DOI: 10.1177/02676591261476511 ISSN: 0267-6591

Serum aquaporin-1 increases with heart failure and aortic valve surgery with cardiopulmonary bypass

María Teresa Politi, Mailén Blanco, Sebastián Raúl Fonseca, Raúl Ferreyra, Guillermo Bortman, Antonio Piazza, Gisela Di Giusto, Claudia Capurro

Introduction

Serum aquaporin-1 increases with inflammation and edema. However, its role as a cardiovascular biomarker remains unexplored. The goal of this study is to evaluate serum aquaporin-1 concentrations across two distinct clinical settings characterized by myocardial stress and congestion: acute heart failure and surgical aortic valve replacement with cardiopulmonary bypass.

Methods

This observational study included healthy volunteers ( n = 8), acute heart failure patients ( n = 11), and surgical aortic valve replacement patients ( n = 11). Serum aquaporin-1 was measured using ELISA. Myocardial biopsies were obtained for aquaporin-1 and aquaporin-4 protein quantification before and after cardiopulmonary bypass in six patients.

Results

Serum aquaporin-1 levels were significantly higher in acute heart failure (3,921 ± 1,396 pg/mL; p = 0.0006) and surgical aortic valve replacement patients (3,318 ± 1,394 pg/mL; p = 0.0070) compared to healthy volunteers (1,755 ± 807 pg/mL). These differences remained significant after adjusting for sex and age. All patients with low cardiac output had serum aquaporin-1 concentrations in the upper half of their group distribution. Serum aquaporin-1 correlated moderately with B-type natriuretic peptide (r = 0.40; p = 0.0265), C-reactive protein (r = 0.42; p = 0.0203), and erythrocyte sedimentation rate (r = 0.45; p = 0.0117). Following cardiopulmonary bypass, myocardial aquaporin-1 increased (73%; p = 0.0310), while aquaporin-4 decreased (53%; p = 0.0440), with a strong but non-significant correlation between cardiac and serum aquaporin-1 changes.

Conclusion

Serum aquaporin-1 levels are elevated in acute heart failure and post-surgical aortic valve replacement patients, particularly in those with low cardiac output.

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