Nitroglycerine-induced vasodilation in coronary and brachial arteries in patients with suspected coronary artery disease

- Nitroglycerine-induced vasodilation (NID) is measured as a vascular function test.
- NID is thought to represent vascular smooth muscle cell function.
- We measured NID in coronary and brachial arteries in the same patients.
- There was a significant correlation between NID in coronary and brachial arteries.
- Vascular smooth muscle cell dysfunction may be a systemic disorder.

BackgroundNitroglycerine-induced vasodilation, an index of endothelium-independent vasodilation, is measured for the assessment of vascular smooth muscle cell function or alterations of vascular structure. Both coronary and brachial artery responses to nitroglycerine have been demonstrated to be independent prognostic markers of cardiovascular events. The purpose of this study was to evaluate the nitroglycerine-induced vasodilation in coronary and brachial arteries in the same patients.MethodsWe measured nitroglycerine-induced vasodilation in coronary and brachial arteries in 30 subjects with suspected coronary artery disease who underwent coronary angiography (19 men and 11 women; mean age, 69.0 ± 8.8 years; age range, 42-85 years).Results and conclusionsThe mean values of nitroglycerine-induced vasodilation in the brachial artery, left anterior descending coronary artery, and left circumflex coronary artery were 12.6 ± 5.2%, 11.6 ± 10.3%, and 11.9 ± 11.0%, respectively. Nitroglycerine-induced vasodilation in the brachial artery correlated significantly with that in the left anterior descending coronary artery (r = 0.43, P = 0.02) and that in the left circumflex coronary artery (r = 0.49, P = 0.006). There was also a significant correlation between nitroglycerine-induced vasodilation in the left anterior descending coronary artery and that in the left circumflex coronary artery (r = 0.72, P < 0.001). These findings suggest that vascular smooth muscle cell dysfunction is a systemic disorder and thus impairment of endothelium-independent vasodilation in peripheral arteries and that in coronary arteries are simultaneously present. Nitroglycerine-induced vasodilation in the brachial artery could be used as a surrogate for that in a coronary artery and as a prognostic marker for cardiovascular events.