Vitamin D status and the risk of major adverse cardiac and cerebrovascular events in cardiac surgery

Aims: A significant proportion of cardiac surgical patients develop critical post-operative complications. We aimed to investigate the association of pre-operative 25-hydroxyvitamin D (25(OH)D) levels with major cardiac and cerebrovascular events (MACCE) in cardiac surgical patients.

Methods and results: From January 2010 to August 2011, we consecutively measured circulating 25(OH)D in 4418 operated patients. Of the study cohort, 38.0% had deficient 25(OH)D values (<30 nmol/L) and additional 32.3% had insufficient values (30-49.9 nmol/L), whereas only 3.1% had values >100 nmol/L. The incidence of MACCE was 11.5%. In multivariable-adjusted logistic regression models, the odds ratio of MACCE at deficient, inadequate, and high 25(OH)D levels was 2.23 [95% confidence interval (CI): 1.31-3.79], 1.73 (95% CI: 1.01-2.96) and 2.34 (95% CI: 1.12-4.89), respectively, compared with 25(OH)D levels of 75-100 nmol/L. A U-shaped association with circulating 25(OH)D was also present for duration of mechanical ventilatory support and intensive care unit stay. Multivariable-adjusted 6- and 12-month mortality were higher in patients with deficient 25(OH)D levels compared with patients with 25(OH)D levels of 75-100 nmol/L.

Conclusion: Deficient 25(OH)D levels are prevalent in cardiac surgical patients in Central Europe and are independently associated with the risk of MACCE. Further research should clarify the potential of vitamin D supplements in reducing cardiovascular risk in vitamin D-deficient patients and also the mechanisms leading to adverse effects on the cardiovascular system in the small group of patients with 25(OH)D levels >100 nmol/L.