Impaired nitrate-mediated dilatation could reflect nitrate tolerance in patients with coronary artery disease

Aim: To investigate whether nitrate-mediated dilatation (NMD) of the brachial artery could be impaired by the use of nitrates and reflect nitrate tolerance in coronary artery disease (CAD) patients. Methods: A total of 243 patients (mean age 61 ± 12 years, 146 male) were recruited before coronary angiography. Gensini score was calculated to assess the severity of CAD. Flow-mediated dilatation (FMD) and NMD of the brachial artery were measured. Results: NMD progressively decreased from subjects without CAD (control group, n = 71) to non-nitrate users (n = 64) and nitrate users (n = 108) with CAD (16.2 ± 6.01% versus 13.4 ± 5.57% versus 9.57 ± 4.52%, P 10), nitrate users (n = 56, 9.00 ± 4.00%) had a significant lower NMD than non-users (n = 28, 12.4 ± 5.45%, P < 0.001), but no difference in other parameters including age, prevalence of hypertension, FMD, Gensini score and use of other medications. Conclusions: The use of nitrates independently impaired NMD in CAD patients. An impaired NMD could be a comprehensive index of nitrate tolerance in patients with CAD. © 2006 Elsevier Ireland Ltd. All rights reserved.link_to_subscribed_fulltex