Cardiac computed tomographic angiography after abnormal ischemia test as a gatekeeper to invasive coronary angiography

This study aimed to determine the impact of systematic coronary computed tomographic angiography (CCTA) use following an abnormal non-invasive ischemia test (NIST) on patient selection strategy for invasive coronary angiography (ICA). In patients with suspected stable coronary artery disease (CAD), NIST use frequently results in sub-optimal diagnostic and revascularization yields of ICA. This randomized clinical trial, conducted at a single academic tertiary center, selected 220 symptomatic patients with mild-to-moderately abnormal NIST results who were referred for ICA. Patients received either the originally intended ICA (n = 105) or CCTA (n = 115). The primary endpoint was the diagnostic yield of ICA in each group. Revascularization yield and major adverse cardiovascular events at 12 months were also assessed. The patients were 69 ± 9 years old, 60% were men, and 31% had typical angina. Mean pre-test probability of obstructive CAD was 34%. Overall prevalence of obstructive CAD was 37.7% on the index angiographic procedure. In the CCTA group, ICA was cancelled by referring physicians in 83 patients (72.2%) after receiving CCTA results. For those undergoing ICA, diagnostic (84.4% vs. 41.7%, p<0.001) and revascularization (71.9% vs. 38.8%, p = 0.001) yields were significantly higher for CCTA-guided ICA than for standard NIST-guided ICA. Mean cumulative radiation exposure was significantly lower in the CCTA-guided ICA arm than in the NIST-guided ICA arm (12 ± 9 vs. 16 ± 10 mSv, respectively, p = 0.024). There were no significant differences in the primary safety endpoint rates between the strategies (p = 0.439). In patients with suspected CAD and mild-to-moderately abnormal ischemia tests, a diagnostic strategy including CCTA as a gatekeeper is safe and effective and significantly improves diagnostic and revascularization yields of ICA.