent cardiovascular events in patients with intermediate pretest probability of CAD or an uninterpretable/equivocal stress test. A positive CCTA finding contributed significantly toward the prediction of subsequent MACE whereas a negative CCTA carried excellent prognostic outcomes at 12 months.
