Poor Preoperative Left Ventricular Function is Associated With Decreased Insulin Sensitivity During Cardiac Surgery

ObjectiveTo investigate the association between preoperative left ventricular ejection function (LVEF) and whole-body insulin sensitivity during cardiac surgery.DesignA prospective, non-randomized trial.SettingA tertiary care hospital setting.ParticipantsPatients undergoing elective cardiac surgery.InterventionsConsenting, non-diabetic patients scheduled for elective cardiac surgery requiring cardiopulmonary bypass (CPB) were assigned either to a group with normal LVEF (EF≥55%) or one with low LVEF (EF≤45%) as assessed by coronary angiography. Insulin sensitivity was assessed by the hyperinsulinemic-normoglycemic clamp technique before and towards the end of CPB. The association between LVEF and insulin sensitivity was tested using Student t-test.ResultsOne hundred forty patients were studied, with 48 patients in the low and 92 patients in the normal LVEF group. Patient demographics were similar in both groups except for preoperative LVEF (p<0.001). Before CPB, patients with normal LVEF showed higher insulin sensitivity when compared to patients with low LVEF (p = 0.04). Insulin sensitivity decreased towards the end of CPB (p<0.001) in both groups, resulting in similar values.ConclusionsPoor preoperative left ventricular function is associated with reduced insulin sensitivity before the onset of CPB in cardiac surgery.