Is a treadmill stress test better than a coronary computed tomography angiography (CTA) scan?

From the Guidelines

Treadmill stress testing is the preferred initial test for evaluating heart disease in patients who can exercise adequately, due to its lower cost, lack of radiation exposure, and ability to correlate symptoms with exertion, as supported by the 2024 AHA/ACC guideline 1. When considering the choice between treadmill stress testing and coronary computed tomography (CT) scans, it's essential to weigh the benefits and drawbacks of each test. Treadmill stress testing is ideal for evaluating functional capacity and exercise-induced symptoms, while coronary CT scans provide better anatomical information about coronary artery blockages.

Key Considerations

• The 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes recommends the standard low-level exercise electrocardiographic stress test as the most reasonable test in patients who are able to exercise and have a resting ECG that is interpretable for ST shifts 1.
• The 2024 AHA/ACC guideline highlights the cost-value considerations for coronary computed tomography angiography, noting that it has been associated with increased interventional coronary angiography and greater healthcare costs versus functional stress testing 1.
• The PROMISE trial evaluated CCTA versus functional testing in symptomatic patients with suspected CAD and reported that CCTA did not improve clinical outcomes versus functional testing over a median of 2 years follow-up 1.

Test Selection

The choice between treadmill stress testing and coronary CT scans should be individualized based on the patient's specific clinical situation, risk factors, and diagnostic questions being addressed.

• Treadmill stress testing is suitable for patients who can exercise adequately, while coronary CT scans are more appropriate for patients unable to exercise, those with equivocal stress test results, or when detailed anatomical information is needed.
• The standard Bruce protocol involves stages of increasing speed and incline every 3 minutes while monitoring ECG, blood pressure, and symptoms.
• CT scans require administration of contrast dye and involve radiation exposure but can detect coronary artery disease even before it causes symptoms or stress test abnormalities.

From the Research

Comparison of Treadmill Stress Test and Coronary Computed Tomography Angiography (CCTA)

• The diagnostic sensitivity and specificity of exercise testing using ST-segment changes alone were 45% and 63%, respectively, whereas the inclusion of all test variables yielded a sensitivity of 72% and a specificity of 37% 2.
• Coronary CTA demonstrated superior diagnostic performance with a sensitivity of 97% and a specificity of 80% for the detection and exclusion of significant coronary artery disease (CAD) 2.
• A study comparing exercise treadmill testing (ETT) and coronary CTA found that ETT was inconclusive in 23% of patients, positive in 31%, and negative in 46%, while CTA demonstrated no CAD in 37%, non-obstructive CAD in 28%, and obstructive CAD in 35% 3.
• The study also found that among low-risk ETT patients, there were 3 MI, 10 late revascularizations, and the frequent presence of non-obstructive (32%) and obstructive CAD (27%) 3.

Prognostic Value of Coronary CTA vs. Exercise Treadmill Testing

• A study found that coronary CTA can provide incremental risk stratification for future cardiovascular events in patients with an intermediate- to high-risk ETT (DTS <5) 3.
• Another study found that noninvasive stress testing, functional capacity, chest pain with exercise, and Duke Treadmill Score (DTS) are not associated with anatomic or functional CAD using a diagnostic strategy of coronary CTA and fractional flow reserve (FFR) 4.
• A systematic review and meta-analysis found that CCTA is associated with a reduced incidence of myocardial infarction but an increased incidence of invasive coronary angiography, revascularization, CAD diagnoses, and new prescriptions for aspirin and statins compared to functional stress testing 5.

Cost-Effectiveness of Coronary CTA

• A study found that performing coronary CTA before cardiac catheterization is a cost-effective strategy in the care of patients without symptoms who have positive stress test results when the probability that the patient has significant coronary artery disease is less than 50% 6.
• The study also found that coronary CTA can avoid many unnecessary cardiac catheterization procedures and result in an average cost saving of $789 per patient with a false-negative rate of 2.5% and average additional radiation exposure of 1-2 mSv 6.