Use of Coronary Computed Tomographic Angiography to Guide Management of Patients With Coronary Disease

Abstract

Background: In a prospective, multicenter, randomized controlled trial, 4,146 patients were randomized to receive standard care or standard care plus coronary computed tomography angiography (CCTA).

Objectives: The purpose of this study was to explore the consequences of CCTA-assisted diagnosis on invasive coronary angiography, preventive treatments, and clinical outcomes.

Methods: In post hoc analyses, we assessed changes in invasive coronary angiography, preventive treatments, and clinical outcomes using national electronic health records.

Results: Despite similar overall rates (409 vs. 401; p = 0.451), invasive angiography was less likely to demonstrate normal coronary arteries (20 vs. 56; hazard ratios [HRs]: 0.39 [95% confidence interval (CI): 0.23 to 0.68]; p < 0.001) but more likely to show obstructive coronary artery disease (283 vs. 230; HR: 1.29 [95% CI: 1.08 to 1.55]; p = 0.005) in those allocated to CCTA. More preventive therapies (283 vs. 74; HR: 4.03 [95% CI: 3.12 to 5.20]; p < 0.001) were initiated after CCTA, with each drug commencing at a median of 48 to 52 days after clinic attendance. From the median time for preventive therapy initiation (50 days), fatal and nonfatal myocardial infarction was halved in patients allocated to CCTA compared with those assigned to standard care (17 vs. 34; HR: 0.50 [95% CI: 0.28 to 0.88]; p = 0.020). Cumulative 6-month costs were slightly higher with CCTA: difference $462 (95% CI: $303 to $621).

Conclusions: In patients with suspected angina due to coronary heart disease, CCTA leads to more appropriate use of invasive angiography and alterations in preventive therapies that were associated with a halving of fatal and non-fatal myocardial infarction. (Scottish COmputed Tomography of the HEART Trial [SCOT-HEART]; NCT01149590).

Keywords: angina pectoris; invasive coronary angiography; myocardial infarction; preventive therapy.

Figure 1

Timing of Noninvasive and Invasive Coronary Angiography Cumulative events from clinic consultation to the conduct of: (A) coronary computed tomography angiography (CCTA) in patients receiving the trial intervention, (B) invasive coronary angiography by trial allocation, and (C) new invasive coronary angiography consequent on the CCTA findings. Hazard ratio: 1.06 (95% confidence interval: 0.92 to 1.22); p = 0.451 for rates of invasive coronary angiography between CCTA + standard care and standard care alone. Orange line indicates CCTA + standard care. Blue line indicates standard care alone.

Figure 2

Timing of Initiation of New Preventive Therapies Cumulative events from clinic consultation to the dispensing of: (A) antiplatelet therapy (hazard ratio: 12.17 [95% confidence interval: 7.52 to 19.71]; p < 0.0001) and (B) statin therapy (hazard ratio: 3.49 [95% confidence interval: 2.63 to 4.42]; p < 0.0001), according to trial allocation. Orange line indicates coronary computed tomography angiography + standard care. Blue line indicates standard care alone.

Figure 3

Fatal and Nonfatal Myocardial Infarction With and Without the 50-Day Implementation Delay Cumulative fatal and nonfatal myocardial infarction over 3 years of follow-up (A) including (26 vs. 42; hazard ratio: 0.62 [95% confidence interval: 0.38 to 1.01]; p = 0.0527) and (B) excluding (17 vs. 34; hazard ratio: 0.50 [95% confidence interval: 0.28 to 0.88]; p = 0.0202) the first 50 days after clinic consultation. Orange line indicates coronary computed tomography angiography + standard care. Blue line indicates standard care alone.

Central Illustration

Clinical Effect of CCTA in Suspected Angina Pectoris: Coronary Heart Disease Death and Nonfatal Myocardial Infarction Post hoc landmark analysis at 50 days to account for the implementation and treatment delay consequent on the conduct, reporting, and communication of the coronary computed tomography angiography (CCTA) findings. HR = hazard ratio.