The value of Coronary Artery computed Tomography as the first-line anatomical test for stable patients with indications for invasive angiography due to suspected Coronary Artery Disease: CAT-CAD randomized trial

Background: The aim of this prospective, randomized trial was to evaluate whether the use of coronary computed tomography angiography (CCTA) as the first-line anatomical test in patients with suspected significant coronary artery disease (CAD) may reduce the number of coronary invasive angiographies (ICA), and expand the use of CCTA in patients currently diagnosed invasively. Methods: 120 patients (age:60.6 +/- 7.9 years, 35% female) with indications to ICA were randomized 1:1 to undergo CCTA versus direct ICA. Outcomes were evaluated during the diagnostic and therapeutic periods. Results: The number of invasively examined patients was reduced by 64.4% in the CCTA group as compared to the direct ICA group (21vs59,p < 0.0001). The number of patients with ICAs not followed by coronary intervention was reduced by 88.1% with the CCTA strategy (5vs42,p < 0.0001). Over the diagnostic and therapeutic course there were no significant differences regarding the median volume of contrast (CCTA 80.3 ml [65.0-165.0] vs ICA 90.0 ml[55.0-100.0], p = 0.099), while a non-significant trend towards higher radiation dose in the CCTA group was observed (9.9 mSv[7.0-22.1] vs 9.4 mSv[5.2-14.0], p = 0.05). There were no acute cardiovascular events. Conclusions: CCTA may hypothetically act as an effective 'gatekeeper' to the catheterization laboratory in the diagnosis of stable patients with current indications for ICA. This strategy may result in non-invasive, outpatient-based triage of two thirds of individuals without actionable CAD, obviating unnecessary invasive examinations. However, the longer follow-up is indispensable.