Hypochloremia in Older Adults with Heart Failure: From Pathophysiology to Prognosis.

Hypochloremia has recently emerged as an independent prognostic marker in heart failure (HF), which is especially common in older adults, where it represents a main cause of death and hospitalization. This narrative review of the literature aims to summarize the main evidence about the clinical significance of hypochloremia in older adults with HF. Particularly, hypochloremia results from the interplay among neurohormonal activation, congestion, renal dysfunction, and diuretic therapy. In older adults, age-related decline in renal function, frailty, multimorbidity, and polypharmacy increase susceptibility to chloride disturbances. Overall, the prevalence of hypochloremia in HF in older people was estimated to be about 25-29%. Although studies specifically involving older adults with HF remain limited, available data support the prognostic relevance of hypochloremia in this population. Moreover, recent evidence has identified distinct hypochloremic phenotypes, namely dilutional and depletional forms, characterized by different pathophysiological mechanisms. Emerging chloride-centered therapeutic strategies may be particularly relevant in older patients. In conclusion, hypochloremia is confirmed as an important marker of disease severity and adverse prognosis in older patients with HF. Routine assessment of serum chloride may improve risk stratification and support a more individualized therapeutic approach. Further prospective studies are needed to clarify the role of chloride-guided management strategies and their impact on clinical outcomes in older patients with HF.