(A–D) Subanalysis by disease category of perioperative mortality per 200-ft increments of 6-minute-walk distance. Mortality rates were estimated using Kaplan-Meier methods. Statistical comparisons are based on the log-rank test using the following grouping: ≤450 ft, 451–787 ft, 788–1,082 ft, and >1,082 ft. *Statistically significant.