[1] Ist Clin Humanitas, Milan, Italy
[2] Azienda Opedaliera Univ Ferrara, Cardiovasc Dept, Ferrara, Italy
[3] Univ Hosp Madrir, Madrid, Spain
[4] Otamendi Hosp, Buenos Aires, DF, Argentina
[5] Policlin San Matteo, Arezzo, Italy
[6] Policlin San Matteo, I-27100 Pavia, Italy