title: Reply.
authors.affiliation: Division of Cardiovascular Surgery, University of Pennsylvania, 3400 Spruce St, 6 Silverstein, Philadelphia, PA19104. Electronic address: ibrahim.sultan@uphs.upenn.edu.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Sultan
authors.affiliation: Division of Cardiovascular Surgery, University of Pennsylvania, 3400 Spruce St, 6 Silverstein, Philadelphia, PA19104.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Bavaria