Treatment of Coronary Aneurysm in Acute Myocardial Infarction with AngioJet Thrombectomy and JoStent Coronary Stent Graft

ABSTRACT: A 54-year-old male with a history of coronary artery disease with a percutaneous transluminal coronary angioplasty and stenting presented to the emergency with an acute myocardial infarction. The patient underwent angiography which showed in-stent thrombosis of the right coronary artery along with 2 aneurysms proximal to the lesion. The right coronary artery was treated with AngioJet rheolytic thrombectomy and the JoStent coronary stent graft. To our knowledge, this is the first report of the use of the AngioJet rheolytic thrombectomy and the JoStent coronary stent graft in acute myocardial infarction. J INVAS CARDIOL 2004;16:294–296 Key words: coronary aneurysm, acute myocardial infarction, coronary stent graft Coronary artery aneurysm is a rare disorder, characterized by the abnormal dilatation of a localized portion or diffuse segments of the coronary artery.¹ The incidence of angiographically detected coronary artery aneurysm is 0.3%-4.9%.¹ The most common etiology of coronary artery aneurysm is atherosclerosis, however other causes include congenital aneurysm, Kawasaki syndrome, connective tissue disorders, infectious arteritis, and those related to coronary trauma, including percutaneous coronary intervention (PCI).² We report a case of coronary aneurysm in acute myocardial infarction (AMI) treated with a polytetrafluoroethylene (PFTE)-covered coronary stent graft (CSG). Case Report. A 54-year-old man with a history of coronary artery disease with a percutaneous transluminal coronary angioplasty and stenting of the proximal right coronary artery (RCA) 2 years ago presented with an AMI. The electrocardiogram (ECG) revealed sinus rhythm and an infarct involving the inferior wall. He was treated in the emergency department with aspirin, metoprolol, intravenous heparin, and eptifibatide and was referred for primary angioplasty. Coronary angiography revealed in-stent thrombosis of the RCA along with 2 aneurysms proximal to the lesion (Figure 1). The left anterior descending artery had mild luminal irregularities, and the proximal left circumflex artery had a 60% stenosis. A 6 French arterial sheath was placed through the right femoral artery for vascular access. Angioplasty of the RCA was performed using a 6 French JCR guiding catheter (Boston Scientific, Maple Grove, Minn.). A temporary right ventricular pacing catheter was inserted. Unfractionated heparin was administered to achieve an activated clotting time greater than 250 seconds. The lesion was successfully crossed with a BMW wire (Guidant Corporation, Santa Clara, Calif.). Rheolytic thrombectomy was performed in the RCA using the AngioJet catheter (Possis Medical, Minneapolis, Minnesota). There was minimal residual angiographically detectable thrombus following 3 passes of the thrombectomy device (Figure 2). There was TIMI 3 flow with no evidence of no-reflow. Intravascular ultrasound (IVUS) was performed to provide detailed characterization of the coronary artery aneurysm’s dimensions (Figure 3). A 19 mm JoStent (JoMed, Helsingborg, Sweden) was hand-crimpled on a 4.0 x 20 mm noncompliant balloon and advanced to the site of the aneurysm. The stent was deployed with high-pressure inflations (18 atm) but was suboptimally expanded in the midportion of the stent. The lesion was postdilated with the 4.0 x 20 mm noncompliant balloon. A 4.5 x 19 mm Ultra stent (Guidant Corporation) was deployed in the area of the thrombosis proximal to the JoStent (Figure 4). After inflation, IVUS was used to confirm the optimal stent expansion and lumen enlargement in the body of the graft (Figure 5). Clopidogrel was added and eptifibatide was continued for 12 hours following PCI. Following the procedure, there was no new the ECG changes or significant elevations of cardiac enzymes. The patient was discharged 2 days after the procedure. Discussion. Post-angioplasty coronary artery aneurysm or pseudoaneurysm formation is rare but is increasingly being described.⁷ Although the exact mechanism of pseudoaneurysm is probably multifactorial and not completely understood, it is believed that histopathological features involve the destruction of the media, and this medial thinning with increased wall stress leads to progressive dilatation of the segment of the coronary artery.⁶ One major complication of coronary artery aneurysm includes the possibility of thrombosis from sluggish or turbulent flow with the propensity for distal embolization and AMI.^3,6 It is speculated that conversion from a laminar to turbulent coronary flow in dilated segments leads to impaired blood flow with increasing coronary luminal enlargement.⁴ Treatment of coronary artery aneurysm includes surgical revascularization with surgical ligation of the aneurysm with distal bypass surgery as well as PCI by sealing of the aneurysm from the coronary lumen with a PTFE-covered CSG and coil embolization with thrombotic occlusion. The rationale for using a CSG is to cover and seal the pseudoaneurysm in order to promote sluggish blood flow leading to stasis and ultimately thrombosis, thereby preventing the expansion and subsequent rupture of the pseudoaneurysm.⁸ The Jostent CSG has been used to treat a variety of coronary artery subsets including coronary perforations, ruptures, aneurysms, degenerated saphenous vein grafts, complex lesions, and in-stent restenosis. To our knowledge, we are the first to report the use of the CSG to treat coronary aneurysm in the setting of AMI. The use of a CSG may be advantageous by preventing the contact of coagulation factors and platelets to the thrombus-containing lesion like the coronary pseudoaneurysm and prevent embolization of thrombi and plaque material.⁵ High-pressure post-dilatation of at least 14 atm to achieve optimal apposition to the vessel wall is essential for a complete and symmetric expansion. To prevent thrombo-occlusive events, the administration of clopidogrel is indicated. The AngioJet rheolytic thrombectomy system has been used to treat the thrombus-laden lesions in AMI. The AngioJet thrombectomy implements multiple high velocity, high pressure saline jets which are introduced through orifices in the distal tip of the catheter to create a localized low-pressure zone (Venturi-Bernoulli effect), resulting in a vacuum effect with the entrainment and dissociation of bulky thrombus. The jets break down thrombus into small particles and propel them proximally through the exhaust lumen, leading to the aspiration and removal of the thrombotic debris without embolization. This prepares the lesion for definitive treatment with coronary artery stenting. In conclusion, the treatment of coronary artery aneurysm in AMI represents a particular challenge to the interventionalist. The appropriate therapy for coronary artery aneurysms remains inconclusive due to the lack of controlled clinical trials. Further evaluation of the treatment of coronary aneurysm in the setting of AMI with the CSG is warranted. Our case demonstrates successful treatment of AMI with AngioJet rheolytic thrombectomy and PTFE-coated JoStent CSG. IVUS is helpful in accurately sizing and demonstrating optimal apposition to the vessel wall.