Assessing the inclusion of frailty scores in either the methodology or results of clinical intervention trials of heart failure: A scoping review

Chronic heart failure is highly prevalent in older adults, in whom frailty is common and associated with poorer outcomes. Despite advances in guideline-directed medical therapy, concerns regarding tolerability and polypharmacy contribute to under-utilization in frail patients. This scoping review aimed to map the existing evidence on how clinical interventional trials of heart failure management have incorporated frailty, specifically, whether trials have (i) stratified outcomes according to frailty status and/or (ii) adjusted treatment strategies based on frailty. We searched MEDLINE, Ovid Embase, Cochrane CENTRAL and ClinicalTrials.gov for interventional trials of heart failure published up to August 2025 that incorporated frailty using validated assessment tools. Eligible studies stratified outcomes by frailty status and/or adjusted interventions based on frailty. Data were extracted and a narrative synthesis was conducted. Ten studies met the inclusion criteria. Seven were post-hoc analyses of randomized controlled trials, two were prespecified analyses, and one was a randomized controlled trial. Two studies evaluated exercise-based interventions, one on implantable cardioverter-defibrillators, and the remainder on pharmacological-based therapies. Nine studies used the Rockwood cumulative deficit approach to measure frailty, although the parameters used varied between studies. Available secondary analyses suggest preserved efficacy across frailty groups for most pharmacological interventions, whereas other modalities did not show convincing improvements in heart failure-specific outcomes among frail patients. Primary evidence of heart failure interventions incorporating frailty remains limited, with a large bulk of the evidence available being retrospective. Although several reported pharmacological interventions appear to have preserved efficacy across frailty levels, some of these therapies were not recommended in current guidelines, and heterogeneity in frailty measurement reduced the confidence of conclusions drawn. The gaps identified in this review highlight the need for further primary evidence that incorporates frailty, plus a standardized holistic method of measuring frailty in heart failure patients.