Background: The utility of exercise echocardiography for evaluating remote ischemia due to noninfarct-related artery (n-IRA) lesions in patients with prior myocardial infarction has not been established.
Methods: Quantitative coronary angiography and treadmill exercise echocardiography were performed within 2 weeks in 115 patients with prior myocardial infarction (>6 weeks) and 224 patients without myocardial infarction. Coronary lumen diameter stenosis > or =50% (by angiography) and the lack of a hyperdynamic response on exercise echocardiography were considered significant. Myocardial infarction size was defined as the number of myocardial segments with severe hypokinesis, akinesis, or dyskinesis on echocardiography at rest.
Results: For detection of n-IRA lesions in patients with prior myocardial infarction, the sensitivity of exercise echocardiography was similar (78% vs 79%, P = not significant), however, the specificity was significantly lower (77% vs 91%, P <.01) than for detection of significant stenoses in patients without prior myocardial infarction. Angiographic percent-diameter stenosis, presence of collateral vessel, achieved exercise level, and presence of peri-infarct ischemia did not affect the specificity of exercise echocardiography. However, the specificity of exercise echocardiography was significantly lower (69% vs 84%, P <.05) in patients with echocardiographically large infarction (infarction size > or =2) than in patients with small infarction (infarction size <2).
Conclusion: In patients with prior myocardial infarction, exercise echocardiography showed low specificity for detection of noninfarct-related artery lesions, especially in patients with echocardiographically large myocardial infarction. These characteristics of treadmill exercise echocardiography should be considered when this technique is applied for patients with healed myocardial infarction.