Association of urinary liver-type fatty acid-binding protein with outcomes after adrenalectomy for unilateral primary aldosteronism

Background and Aims: This study explored the association between urinary liver-type fatty acid-binding protein to creatinine (uL-FABP-cre) ratio and postoperative clinical failure in unilateral primary aldosteronism (PA) patients undergoing adrenalectomy.Materials and Methods: Data from the Taiwan Primary Aldosteronism Investigation Group database were analyzed, including patients with unilateral PA who had adrenalectomy between December 2015 and October 2018. Statistical methods included generalized additive modeling, logistic regression analysis, net reclassification improvement (NRI), and the C statistic.Results: In the study cohort of 131 patients (mean age 52.3 & PLUSMN; 10.8 years; 43.5% male), 117 achieved clinical success, while 14 experienced clinical failure. A uL-FABP-cre ratio >5 predicted clinical failure (odds ratio: 6.22, p = 0.005). Subgroup analysis revealed its efficacy in predicting clinical failure in patients with BMI > 24 kg/m2, normokalemia, or <5 years of hypertension. Furthermore, incorporating uL-FABP-cre ratio into the Primary Aldosteronism Surgical Outcome (PASO) score significantly improved predictive ability. The addition increased the C statistic from 0.671 to 0.762 (p < 0.01) and improved category-free NRI by 0.675 (p = 0.014). Conclusion: A uL-FABP-cre ratio >5 accurately predicted clinical failure post-adrenalectomy in unilateral PA, enhancing PASO score's identification of high-risk patients for postoperative clinical failure.