1. Heart Failure Unit; Hospital Universitari Germans Trias i Pujol; 08916 Badalona Spain
2. Department of Medicine; Autonomous University of Barcelona; Barcelona Spain
3. Biochemistry Service; Hospital Universitari Germans Trias i Pujol; Badalona Spain
4. IMIM-Hospital del Mar Research Institute; Barcelona Spain
5. CIBER de Epidemiología y Salud Pública