OBJECTIVES: Heart failure is a frequent cause of hospitalisation among older patients. This study examines the principal factors leading to acute decompensation of heart failure leading to hospital admission and considers whether these factors are avoidable. METHODS: We conducted a retrospective casenote study of all patients admitted to the department of Geriatric Medicine over a 2 year period who had a principal discharge diagnosis of heart failure (ICD codes 428.0, 428.1, 428.9). Demographic and clinical data on medical history, clinical examination, radiographic findings, echocardiography, blood tests and medications was collected. Each case was evaluated to determine the factor that contributed most to heart failure decompensation. Main factors leading to hospitalisation included: volume overload if patient had all signs of hypervolaemia (pedal oedema, elevated jugular venous pressure, pulmonary crepitations and dilutional hyponatraemia), tachyarrhythmia if heart rate was >150 beats per minute, or uncontrolled hypertension if systolic blood pressure >180mmHg. RESULTS: The study sample included 145 patients. Mean (SD) age was 82(5) years and 74 (51%) were women. All patients were taking diuretics and 75 (51.5%) were taking angiotensin converting enzyme inhibitors. Twenty two (15.2%) were taking non steroidal anti-inflammatory drugs (NSAIDs). Risk factors for admission were identified in this rank order: volume overload 52 (35.9%) patients, chest infection 26 (17.9%) patients, combination of volume overload and chest infection 19 (13.1%) patients, myocardial infarction 17 (11.7%) patients, tachyarrhythmia (mainly atrial fibrillation) 9 (6.2%) patients, uncontrolled hypertension 10 (6.9%) and pulmonary embolus 1 (0.7%). In 11 (7.6%) patients no precipitating factor could be determined. Of the 52 patients with volume overload 12 (23.1%) were receiving NSAIDs on admission. CONCLUSIONS: Our findings show that factors leading to hospitalisation for heart failure may be amenable to intervention, particularly volume overload. Patient education regarding diet and medication, especially NSAIDs, and regular monitoring of blood pressure should be considered.