Pascual-Figal Domingo A, Sánchez-Más Jesús, de la Morena Gonzalo, Casas Teresa, Garrido Iris P, Ruipérez Juan A, Valdés Mariano
Unidad de Insuficiencia Cardiaca, Servicio de Cardiología, Hospital Universitario Virgen de la Arrixaca, Departamento de Medicina Interna, Universidad de Murcia, Murcia, Spain.
Rev Esp Cardiol. 2009 Feb;62(2):136-42. doi: 10.1016/s1885-5857(09)71531-2.
Surfactant protein B (SP-B) is a marker of damage to the alveolar-capillary barrier that could be useful for monitoring functional impairment in patients with chronic heart failure (HF).
Dyspnea-limited cardiopulmonary exercise testing was carried out in 43 outpatients with chronic HF (age 51+/-10 years, 77% male, left ventricular ejection fraction [LVEF] 33+/-11%). Peripheral blood serum samples were obtained at rest and during the first minute of peak exercise. The presence and concentration of SP-B in the serum samples were determined by Western blot analysis.
At rest, SP-B was detected in 35 (82%) patients compared with only six (23%) healthy volunteers in a control group (n=26, age 51+/-10 years, 77% male). The median circulating SP-B level was higher in HF patients, at 174 [interquartile range, 70-283] vs. 77 [41-152] (P< .001) in the control group. In HF patients, the presence of circulating SP-B was associated with a lower LVEF (31.4+/-9.6% vs. 41.8+/-15%; P=.01). Multivariate analysis showed that the resting SP-B level correlated with a greater VE/VCO2 slope (beta=1.45; P=.02). The peak-exercise SP-B level correlated almost perfectly with the resting level (r=0.980; P< .001), but there was no significant increase with exercise (P=.164). Nor was there a correlation with any other exercise parameter.
In patients with chronic HF, the level of pulmonary surfactant protein B in the peripheral circulation is increased and is correlated with ventilatory inefficiency during exercise, as indicated by the VE/VCO2 slope.
