Ebetsu Active Future Study (EAFS) conducts comprehensive annual surveys of individuals who are independent in activities of daily living (ADLs) to track age-related physical and mental changes. These surveys include a variety of assessments such as cognitive function tests, physical function tests, blood tests, self-administered questionnaires about lifestyle and health, and interviews regarding medical and family history. In addition, serum, plasma and DNA samples from these assessments are stored at –80°C to facilitate future analyses and accommodate the potential addition of new measurement items. The purposes of this study are: (1) to identify potential blood-based biomarkers applicable to the detection of various types of mild cognitive impairment (MCI), (2) to explore diet-based strategies for preventing MCI and the progression of dementia, (3) to examine the relationship between urban characteristics, individual attributes and healthy life expectancy in Ebetsu City and (4) to return the research findings to the city.

From August to October 2023, EAFS invited Ebetsu residents to participate in the study. As a result, 1340 individuals applied and 1189 residents aged between 55 and 75 years who were independent in ADLs participated in the baseline survey for the first year.

EAFS initiated a follow-up of 1189 participants (38.9% male; 64.5±5.6 years) in the baseline year of 2023 and maintained a high follow-up rate of 98.5% by wave 3 (2025). The Montreal Cognitive Assessment-Japanese demonstrated that 53.6% of the participants had operational MCI. The proportion of participants with operational MCI increased with ageing. Regarding the APOE4 gene, which is associated with an increased risk of Alzheimer’s disease, 1.2% of the total population were homozygous carriers and 22.1% were heterozygous carriers.

EAFS will conduct annual follow-up surveys until 2032. In addition to analysing data for each objective, we also plan to perform further analysis of the stored specimens.

Heart failure occasionally develops after transcatheter aortic valve implantation (TAVI) for severe aortic stenosis (AS), despite procedural success. Most cases present with mildly reduced or preserved left ventricular ejection fraction (LVEF), underscoring the role of diastolic dysfunction. Sodium-glucose cotransporter 2 (SGLT2) inhibitors have shown benefits across the heart failure spectrum, independent of LVEF. The purpose of this randomised controlled trial is to determine whether adding a SGLT2 inhibitor to conventional medications improves LV diastolic function in patients with preserved LVEF after TAVI.

This study is a prospective, single-centre, open-label, randomised, parallel-group, two-arm trial enrolling patients with mildly reduced or preserved LVEF (≥40%) undergoing TAVI for severe AS. Participants will be randomised in a 1:1 ratio to receive either conventional medications plus empagliflozin or conventional medications alone. In the empagliflozin group, participants will receive conventional medical therapy plus empagliflozin 10 mg orally once daily, initiated 4 weeks after TAVI. Empagliflozin treatment will continue throughout the study period. Participants in the control group will receive conventional medications without empagliflozin. The primary endpoint is the change in E/e’, assessed by echocardiography from treatment initiation at 4 weeks post TAVI (day 1) to day 168 (week 24). Each group will include 50 patients, totalling 100 patients.

Ethical approval for this study has been obtained from the Chiba University Hospital Certified Clinical Research Review Board (CRB0111-25).

jRCT1031250190.