To What Extent Has Frailty Been Incorporated Into Heart Failure Interventional Trials? A Scoping Review

Introduction:
Chronic heart failure (HF) 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-utilisation in frail patients. This study aimed to map existing evidence on how frailty is incorporated into HF interventional trials.

Method:
A scoping review was conducted of Medline, Ovid Embase, Cochrane CENTRAL, and ClinicalTrials.gov for HF interventional studies published up to August 2025 where frailty was assessed using a validated tool. Eligible studies stratified outcomes by frailty status and/or adjusted interventions based on frailty. Data was extracted and a narrative synthesis was conducted.

Results:
Ten studies met the inclusion criteria. Seven were post-hoc analyses of randomised controlled trials, two were prespecified analyses, and one was a randomised controlled trial. Nine studies used the Rockwood cumulative deficit approach to measure frailty, although the parameters used varied between studies. Two studies evaluated exercise-based interventions, one on implantable cardioverter-defibrillators, and the remainder on pharmacological-based therapies. All studies incorporated frailty through outcome stratification. Increasing frailty was associated with worse outcomes regardless of treatment. Pharmacological therapies generally demonstrated preserved efficacy across frailty strata, while non-pharmacological interventions showed less consistent improvements in HF-specific outcomes.

Conclusions:
Evidence on HF interventions in frail populations is limited and largely retrospective, particularly in guideline-recommended therapies. Although treatment benefits appear preserved across frailty levels, heterogeneity in frailty assessment and lack of frailty-informed trial design limit clinical applicability. Prospective trial designs should aim to incorporate frailty, including a standardised frailty assessment tool, to strengthen the evidence base.