Objectives: This study evaluated the relative contribution of serum colloid osmotic pressure (COP) lowering and pulmonary artery wedge pressure (PAWP) elevation in the pathogenesis of pulmonary edema in patients with systolic or isolated diastolic heart failure (DHF).
Background: The role of hypoalbuminemia and the resulting low COP have been shown in some patients with acute systolic heart failure (SHF). Colloid osmotic pressure and PAWP were determined in 100 patients with acute heart failure (HF) (56 with DHF and 44 with SHF; mean age, 78 +/- 12 years), in 35 patients with acute dyspnea from pulmonary origin, and in 15 normal controls. Pulmonary artery wedge pressure was estimated using transthoracic Doppler echocardiography.
Results: Colloid osmotic pressure was significantly lower in the DHF group (20.5 +/- 5 mm Hg) than in the SHF group (24.2 +/- 3.7 mm Hg, p < 0.001), pulmonary disease group (25.1 +/- 4.2 mm Hg, p < 0.001), or normal control group (24.7 +/- 3 mm Hg). Low COP resulted from hypoalbuminemia due to age, malnutrition, and sepsis. Pulmonary artery wedge pressure was significantly higher in patients with SHF (26 +/- 6.3 mm Hg) than in the patients with DHF (20.3 +/- 7 mm Hg, p < 0.001) and was significantly higher in the patients with DHF than in the patients with pulmonary disease (13 +/- 4.2 mm Hg, p < 0.001). The COP-PAWP gradient was similar in patients with SHF (-1.6 +/- 7.1 mm Hg) and patients with DHF (0.7 +/- 6 mm Hg).
Conclusions: Frequent hypoalbuminemia resulting in low COP facilitates the onset of pulmonary edema in patients with DHF who usually have lower PAWP than patients with SHF.