Coronary Computed Tomography Angiography Compared With Single Photon Emission Computed Tomography Myocardial Perfusion Imaging as a Guide to Optimal Medical Therapy in Patients Presenting With Stable Angina: The RESCUE Trial

Abstract

Background The RESCUE (Randomized Evaluation of Patients with Stable Angina Comparing Utilization of Noninvasive Examinations) trial was a randomized, controlled, multicenter, comparative efficacy outcomes trial designed to assess whether initial testing with coronary computed tomographic angiography (CCTA) is noninferior to single photon emission computed tomography (SPECT) myocardial perfusion imaging in directing patients with stable angina to optimal medical therapy alone or optimal medical therapy with revascularization. Methods and Results The end point was first major adverse cardiovascular event (MACE) (cardiac death or myocardial infarction), or revascularization. Noninferiority margin for CCTA was set a priori as a hazard ratio (HR) of 1.3 (95% CI=0, 1.605). One thousand fifty participants from 44 sites were randomized to CCTA (n=518) or SPECT (n=532). Mean follow-up time was 16.2 (SD 7.9) months. There were no cardiac-related deaths. In patients with a negative CCTA there was 1 acute myocardial infarction; in patients with a negative SPECT examination there were 2 acute myocardial infarctions; and for positive CCTA and SPECT, 1 acute myocardial infarction each. Participants in the CCTA arm had a similar rate of MACE or revascularization compared with those in the SPECT myocardial perfusion imaging arm, (HR, 1.03; 95% CI=0.61-1.75) (P=0.19). CCTA segment involvement by a stenosis of ≥50% diameter was a better predictor of MACE and revascularization at 1 year (P=0.02) than the percent reversible defect size by SPECT myocardial perfusion imaging. Four (1.2%) patients with negative CCTA compared with 14 (3.2%) with negative SPECT had MACE or revascularization (P=0.03). Conclusions There was no difference in outcomes of patients who had stable angina and who underwent CCTA in comparison to SPECT as the first imaging test directing them to optimal medical therapy alone or with revascularization. CCTA was a better predictor of MACE and revascularization. Registration Information URL: https://www.clinicaltrials.gov/. Identifier: NCT01262625.

Keywords: angina; cardiovascular imaging; coronary computed tomography angiography; coronary revascularization; ischemia; nuclear medicine.

Figure 1. RESCUE (Randomized Evaluation of Patients with Stable Angina Comparing Utilization of Noninvasive Examinations) Schema and Consolidated Standards of Reporting Trials (CONSORT) diagram.

A, Patients with symptoms of stable angina were randomized to receive either CCTA or SPECT‐MPI. Diagnostic ICA was performed in select patients according to the schema. All were followed for MACE/revascularization. B, CONSORT diagram. There were 1050 patients who were randomized (518 CCTA, 532 SPECT‐MPI). CCTA was performed in 473 and SPECT‐MPI was performed in 464. There were 401 patients for CCTA and 378 patients for SPECT‐MPI for evaluation of the secondary end point. CAD indicates coronary artery disease; CCS, Canadian Cardiovascular Society; CCTA, coronary computed tomographic angiography; ICA, invasive coronary angiography; LMD, Left main disease; MACE, major cardiovascular events; OMT, optimal medical therapy; and SPECT‐MPI, single photon emission computed tomography myocardial perfusion imaging.

Figure 2. Receiver operating characteristic curves show a trend towards improved prediction of the composite end point of major cardiovascular events and revascularization at 1 year using the modified Duke score compared with percent reversible defect.

AUC indicates area under the curve; CCTA, coronary computed tomographic angiography; and SPECT, single photon emission computed tomography.

Figure 3. Proximal and LAD segments for CCTA were significantly better predictors for the composite end point of major adverse cardiovascular event and revascularization than percent reversible defect (Rdefect).

AUC indicates area under the curve; CCTA, coronary computed tomographic angiography; LAD, left anterior descending artery; and SPECT, single photon emission computed tomography.