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The variable extent of jeopardized myocardium in patients with single vessel coronary artery disease: quantification
J J Mahmarian1, C M Pratt, T M Boyce
1Department of Internal Medicine, Methodist Hospital, Baylor College of Medicine, Houston, Texas 77030.
Insights
Severe coronary artery stenosis significantly increases jeopardized myocardium, especially in the left anterior descending artery. Moderate stenosis, however, typically results in smaller perfusion defects, regardless of location.
Area of Science:
- Cardiology
- Nuclear Medicine
- Medical Imaging
Background:
- Single vessel coronary artery disease affects myocardial perfusion.
- Assessing jeopardized myocardium is crucial for patient management.
Purpose of the Study:
- To evaluate the relationship between coronary artery stenosis severity and location with myocardial perfusion defects.
- To quantify the extent of jeopardized myocardium in single vessel coronary artery disease.
Main Methods:
- Quantitative exercise thallium-201 single photon emission computed tomography (SPECT) in 158 patients.
- Analysis of computer-generated polar maps to quantify left ventricular perfusion defects.
- Correlation of stenosis severity and location with perfusion defect size.
Main Results:
- Severe stenosis (≥70%) was associated with larger perfusion defects (≥10% LV) compared to moderate stenosis (51%-69%).
- Perfusion defect size correlated modestly with stenosis severity, particularly in the left anterior descending artery.
- Left anterior descending artery stenosis, especially proximal, caused larger defects than right or circumflex stenosis.
Conclusions:
- Stenosis severity is a key determinant of jeopardized myocardium in single vessel coronary artery disease.
- The left anterior descending artery plays a critical role in left ventricular perfusion.
- Significant heterogeneity in perfusion defects exists, even with comparable stenosis severity.
Abstract:
To assess the extent of jeopardized myocardium in patients with single vessel coronary artery disease of variable severity and location, quantitative exercise thallium-201 single photon emission computed tomography was performed in 158 consecutive patients with angiographically proved single vessel coronary artery disease. The extent of abnormal left ventricular perfusion was quantified from computer-generated polar maps of three-dimensional myocardial radioactivity. Patients with only a moderate (51% to 69%) stenosis tended to have a small perfusion defect irrespective of the coronary artery involved. Whereas a perfusion defect measuring greater than or equal to 10% of the left ventricle was found in 78% of patients with no prior infarction and severe (greater than or equal to 70%) stenosis, this was observed in only 24% of patients with moderate stenosis. Perfusion defect size increased with increasing severity of stenosis for the entire group without infarction and for those with left anterior descending, right and circumflex coronary artery stenosis. However, the correlation between stenosis severity and perfusion defect size was at best only modest (r = 0.38, p = 0.0001). The left anterior descending artery was shown to be the most important of the three coronary arteries for providing left ventricular perfusion. Proximal stenosis of this artery produced a perfusion defect approximately twice as large as that found in patients with a proximal right or circumflex artery stenosis. However, marked heterogeneity in perfusion defect size existed among all three vessels despite comparable stenosis severity. This was most apparent for the left anterior descending coronary artery, where mid vessel stenosis commonly produced a perfusion defect similar in size to that found in proximally stenosed vessels.(ABSTRACT TRUNCATED AT 250 WORDS)