11 August 2016
12 July 2016
By Rob Winwood
The VINDICATE (VitamIN D treating patIents with Chronic heArT failurE) randomized controlled trial (1) produced promising results for a daily intervention of vitamin D in patients with one of the most common forms of heart disease.
10 million people in the US and Europe suffer from chronic heart failure (CHF) due to left ventricular systolic dysfunction (LVSD). While treatment has improved in recent years, approximately 50% of these patients die within five years of diagnosis. It has been observed that approximately 90% of these patients are very deficient in circulating levels of vitamin D (2), though the cause of this is unknown.
The VINDICATE study was comprised of 229 patients with heart failure due to LVSD and with low 25-hydroxyvitamin D levels (less than 50 nmol/L). The intervention group was given a daily dose of 100 µg per day vitamin D for one year. The patients were then assessed for a practical measure of any improvement in heart function by determining how far they could walk in six minutes. In addition to this primary outcome measure, the anatomy and blood flow in the left ventricle of the heart was assessed by echocardiography and cardiac magnetic resonance imaging before and after the intervention.
At the end of the study, there had been no significant improvements in the walking distance, but the left ventricle was shown to be functioning better. The blood ejection fraction improved by 6% (p<0.0001) and there was less adverse remodeling of the shape of the left ventricle that normally occurs after LVSD.
Vitamin D deficiency had been associated with a range of adverse cardiovascular conditions, including high blood pressure, stroke, myocardial infarction, diabetes, congestive heart failure, atherosclerosis and endothelial dysfunction (3). A 2014 meta-analysis of the cardioprotective potential of replete vitamin D levels assessed a total of 26,018 participants aged 50 to 79 years from eight cohorts in the US and Europe, where 2,624 died of CVD. The analysis clearly showed a protective effect of sufficient vitamin D levels against cardiac mortality (4).
The new study by Witte et al. (1) provides further evidence of the potential advantage of using vitamin D supplementation as an adjunct in the treatment of patients with heart failure; although further work is required to determine optimum dose and duration in relation to baseline circulating serum vitamin D levels.
11 August 2016
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