Nitroglycerin-Induced Headache is Associated With Mild Coronary Artery Disease in Patients With Chest Pain

Background and Objectives: We hypothesized that patients with nitroglycerin-induced headache had preserved systemic vasomotion and there might be an increased nitroglycerin-mediated dilation (NMD) response in the brachial artery. The aim of this study is to evaluate whether nitroglycerin (NTG)-induced headache is associated with the level of the NMD and flow-mediated dilation (FMD) or the severity of coronary artery disease (CAD). Subjects and Methods: The study included 87 patients (Group I: mean age: 54.8±9.5 years, 46 males) with headache and new onset chest pain, and 109 patients (Group II: mean age: 57.4±8.9 years, 67 males) without headache and with new onset of chest pain. Patients were excluded from this study if they had a history of chronic headache, long term nitrates use and coronary artery procedures. Coronary angiography was performed within one month after administering nitroglycerin for the usual clinical indications. Results: The clinical characteristics did not differ between the two groups. The NMD was significantly higher in Group I than in Group II (23.0±7.5% vs. 18.5±8.6%, respectively, p<0.001). The FMD was significantly higher in Group I than in Group II (9.0±4.1% vs. 7.5±4.3%, respectively, p=0.007). On multiple regression analysis, NTG-induced headache was a predictor of CAD {odds ratio (OR), 0.04, 95% confidence interval (CI), 0.02-0.11: p<0.001, respectively}. Conclusion: We have shown that the vasodilator response to NTG and FMD are increased in the patients with NTG-induced headache. More NTGinduced headache developed in the patients with normal coronary arteries or minimal CAD than in the patients with obstructive CAD. This finding might be helpful as additional information for evaluating the patients with chest pain syndrome. (Korean Circ J 2008;38:524-528)