[1] Univ Alcala de Henares, Hosp Ramon y Cajal, Dept Med, Div Resp, Madrid 28034, Spain
[2] Zarzuela Hosp, Resp Dept, Madrid, Spain
[3] Hosp Ramon & Cajal, Dept Cardiol, E-28034 Madrid, Spain
[4] Washington Univ, Sch Med, Div Pulm & Crit Care Med, St Louis, MO USA
[5] Washington Univ, Sch Med, Div Gen Med Sci, St Louis, MO USA