BACKGROUND: In the CHAMPION trial, significant reductions in admissions to hospital for heart failure were seen after 6 months of pulmonary artery pressure guided management compared with usual care. We examine the extended efficacy of this strategy over 18 months of randomised follow-up and the clinical effect of open access to pressure information for an additional 13 months in patients formerly in the control group. METHODS: The CHAMPION trial was a prospective, parallel, single-blinded, multicentre study that enrolled participants with New York Heart Association (NYHA) Class III heart failure symptoms and a previous admission to hospital. Patients were randomly assigned (1:1) by centre in block sizes of four by a secure validated computerised randomisation system to either the treatment group, in which daily uploaded pulmonary artery pressures were used to guide medical therapy, or to the control group, in which daily uploaded pressures were not made available to investigators. Patients in the control group received all standard medical, device, and disease management strategies available. Patients then remained masked in their randomised study group until the last patient enrolled completed at least 6 months of study follow-up (randomised access period) for an average of 18 months. During the randomised access period, patients in the treatment group were managed with pulmonary artery pressure and patients in the control group had usual care only. At the conclusion of randomised access, investigators had access to pulmonary artery pressure for all patients (open access period) averaging 13 months of follow-up. The primary outcome was the rate of hospital admissions between the treatment group and control group in both the randomised access and open access periods. Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00531661. FINDINGS: Between Sept 6, 2007, and Oct 7, 2009, 550 patients were randomly assigned to either the treatment group (n=270) or to the control group (n=280). 347 patients (177 in the former treatment group and 170 in the former control group) completed the randomised access period in August, 2010, and transitioned to the open access period which ended April 30, 2012. Over the randomised access period, rates of admissions to hospital for heart failure were reduced in the treatment group by 33% (hazard ratio [HR] 0·67 [95% CI 0·55-0·80]; p<0·0001) compared with the control group. After pulmonary artery pressure information became available to guide therapy during open access (mean 13 months), rates of admissions to hospital for heart failure in the former control group were reduced by 48% (HR 0·52 [95% CI 0·40-0·69]; p<0·0001) compared with rates of admissions in the control group during randomised access. Eight (1%) device-related or system related complications and seven (1%) procedure-related adverse events were reported. INTERPRETATION: Management of NYHA Class III heart failure based on home transmission of pulmonary artery pressure with an implanted pressure sensor has significant long-term benefit in lowering hospital admission rates for heart failure. FUNDING: St Jude Medical Inc.