Vitamin D Deficiency in Acute Coronary Syndrome – A Clinically Relevant or an Incidental Finding?

Objectives: The objective of this study was to determine the relationship of 25-hydroxyvitamin D (25(OH)D) serum level with the coronary artery disease (CAD) severity and prognosis in patients with acute coronary syndrome (ACS) during a three-year follow-up period. Methods: The study included 60 ACS patients hospitalized at the cardiology department for ACS between March 2012 and October 2012 and 60 age- and sex-matched control patients without ACS. Standard laboratory testing and vitamin D determination were performed in all study patients. In addition, ACS patients underwent coronarography and were followed-up for 36 months for major adverse cardiac events (MACE). Results: Patients with ACS had a statistically significantly lower mean 25(OH)D level compared with the control group (35.19 nmol/L vs. 58.08 nmol/L, p<0.001). The lowest mean level of 25(OH)D was recorded in diabetic patients with ACS (30.45 nmol/L). ACS patients were divided into three subgroups according to coronarography findings: single vessel, double vessel, and triple vessel CAD with respective serum levels of 25(OH)D of 36.44 nmol/L, 33.65 nmol/L, and 31.70 nmol/L. During the 36-month follow-up, the event-free survival rate was 60% in the ACS group. The ACS patients having sustained MACE during follow-up had low serum levels of 25(OH)D in the acute phase; however, the difference from ACS patients without MACE during follow-up did not reach statistical significance (32.64 nmol/L vs. 37.01 nmol/L). Conclusion: This study showed significantly lower concentrations of vitamin D among ACS patients, with no effect on 3-year mortality within that group related to baseline vitamin D concentration. Whether vitamin D is an important part of the still unsolved cardiovascular puzzle, or just a prognostic factor for cardiovascular disease, is left for large prospective trials to answer. Additionally, the connection between diabetes, vitamin D metabolism, and coronary artery disease should be investigated more thoroughly in the future, as diabetics showed the lowest concentrations among all.