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

Abstract

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. 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. 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. 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.