Circulating Biomarkers as Predictors of Improvement in Physical Function in Hospitalized Older Adults With Geriatric...

Biomarkers in heart failure (HF) provide mechanistic and prognostic insights, but their role in predicting treatment response is less understood. We evaluated whether multiple baseline biomarker profiles from the REHAB-HF trial (Rehabilitation Therapy in Older Acute Heart Failure Patients) could stratify functional improvement following a 12-week physical rehabilitation intervention (RI).

Participants ≥60 years hospitalized with heart failure were randomized to a 12-week outpatient RI or attention control. Functional outcomes included changes in the short physical performance battery and 6-minute walk distance. Blood collected at baseline and 12 weeks was analyzed for cardiac (cTnI and cTnT, NT-proBNP [N-terminal pro-brain natriuretic peptide]), renal (creatinine), and inflammatory (CRP [C-reactive protein]) biomarkers. Associations between baseline biomarker levels and 12-week functional gains by treatment group were evaluated using adjusted linear regression models and machine learning-based decision trees.

Baseline biomarker data were available for 242 of 349 participants (69%). Using linear regression, higher cTnI and T were associated with greater 12-week gains in the short physical performance battery and 6-minute walk distance, respectively, among RI participants versus attention control (interaction P=0.040 and 0.032). In the decision tree, analyses combining all biomarkers, CRP emerged as the primary biomarker for both outcomes. Among participants with CRP ≥9.9 mg/L, RI was associated with a +2.4 point (95% CI, 1.8-3.1) greater increase in the short physical performance battery and a +79 m (95% CI, 50-109) greater increase in 6-minute walk distance compared with attention control. In contrast, for those with CRP <9.9 mg/L, the differential benefit of the RI was limited (+0.8 in short physical performance battery [95% CI, 0.1-1.6]; +30 m in 6-minute walk distance [95% CI, -1.0 to 61]). The biomarker levels (except for creatinine) decreased by 12 weeks posthospitalization, but with no differences based on treatment assignment.

Higher inflammation, measured by CRP, may identify older adults recently hospitalized for heart failure with the greatest functional benefit from a physical RI. Biomarker profiling may predict the benefits of this treatment.

URL: https://www.clinicaltrials.gov; Unique identifier: NCT02196038.