Aims: Although peak exercise echocardiography has been reported for both bicycle and treadmill exercise and has shown higher sensitivity than post-exercise imaging, little is known about its utility for identifying multivessel involvement. We sought to compare feasibility and accuracy of peak treadmill exercise echocardiography vs post-exercise echocardiography for identification of multivessel coronary artery disease and to assess its incremental value when combined with clinical and exercise test variables.
Methods and results: The study group included 335 patients (228 men; mean (+/- SD) age 60 +/- 11 years). Two hundred and seventy-nine patients were included on the basis of having had an exercise echocardiography and a coronary angiography within 4 months of the exercise test. To avoid bias to coronary angiography, a subgroup of 56 consecutive non-diabetic patients referred for exercise echocardiography with pretest probability of coronary artery disease <10% and had atypical chest pain or were asymptomatic were also included and considered as having no coronary artery disease. Multivessel coronary artery disease (> or = 50% diameter stenosis in >1 vessel) was confirmed in 170 patients, whereas 165 patients were considered to have one-vessel coronary artery disease or no coronary lesions. Positive exercise echocardiography was defined as ischaemia or necrosis in at least two coronary territories. Post-exercise images were acquired within 125 s after exercise (49 +/- 15). Mean heart rate (bpm) was 139 +/- 19 at peak vs 117 +/- 22 at post-exercise imaging (P<0.001). Interpretable peak and post-exercise images were obtained for all patients. Sensitivity for predicting multivessel disease was higher with peak than with post-exercise imaging (79 vs 55%, P<0.001), with lower specificity (79 vs 88%, P<0.05). Predictive positive value was similar (80 vs 83%). Negative predictive value was again higher with peak imaging (78 vs 66%, P<0.01). Total accuracy was not different (79 vs 72%). A stepwise logistic regression analysis identified peak exercise echocardiography positivity for multivessel coronary artery disease as the strongest independent predictor of multivessel disease (odds ratio (OR): 7.36); also significant were male gender (OR: 4.22), diabetes mellitus (OR: 4.28), previous myocardial infarction (OR: 3.12) and increment of product heart rate x blood pressure (OR: 1.00).
Conclusions: Peak treadmill exercise echocardiography is technically feasible and has higher sensitivity and negative predictive value for predicting multivessel disease than post-treadmill exercise echocardiography. This method adds independent and incremental values to clinical and exercise variables for the diagnosis of multivessel coronary artery disease. Therefore, in the clinical setting, peak exercise echocardiography should be performed to diagnose multivessel coronary artery disease.