Background: Angiotensin converting enzyme inhibitors (ACEIs) are widely prescribed. While ACEIs are usually initiated for lifelong treatment, many patients stop or switch treatment. Exploration of such patterns is important because the discontinuation of these drugs is associated with poor clinical outcomes. Objectives: The aim of this study was to study usage patterns for different indications of ACEIs. Methods: We defined a cohort of patients older than 45 years who started ACEI treatment between 2007 and 2013 in the Clinical Practice Research Datalink (CPRD). Indications for ACEI treatment (hypertension (HTN), heart failure (HF), myocardial infarction (MI), renal failure (RF), or combinations of them (COT)) were retrieved from the medical records, and duration of ACEI treatment was calculated. We distinguished between continuous use, discontinued use, switch to an alternative drug, and restart, considering 6 months time interval between two prescription periods. Five-year persistence among the different indications was calculated using the Kaplan-Meier method, and times to discontinuation were compared using the log-rank test. Results: In total, 222058 patients initiating ACEIs were identified with the following indications: HTN (68.2%), MI (5.1%), RF (4.4%), HF (1.9%), and COT (20.4%). Five-year persistence rates were 62.4% for HF, 58% for HTN, 70.1% for MI, 45.5% for RF, and 55% for COT. Time to discontinuation was significantly different between indications (log-rank p-valu
