Metabolic alkalosis and clinical outcomes in acute heart failure: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVE: To assess the relationship between alkalosis or metabolic alkalosis (MA) and mortality or rehospitalisation in patients with acute heart failure (AHF) through a systematic review and meta-analysis. MATERIALS AND METHODS: PubMed, Scopus and Web of Science were searched from inception to February 2025. Eligible studies included at least 50 patients and evaluated the association between alkalosis or MA and mortality or rehospitalisation in AHF. The review was conducted according to PRISMA guidelines and registered in PROSPERO (CRD42024525906). RESULTS: Of 1,395 potentially relevant publications, five studies were included in the systematic review. The prevalence of alkalosis ranged from 12% to 44%, whereas the prevalence of MA ranged from 3% to 9%. Two retrospective studies found an association between MA and in-hospital mortality, although this finding was not confirmed in other studies. Only one prospective study reported an association between MA and rehospitalisation for AHF at 30 and 90 days of follow-up. Four studies including 19,296 patients were included in the meta-analysis. No significant association was observed between alkalosis or MA and in-hospital mortality (OR 1.43, 95% CI 0.91-2.25 and OR 1.47, 95% CI 0.95-2.27, respectively). CONCLUSIONS: Very few studies have evaluated the relationship between alkalosis or MA and mortality or rehospitalisation in patients with AHF. The prognostic impact of MA in AHF remains uncertain. Meta-analysis showed no significant association between MA and in-hospital mortality. However, the limited available data do not allow robust conclusions to be drawn.