Cardioprotection with Intralipid During Coronary Artery Bypass Grafting Surgery on Cardiopulmonary Bypass: A Randomized Clinical Trial

Abstract

Purpose: Coronary artery bypass grafting (CABG) on cardiopulmonary bypass (CPB) is associated with myocardial ischemia-reperfusion injury (IRI), which may limit the benefit of the surgery. Both experimental and clinical studies suggest that Intralipid, a lipid emulsion commonly used for parenteral nutrition, can limit myocardial IRI. We therefore aimed to investigate whether Intralipid administered at reperfusion can reduce myocardial IRI in patients undergoing CABG on CPB.

Methods: We conducted a randomized, double-blind, pilot trial in which 29 adult patients scheduled for CABG were randomly assigned (on a 1:1 basis) to receive either 1.5 ml/kg Intralipid 20% or Ringer's Lactate 3 min before aortic cross unclamping. The primary endpoint was the 72-h area under the curve (AUC) for troponin I.

Results: Of the 29 patients randomized, 26 were included in the study (two withdrew consent and one was excluded before surgery). The 72-h AUC for troponin I did not significantly differ between the control and Intralipid group (546437 ± 205518 versus 487561 ± 115724 arbitrary units, respectively; P = 0.804). Other outcomes (including 72-h AUC for CK-MB, C-reactive protein, need for defibrillation, time to extubation, length of ICU and hospital stay, and serious adverse events) were similar between the two groups.

Conclusion: In patients undergoing CABG on CPB, Intralipid did not limit myocardial IRI compared to placebo.

Trial registration: ClinicalTrials.gov Identifier: NCT02807727 (registration date: 16 June 2016).

Keywords: Cardioprotection; Coronary artery bypass grafting; Intralipid; Ischemia–reperfusion injury.

Fig. 1

Experimental protocol of the study. MLR: Modified Lactate’s Ringer; ICU: intensive care unit

Fig. 2

Flow chart of the study. LEVF: Left ventricle ejection fraction

Fig. 3

Assessment of myocardial injury (cardiac troponin I). Geometric means and 95% confidence intervals of cardiac troponin I levels in blood are presented for the Control group (orange circles) and the Intralipid group (blue squares) at baseline and 1, 6, 9, 12, 24, 48, and 72 h after unclamping the aorta

Fig. 4

Assessment of myocardial injury (CK-MB). Geometric means and 95% confidence intervals of CK-MB levels in blood are presented for the Control group (orange circles) and the Intralipid group (blue squares) at baseline and 1, 6, 9, 12, 24, 48, and 72 h after unclamping the aorta