[1] McGill Univ, Glen Hosp, Dept Med, Div Cardiol,Hlth Ctr, 1001, Decarie Blvd, Montreal, PQ H4A 3J1, Canada
[2] German Heart Ctr Munich, Dept Cardiac Surg, D-80636 Munich, Germany
[3] Natl Univ Ireland, Dept Cardiol, Galway H91 YR71, Ireland
[4] Imperial Coll London, Natl Heart & Lung Inst, London SW3 6LY, England