LAUSR

Acidosis or lactate accumulation is frequently observed in patients with acute decompensated heart failure (ADHF). Although each value can be easily obtained and evaluated by arterial blood sampling, sampling to all patients is difficult in daily clinical practice. Therefore, the prognostic impact of acidosis or lactate accumulation on this condition remains to be identified definitively. The purpose of the study was to verify the effectiveness of selective arterial blood sampling at emergency department in patients with ADHF by evaluating an association with in-hospital mortality. A total of 917 consecutive patients with ADHF from April 2012 to March 2017 were enrolled. We compared baseline characteristics and in-hospital mortality between patients with or without arterial blood sampling. Patients performed blood sampling were assigned to four groups according to the presence or absence of acidosis (PH <7.35) and lactate accumulation (>2.0 mmol/L), and predictive value of acidosis and/or lactate accumulation for in-hospital mortality was calculated by multivariable logistic regression analysis. Of all patients, 689 patients (75.1%) underwent blood sampling. Systolic blood pressure and heart rate at hospital arrival, use of emergency medical service, previous heart failure hospitalization, New York Heart Association classification grade IV, presence of jugular vein distention, and the prevalence of hypertension and dementia, were significantly different between the two groups (P<0.05). There was no difference in the occurrence of in-hospital mortality between patients with or without blood sampling (9.3% in patients with blood sampling versus 9.2% in those without blood sampling, respectively; P=0.972). In 689 patients who underwent blood sampling, we examined combined predictive value of acidosis and/or lactate accumulation for in-hospital mortality by multivariable logistic regression analysis with adjustments for covariates with P<0.05 (age, systolic blood pressure at hospital arrival, left ventricular ejection fraction, and cold profile), and showed that acidosis with lactate accumulation [adjusted odds ratio (OR) 3.30, 95% confidence interval (CI) 1.22–8.93, P=0.019], acidosis without lactate accumulation (adjusted OR 4.06, 95% CI 1.12–14.7, P=0.033), lactate accumulation without acidosis (adjusted OR 2.69, 95% CI 1.14–6.33, P=0.024) were significantly (P<0.05) associated with in-hospital mortality. Our results indicated that patients presenting acidosis without lactate accumulation revealed the highest in-hospital mortality among the four groups. Arterial blood sampling at emergency department could be beneficial for stratifying high risk patients with ADHF. Furthermore, routine blood sampling could be allowed in patients with ADHF if we can secure safety.