Vitamin D deficiency and functional response to CRT in heart failure patients.

BACKGROUND

Vitamin D deficiency has been associated with a poor outcome in patients with heart failure (HF). We examined the role of vitamin D in the response of HF patients to cardiac resynchronization therapy (CRT).

METHODS

The study comprised 50 patients (30 men and 20 women) with HF undergoing CRT implantation who were prospectively enrolled. Response to CRT was defined as a combination of ≥15% reduction in left ventricular end-systolic volume (LVESV) and ≥10% improvement in the 6‑Minute Walk Test within 6 months. Patients were grouped based on their levels of vitamin D prior to CRT implantation. Clinical and echocardiographic examinations were performed prior to and 6 months after the procedure.

RESULTS

Of the patients, 11 (22%) failed to respond to CRT; two patients died within 6 months and an additional nine patients showed no improvement in the 6‑Minute Walk Test and no reduction in their baseline LVESV. A comparison was made between 25 patients with sufficient levels of vitamin D and 25 patients with insufficient levels. Nine patients (36%) in the "insufficient" group and two patients (8%) in the "sufficient" group failed to respond to CRT implantation (p = 0.037).

CONCLUSION

Adequate serum concentrations of vitamin D play a significant role in improving the functional status of patients with systolic HF following CRT implantation.