Clinical and epidemiological characterization of heart failure patients in a high-altitude setting: a retrospective study at a tertiary hospital in Quito, Ecuador.

Background: Heart failure (HF) is a major global health problem and a leading cause of morbidity and mortality. In Latin America, evidence remains limited, and HF characterization in high-altitude care settings is underreported. Quito (-2,800 m a.s.l.) provides a unique clinical context, although retrospective hospital-based data without standardized hypoxia phenotyping or sea-level comparators cannot support altitude-specific causal inference. Objective: This study aims to describe the clinical and epidemiological characteristics of patients diagnosed with HF at the Metropolitan Hospital of Quito, a tertiary care facility located at an altitude of approximately 2,800 meters, from January 2021 to December 2023. Methods: A retrospective observational study was conducted using anonymized medical records of 122 patients diagnosed with HF (ICD-10 codes I500, I501, I509). Data on demographic, clinical, and outcome variables were collected. Exploratory comparisons were performed by discharge survival status (alive vs. deceased) using chi-square or Fisher's exact tests for categorical variables and two-sample Student's Results: Most patients (88.5%) were aged over 65 years, with men comprising 55.7% of the cohort. Hypertension (59.8%), dyslipidemia (18.9%), and atrial fibrillation (44.3%) were the most prevalent comorbidities. Hypertensive heart disease was the most frequent documented etiology of HF (14.8%), although etiology was unavailable in a substantial proportion of records. In-hospital mortality was low (3.3%). Exploratory univariate analyses identified unadjusted associations between in-hospital mortality and dialysis dependency, immunologic diseases, and other vascular diseases. Conclusions: This study provides a contemporary clinical and epidemiological profile of HF patients managed at a high-altitude tertiary hospital in Quito and identifies exploratory factors associated with in-hospital mortality in this care setting. Future multicenter studies incorporating standardized hypoxia-related measurements and appropriate comparator cohorts are needed to better understand HF phenotypes and outcomes in Andean populations.