Nonselective Beta Blockers Are Beneficial in Patients with Cirrhotic Ascites and Spontaneous Bacterial Peritonitis: A Propensity-Matched Study

<b>Background:</b> The role of nonselective beta blockers (NSBB) in patients with cirrhosis and spontaneous bacterial peritonitis (SBP) has been a subject of debate. Conflicting studies exist regarding their impact on mortality in this population. This study aims to evaluate the effect of NSBB on mortality in patients with cirrhotic ascites and a history of SBP. <b>Methods:</b> Data were obtained from the TRNETX database, identifying patients aged 18 to 80 years with cirrhosis, ascites, and SBP using ICD-9 and ICD-10 codes. The study period spanned from September 2001 to January 2024. Patients were divided into two groups: those with SBP receiving NSBB (SBP + NSBB), such as carvedilol, nadolol, and propranolol, and those with SBP not receiving NSBB (SBP - NSBB). The primary outcome was all-cause mortality, and the secondary outcome was the development of acute kidney injury (AKI). Outcomes were assessed over a two-year follow-up period. Additionally, we evaluated the association of NSBB use and mortality in cirrhotic ascites by creating two separate cohorts: patients with cirrhotic ascites on NSBB (Ascites + NSBB) and those not on NSBB (Ascites - NSBB). A 1:1 propensity score matching was conducted based on baseline demographics, comorbidities, and laboratory parameters, including creatinine, INR, sodium, albumin, and bilirubin. <b>Results</b>: Before propensity matching, 18,160 patients were identified in the SBP-NSBB cohort, and 14,198 patients were in the SBP + NSBB cohort. After matching, each group comprised 11,801 patients. Patients with SBP who did not receive NSBB therapy exhibited higher mortality than those on NSBB therapy [OR 1.12, 95% CI 1.05-1.21]. Conversely, the incidence of AKI was higher in the SBP + NSBB group [OR 0.91, 95% CI 0.87-0.95]. In the cirrhotic ascites cohort, patients not receiving NSBB (Ascites - NSBB) demonstrated higher mortality compared to those on NSBB (Ascites + NSBB) [OR 1.17, 95% CI 1.13-1.20]. <b>Conclusions</b>: In a propensity-matched analysis of large patient cohorts, NSBB therapy was associated with reduced mortality in both patients with cirrhotic ascites and those with SBP. Despite a higher incidence of AKI in the SBP + NSBB group, NSBB treatment appears beneficial in reducing overall mortality in these populations.