Spontaneous Coronary Dissection as an Expression of Coronary Artery Disease: Correlation with Vasospasm

Background: Artificial coronary artery dissection is observed occasionally during percutaneous coronary intervention. However, “spontaneous” coronary artery dissection (SCAD) is not common and we tried to clarify its characteristics. Methods and Results: We reviewed the serial diagnostic coronary angiograms of 21,500 patients retrospectively. Sixty-two patients showed linear, longitudinal defects that were considered to be the angiographic expression of SCAD, in at least one major coronary artery. Vasospasm was shown in 38 patients. Among the remaining 24 subjects, 18 patients had chest pain even after all coronary narrowings of ≧50 %were treated with coronary intervention or bypass surgery. Chest pain was relieved promptly with sublingual administration of nitrate. Thus, 56 patients (90.3%) with SCAD were demonstrated or considered to have vasospasm. Fifty-two patients of these 56 individuals showed significant (≧50%) narrowing in at least one of the major coronary arteries. In the remaining 4 subjects, 3 patients subsequently developed significant coronary artery disease. Comparison of coronary risk factors was done in the 38 patients shown to have vasospasm and 144 patients with ordinary coronary artery disease. Smoking was more common in the group with vasospasm but there was no difference with regard to the other risk factors. Conclusion: SCAD seems to be an expression of coronary artery disease. However, vasospasm is a common factor in these patients.