Abstract

Background

The comorbidity of heart failure (HF) and stroke is associated with delayed stroke recovery, prolonged hospitalization, and a decreased quality of life. HF can lead to acute cerebral injury, while conversely, acute cerebral injury can exacerbate HF by disrupting neural and cardiovascular regulation. This association is now recognized as the "cardio-cerebral syndrome" and the "stroke-heart syndrome," endorsed by the European Society of Cardiology (ESC). However, in many cases of newly diagnosed stroke patients, the appropriate diagnosis of HF is often overlooked.

Brain natriuretic peptide (BNP) and the N-terminal prohormone of BNP (NT-proBNP) are used for HF screening and risk assessment. Nevertheless, their potential as predictive markers for functional independence in post-acute stroke patients remains uncertain.

Purpose

This study aimed to investigate the correlation between BNP or NT-proBNP levels and walking independence in patients with ischemic or hemorrhagic stroke during the post-acute phase.

Methods

This retrospective observational study included 650 post-acute phase ischemic or hemorrhagic stroke patients admitted to our hospital for rehabilitation between February 2019 and December 2022, all of whom underwent BNP or NT-proBNP testing upon admission. Patients were categorized into two groups: those with BNP≥200 pg/ml or NT-proBNP≥900 pg/ml ("High group") and those without ("Low group"). We examined the relationship between BNP or NT-proBNP levels and ambulatory independence within 90 days using multivariable logistic regression analysis. We also performed subgroup analyses to take into account factors such as age, atrial fibrillation, obesity and renal function that may affect BNP or NT-proBNP levels. Walking independence was defined as the ability to walk without assistance or supervision, irrespective of the use of walking aids and orthoses.

Results

The mean age of the subjects was 75.1±11.2 years, with males comprising 53.2% of the population. One hundred and seven patients (16.4% of the total) were classified as the High group. High BNP or NT-proBNP levels were significantly associated with difficulty walking independently within 90 days after adjusting for other functional prognostic factors (odds ratio, 2.62; 95% confidence interval, 1.30-5.27; p=0.007). Furthermore, even in subgroup analyses with factors influencing BNP or NT-proBNP levels, elevated BNP or NT-proBNP levels were associated with difficulty walking independently within 90 days (p<0.05, respectively).

Conclusions

Our findings suggest that elevated serum levels of BNP or NT-proBNP may serve as functional prognostic indicators in post-acute stroke patients.