Refined Heart Failure Stages Incorporating Cardiorespiratory Fitness Are Differentially Associated With Heart Failure...

Area of Science:

• Cardiology
• Preventive Medicine
• Exercise Physiology

Background:

• Heart failure (HF) progresses through distinct stages (A, B, C) based on risk factors and clinical presentation.
• Current staging methods may not adequately identify individuals in stage B who are likely to progress to clinical HF.
• Refined phenotyping is crucial for early intervention and prevention of HF progression.

Purpose of the Study:

• To investigate the association between cardiorespiratory fitness (CRF) and incident heart failure (HF) risk.
• To refine HF staging by incorporating CRF levels.
• To identify individuals at higher risk for HF progression within preclinical stages.

Main Methods:

• An observational cohort study using data from the Framingham Heart Study (FHS).
• Cardiorespiratory fitness (CRF) was estimated using submaximal exercise testing (Bruce protocol stage 2).
• Cox models were used to assess the association of HF substages (defined by CRF relative to sex-specific medians) with incident HF, adjusting for age and sex.

Main Results:

• Among 1683 participants, 468 were classified as stage B at baseline.
• Stage B participants with low CRF exhibited a >2.5-fold increased risk of developing HF (HR, 2.75).
• Each one-standard deviation increase in CRF was associated with a significant reduction in HF risk among stage B individuals (HR, 0.57).

Conclusions:

• Cardiorespiratory fitness is a critical factor in predicting HF risk within preclinical stages.
• Integrating CRF into HF staging criteria can enhance risk stratification for individuals in stage B.
• This approach may enable more precise targeting of preventive therapies to mitigate HF development.