Angiotensin converting enzyme inhibitors prescribing pattern for different indications: A population based study

Objectives: To investigate whether usage patterns differ for different indications of angiotensin converting enzyme inhibitors (ACE-inhibitors). Methods: Patients older than 45 years who started ACE-inhibitor treatment between January 2007 and January 2014 were selected in the Clinical Practice Research Datalink (CPRD). Indications for ACE-inhibitor treatment were retrieved from the medical records. Stratified by indication we distinguished between continuous use, discontinued use, switch to an alternative drug, and restart, considering a 6 months' time interval between two prescription periods. Five-years persistence rates among the different indications were calculated using the Kaplan-Meier method and compared by the log-rank test. Results: In total 276,977 patients initiating ACE-inhibitors were identified with the following indications: hypertension (56.9 %), myocardial infarction (4.3%), renal failure (3.7%), heart failure (1.6%), combinations of them (17%) and none of the above (16.5%). Five-year persistence rates ranged from 44.1% for renal failure to 68.9% for myocardial infarction (p<0.0001). Heart failure and renal failure patients used ACE-inhibitors for the shortest period of time (average 21.8 and 21.9 months, respectively). Within the discontinuation group the percentages of switchers ranged from 35.9% for renal failure to 53.9% for hypertension (61.0% switched to an angiotensin II-receptor blocker) and for the restarter group ranged from 15.0% for heart failure to 18.1% for the group without indication retrieved. Conclusions: Dependent on the indication the rates of ACE-inhibitor discontinuation differ. Patients with renal failure are most likely to discontinue treatment.