Risk factors of postcardiotomy ventricular dysfunction in moderate-to-high risk patients undergoing open-heart surgery.

INTRODUCTION: Ventricular dysfunction requiring inotropic support frequently occurs after cardiac surgery, and the associated low cardiac output syndrome largely contributes to postoperative death. We aimed to study the incidence and potential risk factors of postcardiotomy ventricular dysfunction (PCVD) in moderate-to-high risk patients scheduled for open-heart surgery.

METHODS: Over a 5-year period, we prospectively enrolled 295 consecutive patients undergoing valve replacement for severe aortic stenosis or coronary artery bypass surgery who presented with Bernstein-Parsonnet scores >7. The primary outcome was the occurrence of PCVD as defined by the need for sustained inotropic drug support and by transesophageal echography. The secondary outcomes included in-hospital mortality and the incidence of any major adverse events as well as Intensive Care Unit (ICU) and hospital length of stay.

RESULTS: The incidence of PCVD was 28.4%. Patients with PCVD experienced higher in-hospital mortality (12.6% vs. 0.6% in patients without PCVD) with a higher incidence of cardiopulmonary and renal complications as well as a prolonged stay in ICU (median + 2 days). Myocardial infarct occurred more frequently in patients with PCVD than in those without PCVD (19 [30.2%] vs. 12 [7.6%]). By logistic regression analysis, we identified four independent predictors of PCVD: left ventricular ejection fraction <40% (odds ratio [OR] = 6.36; 95% confidence interval [CI], 2.59-15.60), age older than 75 years (OR = 3.35; 95% CI, 1.64-6.81), prolonged aortic clamping time (OR = 3.72; 95% CI, 1.66-8.36), and perioperative bleeding (OR = 2.33; 95% CI, 1.01-5.41). The infusion of glucose-insulin-potassium was associated with lower risk of PCVD (OR = 0.14; 95% CI, 0.06-0.33).

CONCLUSIONS: This cohort study indicates that age, preoperative ventricular function, myocardial ischemic time, and perioperative bleeding are predictors of PCVD which is associated with poor clinical outcome.