Arteriopathy of the Internal Mammary Artery: Implications for Patients With Spontaneous Coronary Artery Dissection.

backgroundSpontaneous coronary artery dissection (SCAD) is frequently associated with systemic arteriopathies, particularly fibromuscular dysplasia. Although extracoronary arterial screening is recommended, abnormalities of the internal mammary artery (IMA), the usual preferred conduit for coronary artery bypass grafting, is rarely described. CASE SUMMARY: We report 2 women with systemic arteriopathy and recurrent SCAD who had structural abnormalities of the IMA. The first had Loeys-Dietz syndrome and prior cervical artery dissections, presented with neck pain, and was found to have vertebral artery dissection and focal aneurysmal dilation and suspected dissection of the left IMA. The second had multifocal fibromuscular dysplasia involving renal, cervicocephalic, and thoracic arteries, and presented with recurrent SCAD myocardial infarction. Beaded irregularity of the left IMA was noted. Both patients were managed conservatively. DISCUSSION: These cases highlight under-recognized IMA involvement in patients with SCAD and systemic arteriopathy, raising considerations regarding conduit assessment when surgical revascularization is contemplated.