Surfactant proteins changes after acute hemodynamic improvement in patients with advanced chronic heart failure treated with Levosimendan

Abstract

Alveolar-capillary membrane evaluated by carbon monoxide diffusion (DLCO) plays an important role in heart failure (HF). Surfactant Proteins (SPs) have also been suggested as a worthwhile marker. In HF, Levosimendan improves pulmonary hemodynamics and reduces lung fluids but associated SPs and DLCO changes are unknown. Sixty-five advanced HF patients underwent spirometry, cardiopulmonary exercise test (CPET) and SPs determination before and after Levosimendan. Levosimendan caused natriuretic peptide-B (BNP) reduction, peakVO₂ increase and VE/VCO₂ slope reduction. Spirometry improved but DLCO did not. SP-A, SP-D and immature SP-B reduced (73.7 ± 25.3 vs. 66.3 ± 22.7 ng/mL*, 247 ± 121 vs. 223 ± 110 ng/mL*, 39.4 ± 18.7 vs. 34.4 ± 17.9AU*, respectively); while mature SP-B increased (424 ± 218 vs. 461 ± 243 ng/mL, * = p < 0.001). Spirometry, BNP and CPET changes suggest hemodynamic improvement and lung fluid reduction. SP-A, SP-D and immature SP-B reduction indicates a reduction of inflammatory stress; conversely mature SP-B increase suggests alveolar cell function restoration. In conclusion, acute lung fluid reduction is associated with SPs but not DLCO changes. SPs are fast responders to alveolar-capillary membrane condition changes.

Keywords: Alveolar capillary membrane; Gas diffusion; Surfactant proteins.