Impact of Changes in Rectus Femoris Cross-Sectional Area Measured by Ultrasound on the Prognosis of Patients With Acute Heart Failure

Background: Low muscle mass in patients with acute heart failure (AHF) is associated with poor prognosis; however, this is based on a single baseline measurement, with little information on changes in muscle mass during hospitalization and their clinical implications. This study investigated the relationship between changes in rectus femoris cross-sectional area (RFCSA) on ultrasound and the prognosis of patients with AHF. Methods and Results: This is a retrospective evaluation of 284 AHF patients (mean [ +/- SD] age 79.1 +/- 11.9 years; 116 female). RFCSA assessments at admission (pre-RFCSA), triangle RFCSA (i.e., the percentage change in RFCSA from admission to 2 weeks), and composite prognosis (all -cause death and heart failure -related readmission) within 1 year were determined. Patients were divided into 4 groups according to their median pre-RFCSA and triangle RFCSA after sex stratification: Group A, higher pre-RFCSA/better triangle RFCSA; Group B, higher pre-RFCSA/worse triangle RFCSA; Group C, lower pre-RFCSA/better triangle RFCSA; Group D, lower pre-RFCSA/worse triangle RFCSA. In the Cox regression analysis, with Group A as the reference, the cumulative event rate of Group C (hazard ratio [HR] 3.39; 95% confidence interval [CI] 0.71-16.09; P=0.124) did not differ significantly; however, the cumulative event rates of Group B (HR 7.93; 95% CI 1.99-31.60; P=0.003) and Group D (HR 9.24; 95% CI 2.57-33.26; P<0.001) were significantly higher. Conclusions: triangle RFCSA during hospitalization is useful for risk assessment of prognosis in patients with AHF.