[1] Policlin San Matteo, Div Cardiol, IRCCS, I-27100 Pavia, Italy
[2] Policlin San Matteo, Biometry & Clin Epidemiol Unit, IRCCS, I-27100 Pavia, Italy
[3] Arcispedale St Anna, Dept Cardiol, Ferrara, Italy
[4] Peterfy Hosp, Budapest, Hungary
[5] St Stepan Hosp I, Budapest, Hungary
[6] Menarini Ric SpA, Florence, Italy
[7] Univ London Imperial Coll Sci Technol & Med, Natl Heart & Lung Inst, London, England