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Incidence of post myocardial infarction left ventricular thrombus formation in the era of primary percutaneous intervention and glycoprotein IIb/IIIa inhibitors. A prospective observational study
- Arshad Rehan†1,
- Manpreet Kanwar†1,
- Howard Rosman†1Email author,
- Sujood Ahmed†1,
- Arshad Ali†2,
- Julius Gardin†1 and
- Gerald Cohen†1
© Rehan et al; licensee BioMed Central Ltd. 2006
Received: 19 February 2006
Accepted: 06 April 2006
Published: 06 April 2006
Before the widespread use of primary percutaneous coronary intervention (PCI) and glycoprotein IIb/IIIa inhibitors (GP IIb/IIIa) left ventricular (LV) thrombus formation had been reported to complicate up to 20% of acute myocardial infarctions (AMI). The incidence of LV thrombus formation with these treatment modalities is not well known.
92 consecutive patients with ST-elevation AMI treated with PCI and GP IIb/IIIa inhibitors underwent 2-D echocardiograms, with and without echo contrast agent, within 24–72 hours.
Only 4/92 (4.3%) had an LV thrombus, representing a significantly lower incidence than that reported in the pre-PCI era. Use of contrast agents did not improve detection of LV thrombi in our study.
The incidence of LV thrombus formation after acute MI, in the current era of rapid reperfusion, is lower than what has been historically reported.
A well-recognized complication of acute myocardial infarction (AMI) is the development of a left ventricular (LV) thrombus. Causes of LV thrombus include segmental dysfunction of the infarcted myocardium causing stasis, endocardial tissue inflammation providing a thrombogenic surface, and a hypercoagulable state [1–6]. There is evidence that LV thrombi usually develop within a few days after AMI [2, 7–9].
Historically, the incidence of LV thrombi complicating AMI had been reported to be 20–40%, and may reach 60% among patients with large anterior wall AMI . Early thrombolytic therapy reduces this incidence [5, 6, 11]. However, there is little data on the incidence of LV thrombus formation after primary percutaneous coronary intervention (PCI), with concurrent use of IIb/IIIa inhibitors, for AMI. We hypothesized that with improved reperfusion using catheter-based techniques, together with the use of potent platelet glycoprotein IIb/IIIa inhibitor therapy , the incidence of post AMI LV thrombus formation would be lower than what had been reported in the pre-PCI era. To increase the sensitivity of standard two-dimensional echocardiography (2-D echo) for detection of an LV thrombus, we used a third-generation contrast agent to outline the LV cavity structures.
Ninety-two consecutive patients presenting to our institution with ST elevation AMI and treated with PCI, rescue angioplasty after failed thrombolysis, or 'facilitated' PCI were enrolled in the study. Written informed consent was obtained from the patients prior to enrolment. Baseline demographic characteristics, pre- and post-intervention Thrombolysis in Myocardial Infarction flow grade, type of intervention, and other therapies instituted were recorded. Two-dimensional echocardiography was performed using a Vivid-7 ultrasound machine (GE Medical Systems) within three days of the PCI, by a registered sonographer, with and without an echo contrast agent (Perflutren Lipid Microspheres – Definity®, Bristol-Myers Squibb Inc), with digital storage for later off-line analysis. Second harmonic imaging was used to optimise endocardial visualization. Two level-3 echocardiographers blinded to the clinical details separately reviewed the echo images in each patient. The contrast images were stored and reviewed separately from the non-contrast images. LV thrombus was defined as an echodense mass with definite margins, contiguous but distinct from the endocardium, adjacent to an area of hypo- or akinetic myocardium . In cases where there was a difference of interpretation between the two readers, both readers reviewed the images together and came to a consensus. A single reader, blinded to the clinical and 2-D echo details of the patients reviewed the angiographic data.
n(%) (Total n = 92)
Mean Age in Years (Range)
History of coronary disease
Congestive Heart Failure
Medications on admission
Relationship between infarct location and thrombus formation
Number of Patients
LV Thrombus n (%)
Features of patients with left ventricular thrombi
Previous studies have shown that mural thrombi occur in approximately 20% of all patients who do not receive reperfusion therapy . This incidence rises to 40% in case of anterior AMI and further to 60% in cases of large anterior AMI involving the LV apex10. Patients with LV thrombi have a worse overall prognosis , with about 10% thrombi resulting in systemic embolization . Strategies to prevent this complication therefore represent an important therapeutic goal.
Although the introduction of thrombolytic therapy for treatment of AMI improved survival, its impact on the incidence of LV thrombus formation has varied. Bhatnagar, et-al showed a 3-fold reduction in the incidence of LV thrombus in patients receiving early intravenous recombinant tissue plasminogen activator . A sub study of the Gruppo Italiano per lo Studio della Sopravvivenza nell'infarto miocardico (GISSI-2), however, failed to show a significant reduction in the incidence of LV thrombus formation in AMI patients with thrombolytic agents . An analysis of the subsequent GISSI-3 database by Chiarella et al, however, showed a significant reduction in the incidence of LV thrombus in patients with AMI . In a meta-analysis of 6 studies, Vaitkus and Barnathan found an association between thrombolytic therapy and reduced LV thrombus formation, although it did not achieve statistical significance .
Catheter-based reperfusion therapy is superior to thrombolytics in promoting early myocardial recovery, with improved clinical outcomes . Primary PCI, with or without stenting, has thus become the treatment of choice for patients with AMI in institutions with facilities for emergency cardiac catheterization [16, 17]. The introduction of potent glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitor agents has further improved the procedural outcomes for PCI with stenting in AMI [12, 18, 19]. In one small study, the incidence of LV thrombus formation after AMI in patients undergoing primary PCI, was reported to be as low as to 4% . Porter et al, in a retrospective study of AMI patients who received either thrombolytics or primary PCI, with or without GP IIb/IIIa inhibitors, reported a 23.5% incidence of LV thrombus after anterior AMI . Our study is unique in that it prospectively evaluates LV thrombus formation in AMI patients receiving both primary PCI and GP IIb/IIIa inhibitors. It confirms a significant reduction in this complication that parallels improvement in other post-MI outcomes as a result of better contemporary therapy. We also used echo contrast agent in all patients and found no additive value in detection of post MI LV thrombi.
It is important to review the role of echocardiography in the diagnosis of LV thrombi. The sensitivity and specificity of 2-D echo in the diagnosis of LV thrombi has been established, even with first and second-generation echo equipment, to be in excess of 92% and 86–88%, respectiviely1. With modern, improved imaging equipment, the sensitivity is expected to be even higher. Nonetheless 2-D echo has certain limitations. First, a small thrombus (e.g., < 5–6 mm) may not be accurately detected . Second, differences in acoustic impedance between endocardium and freshly formed thrombus may not be sufficient to allow clear definition of the thrombus. Third, various other anatomic structures, such as false tendons or trabeculae, may confound the diagnosis .
The use of contrast agents has been reported to add to the sensitivity of non-contrast 2-D echo  in the diagnosis of LV thrombi, although in our study, contrast agents did not detect any additional thrombi. The use of contrast adds US $110 to the cost of each study and involves approximately 5 minutes of additional imaging time. Perhaps it would be reasonable to reserve contrast agents for patients with sub-optimal 2D imaging which precludes adequate visualization of the endocardium. Given the small number of patients with thrombi in our study the additive value of contrast should be interpreted with caution.
In conclusion, the incidence of early LV thrombus formation is lower (4% for all MI's, 11% for anterior MI's) in this era of primary PCI, coupled with the use of potent antithrombotic and anti-platelet agents, compared to historical data in the pre-PCI era (up to 20 % for all MI's, 40% for anterior MI's). Routine use of echo contrast agents did not improve detection of LV thrombi in our study.
Renee Bess RDCS, RVT, FASE.
St John Hospital and Medical Centre, Detroit, Michigan, USA.
- Stratton JR, Lighty GW, Pearlman AS, Ritchie JL: Detection of left ventricular thrombus by two-dimensional echocardiography: sensitivity, specificity and causes of uncertainty. Circulation. 1982, 66: 156-166.View ArticlePubMedGoogle Scholar
- Visser CA, Kan G, David GK, Lie KI, Durrer D: Two-dimensional echocardiography in the diagnosis of left ventricular thrombus. A prospective study of 67 patients with anatomic validation. Chest. 1983, 83: 228-232.View ArticlePubMedGoogle Scholar
- Domenicucci S, Bellotti P, Chiarella F, G Lupi, Vecchio C: Spontaneous morphologic changes in left ventricular thrombi: a prospective two dimensional echocardiographic study. Circulation. 1987, 75: 737-743.View ArticlePubMedGoogle Scholar
- Lamas GA, Vaughan DE, Pfeiffer MA: Left ventricular thrombus formation after first anterior wall acute myocardial infarction. Am J Cardiol. 1986, 57: 1244-1247.View ArticleGoogle Scholar
- Bhatnagar SK, Al-Yusuf AR: Effects of intravenous recombinant tissue-type plasminogen activator therapy on the incidence and associations of left ventricular thrombus in patients with a first acute Q wave anterior myocardial infarction. Am Heart J. 1991, 122: 1251-1256.View ArticlePubMedGoogle Scholar
- Pizzetti G, Belotti G, Margonato A, Carlino M, Gerosa S, Carandete O, Chierchia SL: Thrombolytic therapy reduces the incidence of left ventricular thrombus formation in acute anterior myocardial infarction. Relationship to vessel patency and infarct size. Eur Heart J. 1996, 17: 421-428.View ArticlePubMedGoogle Scholar
- Weinreich DJ, Burke JF, Pauletto FJ: Left ventricular mural thrombi complicating acute myocardial infarction. Long-term follow-up with serial echocardiography. Ann Intern Med. 1984, 100: 789-794.View ArticlePubMedGoogle Scholar
- Davis MJ, Ireland MA: Effect of early anticoagulation on the frequency of left ventricular thrombi after anterior wall acute myocardial infarction. Am J Cardiol. 1986, 57: 1244-1247.View ArticlePubMedGoogle Scholar
- Asinger RW, Mikell FL, Elsperger J, Hodges M: Incidence of left-ventricular thrombosis after acute transmural myocardial infarction. Serial evaluation by two-dimensional echocardiography. N Engl J Med. 1981, 305: 297-302.View ArticlePubMedGoogle Scholar
- Keeley EC, Hillis LD: Left ventricular mural thrombus after acute myocardial infarction. Clin Cardiol. 1996, 19 (2): 83-86.View ArticlePubMedGoogle Scholar
- Vaitkus PT, Barnathan ES: Embolic potential, prevention and management of mural thrombus complicating anterior myocardial infarction: a meta-analysis. J Am Coll Cardiol. 1993, 22: 1004-1009.View ArticlePubMedGoogle Scholar
- Schomig A, Kastrati A, Dirschinger J, Mehilli J, Schricke U, Pache J, Martinoff S, Neumann FJ, Schwaiger M: Coronary stenting plus platelet glycoprotein IIb/IIIa blockade compared with tissue plasminogen activator in acute myocardial infarction. N Engl J Med. 2000, 343: 385-391.View ArticlePubMedGoogle Scholar
- Held AC, Cole PL, Lipton B, Gore JM, Antman EM, Hockman JS, Corrao J, Goldberg RJ, Alpert JS: Rupture of the interventricular septum complicating acute myocardial infarction: A multicenter analysis of clinical findings and outcome. Am Heart J. 1988, 116: 1330-1336.View ArticlePubMedGoogle Scholar
- Vecchio C, Chiarella F, Lupi G, Bellotti P, Domenicucci S: Left ventricular thrombus in anterior acute myocardial infarction after thrombolysis. A GISSI-2 connected study. Circulation. 1991, 84: 512-519.View ArticlePubMedGoogle Scholar
- Chiarella F, Santoro E, Domenicucci S, Maggioni A, Vecchio C: Predischarge two-dimensional echocardiographic evaluation of left ventricular thrombosis after acute myocardial infarction in the GISSI-3 study. Am J Cardiol. 1998, 81: 822-827.View ArticlePubMedGoogle Scholar
- Weaver WD, Simes RJ, Betriu A, Grines CL, Zijlstra F, Garcia E, Grinfeld L, Gibbons RJ, Ribeiro EE, DeWood MA, Ribichini F: Comparison of primary coronary angioplasty and intravenous thrombolytic therapy for acute myocardial infarction: a quantitative review. JAMA. 1997, 278: 2093-2098.View ArticlePubMedGoogle Scholar
- Yusuf S, Pogue J: Primary angioplasty compared with thrombolytic therapy for acute myocardial infarction. JAMA. 1997, 278: 2110-2111.View ArticlePubMedGoogle Scholar
- Gold HK, Garabedian HD, Dinsmore RE, Guerrero LJ, Cigarroa JE, Palacios IF, Leinbach RC: Restoration of coronary flow in myocardial infarction by intravenous chimeric 7E3 antibody without exogenous plasminogen activators: Observations in animals and humans. Circulation. 1997, 95: 1755-1759.View ArticlePubMedGoogle Scholar
- Lefkovits J, Ivanhoe RJ, Califf RM, Bergelson BA, Anderson KM, Stoner GL, Weisman HF, Topol EJ, : Effects of platelet glycoprotein IIb/IIIa receptor blockade by a chimeric monoclonal antibody (abciximab) on acute and six-month outcomes after percutaneous transluminal coronary angioplasty for acute myocardial infarction. EPIC investigators. Am J Cardiol. 1996, 77: 1045-1051.View ArticlePubMedGoogle Scholar
- Kalra A, Jang IK: Prevalence of early left ventricular thrombus after primary coronary intervention for acute myocardial infarction. J Thromb Thrombolysis. 2000, 10 (2): 133-6.View ArticlePubMedGoogle Scholar
- Porter A, Kandalker H, Iakobishvili Z, Sagie A, Imbar S, Battler A, Hasdai D: Left ventricular mural thrombus after acute myocardial infarction in the era of aggressive reperfusion therapy – still a frequent complication. Coronary Artery Disease. 2005, 16: 275-279.View ArticlePubMedGoogle Scholar
- Pechacek LW, Lazar AV, Sonnemaker RE, Edelman SK, De Castro CM, Hall RJ: Comparison of two-dimensional echocardiography, radionuclide ventriculography and cineangiography in detecting surgically documented left ventricular thrombi. Tex Heart Inst J. 1984, 11: 118-127.PubMedPubMed CentralGoogle Scholar
- Sieswerda GT, Kamp O, Visser CA: Myocardial contrast echocardiography: Clinical benefit and practical issues. Echocardiography. 2000, 17: S25-S36.View ArticlePubMedGoogle Scholar
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