Background: We have recently demonstrated that left ventricular ejection fraction (LVEF) dynamically changes over time with prognostic impacts in Stage C/D patients, namely, those who have a current or past history of heart failure (HF). However, it is unknown whether this is also the case in asymptomatic Stage B patients, namely, those who have a risk of HF, but do not have a history of HF. Methods: In our CHART-2 Study (N = 10,219), we enrolled 4005 Stage B patients and divided them into 3 groups by LVEF; preserved EF (pEF, LVEF >= 50%, N = 3526), mid-range EF (mrEF, LVEF 41-49%, N = 302), and reduced EF (rEF, LVEF <= 40%, N = 177). We examined the prognostic impacts of LVEF transitions among the 3 groups in comparison with 4477 patients with Stage C/D HF. Results: Stage B were characterized by less severe clinical status and better prognosis compared with Stage C/D. Stage B in mrEF and rEF at baseline dynamically transitioned to other groups at 1-year, whereas those in pEF unchanged; at 1-year, mrEF transitioned to pEF/rEF by 50/16%, and rEF transitioned to pEF/mrEF by 25/31%, respectively, whereas pEF transitioned to mrEF/rEF by only 3.6/0.7%, respectively, which were consistent with findings in findings with Stage C/D. Although LVEF decrease was directly associated with all-cause mortality in both the Stage B and Stage C/D with pEF, factors related to LVEF changes were different between the 2 groups. Conclusions: In Stage B, LVEF dynamically changes with prognostic impacts as in Stage C/D, whereas different determination factors may be involved in the 2 stages. Clinical trial registration: Chronic Heart Failure Analysis and Registry in the Tohoku District (CHART)-2 (NCT00418041). (c) 2020 Elsevier B.V. All rights reserved.