Heart Failure Efficacy and Research Trial (HEART) Platform

The Heart Failure Efficacy and Research Trial (HEART) Platform is a multicenter, randomized platform clinical trial infrastructure designed to improve outcomes for adults with heart failure through the efficient and continuous evaluation of multiple interventions. The platform enables the simultaneous and sequential testing of therapies across the spectrum of heart failure, with the ability to add, modify, or close interventions ("domains") over time as evidence accumulates and new research questions emerge.

HEART uses a master protocol framework with Domain-Specific Appendices (DSAs) that provide intervention-specific eligibility criteria, procedures, safety monitoring, and outcomes, while using shared platform-wide processes for governance, operations, data collection, and participant protections. This modular documentation structure allows platform updates and domain evolution without requiring complete revisions to all platform components, supporting long-term sustainability and reduced regulatory burden.

Participants are enrolled into one of two mutually exclusive patient states at the time of randomization: (1) State 1: Worsening Heart Failure (WHF), which includes patients hospitalized or treated in the emergency department for acute heart failure requiring active management; and (2) State 2: Ambulatory Heart Failure, which includes stable outpatients with established heart failure receiving ongoing management and without recent heart failure hospitalization. Patient state determines eligibility for specific domains and supports state-specific analyses.

Each HEART domain operates as a semi-autonomous trial within the broader infrastructure, with domain-specific scientific leadership and funding, while benefiting from shared core trial procedures. Domains may be conducted as vanguard/feasibility studies, Phase II trials, or Phase III trials, depending on the maturity of evidence and research objectives, and interventions may advance ("graduate") to later-phase evaluations within the platform.

The default primary endpoint for Phase III trials within the platform is time to first event of death or cardiovascular hospitalization; however, specific primary outcomes are determined at the domain level to match the intervention and development phase.

The HEART Platform incorporates formal governance and safety oversight, including a Platform Steering Committee and independent Data Safety Monitoring Board (DSMB), with standardized adverse event definitions and reporting procedures. The platform is conducted in accordance with Good Clinical Practice, the Declaration of Helsinki, and applicable ethical and regulatory requirements, with ethics approval obtained for the master protocol and each individual domain.

Inclusion criteria

(HEART Platform)

• Participants are eligible for inclusion if they meet all of the following:
• Age ≥18 years (or legal age of majority in participant's country of residence).
• Diagnosis of heart failure, and eligible to be classified into one of the HEART platform states at the time of randomization:
• State 1: Worsening Heart Failure (WHF): currently hospitalized for acute decompensated heart failure or emergency department patients requiring intravenous therapy for heart failure; OR
• State 2: Ambulatory Heart Failure: stable outpatients with established heart failure diagnosis, receiving ongoing HF management and without HF hospitalization within the prior 30 days.
• Able and willing to provide written informed consent (or consent via a legally authorized representative, where applicable).
• Meets all applicable domain-specific eligibility criteria for at least one active HEART Platform domain at the time of screening/randomization.

Exclusion criteria

(HEART Platform)

• Participants will be excluded if any of the following apply:
• Inability to provide informed consent (and no legally authorized representative available when applicable).
• Not eligible for assignment to either HEART platform state (State 1 or State 2).
• Presence of conditions or circumstances that, in the investigator's opinion, would make study participation unsafe or not feasible (e.g., inability to comply with study procedures or follow-up).
• Does not meet the eligibility requirements for any active HEART Platform domain.
• Any domain-specific exclusion criteria applicable to the intervention/domain(s) for which the participant would otherwise be eligible.
• Additional inclusion and exclusion criteria apply for each individual HEART Platform domain and will be specified in the relevant domain protocol(s).