Serum intact parathyroid hormone levels independently predict exercise capacity in stable heart failure patients - Agapitou, Varvara; Dimopoulos, Stavros; Mpouchla, Anthi; Samartzis, Lampros; Tseliou, Eleni; Kaldara, Elissavet; Terrovitis, John; Tasoulis, Athanasios; Karga, Eleni; Nanas, Serafim (International Journal of Cardiology, 2011)