Excessively Enlarged Right Coronary Artery Aneurysm With Intramural Thrombus Causing Recurrent Acute Coronary Syndrome
A 45-year-old man was admitted to our hospital with exertional chest pain. He had been diagnosed with membranoproliferative glomerulonephritis at the age of 20 and had undergone kidney transplantation at the age of 33. After that, he had taken some immunosuppressant drugs and steroids.
Two years previously, he had presented with acute chest pain. On that occasion, cardiac enzymes were not elevated, but ECG showed the inversion of the T waves in II, III, aVF, V5, and V6 leads. We diagnosed angina pectoris and performed cardiac catheterization. Cardiac catheterization revealed a 75%-stenosed left anterior descending coronary artery (LAD) and a giant right coronary artery (RCA) aneurysm (50 mm) with intramural thrombus. Because the intravascular lumen of the RCA had been kept, we diagnosed a microembolism of the distal RCA by the intramural thrombus. We decided to administer warfarin potassium as anticoagulant therapy. After that, he was followed up at our hospital as an outpatient.
On the present occasion, ECG showed Q waves in III and aVF leads, slight ST elevations in II, III, and aVF leads, and ST depressions in V4 and V5 leads (Figure 1), indicating inferior wall infarction. Cardiac catheterization and cardiac magnetic resonance imaging (CMR) revealed an occluded LAD and an excessively enlarged RCA aneurysm with increasing intramural thrombus, communicating proximally with the RCA ostium and distally with the distal RCA (segmentation No. 4). The maximum diameter of the proximal and distal RCA aneurysms were 64 and 49 mm, respectively (Figures 2 and 3⇓ and online-only Data Supplement Movies I through III). Resting first-pass perfusion CMR images with gadodiamide demonstrated regional hypoperfusion at the RCA perfusion area, indicating disturbed flow and comparatively slow blood flow rate as a result of the RCA aneurysm (Figure 4A and online-only Data Supplement Movie IV). Delayed-enhancement images demonstrated regional contrast enhancement at the inferior wall, indicating myocardial infarction as a result of intramural thrombus of the RCA aneurysm (Figure 4B). The atherosclerosis and the aneurysm were progressing at speed. The revascularization procedure to the LAD and the RCA and the excision of the aneurysm were necessary because of the impending rupture. The left internal thoracic artery was anastomosed to the LAD, and a saphenous vein graft and radial artery were anastomosed to the distal RCA (segmentation No. 4AV and 4PD). The RCA aneurysm was then opened, and thrombectomy and ligation of both ends of the aneurysm were performed. The patient’s postoperative course was uneventful, and we have continued with careful medical management.
The online-only Data Supplement can be found with this article at http://circ.ahajournals.org/cgi/content/full/118/10/e145/DC1.