Usefulness of Repeat Angiography to Establish Spontaneous Coronary Artery Dissection in Small Vessels

Background: Spontaneous coronary artery dissection (SCAD) is a rare disease that is often misdiagnosed, except in typical cases. Although intracoronary imaging and multislice coronary computed tomography angiography (CCTA) are useful in establishing dissection, they may not be feasible in all instances, especially in small vessels. Methods and Results: We describe a series of 7 patients with acute coronary syndrome secondary to small vessel SCAD that was detected only upon repeat coronary angiography (CAG). This cohort had a mean (±SD) age of 50±6 years, was predominantly female (n=6; 86%), and had few coronary risk factors. Three patients (43%) had dissection of the distal segment of the right coronary artery, 3 (43%) had distal left circumflex artery dissection, and 1 patient (14%) had a diagonal branch dissection. None of the patients required percutaneous coronary intervention, and received conservative therapy only, because the infarct area was sufficiently small. No definitive diagnosis of SCAD could be established in any of the patients at first admission because CAG alone or CCTA did not reveal the presence of a flap or intraluminal hemorrhage. However, in such patients without a definitive diagnosis, repeat CAG in the chronic stage showed enlargement of vessels, suggesting the healing of an SCAD. Conclusions: Repeat CAG may be useful for suggesting the occurrence of SCAD.