Author Contributions: Drs Herrin and Bratzler had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: Curtis, Herrin, Bradley, and Krumholz. Acquisition of data: Bratzler. Analysis and interpretation of data: Curtis, Herrin, Bratzler, Bradley, and Krumholz. Drafting of the manuscript: Curtis and Herrin. Critical revision of the manuscript for important intellectual content: Curtis, Herrin, Bratzler, Bradley, and Krumholz. Statistical analysis: Herrin. Administrative, technical, and material support: Bratzler. Study supervision: Krumholz.