Functional testing after coronary artery bypass graft surgery: A meta-analysis

BACKGROUND: A number of studies have examined the diagnostic abilities of various functional tests to assess graft stenosis or the progression of coronary artery disease after coronary artery bypass graft (CABG) surgery. However, a meta-analysis of these studies has not been performed. OBJECTIVES: To pool the results of studies examining the diagnostic abilities of exercise treadmill testing (ETT), stress myocardial perfusion imaging and stress echocardiography to predict graft stenosis or progression of disease in the native circulation post-CABG. METHODS: A MEDLINE search was conducted to identify studies examining post-CABG functional testing for the diagnosis of graft stenosis or progression of native disease. Sensitivities and specificities of these studies were pooled, and predictive values and likelihood ratios were calculated. RESULTS: A pooled analysis demonstrates that for the identification of graft stenosis or progression of native disease, ETT alone has a sensitivity of 45% (95% CI 36% to 54%) and a specificity of 82% (95% CI 68% to 95%). The use of stress myocardial perfusion imaging increased the sensitivity to 68% (95% Cl 51% to 86%) and specificity to 84% (95% CI 78% to 91%). The use of stress echocardiography also resulted in an increased sensitivity of 86% (95% CI 78% to 94%) and specificity of 90% (95% Cl 84% to 95%). CONCLUSION: If post-CABG functional testing is performed, stress ventricular imaging is superior to ETT alone for the diagnosis of graft stenosis or progression of disease in the native vessels.