CLINICAL DECISION MAKING

PCI for Totally Occluded Site Consisting of Huge Thrombus

Naotsugu Oyama, MD, Kazushi Urasawa, MD, Hidetsugu Sakai, MD, Akira Kitabatake, MD
Naotsugu Oyama, MD, Kazushi Urasawa, MD, Hidetsugu Sakai, MD, Akira Kitabatake, MD
Case Report. A 53-year-old male was admitted to our hospital complaining of persistent chest pain. He was diagnosed as having acute posterior myocardial infarction based on the clinical findings of ST segment elevation in posterior ECG leads and echocardiographic posterior-lateral wall motion abnormality. Emergency coronary angiography (CAG) revealed total occlusion of the distal left circumflex coronary artery. The culprit lesion was successfully treated with primary implantation of a 4.0 X 13 mm ACS Multi-Link RX Tristar stent (Guidant Corporation, Santa Clara, California). CAG also revealed a 90% stenosis of the left anterior descending coronary artery (LAD). Directional coronary atherectomy (DCA) for the LAD lesion was planned one month later. Control CAG before DCA, however, showed a total occlusion at the proximal site of the LAD (Figure 1A). We succeeded in crossing a guidewire to a distal portion. After the target lesion had been dilated by a 2.0 mm Apollo balloon catheter (Avantec Vascular Corporation, Sunnyvale, California), CAG and intravascular ultrasound (IVUS) conclusively revealed the existence of a huge thrombus within a large proximal LAD. In order to avoid distal embolism, we decided to perform thrombolysis and thrombectomy prior to DCA. An infusion catheter (Lumine, Tokai Medical Products) was advanced to just proximal to the target lesion, and 1,500 units of pro-urokinase were injected through the infusion catheter. After removing the infusion catheter, we attempted thrombectomy using a thrombuster catheter (Kaneka). However, only a limited amount of thrombus was removed through the catheter. Although the same procedure was repeated 4 more times to achieve optimal angiographic findings, a sphere-shaped thrombus remained within the proximal LAD (Figure 1B). An additional intervention procedure seemed to be inappropriate because of the remaining thrombus and positively remodeled proximal LAD, whose diameter was 6 mm. Thus, we attempted to reduce the volume of the thrombus by using systemic thrombolytic therapy (240,000-unit urokinase and 12,000-unit heparin per day) for a week. One week later, a control CAG revealed the disappearance of the thrombus, and preceded to DCA to this lesion as planned (Figure 2A). A Fexicut-L (Guidant) was advanced to the site and an atherectomy was carried out 13 times. After optimal debulk was confirmed by IVUS, an additional 4.0 X 23 mm ACS Multi-Link RX Tristar stent (Guidant) was deployed at the target lesion appropriately. Post-procedural CAG revealed a satisfactory coronary flow and angiographical findings (Figure 2B). There was no leak of creatine kinase after the procedure. How Would you Manage this Case? Rafael Beyar, MD, DSc Dean, Bruce Rappaport Faculty of Medicine, Technion Women’s Division/Dr. Phillip and Sarah Gottlieb Professor, Medicine and Biomedical Engineering Director, Division of Invasive Cardiology, Rambam Medical Center, Haifa, Israel A challenging case is presented in this case by Dr. Oyama et al. A young patient with an acute myocardial infarction was treated with primary PCI for an occluded distal circumflex artery, and a 90% LAD lesion was staged for a month later and planned for Directional Coronary Atherectomy (DCA) due to is bulky appearance. Upon angiography a month later (second procedure) the LAD was shown to be totally occluded. Partial re-canalization with a wire and predilatation showed a huge thrombus in the LAD, which could not be adequately resolved with intracoronary Pro-Urokinaze or thrombectomy using a "Thrombuster" catheter (Kaneka). The procedure was then deferred and a systemic thrombolytic therapy was given. A week later (Third procedure) complete resolution of the thrombus was observed and debulking by directional atherectomy followed by stenting was uneventful. Three different aspects are discussed below: 1. Staging the procedure. 2. Using thrombolysis vs. mechanical distal protection 3. Debulking as a strategy for proximal bulky lesions. Staging: In our institute this patient would most likely be treated at the time of PCI in the infarct related artery only, and the lesion in the LAD would have been deferred for 2–4 weeks. The few reasons to continue and treat a non-infract related artery at the same session is suspicion or evidence for further active ischemia in that territory. Nikolsky et al.1 have recently published our experience with a staging approach for multi-lesion cases in the context of non-urgent PCI. Revascularization was conducted in a single session in 129 patients and was staged in 135 patients with an interval of 45.6 ± 22.3 days. The rates of major adverse cardiac events (MACE) during in-hospital stay did not differ significantly between the staged (both stages together) and non-staged groups (2.2% vs. 4.6%; p = 0.28). There was no MACE between the procedures at the staged arm in spite of progression and occlusion of the artery in some cases. Therefore, a staging strategy within 4–8 weeks is safe in the majority of patients. In the case discussed here, the LAD lesion progressed to total occlusion at the interval time between procedures, but this progression was uneventful, in agreement with our published experience regarding the safety of staging. Pharmacologic vs. mechanical distal protection: At the time of the second procedure a total occlusion of the LAD was noted. An attempted re-canalization was the selected approach of the operators and we share that view. The chance of recanalization is high (> 90%) since it is a fresh thrombotic occlusion, and therefore respond favorably to mechanical reperfusion. The strategy of the authors to try and combat the thrombus with intra-coronary thrombolysis and thrombus-aspiration was not successful. Therefore, the operators selected week duration of systemic thrombolytic therapy followed by atherectomy. We would, most likely, use a different strategy, combining pharmacologic IIb/IIIa inhibitors and mechanical umbrella-based microvascular protection to prevent distal embolization during stent placement. The EPI filter wire2 (Boston Scientific, Maple Grove, Minnesota) or the Angioguard filter3 (Cordis Corporation, Miami Lakes, Florida) would have been our fist choice due to our larger experience with those devices. Other filters such as the SPIDER (EV3) or the Emboshield (Abbot Vascular, MEDNOVA) could have been used as well. The balloon occlusion system (Percusurge, Medtronic)4 have been shown to provide adequate protection in previous trials; however, we feel that user-unfriendliness prohibits it wide use. The evidence for the efficiency of protection systems for prevention of distal embolizations and clinical events has been shown in the SAFER trial, the proving superiority of the balloon protection device for treatment of degenerated vein grafts5 and from further comparative equivalence studies between the Percusurge and the filter systems (FIRE trial4). With adequate distal protection and pharmacologic anti- platelet environment, regular gentle predilatation (with a 2.5 balloon) followed by stenting would have most likely result in success, similar to that presented here. Debulking as a strategy for proximal bulky lesions. The authors approach to use atherectomy for the bulky, thrombus containing lesion, after a week duration systemic thrombolysis was proven effective and successful. Acute atherectomy, in cases where a clear visible thrombus is present, is likely to be associated with distal embolization, as was adequately recognized by the authors. Atherectomy was selected to maximize the odds for long-term patency. Previous trials have demonstrated a restenosis advantage for debulking followed by stenting vs. stenting alone.6 Other atherectomy system may be also used in these cases with a high likelihood of success. Among these the X-sizer (EV3, USA) have been proposed to limit distal embolization.7 Yet, in spite of various attempts to improve the atherectomy systems, it is still a cumbersome method in comparison to stenting, requiring highly experience operators. These systems do not offer a clear and unequivocal advantage. In our laboratory, the X-sizer system could be considered at the time of the second procedure, however, the chance of distal embolization would direct us to favor stenting with distal protection. In summary, the case presented here is a tutorial of the complexity of coronary interventions. It demonstrates the complex considerations involving staging of the procedure, treatment of bulky thrombus containing lesions, and the juggle between distal protection, thrombolysis, antiplatelet agents and atherectomy. The authors are praised for the beautiful, uneventful results of their complex, carefully rationalized strategy. Deepak L. Bhatt MD, FACC, FSCAI Director, Interventional Cardiology Fellowship Cardiac, Peripheral, and Carotid Intervention Associate Director, Cardiovascular Fellowship Cleveland Clinic Foundation, Dept. of Cardiovascular Medicine Cleveland, Ohio Angiographic thrombus remains a thorn in the side of the interventional cardiologist. One approach that has been useful to prevent distal embolization of thrombus is the use of emboli protection devices. The PercuSurge occlusion balloon has been studied in saphenous vein grafts and in carotid arteries with favorable results.1 It has also been used in native coronary arteries and is being formally studied in acute MI in the Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberated Debris (EMERALD) trial.2 It is reasonably easy to use, as long as there is some degree of flow to visualize an adequate distal landing zone. In my experience, it is most easy to treat large native RCAs. For an LAD, especially with multiple large diagonal branches, it is less than ideal to use this device. Just recently the FilterWire has been FDA-approved for use in vein grafts. It too has been used in coronary arteries, and while side branches are not an issue with the filters, again it is not ideal for small distal landing zones. Lower profile filters designed specifically for coronary artery sizes will likely be the future. The Angiojet has become quite popular for aspiration of thrombus and the anecdotal experience in acute MI has been quite good. There is an ongoing clinical trial examining the value of the Angiojet in acute MI. If I see a large filling defect, I typically do utilize the Angiojet and will sometimes couple its use with an emboli protection device.3 While devices are clearly important in preventing macroembolization, pharmacotherapy is also important in treating thrombus. Intravenous (and perhaps intracoronary) glycoprotein IIb/IIIa inhibitors are useful to help dissolve thrombus and minimize the sequelae of embolization. While I was initially somewhat skeptical of any incremental value of intracoronary GP IIb/IIIa inhibitor administration over intravenous administration, recent data (as well as numerous anecdotes) support a possible benefit.4 Low doses of intracoronary fibrinolytic can be useful to treat intraprocedural thrombus, less so for more established thrombus. Preprocedural aspirin and clopidogrel are also important. A course of therapy with warfarin had been a strategy in the past, but appears to have fallen out of favor in recent years. In this case, the authors achieved a nice result with use of systemic fibrinolysis. The major downside to this approach, other than bleeding risk, is prolongation of hospital stay. It is not clear that DCA was absolutely necessary in this case. It adds time, complexity, risk of complications, and cost to the procedure. There are no compelling data that show that DCA reduces either restenosis or major adverse cardiac events, though it may be useful in certain circumstances to facilitate stent deployment and minimize plaque shift. Another important lesson from this case has to do with the risk of staging procedures. Of course, the conventional approach to acute MI is to treat the culprit lesion and come back another day for any other lesions. That is what the authors did in this case and I would have likely done the same. But inherent in staging procedures is a potential hazard introduced by the delay. This is probably even more pertinent in non-ST segment elevation MI, where it is not always possible to identify the “culprit” stenosis with absolute certainty. Even if the culprit lesion is crystal clear, the concept of multiple plaque rupture is real.5 Leaving potentially ruptured plaques untreated with a stent could lead to recurrent ischemic episodes. This may be less relevant in multivessel disease with stable angina, but it is worth at least considering these points before staging procedures, a practice that will likely increase in prevalence as more complex multivessel stenting occurs, especially in the drug-eluting stent era.
References
References for Rafael Beyar, MD: 1. Nikolsky E, Halabi M, Gruberg L, et al. Staged versus one step approach for multivessel percutaneous coronary interventions. Am Heart J 2002;143:1017–1026. 2. Popma JJ, Cox N, Hauptmann KE, et al. Initial clinical experience with distal protection using the Filter Wire in patients undergoing coronary artery and saphenous vein graft percutaneous intervention Cathet Cardiovasc Intervent 2002;57:125–134. 3. Blake JWH, Webster MWI, Butler R, et al. Stent deployment with distal vascular protection for the culprit vein graft stenosis in a patient with an acute infarct and cardiogenic shock Cathet Cardiovasc Intervent 2002;57:234–238. 4. Stone GW, Rogers C, Hermiller J, et al. Randomized comparison of distal protection with a filter-based catheter and a balloon occlusion and aspiration system during percutaneous intervention of diseased saphenous vein aorto-coronary bypass grafts Circulation 2003;108:548–553. 5. Cohen DJ, Murphy SA, Lavelle T, et al. Cost-effectiveness of distal protection for patients undergoing vein graft intervention: Results from the SAFER trial Circulation 2001;104(Suppl):3661. 6. Takagi T, Colombo A, Nishida T, et al. A randomized study of directional atherectomy prior stenting versus stenting alone: A single site experience. Eur Heart J 2001;22(Suppl S):118–118. 7. Stone GW. The X-Sizer for treatment of thrombus and atherosclerosis in coronary interventions trial (XTRACT) Am Heart J 2003;145:561–562. References for Deepak Bhatt, MD: 1. Baim DS, Wahr D, George B, et al. Randomized trial of a distal embolic protection device during percutaneous intervention of saphenous vein aorto-coronary bypass grafts. Circulation 2002;105:1285–1290. 2. Haery C, Exaire JE, Bhatt DL, et al. Use of Percusurge Guardwire in native coronary arteries during acute myocardial infarction: report of 4 cases. J Invas Cardiol 2003; in press. 3. Popma J, Bhatt DL. Case presentations and discussions. J Invas Cardiol 2003;15(Suppl B):34B–41B. 4. Wohrle J, Grebe OC, Nusser T, et al. Reduction of major adverse cardiac events with intracoronary compared with intravenous bolus application of abciximab in patients with acute myocardial infarction or unstable angina undergoing coronary angioplasty. Circulation 2003;107:1840–1843. 5. Rioufol G, Finet G, Ginon I, et al. Multiple atherosclerotic plaque rupture in acute coronary syndrome: A three-vessel intravascular ultrasound study. Circulation 2002;106:804–808.