[1] S Maria delle Croci Hosp, Dept Emergency Internal Med & Cardiol, Div Cardiol, Viale Randi 5, I-48121 Ravenna, Italy
[2] Univ Hertfordshire, Sch Life & Med Sci, Postgrad Med Sch, Coll Lane, Hatfield AL10 9AB, England
[3] Imperial Coll, Natl Heart & Lung Inst, Fac Med, London SW3 6LY, England
[4] IIB St Pau, IR Hosp Santa Creu & St Pau, Cardiovasc Program ICCC, Barcelona 08025, Spain
[5] Ciber CV ISCIII, Madrid 28029, Spain