title: Poor tolerance and limited effects of isosorbide-5-mononitrate in microvascular angina.
abstract: OBJECTIVE
  To assess the effects of isosorbide-5-mononitrate (ISMN) in patients with microvascular angina (MVA).
  
  
  METHODS
  We randomized 20 MVA patients, treated with a β-blocker or a calcium antagonist, to 60 mg slow-release ISMN (halved to 30 mg if not tolerated) or placebo once a day for 4 weeks; the patients were then switched to the other treatment for another 4 weeks. Their clinical status was assessed with the Seattle Angina Questionnaire (SAQ) and the EuroQoL score for quality of life. The exercise stress test (EST), coronary blood flow (CBF) response to nitrate and the cold pressor test (CPT), brachial artery flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) were also assessed.
  
  
  RESULTS
  Nine patients (45%) did not complete the ISMN phase due to side effects; 2 patients refused a follow-up. Nine patients completed the study. The SAQ and EuroQoL scores were significantly better with ISMN than with placebo, although the differences were small. No differences were found between the treatments in the EST results, CBF response to nitroglycerin (p = 0.55) and the CPT (p = 0.54), FMD (p = 0.26) and NMD (p = 0.35).
  
  
  CONCLUSIONS
  In this study, a high proportion of MVA patients showed an intolerance to ISMN; in those tolerating the drug, significant effects on their angina status were observed, but the benefit appeared to be modest and independent of effects on coronary microvascular function.
authors: Department of Cardiovascular Sciences, Università Cattolica del Sacro Cuore, Roma, Italy.
authors: Monica
authors: M
authors: Wu
authors: Angelo
authors: A
authors: Villano
authors: Giulio
authors: G
authors: Russo
authors: Antonino
authors: A
authors: Di Franco
authors: Alessandra
authors: A
authors: Stazi
authors: Christian
authors: C
authors: Lauria
authors: Alfonso
authors: A
authors: Sestito
authors: Gaetano A
authors: GA
authors: Lanza
authors: Filippo
authors: F
authors: Crea
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D001916:Brachial Artery / Q000000981:diagnostic imaging; D002121:Calcium Channel Blockers / Q000627:therapeutic use; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015150:Echocardiography, Doppler; D005080:Exercise Test; D005260:Female; D006801:Humans; D007548:Isosorbide Dinitrate / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D008297:Male; D017566:Microvascular Angina / Q000188:drug therapy*; D008875:Middle Aged; D011788:Quality of Life; D014665:Vasodilator Agents / Q000009:adverse effects* / Q000627:therapeutic use*
chemical_list: D000319:Adrenergic beta-Antagonists; D002121:Calcium Channel Blockers; D014665:Vasodilator Agents; D007548:Isosorbide Dinitrate; C030397:isosorbide-5-mononitrate