Lower Levels of Vitamin D Are Associated with Higher Vasoactive-Inotropic Scores in Major Cardiac Surgery

Abstract

Background: The vasoactive-inotropic score (VIS) predicts unfavorable outcomes after cardiac surgery in both children and adults. In our adult population, we investigated whether preoperative levels of vitamin D can predict the VIS and whether both vitamin D and the VIS can predict adverse outcomes following major heart surgery.

Methods: Between 1 October 2021 and 28 February 2022, 300 patients underwent major cardiac surgery at our institution. Eighty-three of them had their 25-OH vitamin D levels measured before surgery. For this cohort, we calculated the VIS based on doses of vasoactive and inotropic medications administered post-surgery. Utilizing receiver operating curves, the predictive accuracy of vitamin D levels and the VIS in predicting acute kidney injury was assessed.

Results: The median age of the cohort was 66 (IQR 61-71) years, with 59% being male and a median BMI of 28.4 (IQR 25.2-31.6). The most common procedures were aortic valve replacement, mitral valve replacement, coronary artery bypass grafting, aortic valve and ascending aorta repair, and ASD correction. There was a significant difference in the postoperative VIS between patients with vitamin D deficiency, i.e., <20 ng/mL, and patients with vitamin D values > 20 ng/mL (3.5 vs. 1.3 p < 0.04). We also found a significant correlation between the VIS and the days of hospitalization (r = 0.335; p = 0.002), the days of stay in the intensive care unit (r = 0.547; p < 0.00001), and the mechanical ventilation time (r = 0.327; p = 0.025). Both vitamin D levels and the VIS predicted postoperative acute kidney injury (p < 0.05).

Conclusions: Vitamin D deficiency is correlated with the VIS in adults undergoing major cardiac surgery. Both vitamin D levels and the VIS can predict unfavorable postoperative outcomes.

Keywords: cardiopulmonary bypass; major cardiac surgery; renal failure; vasoactive–inotropic score; vitamin D.

Figure 1

Receiver operator curves for vitamin D and VIS as predictors of postoperative acute kidney injury. (a) Vitamin D levels predict postoperative acute kidney injury—AUC: 0.662. A value of 15.5 ng/mL predicts development of renal failure with a sensitivity of 78% and specificity of 56%. (b) VIS predicts postoperative acute kidney injury—AUC: 0.61. A value of 2 ng/mL predicts development of acute kidney injury with a sensitivity of 61% and specificity of 56%.