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[Value of the stress test in patients with coronary spasm]
Insights
Stress testing in patients with coronary artery spasm effectively correlates with coronary anatomy. ST depression during exercise is a strong indicator of underlying coronary stenosis, proving particularly useful for diagnosing patients with angina at rest.
Area of Science:
- Cardiology
- Diagnostic Imaging
- Exercise Physiology
Context:
- Coronary artery spasm presents diagnostic challenges.
- Early and accurate diagnosis is crucial for managing coronary artery disease.
- Stress testing is a common non-invasive tool for evaluating cardiac function.
Purpose:
- To evaluate the correlation between bicycle stress test results and coronary anatomy in patients with documented coronary spasm.
- To determine the diagnostic value of ST segment shifts during stress testing for identifying coronary stenosis.
- To assess the utility of stress testing in different angina presentations.
Summary:
- Ninety-one patients with coronary spasm underwent bicycle stress testing prior to coronary angiography.
- ST depression during stress testing showed high specificity (89% positive predictive value) for underlying coronary lesions.
- Stress testing demonstrated a strong correlation with coronary anatomy and was particularly useful for patients with angina at rest.
Impact:
- ST depression on stress tests is a significant predictor of coronary stenosis in patients with spasm.
- Stress testing provides valuable prognostic information, especially in patients experiencing angina at rest.
- This study refines the application of stress testing in the etiological diagnosis of coronary artery spasm.
Unlabelled:
Ninety-one consecutive patients with angiographically documented spasm who performed a bicycle stress test within one week before diagnostic coronary angiography are studied. Stress test induced ST elevation in 8 patients (9%), ST depression in 37 (41%) and no ST shifts in 46 (50%). ST response to exercise did not correlate with any of the clinical variables assessed except for coronary anatomy. ST depression was a highly specific sign of underlying coronary lesions, with a high positive predictive value (89%). Patients were stratified according to the type of angina and their post-test probability of significant coronary disease was calculated following Bayes' theorem. The post-test likelihoods of significant coronary stenosis (positive and negative test, respectively) were: 82 and 37% for patients with angina at rest; 90 and 53% for those with effort angina, and 98 and 85% for those with mixed angina.
In Conclusion:
1) stress testing in patients with coronary spasm correlates well with coronary anatomy; 2) ST depression strongly suggests the presence of underlying coronary stenosis; 3) stress testing is especially useful in patients with angina exclusively at rest.