Data from prior to the pulmonary artery pressure sensor implant include heart failure events (treatment cohort, 2532; control cohort, 2532; P > .99); length of stay per heart failure hospitalization (mean [SD]: treatment cohort, 5.5 [4.9] days; control cohort, 4.9 [4.1] days; P = .003); time in hospital per patient (mean [SD]: 12.7 [12.7] days; 11.4 [11.4] days; P = .05); and total hospital time (treatment cohort, 13 857 days; control cohort, 12 442 days; P > .99).