Glutathione s-transferase pi is a marker of loop diuretic resistance in patients with congestive heart failure exacerbation

Abstract Background Loop diuretic resistance (LDR) in patients with heart failure (HF) exacerbation is associated with worse clinical outcomes, greater symptom burden and mortality. Diagnosis and treatment of LDR remains a significant clinical dilemma. Purpose To assess the ability of different urine biomarkers to predict LDR in patients with HF exacerbation. Methods Consecutive patients with congestive HF exacerbation were prospectively included in the study. HF was diagnosed according to ESC 2021 HF Guidelines definition. Congestion was defined as a presence of one or more of the following signs: edema, ascites, pleural effusion. LDR was defined as persistent congestion on the 4th day of hospital stay despite high i.v. loop diuretic dose. Urine biomarkers released from different parts of the nephron (Kidney Injury Molecule-1 - KIM-1, N-acetyl-β-D-glucosaminidase - NAG, uromodulin, glutathione S-transferase Pi - pi-GST, aquaporin-2), transthoracic echo, clinical and biochemical parameters were evaluated on the 1st and 4th day of hospital stay. Results are presented as mean ±standard deviation or median (interquartile range). Results 40 patients were included in the study with median age 84 (72,8; 86) years, median left ventricle ejection fraction (EF) 35.3 (26,5; 49) %, median NT-proBNP 8967.5 (3024; 15241) pg/ml. LDR was found in 14 (35%) patients. Univariate analysis identified the following risk factors for LDR: urine pi-GST concentration on admission and on the 4th day, right ventricle to pulmonary circulation coupling index (TAPSE/PASP ratio), presence of mitral regurgitation, serum creatine concentration, serum urea concentration, serum LDL concentration. Logistic regression analysis identified pi-GST concentration as a significant independent risk factor for LDR in this population: odds ratio (OR) 5.75 [95% confidence interval (CI) 1.271–25.990]. Conclusions Urine pi-GST on admission and after 4 days of treatment might be a marker for a development of LDR in patients with congestive HF exacerbation.