[1] Ain Shams Univ, Fac Med, Cairo, Egypt
[2] Harvard Med Sch, Brigham & Womens Hosp, Dept Med, Boston, MA USA
[3] Houston Methodist DeBakey Heart & Vasc Ctr, Houston, TX USA
[4] Cedars Sinai Med Ctr, Smidt Heart Inst, Barbra Streisand Womens Heart Ctr, Los Angeles, CA USA
[5] Univ Queensland, John Ochsner Heart & Vasc Inst, Ochsner Clin Sch, Dept Cardiovasc Dis,Sch Med, New Orleans, LA USA
[6] Baylor Coll Med, Ton, TX USA
[7] Michael E DeBakey VA Med Ctr, Ton, TX USA
[8] Aga Khan Univ, Karachi, Pakistan
[9] Michael E DeBakey VA Med Ctr, Hlth Serv Res & Dev, 2002 Holcombe Blvd, Houston, TX 77030 USA