title: Impact of ramipril on the circadian periodicity of acute myocardial infarction.
abstract: Onset of acute myocardial infarction (AMI) follows a diurnal periodicity, with a peak incidence between 6:00 a.m. and noon. Beta blockers and aspirin decrease the rate of AMI and blunt the peak incidence, but such an effect has not been evaluated for angiotensin-converting enzyme inhibitors. The effect of ramipril on onset of symptomatic AMI was evaluated in 4-hour periods over a 24-hour cycle in men and women who were > or =55 years of age, had cardiovascular disease or diabetes mellitus with > or =1 other risk factor, and participated in the Heart Outcomes Prevention Evaluation (HOPE) trial. During the 4.5-year follow-up, AMI was documented in 383 of 4,596 participants allocated to ramipril and in 491 of 4,598 participants allocated to placebo (8.3% vs 10.7%, p <0.001). Ramipril decreased rates of AMI at each period and attenuated, but did not blunt, the peak incidence. In conclusion, inhibiting angiotensin-converting enzyme decreased AMI over a 24-hour period, but this enzyme does not seem to play a major role in the circadian periodicity of this acute event.
authors.affiliation: University Heart and Lung Institute, Laval Hospital, and the Department of Medicine, Laval University, Quebec, Quebec, Canada.
authors.forename: Gilles R
authors.initials: GR
authors.lastname: Dagenais
authors.forename: Janice
authors.initials: J
authors.lastname: Pogue
authors.forename: Koon K
authors.initials: KK
authors.lastname: Teo
authors.forename: Eva M
authors.initials: EM
authors.lastname: Lonn
authors.forename: Salim
authors.initials: S
authors.lastname: Yusuf
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002940:Circadian Rhythm; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000517:prevention & control; D017257:Ramipril / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D017257:Ramipril