1614: The Serum Levels of Renin and Aldosterone in Patients With Out-of-Hospital Cardiac Arrest

Introduction: Although epinephrine (Ep) is the first choice as a vasopressor in cardiopulmonary resuscitation (CPR), its role in CPR is still controversial. Renin and aldosterone are hormones which have important roles in circulation, however, those dynamics in serum in patients with cardiopulmonary arrest (CPA) are unclear. The aim of this study is to evaluate the relation between serum concentration of renin and aldosterone and return of spontaneous circulation in patients with CPA. Methods: This prospective, observational, clinical study was approved by the ethics committee of Gunma University Hospital (IRB2020-044). The serum concentrations of renin, aldosterone and catecholamines such as Ep, norepinephrine (Nep) and dopamine (DOA) in out-of-hospital cardiac arrest (OHCA) patients transferred to our hospital were measured using blood samples obtained immediately upon arrival to our hospital between November 2020 to May 2025. Patients were divided into two groups; ROSC(+) and ROSC(-) groups. The serum levels of catecholamines and renin and aldosterone, as well as the conditions of resuscitation prior to and after arrival at the hospital, were compared between the two groups. Data were shown as the median (Q1, Q3) or actual numbers. Mann-Whitney U test, Fisher exact test or chi-squared test were used for comparisons. Statistical significance was defined as p value of less than 0.05. Results: We evaluated 131 OHCA patients in this study, and the ROSC(+) and the ROSC(−) groups included 27 and 104 patients, respectively. There were no significant differences in age, the duration between the CPR start and 1st administration of Ep, and the total dosage of administered Ep before blood collection. The serum concentration of Ep and DOA was higher in ROSC(+) group than ROSC(-) group without significant differences. The serum renin concentration was almost same between the two groups, however, the serum aldosterone level was significantly higher in the ROSC(+) group 83.8 (35.6, 174.0) pg/ml than in the ROSC(-) group 46.3 (22.4, 94.4) pg/ml, p=0.043. Conclusions: There is a possibility that the serum aldosterone level is associated with ROSC in OHCA patients.