Characteristics of Patients with an Abnormally Decreased Plasma Xanthine Oxidoreductase Activity in Acute Heart Failure Who Visited the Emergency Department.

BACKGROUND: The factors associated with a low plasma xanthine oxidoreductase (XOR) activity were not elucidated in patients with acute heart failure (AHF). METHODS: Two-hundred and twenty-nine AHF patients who visited the emergency department were prospectively analyzed. AHF patients were divided into 3 groups according to the plasma XOR quartiles (Q1 = low-XOR group [n = 57], Q2/Q3 = middle-XOR group [n = 115], and Q4 = high-XOR group [n = 57]). The prognostic nutritional index (PNI) and the controlling nutritional status (CONUT) score were evaluated. RESULTS: The multivariate logistic regression model showed that the nutritional status (PNI: OR 1.044, 95% CI 1.000-1.088; CONUT: OR 3.805, 95% CI 1.158-12.498), age, and serum creatinine level were independently associated with a low plasma XOR activity. The Kaplan-Meier curve showed a significantly lower incidence of heart failure events in the low-XOR group than in the middle + high-XOR group (hazard ratio, HR 1.648, 95% CI 1.061-2.559). In particular, a low XOR activity with an increased serum creatinine level (>1.21 mg/dL) was independently associated with heart failure events (HR 1.937, 95% CI 1.199-3.130). CONCLUSION: A low plasma XOR activity was associated with malnutrition, renal dysfunction, and aging in AHF. A low XOR activity complicated with renal dysfunction leads to adverse long-term outcomes.

Plasma xanthine oxidoreductase activity in patients with decompensated acute heart failure requiring intensive care.

AIMS: Plasma xanthine oxidoreductase (XOR) activity during the acute phase of acute heart failure (AHF) requires further elucidation. METHODS AND RESULTS: One hundred eighteen AHF patients and 231 control patients who attended a cardiovascular outpatient clinic were prospectively analysed. Blood samples were collected within 15 min of admission from AHF patients (AHF group) and control patients who visited a daily cardiovascular outpatient clinic (control group). Plasma XOR activity was compared between the two groups, and factors independently associated with extremely elevated XOR activity were identified using a multivariate logistic regression model. Plasma XOR activity in the AHF group (median, 104.0 pmol/h/mL; range, 25.9-423.5 pmol/h/mL) was significantly higher than that in the control group (median, 45.2 pmol/h/mL; range, 19.3-98.8 pmol/h/mL). The multivariate logistic regression model showed that serum uric acid (per 1.0 mg/dL increase, odds ratio: 1.280; 95% confidence interval: 1.066-1.536; P = 0.008) and lactate levels (per 1.0 mmol/L increase, odds ratio: 1.239; 95% confidence interval: 1.040-1.475; P = 0.016) were independently associated with high plasma XOR activity (>300 pg/h/mL) during the acute phase of AHF. CONCLUSIONS: Plasma XOR activity was extremely high in patients with severely decompensated AHF. This would be associated with a high lactate value and would eventually lead to hyperuricaemia in patients with AHF.