Assessing fluid volume and determining outcomes of acute heart failure using plasma human atrial natriuretic peptide.

BACKGROUND: The post-dialysis plasma level of human atrial natriuretic peptide (hANP) reflects the fluid volume in patients on hemodialysis. The threshold hANP level is reportedly 100 pg/mL; however, the clinical usefulness of the threshold hANP level for volume control has not been sufficiently studied. METHODS: We conducted a single-center, retrospective, observational study that included 156 hemodialysis patients without atrial fibrillation. First, we examined the usefulness of the threshold hANP level (100 pg/mL) for predicting hypoxemia due to congestion in a short-term observational study from December 30, 2015 to January 5, 2016. Subsequently, we conducted a 5-year follow-up study wherein the outcomes were hospitalization due to acute heart failure (AHF), development of cardiovascular diseases (CVD), and all-cause death. Finally, we collected echocardiography data to investigate the relationship between cardiac function and hANP. RESULTS: Our short-term observational study showed that patients with an hANP level ≥ 100 pg/mL developed hypoxemia due to congestion (odds ratio, 3.52; 95% confidence interval, 1.06-11.71; P = 0.040). At the 5-year follow-up, patients with an hANP level ≥ 100 pg/mL had significantly higher rates of hospitalization due to AHF, CVD, and all-cause death based on the log-rank test (P = 0.003, P = 0.019, P < 0.001, respectively). Cardiac disfunctions were significantly associated with the high hANP level. CONCLUSIONS: The hANP level is indicative of both fluid volume and cardiac dysfunction. A threshold hANP level of 100 pg/mL can serve as a predictive marker for AHF and a practical indicator for volume control.