Research presented at the Society of Critical Care Medicine meeting reports that vitamin D deficiency before coronary artery bypass graft surgery predicts risk of mortality after 3 months.
Coronary artery bypass grafting (CABG) is a surgery which helps improve blood flow to the heart. CABG is used to treat people who have severe coronary heart disease.
Takuhiro Moromizato, MD, of Brigham and Women’s Hospital in Boston, and colleagues found that patients with vitamin D deficiency or insufficiency had a significantly higher risk of mortality within 90 days of CABG compared to those with sufficient vitamin D levels.
In this retrospective cohort study, the authors collected data from 324 patients included in the Research Patient Data Registry in Boston between 2001 and 2011. All participants had vitamin D levels assessed up to a year prior to hospitalization.
The authors found that 90-day mortality was higher in patients who were deficient (< 15 ng/ml) and insufficient (15-30 ng/ml) compared to those who had sufficient levels (> 30 ng/ml). Nine percent of patients with vitamin D deficiency died within 3 months after the surgery, 7.5% of those with insufficient levels, compared to 1.9% of patients with sufficient levels.
Deficiency remained a significant predictor of mortality after adjusting for age, gender, race, and acute kidney injury. Both deficiency and insufficiency findings were significant when additionally controlling for end-stage renal disease.
Of course, the study does not prove causality. The authors recognize the potential for selection bias and unmeasured confounders as limitations to the study.