Prognostic Value of Left Ventricular Myocardial Performance Index in Patients Undergoing Coronary Artery Bypass Graft Surgery

Background: Left ventricular myocardial performance index is a Doppler-derived parameter of nongeometrical ventricular function that measures both systolic and diastolic function of the left ventricle. The objective of this study was to compare prognostic value of left ventricular myocardial performance index with global left ventricle function in patients undergoing coronary artery bypass graft surgery. Methods: One hundred consecutive patients who underwent coronary artery bypass graft surgery for coronary artery disease were studied from March 2004 through September 2006. Recovery of global left ventricle function and left ventricular myocardial performance index were measured serially by Doppler echocardiography after coronary artery bypass graft surgery. The patients were under supervision for four months after discharging from hospital. We studied the incidence of atrial fibrillation, postoperative myocardial infarction, pericardial and pleural effusion, infection, and also ventilation time and intensive care unit stay. For analysis of the events, we divided the patients into two groups. Group A was considered with left ventricle ejection fraction of <40% and group B had a left ventricle ejection fraction of >40%. Results: Global left ventricle ejection fraction and left ventricular myocardial performance index were not related to pericardial effusion, pleural effusion, and postoperative infection. In group A, left ventricular myocardial performance index had more prognostic value for prediction of incidence of atrial fibrillation rhythm and postoperative myocardial infarction than the global left ventricle ejection fraction. But global left ventricle ejection fraction had more prognostic value for ventilation time and intensive care unit stay in comparison with left ventricular myocardial performance index. These associations were not seen in group B. Conclusion: The prognostic effect of left ventricular myocardial performance index was no more than global left ventricle ejection fraction in early and late complications of coronary artery bypass graft surgery but only affirm global left ventricle ejection fraction in some situations.