[1] Bern Univ Hosp, Dept Cardiol, Bern, Switzerland
[2] Univ Bern, Inst Social & Prevent Med, Bern, Switzerland
[3] Copenhagen Univ Hosp, Rigshosp, Copenhagen, Denmark
[4] Geneva Univ Hosp, Div Cardiol, Geneva, Switzerland
[5] Cardioctr Ticino, Lugano, Switzerland
[6] Imperial Coll London, Natl Heart & Lung Inst, Int Ctr Circulatory Hlth, London, England
[7] Washington Hosp Ctr, Intervent Cardiol, Washington, DC 20010 USA