Calcium imaging and selective computed tomography angiography in comparison to functional testing for suspected...

To compare the effectiveness and safety of a cardiac computed tomography (CT) algorithm with functional testing in patients with symptoms suggestive of coronary artery disease (CAD).

Between April 2011 and July 2013, 350 patients with stable angina, referred to the outpatient clinic of four Dutch hospitals, were prospectively randomized between cardiac CT and functional testing (2 : 1 ratio). The tiered cardiac CT protocol included a calcium scan followed by CT angiography if the Agatston calcium score was between 1 and 400. Patients with test-specific contraindications were not excluded from study participation. By 1 year, fewer patients randomized to cardiac CT reported anginal complaints (P = 0.012). The cumulative radiation dose was slightly higher in the CT group (6.6 ± 8.7 vs. 6.1 ± 9.3 mSv; P < 0.0001). After 1.2 years, event-free survival was 96.7% for patients randomized to CT and 89.8% for patients randomized to functional testing (P = 0.011). After CT, the final diagnosis was established sooner (P < 0.0001), and additional downstream testing was required less frequently (25 vs. 53%, P < 0.0001), resulting in lower cumulative diagnostic costs (€369 vs. €440; P < 0.0001).

For patients with suspected stable CAD, a tiered cardiac CT protocol offers an effective and safe alternative to functional testing. Incorporating the calcium scan into the diagnostic workup was safe and lowered diagnostic expenses and radiation exposure.