1 Department of Epidemiology, Baylor Healthcare System, Dallas, Tex.
2 The Heart Hospital Baylor Plano, Plano, Tex; Department of Cardiac Surgery, Kerckhoff Clinic Heart Center, Bad Nauheim, Germany.
3 Spectral MD, Inc, Dallas, Tex.
4 Department of Epidemiology, Baylor Healthcare System, Dallas, Tex; The Heart Hospital Baylor Plano, Plano, Tex. Electronic address: jmdimaio@yahoo.com.