Findings
Existing PROs for HF, such as KCCQ and MLHFQ, are insufficiently sensitive and rely on subjective assessments.
Accelerometer technology offers objective and continuous real-world data that may better capture patient activity and health.
Novel endpoints must be validated through analytical and cross-sectional studies, correlating “time walking” with HF severity and clinical outcomes.
Developing and validating these endpoints is more feasible for patients with NYHA class II/III HF due to their moderate activity levels.
Future refinements and central databases of accelerometer data will enhance endpoint development and application.

Recommendations
Use accelerometer-derived metrics, such as “time spent walking per day,” as novel endpoints to complement traditional clinical measures.
Validate novel endpoints through controlled and real-world studies, including correlating them with existing HF measures and clinical outcomes.
Include accelerometer endpoints in exploratory analyses within ongoing HF trials to gather supportive data without requiring regulatory submission.
Establish data standards and centralized databases for accelerometer-derived endpoints to streamline future development.
Collaborate across stakeholders, including patients, clinicians, investigators, and regulators, to align endpoint development with real-world applicability and regulatory requirements.

Regulatory Considerations
Demonstrate that accelerometer-derived endpoints reflect meaningful changes in patient health and correlate with established HF measures.
Validate endpoints in diverse patient populations and real-world settings to support generalizability and regulatory acceptance.
Address missing data and potential biases in accelerometer readings during endpoint analysis and validation.
Ensure endpoints align with regulatory trial design and analysis standards, including blinding and pre-specified analytical plans.
Develop frameworks for incorporating accelerometer-based endpoints into regulatory submissions alongside traditional clinical outcomes.