title: In women with symptoms of cardiac ischemia, nonobstructive coronary arteries, and microvascular dysfunction, angiotensin-converting enzyme inhibition is associated with improved microvascular function: A double-blind randomized study from the National Heart, Lung and Blood Institute Women's Ischemia Syndrome Evaluation (WISE).
abstract: BACKGROUND
  We investigated the role of the renin-angiotensin system in women with signs and symptoms of ischemia without obstructive coronary artery disease (CAD). Although microvascular dysfunction has been suggested to explain this syndrome and recently was found to predict adverse outcomes, the mechanisms and treatments remain unclear.
  
  
  METHODS
  In a substudy within the WISE, 78 women with microvascular dysfunction (coronary flow reserve [CFR] <3.0 following adenosine) and no obstructive CAD were randomly assigned to either an angiotensin-converting enzyme inhibition (ACE-I) with quinapril or a placebo treatment group. The primary efficacy parameter was CFR at 16 weeks adjusted for baseline characteristics and clinical site. The secondary response variable was freedom from angina symptoms assessed using the Seattle Angina Questionnaire.
  
  
  RESULTS
  A total of 61 women completed the 16-week treatment period with repeat CFR measurements, and treatment was well tolerated. For the primary outcome, at 16 weeks, CFR improved more with ACE-I than placebo (P < .02). For the secondary outcome of symptom improvement, ACE-I treatment (P = .037) and CFR increase (P = .008) both contributed.
  
  
  CONCLUSIONS
  Microvascular function improves with ACE-I therapy in women with signs and symptoms of ischemia without obstructive CAD. This improvement is associated with reduction in angina. The beneficial response of the coronary microvasculature was limited to women with lower baseline CFR values, suggesting that the renin-angiotensin system may be more involved among women with more severe microvascular defects.
authors: Division of Cardiovascular Medicine, University of Florida, Gainesville, USA.
authors: Daniel F
authors: DF
authors: Pauly
authors: B Delia
authors: BD
authors: Johnson
authors: R David
authors: RD
authors: Anderson
authors: Eileen M
authors: EM
authors: Handberg
authors: Karen M
authors: KM
authors: Smith
authors: Rhonda M
authors: RM
authors: Cooper-DeHoff
authors: George
authors: G
authors: Sopko
authors: Barry M
authors: BM
authors: Sharaf
authors: Sheryl F
authors: SF
authors: Kelsey
authors: C Noel Bairey
authors: CN
authors: Merz
authors: Carl J
authors: CJ
authors: Pepine
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D055806:Microvessels / Q000503:physiopathology; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors