Nitrate-Induced Headache Response in Patients with Coronary Artery Disease and Coronary Artery Ectasia: A Retrospective Case-Control Study

Coronary artery ectasia (CAE), while being considered a variant of atherosclerosis, harbors distinct features that significantly differ from atherosclerosis in terms of pathophysiological mechanisms. On the other hand, headache appears to be the most common side effect of nitrates that have been used traditionally for decades. In this context, we aimed to compare the frequency and temporal characteristics of nitrate-induced headache (NIH) between subjects with sole coronary artery disease (CAD) and subjects with CAD and coexisting CAE. Two hundred and forty-four patients who had undergone coronary angiogram (CAG) and received a single dose of sublingual isosorbide dinitrate during the procedure comprised in this retrospective study population. CAG is performed in the indications due to guidelines. All patients who had undergone CAG were held under close supervision, at least, for 6 h following CAG (and administration of sublingual nitrate); duration and emergence time of NIH were recorded for all patients. Of these 244 patients, 225 patients having sole CAD were assigned to Group I, whereas 19 patients having both CAD and CAE were assigned to Group II. NIH was observed in 19 out of 225 patients (8%) with sole CAD and in 9 out of 19 patients (56%) with CAD and CAE (P = 0.003). The mean interval between the administration of sublingual isosorbide dinitrate and NIH onset was significantly lower in Group II in comparison to Group I (44 ± 14 min vs. 87 ± 63 min, respectively, P = 0.018). However, the duration of NIH was comparable between the two groups (Group I: 203 ± 53 min vs. Group II: 173 ± 61 min, P = 0.24); logistic regression analysis revealed an independent association between NIH and CAE (odds ratio: 11.5, 95% confidential interval: 3.9–33.8, P < 0.001). We have demonstrated that sublingual nitrates might induce NIH more frequently in subjects with CAE and CAD in comparison to those with sole CAD. Furthermore, NIH has been demonstrated to be independently associated with CAE.