From the Guidelines
An abnormal stress test is a significant indicator of potential coronary artery disease and necessitates immediate consultation with a cardiologist to discuss further diagnostic steps and management options. The most recent and highest quality study, 1, emphasizes the importance of recognizing that moderate to severe abnormalities on stress tests predict an annual risk for cardiovascular death or MI rates of 5% or higher.
Key Considerations
- If you've received an abnormal result, contact your doctor immediately to discuss next steps, which typically include additional cardiac testing such as a coronary angiogram, cardiac CT, or nuclear imaging to determine the extent of any blockages.
- While awaiting further evaluation, consider starting aspirin 81mg daily unless contraindicated, and statin therapy such as atorvastatin 20-40mg daily if your cholesterol is elevated, as suggested by general cardiovascular guidelines.
- Modify risk factors by maintaining blood pressure below 130/80 mmHg, controlling diabetes with a target HbA1c below 7%, stopping smoking, exercising moderately for 30 minutes daily as tolerated, and following a heart-healthy diet low in saturated fats.
- Recognize warning signs requiring emergency care: chest pain lasting more than a few minutes, pain radiating to the arm or jaw, shortness of breath, nausea, lightheadedness, or cold sweats.
Management Approach
Based on the evidence from 1 and considering the principles of managing patients with suspected coronary artery disease, the management approach should focus on risk stratification and reduction of modifiable risk factors. For patients who cannot exercise, pharmacologic stress testing with imaging is a valuable tool for assessing the risk of subsequent cardiac events, as noted in 1.
Pharmacologic Stress Testing
- The use of a pharmacologic stressor with imaging, such as nuclear myocardial perfusion imaging with a vasodilator, accurately assesses the risk for subsequent events in patients with stable ischemic heart disease, with an annualized event rate of 1.6% observed in patients with a normal study result compared with 10.6% in patients with a severely abnormal result, as reported in 1.
- Stress echocardiography with dobutamine also accurately classifies patients into high- and low-risk categories, with a normal dobutamine echocardiogram associated with a risk for an adverse cardiac event of 1% to 2%, as indicated in 1.
Clinical Decision Making
Clinical decision making should be guided by the principle of minimizing morbidity, mortality, and improving quality of life. Given the potential for significant morbidity and mortality associated with untreated coronary artery disease, an abnormal stress test should prompt aggressive management and risk factor modification, as generally recommended in cardiovascular practice guidelines, including those referenced in 1.
From the Research
Abnormal Stress Test Overview
- An abnormal stress test result can be caused by various factors, including coronary artery disease, and may not always be associated with angiographically significant coronary artery disease 2.
- The outcomes of patients with false-positive stress test results are similar to those with true-positive results, suggesting that patients with false-positive results should still receive intensive risk factor management and careful clinical follow-up 2.
Types of Stress Tests
- There are several types of stress tests, including electrocardiographic exercise stress test, myocardial imaging exercise stress test, and myocardial imaging pharmacological stress tests 3.
- Nuclear imaging stress test is a preferable modality in women, and exercise-based stress tests provide evaluations of functional capacity, as well as blood pressure and heart rate recovery rate 3.
Interpretation of Abnormal Stress Test Results
- The interpretation of abnormal stress test results can be challenging, especially when the results are discordant with cardiac imaging 4.
- A meta-analysis of published studies found that patients with discordant results (abnormal stress electrocardiography with normal cardiac imaging) were more likely to suffer from major adverse cardiovascular events, such as all-cause death or myocardial infarction 4.
Clinical Implications
- The choice of stress test modality depends on the patient's characteristics and medications, and different exercise protocols are available depending on the patient's clinical status 3.
- Patients with abnormal stress test results should be carefully evaluated and managed, taking into account the prognostic impact of the stress test results 2, 4.