Prognostic impact of Vitamin D deficiency in patients with coronary artery disease undergoing percutaneous coronary intervention

Background: Whether Vitamin D deficiency represents an independent predictor of mortality and major cardiovascular events or rather the mirror of a more advanced clinical condition with increased comorbidities is still debated. We aimed at assessing the impact of vitamin D levels on the long-term outcomes among patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention. Methods: Consecutive patients from a single centre were included. Vitamin D levels were measured at admission by chemiluminescence immunoassay kit LIAISON (R) Vitamin D assay (Diasorin Inc). Severe deficiency was defined for 25(OH)D < 10 ng/ml. The primary study endpoint was overall mortality. Secondary endpoints were cardiovascular mortality, recurrent acute coronary syndrome or major cardiovascular events (a composite of death, recurrent MI and target vessel revascularization) at the longest available follow-up. Results: We included a total of 705 patients, that were divided according to vitamin D tertiles (<12.7; 12.721.59; >= 21.6 ng/ml). Lower levels of Vitamin D were associated with renal failure (p = 0.03), more severe coronary disease (p = 0.001), diabetes mellitus and previous CABG (p <0.001), lower ejection fraction (p = 0.02), acute presentation (p = 0.04), use of statins (p = 0.02), diuretics, nitrates and clopidogrel (p <0.001) and RASI (p = 0.008). An inverse association was documented with BMI, glycemia, total cholesterol (p < 0.001), creatinine and WBC (p = 0.001). At a median follow-up of 996.5 [377-1552] days, 3.8% of the patients died. Vitamin D deficiency was significantly associated with overall mortality (7.6% vs 2.9% vs 0.4%, adjusted HR[95%CI] =3.6[1.43-8.9], p = 0.006), MACE (adjusted HR[95%CI] = 1.32[1.07-1.63], p = 0.01) and the composite of death and MI (adjusted HR[95%CI] = 1.3[1.03-1.65], p = 0.03). A similarly increased risk was confirmed for all major higher-risk subsets of patients, with no significant interaction according to age, gender, diabetes mellitus or chronic kidney disease. Conclusion: Among patients undergoing percutaneous coronary interventions, lower levels of vitamin D are associated with an over 3-fold increased risk of mortality and major cardiovascular events. Future larger studies are certainly warranted in order to define the prognostic implications of cholecalciferol supplementation among high-risk patients with established coronary artery disease.