The American College of Radiology Imaging Network (ACRIN) has activated a multicenter clinical trial to evaluate the effect of cardiac CT angiography (CCTA) and single photon emission tomography myocardial perfusion imaging (SPECT-MPI) on outcomes in patients with stable angina.
Known as RESCUE (Randomized Evaluation of Patients with Stable Angina Comparing Utilization of Noninvasive Examinations), the study addresses the hypothesis that, in comparison to SPECT-MPI, CCTA will not result in an increase of myocardial infarction, cardiac-related death or revascularization; offer reduced risks to patients (eg, less radiation exposure); provide additional insights into alternate explanations of chest pain and prove more cost-effective.
A total of 4,300 study participants will be enrolled at up to 80 institutions internationally and randomly assigned to one of the two diagnostic imaging procedures. Participants diagnosed with coronary artery disease (CAD) by either CCTA or SPECT-MPI examination will be treated initially by optimal medical therapy (OMT), unless these diagnostic tools show evidence of significant left main coronary artery CAD (greater than 50% stenosis) on CCTA or a markedly abnormal stress test with SPECT-MPI (greater than 10% reversible perfusion defect). In these cases, they will undergo invasive coronary angiography (ICA) and possibly revascularization as is standard practice. Participants will be followed to collect health care utilization data, cardiac events, and quality-of-life questionnaires.
The RESCUE trial is being conducted through the ACRIN Cardiovascular Committee and is funded by the Agency for Healthcare Quality and Research. Committee chair, Pamela K. Woodard, MD (Washington University) explains, “Comparison of the effectiveness of CCTA and conventional angiography in assessing patients at moderate risk of CAD is a research priority highlighted in the 2009 Institute of Medicine’s report: Initial National Priorities for Comparative Effectiveness Research,” explained Committee Chair Pamela K. Woodard, MD, of Washington University. The trial “holds significant promise to improve clinical care.”
Principal investigator Arthur Stillman, MD, PhD, of Emory University, corroborated Woodard’s comments, adding that with traditional SPECT-MPI, patients with a positive test for CAD will require ICA to determine if they can safely be treated with OMT. However, he noted “recent research suggests that CCTA alone (also) has the potential to determine which patients can be treated with OMT,” in a non-invasive manner and at a lower cost.