Coronary CT Angiography versus Stress Testing

Patients with suspected coronary artery disease (CAD) are increasingly being diagnosed using coronary computed tomography angiography (CCTA). This new technology provides anatomic information that differs from the functional information available through stress testing using electrocardiography (ECG). Among Medicare beneficiaries, the number of CCTA procedures has grown from 38,171 in 2006, when the procedure was first reimbursed, to 78,009 in 2008. According to researchers, there have been few studies that examined healthcare utilization and spending among patients evaluated in the outpatient setting for suspected CAD who have received CCTA versus stress testing. In addition, the impact of CCTA on healthcare use and spending in an older population and over a long period is not known. The researchers recently designed a study to compare healthcare utilization and Medicare expenditures of patients who were initially evaluated for CAD in the outpatient setting using either CCTA or stress testing (myocardial perfusion scintigraphy [MPS], stress echocardiography, or exercise ECG). They reported study results in the Journal of the American Medical Association [2011;306(19):2128-2136]. The final study cohort included 282,830 patients. Current Procedural Terminology codes were used to identify patient receipt of CCTA, stress echocardiography, exercise ECG or pharmacologic stress test, and MPS. The most commonly used diagnostic test was MPS (46.8% [n=132,343]), followed by stress echocardiography (28.5% [n=80,604]), exercise ECG (21.6% [n=61,063]), and CCTA (3.1% [n=8820]). Median age of the study cohort was 73.6 years, 46% were male, and 89% were white. Compared with patients undergoing MPS, those undergoing CCTA were somewhat younger and had fewer comorbid conditions, including Framingham risk factors (diabetes, tobacco abuse, hyperlipidemia, hypertension). Compared with patients undergoing stress echocardiography or exercise ECG, those undergoing CCTA were somewhat older and had more comorbid conditions. In the year prior to the index test, patients undergoing CCTA had lower mean healthcare spending compared with patients undergoing MPS ($10,984 vs $11,606; P<.001), but had higher mean spending than patients undergoing stress echocardiography ($8636) or exercise ECG ($7467). In the 180-day follow-up period following the index test, 7.4% of the cohort underwent additional noninvasive testing, 11.1% underwent cardiac catheterization, 4.6% underwent coronary revascularization (3.1% percutaneous coronary intervention and 1.6% coronary artery bypass graft surgery), 0.37% were hospitalized for acute MI, and 1.1% died. Additional noninvasive testing was performed more often following CCTA than after MPS (5.0% vs 3.2%), but less frequently than after an exercise ECG (19.3%). Patients who underwent CCTA were nearly twice as likely to undergo subsequent cardiac catheterization compared with patients who underwent MPS, and approximately 2.5 times as likely to undergo coronary revascularization. Mean total spending was higher among patients undergoing CCTA ($4200; P<.001), which was almost entirely attributable to payments for any claims for CAD ($4007). Compared with MPS, there was lower associated spending with stress echocardiography (–$4981; P<.001) and exercise ECG (–$7449; P<.001). In summary, the researchers noted, “Medicare beneficiaries who underwent CCTA in a nonacute setting were more likely to undergo subsequent invasive cardiac procedures and have higher CAD-related spending than patients who underwent stress testing.”