Dr. Kaustubh Bondre, recently took to his IG handle to talk about heart health. He spoke about a patient who, despite having a normal ECG, and stress test insisted on getting a CT Angiography done, because he ‘saw it on a podcast.‘ Dr. Bondre added that the man was asymptomatic, and was simply driven by fear. Here is what a CT Angio is exactly, and why it is not always needed, as revealed by Dr. Bondre.Understanding ECG and Stress TestsAn electrocardiogram (ECG) tracks the heart’s electrical signals during brief periods, to identify abnormal heart rhythms, blockages, and indicators of previous heart injury. A typical ECG result helps doctors to exclude various urgent heart conditions. A stress test takes this further by challenging your heart with exercise on a treadmill or medication that mimics exercise, while monitoring for reduced blood flow (ischemia) through ECG changes, echocardiogram images of heart wall motion, or nuclear perfusion scans. When these tests come back normal, they predict a very low risk of major heart events, often less than 1% per year in stable patients. The test evaluates heart function through pressure tests to diagnose patients who experience continuous symptoms or need scheduled screenings. The test shows artery structures only when a medical issue appears during the evaluation.
Limits of normal test resultsThe tests provide complete diagnostic results, but do not detect all possible conditions. The system fails to detect 10-20% of important artery blockages, which include non-obstructive plaque that might lead to future complications. The stress ECG demonstrates sensitivity levels ranging from 47% to 68%, but it does not identify patients who have balanced blockages in multiple arteries, or who cannot perform sufficient exercise. The tests assess heart performance but do not detect the formation of artery plaques. Research shows that atherosclerosis develops in 50% of people who remain asymptomatic during stress tests. However, for patients with a low pretest probability of coronary artery disease (under 15% chance), a negative stress test confirms safety without needing CT Angio in most situations.What CT Angio reveals, and its downsidesThe imaging technique of CT angiography produces 3D images of coronary arteries through computed tomography scanning and intravenous contrast dye administration, enabling doctors to detect artery narrowing above 50% with 96% accuracy. The test reveals both the amount and specific type of plaque, which doctors use to select appropriate treatment options, including statins for stabilization. The system includes multiple useful elements which make up its structure. The radiation exposure levels span from 5 to 15 millisieverts, which equals 100 to 600 chest X-rays. This increases the risk of developing cancer throughout a person’s lifespan, with breast cancer, being the most significant risk for women at 1 in 1,000. Contrast dye used in medical procedures poses two major risks: allergic reactions and kidney damage, especially in patients with existing medical conditions. The test can also produce false negatives, affecting 20–30% of patients who receive incorrect test results, showing abnormal artery function thus leading to unnecessary catheter procedures. Research indicates that 40-60% of these procedures result in negative test outcomes.
When CT Angio is not neededThe medical team will not perform CT Angio when your ECG and stress test results show no issues, and you belong to a low-risk group for heart problems. The American College of Cardiology and American Heart Association provide guidelines stating that stable chest pain patients should begin with functional tests, like stress testing before doctors use CT Angio as their secondary diagnostic tool. The PROMISE trial conducted a large study evaluating CT Angio against stress testing for stable patients. It demonstrated that both methods produced equal results for major heart events but CT Angio required an additional invasive test, without providing any additional advantages. The SCOT-HEART trial demonstrated that CT Angio helps decrease the number of events occurring in patients with moderate to high risk, by detecting plaque that needs treatment at its initial stage. The additional radiation and higher costs of screening do not benefit people with low risk factors, because lifestyle modifications such as diet control, exercise and quitting smoking provide superior preventive measures.When CT Angio makes senseCT Angio becomes valuable for patients at intermediate or high risk, such as those with atypical chest pain, an abnormal ECG, diabetes, family history of early heart disease, or men over age 50 or women over age 60 with multiple risk factors. The test delivers its best results when stress test results show unclear or unusual patterns because it enables doctors to verify or eliminate blockages through non-invasive procedures before they perform cardiac catheterization. The CT Angio test provides a 94-99% negative predictive value, which enables doctors to confirm the absence of coronary artery disease without performing invasive medical procedures. The test provides essential information for non-heart surgery preoperative evaluation, and for patients who show persistent symptoms even though their functional tests show normal results, because it shows the extent of plaque buildup which standard tests cannot detect. The test delivers enough anatomical data to support its costs and risks which occur during these particular medical procedures.Balancing risks, and benefitsThe diagnostic performance of CT Angio remains excellent, but its application in patients with no ECG abnormalities and normal stress test results leads to radiation exposure, medical risks and expensive costs which do not enhance treatment results. The most effective method for decision-making involves doctors and patients working together to evaluate pretest probability, age and life expectancy and individual preferences regarding testing. The combination of lifestyle measures which includes heart-healthy eating, physical activity, weight management and risk control produces better long-term prevention results than any scanning method.
