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Identification of high-risk patients with left main and three-vessel coronary artery disease using stepwise
A S Iskandrian1, J Heo, J Lemlek
1Philadelphia Heart Institute, Presbyterian Medical Center, PA 19104.
Insights
This study identified key predictors for detecting high-risk patients with three-vessel or left main coronary artery disease. Exercise thallium imaging, combined with discriminant analysis, effectively stratifies patients based on disease severity.
Area of Science:
- Cardiology
- Medical Imaging
- Biostatistics
Background:
- Accurate detection of high-risk coronary artery disease (CAD) is crucial for patient management.
- Coronary artery disease, particularly three-vessel or left main disease, carries a significant risk of adverse cardiac events.
- Non-invasive diagnostic tools are essential for identifying patients requiring aggressive treatment strategies.
Purpose of the Study:
- To evaluate the efficacy of stepwise discriminant analysis using clinical, exercise, and thallium tomographic data in identifying high-risk patients.
- To determine the independent predictors of three-vessel or left main coronary artery disease.
- To develop a risk stratification model for patients undergoing coronary artery evaluation.
Main Methods:
- A large-scale study involving 834 patients, categorized into high-risk (three-vessel or left main disease) and lower-risk groups.
- Multivariate stepwise discriminant analysis was applied to clinical, exercise stress test, and thallium-201 tomographic imaging data.
- Patient data included demographics, exercise parameters (heart rate, blood pressure, ST depression), and thallium scan results (abnormality extent, perfusion defects, lung uptake).
Main Results:
- Three independent predictors for high-risk disease were identified: multivessel thallium abnormality, exercise heart rate, and ST segment depression during exercise.
- A risk stratification model using these three variables categorized patients into groups with 53%, 24%, and 12% prevalence of left main or three-vessel disease.
- Thallium tomographic data demonstrated significantly higher predictive power compared to clinical or treadmill exercise data alone.
Conclusions:
- Stepwise discriminant analysis of exercise thallium tomographic imaging is a powerful tool for identifying high-risk patients with three-vessel or left main coronary artery disease.
- The developed model allows for effective risk stratification, aiding in clinical decision-making.
- Exercise thallium imaging provides superior diagnostic information for detecting severe coronary artery disease compared to traditional exercise testing.
Abstract:
This large-scale study examined the ability of stepwise discriminant analysis of clinical, exercise, and thallium tomographic data to detect high-risk patients with three-vessel or left main disease. There were 834 patients, 229 with three-vessel or left main disease (group 1) and 605 (group 2) with either two-vessel disease (n = 236), one-vessel disease (n = 195), or no coronary artery disease (n = 174). The two groups were different in age, exercise heart rate, ST segment depression during exercise, exercise systolic blood pressure, abnormal thallium scans, reversible perfusion defects, extent of thallium abnormality, number of vascular territories with perfusion abnormalities, left ventricular cavity dilatation, and increased lung thallium uptake. On multivariate stepwise discriminant analysis, only three variables were independent predictors of high risk. These included multivessel thallium abnormality (F = 107, p < 0.001), exercise heart rate (F = 27, p < 0.001), and ST segment depression (F = 8, p < 0.01). Based on these three variables, patients could be stratified into three categories with different prevalences of left main or three-vessel disease; the prevalence was 53% in 239 patients, 24% in 271 patients, and 12% in 324 patients. Thus high-risk patients with left main or three-vessel disease can be identified by exercise thallium tomographic imaging that uses a model based on stepwise discriminant analysis. The thallium data are far more powerful than the clinical or treadmill exercise data.