Plasma volume status predicts prognosis in patients with acute heart failure syndromes

Background: The intravascular compartment is known as the plasma volume, and the extravascular compartment represents fluid within the interstitial space. Plasma volume expansion is a major symptom of heart failure. The aim of the current study was to investigate the impact of plasma volume status on the prognosis of acute heart failure syndromes. Methods and results: We analyzed 1115 patients with acute heart failure syndromes who were admitted to our hospital. These patients were divided into three groups based on their plasma volume status at admission: first tertile (plasma volume status <41.9%, n = 371), second tertile (41.9% plasma volume status <49.0%, n = 372), and third tertile (49.0% plasma volume status, n = 372). Plasma volume status was defined as follows: actual plasma volume = (1 - hematocrit) x [a + (b x body weight)] (a=1530 in males and a=864 in females, b=41.0 in males and b=47.9 in females); ideal plasma volume = c x body weight (c=39 in males and c=40 in females); and plasma volume status = [(actual plasma volume - ideal plasma volume)/ideal plasma volume] x 100 (%). In the Kaplan-Meier analysis, all-cause mortality, cardiac mortality and cardiac events increased progressively from the first to third tertile (p <0.001, respectively). In the Cox proportional hazard analysis, after adjusting for potential confounding factors, plasma volume status was an independent predictor of all-cause mortality (hazard ratio 1.429, p < 0.001), cardiac mortality (hazard ratio 1.416, p = 0.001) and cardiac events (hazard ratio 1.207, p = 0.004). Conclusion: Increased congestion is associated with increased morbidity and mortality in heart failure patients. Plasma volume status, which represents intravascular compartment and congestion, can identify poor prognosis in patients with acute heart failure syndromes.