Methylprednisolone and Endothelial Dysfunction in Cardiac Surgery: A Pilot Randomized Trial

Cardiac surgery involving cardiopulmonary bypass (CPB) serves as a clinical model of ischemia-reperfusion injury and endothelial dysfunction. Endothelial injury is often manifested clinically by vasoplegia and microcirculatory disturbances. The administration of a single dose of corticosteroids at the time of anesthesia induction has been hypothesized to exert a protective effect.

In this parallel-group, randomized, controlled single-center trial, patients scheduled for elective cardiac surgery with CPB were assigned to receive intravenous methylprednisolone or placebo at anesthesia induction. The primary outcome was the occurrence of endothelial dysfunction, assessed using flow-mediated dilation (FMD) during a vascular occlusion test. Secondary outcomes included peripheral tissue reperfusion slope measured by near-infrared spectroscopy (NIRS StO₂) and syndecan-1 levels, variations of FMD, NIRS StO₂, and syndecan-1 over time, and the correlation between the three measurements.

Thirty-nine patients were assigned to receive either methylprednisolone (n = 20) or placebo (n = 20). Maximal post-CPB median FMD was 5.7% (IQR: 3.4%-7.0%) in the methylprednisolone group and 4.7% (2.2%-6.6%) in the placebo group (difference: 0.60, 95% CI: -1.5 to 2.7; p = 0.57). On the first postoperative day, median FMD was 6.9% (3.6%-9.8%) in the methylprednisolone group and 8.1% (4.3%-11.6%) in the placebo group (difference: -1.0, 95% CI: -3.6 to 1.6; p = 0.46). No other significant differences between groups were observed for other measurements. A significant correlation was found between the severity of FMD alteration and syndecan-1 levels (r = 0.21, p = 0.03).

Methylprednisolone did not significantly affect CPB-associated endothelial dysfunction markers in elective cardiac surgery patients. Nevertheless, a correlation between syndecan-1 levels and the peak arterial dilation suggests a link between the severity of glycocalyx damage and vascular reactivity.

Glycocalyx damage has been associated with impaired vascular reactivity. This pilot trial assessed methylprednisolone effect on flow-mediated arterial dilation and also tissue oxygen saturation during a vascular occlusion test as well as syndecan-1 levels, these in an elective cardiac surgical cohort, to see if a single steroid dose could limit cardiopulmonary bypas-related endothelial dysfunction. Single steroid dose here did not effect the main outcome, flow mediated areterial dilation, in this cohort.