Body Mass Index-Adjusted Rectus Femoris Muscle Thickness as a Simple Indicator for Exercise Tolerance in Patients...

Area of Science:

• Cardiology
• Exercise Physiology
• Medical Imaging

Background:

• Heart failure (HF) significantly impacts exercise tolerance.
• Oxygen uptake at anaerobic threshold (AT-V̇O2) is a critical measure of exercise capacity and prognosis in HF patients.
• Non-invasive methods to assess exercise tolerance in HF are valuable.

Purpose of the Study:

• To evaluate the association between rectus femoris muscle thickness adjusted by body mass index (RFT/BMI) and AT-V̇O2 in patients with HF.
• To determine if RFT/BMI can serve as a surrogate marker for exercise tolerance in HF.

Main Methods:

• Retrospective cross-sectional study of 103 HF patients.
• Ultrasound-derived RFT measurements and cardiopulmonary exercise testing (CPX) were performed.
• Statistical analyses included multivariable linear regression, restricted cubic spline, ROC curve analysis, and modified Poisson regression.

Main Results:

• RFT/BMI was independently and significantly associated with AT-V̇O2 (β=0.62, P<0.001) with a nonlinear relationship.
• Optimal RFT/BMI cutoffs (0.55 and 0.69) effectively discriminated between different levels of AT-V̇O2.
• Higher RFT/BMI values were associated with a lower risk of reduced AT-V̇O2.

Conclusions:

• Ultrasound-derived RFT/BMI is associated with AT-V̇O2 in HF patients.
• RFT/BMI may offer valuable supportive information regarding exercise tolerance.
• This method could be particularly useful when CPX is not feasible for assessing HF patients.