Clinical Epidemiology, Phenotypes, and Seasonal Patterns of Heart Failure Among Hospitalized Patients in Northeastern Nigeria: A Five-Year Multicenter Retrospective Study

Abstract Background: Heart failure (HF) poses a significant healthcare burden globally, with varying epidemiological profiles across regions. This study aimed to describe the clinical epidemiology, echocardiographic phenotypes, temporal trends, and seasonal patterns of HF admissions in northeastern Nigeria. Methods: This retrospective study was conducted among patients admitted with HF between 2018 and 2022. Data on socio-demographic characteristics, clinical presentation, aetiology, New York Heart Association (NYHA) functional class, echocardiographic left ventricular ejection fraction (LVEF) phenotypes, and seasonal admission patterns were extracted and analyzed using descriptive statistics. Results: A total of 620 HF patients were admitted during the study period. The mean age was 50.7 ± 19.2 years, and 59.2% were female. Most patients were married (89.5%) and economically dependent or unemployed (55.3%). The predominant symptoms were orthopnoea/paroxysmal nocturnal dyspnoea (77.1%), cough (75.0%), and peripheral oedema (64.6%). Hypertensive heart disease was the leading aetiology (64.1%), followed by peripartum cardiomyopathy (18.4%). Among patients with echocardiography, HF with reduced ejection fraction (HFrEF) was the most common phenotype, with a mean LVEF of 35.6 ± 20.9%. HF admissions increased over time, with a marked reduction in 2020, followed by a rebound in subsequent years. A statistically significant seasonal pattern was observed, with higher admissions during the second and third quarters of the year. Conclusion: Heart failure in Northeastern Nigeria predominantly affects middle-aged individuals, with a significant burden from hypertensive heart disease. Late-stage presentations were frequent, and admissions demonstrated clear temporal variation and significant seasonal clustering, suggesting important environmental and infectious contributions to acute heart failure decompensation.