Ultrasound-measured Quadriceps Muscle Thickness and Mortality in Older Patients With Heart Failure

Background: Ultrasound might be helpful for muscle mass assessment in patients with heart failure (HF). We aimed to determine the feasibility and prognostic implications of ultrasound-measured quadriceps muscle thickness (QMT) in older patients with HF.

Methods: This was a post hoc analysis of a multicentre prospective cohort study including patients hospitalized for HF aged 65 years and older. QMT at rest and during isometric contractions using ultrasound was measured with the patient in the supine position before discharge.

Results: The interobserver agreement for measuring QMT was excellent, with intraclass correlation coefficients of 0.979 (95% confidence interval [CI], 0.963-0.988) at rest and 0.997 (95% CI, 0.994-0.998) during isometric contraction. The intraobserver reproducibility was also excellent (intraclass correlation coefficient > 0.92). Of the 595 patients (median age, 81 years; 56% male), median QMT at rest and during contraction were 18.9 mm and 24.9 mm, respectively. The patients were grouped according to sex-specific tertiles of height-adjusted QMT. During the median follow-up of 735 days, 157 deaths occurred, and Kaplan-Meier curve analysis showed that the lowest tertile of the height-adjusted QMT was associated with a higher mortality. Cox proportional hazard analysis revealed that thinner height-adjusted QMT was independently associated with higher mortality, even after adjusting for conventional risk factors (per 1 mm/m increase: hazard ratio, 0.94; 95% CI, 0.89-0.99; P = 0.030 [at rest] and hazard ratio, 0.94; 95% CI, 0.90-0.99; P = 0.015 [during isometric contraction]).

Conclusions: Ultrasound-measured QMT in older patients with HF is feasible, and thinner height-adjusted QMT at rest and during isometric contraction was independently associated with higher mortality.