Does cardiopulmonary exercise testing improve the diagnostic accuracy for detecting exercise-induced myocardial ischaemia compared to standard ECG stress testing in patients with documented CAD?
The addition of gas exchange analysis (CPET) significantly improves the sensitivity and specificity of standard ECG stress testing for detecting exercise-induced myocardial ischemia in patients with CAD.
BACKGROUND: The objective of the study was to identify the parameter(s) of cardiopulmonary exercise testing (CPET) that can detect exercise-induced myocardial ischaemia (EIMI), and to determine its diagnostic accuracy for identifying patients with coronary artery disease (CAD). METHODS AND RESULTS: We prospectively studied 202 consecutive patients (173 men, 29 women, mean age 55.7+/-10.8 years) with documented CAD. All patients underwent an incremental exercise stress testing (ECG-St) with breath-by-breath gas exchange analysis, followed by a 2-day stress/rest gated SPECT myocardial scintigraphy (GSMS) as the gold standard for ischaemia detection. ROC analysis selected a two-variable model-O(2)pulse flattening duration, calculated from the onset of myocardial ischaemia to peak exercise, and deltaVO(2)/deltawork rate slope-to predict EIMI by CPET. GSMS identified 140 patients with reversible myocardial defects, with a Summed Difference Score (SDS) of 9.7+/-2.8, and excluded EIMI in 62 (SDS 1.3+/-1.6). ECG-St had low sensitivity (46%) and specificity (66%) to diagnose EIMI as compared with CPET (87% and 74%, respectively). CONCLUSIONS: The addition of gas exchange analysis improves the diagnostic accuracy of standard ECG stress testing in identifying EIMI. A two-variable model based on O(2)pulse flattening duration and deltaVO(2)/deltawork rate slope had the highest predictive ability to identify EIMI.
Romualdo Belardinelli (2003) studied this question.