Heart failure in low- and middle-income countries: Background, rationale, and design of the INTERnational Congestive Heart Failure Study (INTER-CHF)

Background Although heart failure (HF) has been referred to as a global epidemic, most HF information comes from high-income countries, with little information about low-income countries (LIC) and middle-income countries (MIC) in Africa, Asia, the Middle East, and South America, which make up the majority of the world's population. Methods The INTERnational Congestive Heart Failure Study is a cohort study of 5,813 HF patients enrolled in 108 centers in 16 LIC and MIC. At baseline, data were recorded on sociodemographic and clinical risk factors, HF etiology, laboratory variables, management, and barriers to evidence-based HF care at the patient, physician, and system levels. We sought to enroll consecutive and consenting patients ≥18 years of age with a clinical diagnosis of HF seen in outpatient clinics (2/3 of patients) or inpatient hospital wards (1/3 of patients). Patients were followed up at 6 and 12 months post-enrollment to record clinical status, treatments, and clinical outcomes such as death and hospitalizations. In the 5,813 enrolled HF patients, the mean age was 59 ± 15 years, 40% were female, 62% had a history of hypertension, 30% had diabetes, 21% had prior myocardial infarction, 64% were recruited from outpatient clinics, 36% lived in rural areas, and 29% had HF with preserved left ventricular ejection fraction. Conclusions This unique HF registry aims to systematically gather information on sociodemographic and clinical risk factors, etiologies, treatments, barriers to evidence-based care, and outcomes of HF in LIC and MIC. This information will help improve the management of HF globally.