Recently, we have been working on enhancing the effectiveness of treatment for acute heart failure (HF) through team-based care. This study was designed to assess the benefits of this initiative by quantifying the prognostic impact on HF patients receiving treatment at our hospital. We identified 1977 consecutive HF patients (mean age 78.3 ± 11.9 years) being discharged from our hospital between February 2015 and December 2018, divided them by admission year, and tracked changes over time, with 2015 as a reference. The postdischarge clinical outcome measures were defined as a composite of all-cause death or rehospitalization for HF, all-cause death, and rehospitalization for HF. The risk of a composite of all-cause death or rehospitalization for HF was lower in 2017 (adjusted hazard ratio, 0.72; 95% confidence interval: 0.57 to 0.91; p = 0.005) and 2018 (adjusted hazard ratio, 0.78; 95% confidence interval: 0.61 to 0.99; p = 0.045) than in 2015, and that of all-cause death was lower in 2017 (adjusted hazard ratio, 0.72; 95% confidence interval: 0.53 to 0.98; p = 0.04) and 2018 (adjusted hazard ratio, 0.60; 95% confidence interval: 0.43 to 0.85; p = 0.004) than in 2015, but that of rehospitalization for HF was not significantly different through the study period. The mortality rate decreased at the end of the study period, but the rate of rehospitalization for HF did not. The benefits of team-based care were difficult to evaluate by quantification.