Effect of vitamin D on ventricular remodelling in heart failure: a meta-analysis of randomised controlled trials

OBJECTIVES: The level of vitamin D is considered to be associated with the development and progression of heart failure (HF). However, it is still unclear whether supplementation of vitamin D could improve ventricular remodelling in patients with HF. This study aimed to systematically evaluate the influence and safety of additional vitamin D supplementation on ventricular remodelling in patients with HF. DESIGN: This study is a meta-analysis of randomised controlled trials (RCTs). SETTING: The PubMed, EMBASE, CNKI, Cochrane library, Web of Science databases and grey literature were searched for RCTs regarding the effect of vitamin D on ventricular remodelling in patients with HF (from database creation to October 2017). RevMan V.5.3 software was employed for data analysis. PARTICIPANTS: Seven RCTs with a total of 465 patients, including 235 cases in the vitamin D group and 230 cases in the control group, were included. PRIMARY AND SECONDARY OUTCOME MEASURES: Left ventricular end-diastolic dimension (LVEDD), left ventricular ejection fraction (LVEF) and the incidence of adverse reactions. RESULTS: Compared with the control group, a decrease in the LVEDD (mean difference (MD)=-2.31 mm, 95% CI -4.15 to -0.47, p=0.01) and an increase in the LVEF (MD=4.18%, 95% CI 0.36 to 7.99, p=0.03) were observed in the vitamin D group. Subgroup analysis also revealed a reduced LVEDD in adults (>18 years) and adolescents (<18 years) of the vitamin D group relative to that in those of the control group. High-dose vitamin D (>4000 IU/day) was more effective at reducing the LVEDD than low-dose vitamin D (<4000 IU/day). Moreover, vitamin D supplementation was more effective at reducing the LVEDD and increasing the LVEF in patients with reduced ejection fraction than in patients without reduced ejection fraction. CONCLUSION: Vitamin D supplementation inhibits ventricular remodelling and improves cardiac function in patients with HF. TRIAL REGISTRATION NUMBER: CRD42017073893.