Clinical question: Does CT angiography (CTA) improve clinical outcomes in patients with new-onset stable chest pain more than functional testing?
Background: Chest pain is a common clinical problem, and multiple noninvasive tests are available to detect coronary artery disease (CAD). CT angiography is more accurate than noninvasive testing and may decrease unnecessary invasive testing and improve outcomes in patients with new-onset stable chest pain.
Study design: Pragmatic, comparative-effectiveness design.
Setting: One hundred ninety-three North American sites.
Synopsis: Ten thousand three symptomatic outpatients, mean age 60 years, with at least one cardiovascular risk factor, were randomized to CTA or functional testing to detect CAD. Primary endpoints including death, myocardial infarction, hospitalization for unstable angina, or major procedural complication occurred in 3.3% of CTA patients and 3.0% of functional testing patients (adjusted hazard ratio, 1.04; 95% confidence interval, 0.83 to 1.29; P=0.75). CTA patients received fewer catheterizations showing nonobstructive CAD (3.4% of versus 4.3%, P=0.02).
More CTA patients underwent catheterization within 90 days after randomization (12.2% vs 8.1%), however. Patients in the CTA group had higher exposures to radiation overall, but, per patient, their mean cumulative radiation dose was lower than that of the functional testing group (10.0 mSv vs. 11.3 mSv).
Interestingly, 6.2% of CTA patients versus 3.2% of functional testing patients underwent revascularization, but the study was not powered to assess invasive catheterization or revascularization rates on outcomes.
This study is interesting because results are generalizable to real-world settings; CTA did not improve outcomes compared to functional testing in patients undergoing testing for CAD.
Bottom line: No improvement was seen in clinical outcomes for symptomatic patients undergoing evaluation for CAD with CTA compared with those receiving functional testing.
Citation: Douglas PS, Hoffmann U, Patel MR, et al. Outcomes of anatomical versus functional testing for coronary artery disease. N Engl J Med. 2015;372(14):1291-1300.