A multicenter prospective cohort study to develop frailty-based prognostic criteria in heart failure patients (FLAGSHIP): rationale and design

BACKGROUND: Heart failure (HF) and frailty often co-exist, and frailty in HF results in a poor prognosis. However, in Asian populations, prognostic criteria are needed to examine the effect of frailty on HF. Therefore, we conducted a nationwide cohort study to develop frailty-based prognostic criteria in HF patients (FLAGSHIP). FLAGSHIP mainly aims to 1) develop the frailty criteria based on HF-specific outcomes, 2) propose a hypothesis of the potential mechanisms of frailty manifestations in HF, and 3) examine the effects of outpatient cardiac rehabilitation on frailty. METHODS: In this prospective study, we consecutively enroll ambulatory patients admitted because of acute HF or exacerbation of HF and elderly patients admitted for acute myocardial infarction (age ≥ 70 years). They will be followed up for 2 years to assess frailty and hard clinical events. The primary endpoints of FLAGSHIP are cardiac events including cardiac mortality and HF-related readmission after discharge. Secondary endpoints are readmissions because of fracture or pneumonia and all-cause mortality. We used clinical data, including the items related to the frailty phenotype to develop diagnostic criteria for frailty and known prognostic factors of HF. Cognitive function, depression, and anorexia are also considered as potential components of frailty. As of March 2018, 2650 patients (85% was patients admitted for HF) have been registered from 30 collaborating hospitals nationwide in Japan. DISCUSSION: FLAGSHIP provides diagnostic criteria and fundamental information on frailty manifestations to develop the best practices for the long-term management of HF. Diagnostic criteria on frailty developed by FLAGSHIP is expected to become a novel indicator for the stratification of patients at risk to functional decline after medical or surgical treatment, and in turn to contribute to the best practices in the long-term management of HF. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12872-018-0897-y) contains supplementary material, which is available to authorized users.