Improved diagnosis of post-operative myocardial infarction by contrast echocardiography after coronary artery bypass graft surgery

OBJECTIVE: Contrast echocardiography is a more accurate means of assessment of left ventricular (LV) regional motion compared with non-enhanced echocardiography. Despite new tests, the diagnosis of post-operative myocardial infarction (MI) remains difficult. The aim of this study was to determine whether contrast echocardiography can facilitate this diagnosis. METHODS: We performed standard and contrast echocardiography in 79 consecutive patients before and up to 10 days after they underwent isolated coronary artery bypass graft (CABG) surgery. RESULTS: The post-operative intra- and interobserver reproducibility of echocardiographic measurements of the LV ejection fraction and wall motion score was significantly higher with than without contrast enhancement. The proportion of non-visualized LV myocardial segments was significantly greater with non-enhanced (6.6%) than with contrast (0.3%) echocardiography (P< 0.0001). The mean peak serum cardiac troponin (cTnI) concentration was significantly higher in the group of patients with new wall motion abnormalities detected with contrast-enhanced echocardiography. A correlation was found (r = -0.43, P< 0.01) between peak cTnI and changes in wall motion score only when a contrast agent was used. CONCLUSION: Contrast echocardiography facilitated the detection of new LV wall motion abnormalities after CABG. This observation, added to other markers, might facilitate the diagnosis of post-operative MI.