Association of Free Triiodothyronine with Long-Term Prognosis in Hypertrophic cardiomyopathy patients with HFpEF: A Dual center research study

Abstract Objective: The objective of this study was to identify prognostic factors in Hypertrophic cardiomyopathy patients with HFpEF, with a particular focus on the role of FT3 levels. Research Design and Methods: We conducted a retrospective cohort study of 992 patients with HFpEF who were admitted to our two medical centers between 2009 and 2019. We collected demographic and clinical data, including FT3 levels, and conducted univariate and multivariate Cox analyses, KM survival curve analysis, and RSC curve analysis to identify prognostic factors and evaluate the non-linear predictive value of FT3. Results: We found that age, atrial fibrillation, and NT-proBNP levels were all significant prognostic factors in patients with heart failure. Additionally, FT3 levels were a significant independent predictor of all-cause mortality and cardiac transplantation. Patients with lower FT3 levels had worse long-term prognoses, and the critical value of FT3 was 2.885. Conclusions: Our findings suggest that FT3 levels are an important prognostic factor in patients with heart failure and should be considered when evaluating patient outcomes. Clinicians should monitor FT3 levels and consider interventions to maintain or improve thyroid function in patients with heart failure. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by: National Key R&D Program of China (2020YFC2004705), National Natural Science Foundation of China (81825003, 91957123, 82270376), CAMS Innovation Fund for Medical Sciences (2022-I2M-C&T-B-119, 2021-I2M-5-003), Beijing Nova Program from Beijing Municipal Science & Technology Commission(Z201100006820002), CSC Special Fund for Clinical Research (CSCF2021A04). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The study was in accordance with the ethical guidelines of the declaration of Helsinki and China's regulations and guidelines on good clinical practice and was approved by the Ethics Committee of the Peking University Third Hospital. Before the start of the study, we received written informed consents from all participants. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The datasets generated during and/or analyzed in the current study are available from the corresponding author upon reasonable request.