Diagnostic value of nitroglycerin-induced headache as a negative predictor of coronary atherosclerosis.

The purpose of the present study was to clarify the possible relationship between nitroglycerin (NTG)-induced headache and both vascular functional and organic atherosclerosis. The study included 96 patients with NTG-induced headache (group I: 54.7±9.5 years, 52 males) and 204 patients without headache (group II: 58.1±9.1 years, 127 males) who suffered from new-onset chest pain. Flow-mediated dilation and nitroglycerin-mediated dilation were significantly greater in group I than in group II (8.8±4.1% vs. 7.1±3.5%, p=0.001, and 23.1±7.3% vs. 17.1±11.8%, p<0.001, respectively). The carotid intima-media thickness was significantly smaller in group I than in group II (0.55±0.15 mm vs. 0.67±0.22 mm, p=0.001). Heart-carotid pulse wave velocity was significantly lower in group I than in group II (784.5±160.1 m/s vs. 979.1±215.6 m/s, p=0.003). In the multiple regression analysis, the absence of NTG-induced headache was a predictor of coronary artery disease (CAD) (odds ratio: 17.89, 95% confidence interval: 7.89-40.02, p<0.001). NTG-induced headache developed more frequently in patients with normal coronary arteries or minimal CAD than in patients with obstructive CAD. The presence of NTG-induced headache might be helpful and provide additional information in evaluating patients with chest pain syndrome.