Predictive factors of inotropic support in myocardial revascularization surgery

OBJECTIVES: The use of perioperative inotropics in myocardial revascularization surgery can be considered a marker of ventricular dysfunction, the etiology of which involves a variety of pre- and intraoperative factors. Knowledge of the risk factors and their relative importance can allow them to be modified for improved outcome. This study aims to determine the incidence of and factors that predict the need for inotropic support in order to finalize extracorporeal circulation and in the first 6 hours after myocardial revascularization. PATIENTS AND METHODS: Two hundred forty-two patients who underwent myocardial revascularization were studied retrospectively. The parameters collected were age, sex, NYHA classification, left ventricular telediastolic pressure at baseline and after contrast, ejection fraction, collateral circulation, number of distal anastomoses, time of clamping, time of extracorporeal circulation, need for inotropic support to end extracorporeal circulation and during the first 6 hours after surgery. RESULTS: Inotropics were used in 27.6% of the sample. The need for inotropic support was related to female sex (odds ratio [OR] 3.85 with 95% confidence interval [CI], 1.56-9.49); NYHA class III (OR 2.13 with 95% CI, 1.05-4.32) or IV (OR 10.16 with 95% CI, 3.22-32.13); low injection fraction (OR 2.41 with 95% CI, 1.22-4.76); and prolonged extracorporeal circulation (OR 2.97 with 95% CI, 1.54-5.76). CONCLUSIONS: The independent variables associated with the need for inotropic support during the perioperative period in myocardial revascularization are NYHA functional class III and IV, female sex, low injection fraction and prolonged extracorporeal circulation. New techniques for myocardial protection during extracorporeal circulation, plus adequate peroperative stabilization of patients and shorter time of extracorporeal circulation will probably diminish short term morbidity in revascularization surgery.