Tissue Doppler imaging is useful for predicting the need for inotropic support after cardiac surgery

Abstract

Low preoperative left ventricular ejection fraction (EF) is a predictor of the need for inotropic support after cardiac surgery. However, EF can be misinterpreted and difficult to measure in some cases. The purpose of this study was to compare the value of preoperative EF and intraoperative tissue Doppler imaging variables in predicting the need for postoperative inotropic support. Forty-eight consecutive adult patients undergoing cardiac surgery were enrolled in this study. Systolic mitral annular velocity (S(m)), early diastolic mitral annular velocity (E(m)), the ratio of E(m) to late diastolic mitral annular velocity (E(m)/A(m)), and the ratio of early diastolic transmitral velocity to E(m) (E/E(m)) were measured using transesophageal echocardiography before median sternotomy. The primary outcome was the need for inotropic support for 12 or more hours after surgery. Preoperative, intraoperative, and echocardiographic characteristics were analyzed to determine the independent predictors of the need for postoperative inotropic support. Postoperative inotropic support was required for ≥12 h in 26.7% of patients. Multivariate logistic regression identified only cardiopulmonary bypass (CPB) time as an independent predictor of inotropic support (odds ratio, 1.015; 95% CI, 1.004-1.025; P = 0.004). Additional analysis was performed in the 25 patients with a CPB time of ≥200 min. In this analysis, only S(m) was significantly associated with the need for inotropic support for ≥12 h. This study suggests that those patients who have decreased S(m) and extended CPB times are more likely to require inotropic support after surgery, independent of a preserved left ventricular EF.