Spontaneous morphologic changes in left ventricular thrombi: a prospective two-dimensional echocardiographic study

Left ventricular thrombus in ischaemic heart disease: diagnosis, treatment, and gaps of knowledge

Although the management of ischaemic heart disease has markedly improved over the last decades, left ventricular thrombus remains a serious finding in patients with myocardial infarction. Routine diagnostic detection of left ventricular thrombus relies mainly on echocardiography; however, cardiac magnetic resonance has emerged as a method with higher diagnostic accuracy, while cardiac computed tomography angiography represents a valuable alternative modality. To reduce the left ventricular thrombus-associated morbidity and mortality, optimal selection of anticoagulation is warranted after balancing the risk of bleeding. In this review, we will discuss contemporary diagnostic modalities to detect left ventricular thrombus in ischaemic heart disease and summarize evidence on risk stratification and therapy. In addition, we propose a novel diagnosis, follow-up imaging, and treatment algorithm. Further, we identify knowledge gaps at different levels to address emerging research questions and to refine the design of future studies aiming to improve the management of patients in this clinical setting.

Use of Direct Oral Anticoagulants in the Treatment of Left Ventricular Thrombi: A Systematic Review

The off-label use of direct oral anticoagulants (DOACs) for the treatment of left ventricular thrombi has grown over the past several years given the ease of administration, absence of a requirement for international normalized ratio (INR) monitoring, and freedom from dietary restrictions; however, the evidence for their safety and efficacy is contradictory. We systematically searched PubMed and Google Scholar from January 1, 2009, to April 25, 2020, for studies of DOACs for treatment of left ventricular thrombi. Fifty-three articles (of 1,168 patients) met our inclusion criteria. We found that the studies have reached conflicting results; based on our findings, their routine use for the treatment of left ventricular thrombi cannot be recommended. Adequately powered randomized controlled trials are needed to determine the safest and most effective treatment for left ventricular thrombi.

Anticoagulation and stress-induced cardiomyopathy

Stress-induced cardiomyopathy (SCM), is a reversible cardiomyopathy characterized by transient systolic dysfunction following an acute physiologic stress. Thromboembolism occurs at a high frequency in patients with intracardiac thrombus secondary to SCM, with one systematic review reporting a rate of 33.3%. The risk of thrombus formation following SCM has been associated with left-ventricular (LV) contraction abnormalities, catecholaminergic surge, and other associated comorbidities. However, established guidelines for screening and management of intracardiac thrombus in the setting of SCM do not exist at present due to a lack of sufficient clinical trial data. The purpose of this article is to discuss the pathophysiological theory and previously documented evidence from cases of LV thrombus secondary to SCM, and to present our recommendations for management of intracardiac thrombus secondary to SCM.

Incidence of Left Ventricular Thrombus in Patients With Acute ST-Segment Elevation Myocardial Infarction Treated with Percutaneous Coronary Intervention

Previous studies using 2-dimensional non-contrast echocardiography have reported a post-ST segment elevation myocardial infarction (STEMI) left ventricular (LV) thrombus incidence of 3% to 24%. However, these studies were not performed with ultrasound contrast agents (UCAs), which improve accuracy in the diagnosis of LV thrombus. We aimed to determine the early incidence and clinical correlates of LV thrombus in a large consecutive cohort of patients with STEMI. This study included consecutive patients admitted to Saint Luke's Mid America Heart Institute with STEMI who also underwent early percutaneous coronary intervention (PCI) and an echocardiogram. A total of 1,698 patients (1,205 men, mean age 61 ± 13 years) comprised the study group. Echocardiography was performed on hospital day 2, and a UCA was used in 1,292 patients (76%). LV thrombus was identified in 28 (1.6%) patients. A multivariable logistic regression model showed that left anterior descending intervention was independently associated with LV thrombus (odds ratio = 7.58, 95% confidence interval [CI] 2.20 to 26.19, p = 0.001), thrombolysis in myocardial infarction III flow was marginally associated with less LV thrombus (odds ratio = 0.41, 95% CI 0.16 to 1.04, p = 0.060), and higher LVEF was associated with less LV thrombus (odds ratio = 0.96, 95% CI 0.91 to 0.97, p <0.001). In conclusion, LV thrombus was identified in only 1.6% of patients in a large STEMI cohort, significantly lower than previous studies. A UCA was used in most echocardiograms, and it improves accuracy in the detection and exclusion of LV thrombus.

Large In-transient Left Ventricular Thrombus due to Anabolic Steroid-induced Cardiomyopathy

The presence of small or moderate size thrombosis is not uncommon in left ventricle (LV) as results of basic co-moribund disease, but huge LV thrombosis that protrudes to aortic valve in the LV outflow tract (LVOT) tract is an exceptionally rare phenomenon. We report a 34-year-old bodybuilder athlete with cardiomyopathy and massive LV thrombosis. The thrombosis extended to LVOT and protruded through the aortic valve in systole and posed a high risk of systemic emboli. The patient underwent open heart surgery, and the clot was removed. The operation was complicated by low cardiac output syndrome that managed by intra-aortic balloon pump and high dose of inotropic drugs and hemodialysis. The patient died on the 15^th day after surgery with multiorgan failures.

Guidelines for the Use of Echocardiography in the Evaluation of a Cardiac Source of Embolism

Embolism from the heart or the thoracic aorta often leads to clinically significant morbidity and mortality due to transient ischemic attack, stroke or occlusion of peripheral arteries. Transthoracic and transesophageal echocardiography are the key diagnostic modalities for evaluation, diagnosis, and management of stroke, systemic and pulmonary embolism. This document provides comprehensive American Society of Echocardiography guidelines on the use of echocardiography for evaluation of cardiac sources of embolism. It describes general mechanisms of stroke and systemic embolism; the specific role of cardiac and aortic sources in stroke, and systemic and pulmonary embolism; the role of echocardiography in evaluation, diagnosis, and management of cardiac and aortic sources of emboli including the incremental value of contrast and 3D echocardiography; and a brief description of alternative imaging techniques and their role in the evaluation of cardiac sources of emboli. Specific guidelines are provided for each category of embolic sources including the left atrium and left atrial appendage, left ventricle, heart valves, cardiac tumors, and thoracic aorta. In addition, there are recommendation regarding pulmonary embolism, and embolism related to cardiovascular surgery and percutaneous procedures. The guidelines also include a dedicated section on cardiac sources of embolism in pediatric populations.

Brain Natriuretic Peptide and Particular Left Ventricle Segment Asynergy Associated with Cardioembolic Stroke from Old Myocardial Infarction

BACKGROUND

It is important to determine the usage of anticoagulants by defining the actual risk of cardioembolic stroke in patients with old myocardial infarction. In the present study, we aimed to more precisely evaluate the risks of each segment associated with cardioembolic stroke using a 16-segment model. The usage of the plasma brain natriuretic peptide (BNP) associated with cardioembolic stroke was also evaluated in comparison with a left ventricle ejection fraction less than 40%.

METHODS

There were a total of 190 ischemic stroke patients who had premorbid myocardial infarction. The study included a total of 143 ischemic stroke patients with old myocardial infarction who were available for evaluation and excluded patients with atrial fibrillation or acute myocardial infarction. Their left ventricle wall motion abnormality and the level of plasma BNP at their admission were analyzed.

RESULTS

Hypertension and a plasma BNP level of 206.9 pg/mL or higher, determined from the receiver operating characteristic curve, were independently associated with cardioembolic stroke (χ(2) = 35.6, R(2) = .30, P < .001). Adjusting for these factors, statistically independent high risk was observed at the basal-inferior, basal-inferolateral, mid-anterior, mid-anteroseptal, apical-anterior, and apical-septal left ventricles.

CONCLUSION

High plasma BNP levels and left ventricular wall motion abnormalities in the segments perfused with left anterior descending coronary artery or right coronary artery show a high risk for cardioembolic stroke in patients with old myocardial infarction. Considering these factors, it could be possible to more precisely define the risk of cardioembolic stroke and to perform appropriate antithrombotic treatments in old myocardial infarction patients.

Unusual Site of Left Ventricular Thrombus after Acute Myocardial Infarction

Left ventricular (LV) thrombus formation is a frequent complication in patients with acute anterior myocardial infarction (MI). Its incidence is lower with inferior wall MI. Risk factors for the development of LV thrombus are consistently irrespective of infarct treatment and include large infarct size, severe apical akinesia or dyskinesia LV aneurysm, and anterior MI.

Risk factors for development of left ventricular thrombus after first acute anterior myocardial infarction-association with anticardiolipin antibodies

Background

Left ventricular thrombus(LVT] formation is a frequent complication in patients with acute anterior myocardial infarction(MI). LVT is associated with increased risk of embolism and higher mortality rates after acute MI. Anticardiolipin antibodies (ACA) are immunoglobulins that react with phospholipid-binding proteins interfering with the prothrombin activator complex. The effects of phospholipids on pathophysiology of cardiovascular thrombotic events are well known. In this study, we aimed to evaluate the importance of clinical and biochemical parameters including anticardiolipin antibodies on left ventricular thrombus formation after acute anterior MI.

Methods and Results

Seventy patients with a first anterior AMI were prospectively and consecutively enrolled. Patients with previous MI, autoimmune disease, collagen vascular disease and arterial or venous thrombosis history were excluded from this study. At the time of hospitalization, key demographic and clinical characteristics were collected including age, gender, ethanol intake and presence of traditional risk factors for atherosclerosis (hypertension, diabetes, smoking, hyperlipidemia, positive family history). Patients were evaluated for echocardiographic data, blood chemistry and ACA. Two-dimensional and Doppler echocardiographic examinations were performed in all patients within the first week and at 14 days after MI. LV thrombus was detected in 30 (42.8%) patients. ACA IgM levels were significantly higher in the patient group with LV thrombus than in the group without thrombus (12.44 ±4.12 vs. 7.69 ± 4.25 mpl, p = 0,01). ACA IgG levels were also found higher in the group with LV thrombus (24.2 ± 7.5 vs.17.98 ± 6.45 gpl, p = 0.02). Multivariate analyses revealed diabetes mellitus, higher WMSI, lower MDT and higher ACA IgM and higher ACA IgG levels as independent predictors of left ventricular thrombus formation.

Conclusions

Our data demonstrate that beside the low ejection fraction, lower MDT and higher wall motion score index, modestly elevated ACA IgM and ACA IgG levels are associated with LV thrombus formation in patients with anterior MI.

[Value of cardiac MRI for intraventricular thrombi's diagnosis]

BACKGROUND

Intraventricular thrombosis is a serious event, generally complicating a wide myocardial infarction. It requires an adapted therapy, based on the oral anticoagulants. The diagnosis is generally carried out by trans-thoracic echocardiography but with an insufficient sensitivity and a specificity. In this context, the place of cardiac MRI remains to be explored.

PATIENTS AND METHOD

We carried out a retrospective registry of all cardiac MRI done in our hospital since 2003, for assessment of an intracardiac mass or an cerebral stroke. The aim was to compare the results of cardiac MRI with those of echocardiography and contrast ventriculography.

RESULTS

Our registry includes 26 cases of intraventricular thrombi, confirmed by cardiac MRI. Our results confirm the lack of sensitivity of echocardiography and the ventriculography. The Kappa correlation coefficient of echocardiography and ventriculography, with respect to the MRI, are very weak, respectively of -0.08 and 0.16.

CONCLUSIONS

The values of echocardiography and contrast ventriculography seem limited. The realization of a complementary cardiac MRI must be recommended as often as possible in case of doubt or high risk disease.

Detection of left ventricular thrombus by coronary computed tomography angiography

Left ventricular thrombus is a recognized complication of acute myocardial infarction. The following case report presents a rare case of left ventricular thrombus detection originally via coronary computed tomography angiography, followed by a brief review of imaging modalities that have been used for the detection of left ventricular thrombus in the past.

Plasma homocysteine level and left ventricular thrombus formation in acute anterior myocardial infarction patients following thrombolytic therapy with t-PA

AIMS

The aim of this study was to evaluate the relationship between homocysteine levels and the development of left ventricular thrombus in acute anterior myocardial infarction patients directed to thrombolytic therapy.

METHODS AND RESULTS

Seventy-nine patients presenting with ST elevated acute anterior myocardial infarction and treated with thrombolytic agent, t-PA, were included in the study. Two-dimensional echocardiography was used to divide patients into 2 groups according to the presence (n = 14) or absence (n = 65) of thrombus in the left ventricle following myocardial infarction. The levels of fasting plasma total homocysteine, total cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, vitamin B12 and folic acid were assessed. There were no significant differences between two groups in terms of age, gender, hyperlipidemia and smoking. History of diabetes mellitus (28.57% versus 6.15%, p = 0.04), peak creatine phosphokinase levels (4153.54 +/- 1228.41 U/L versus 2456.92 +/- 1421.36 U/L, p < 0.001), mean left ventricular wall motion score index (2.21 +/- 0.18 versus 1.83 +/- 0.23, p < 0.001) and total fasting homocysteine levels (18.24 +/- 5.67 mmol/L versus 12.31 +/- 3.52 mmol/L, p < 0.001) were significantly higher in patients with left ventricular thrombus. In multivariate analysis; only diabetes mellitus (p = 0.03), higher wall motion score index (p = 0.001) and higher homocysteine levels (p = 0.04) were independent predictors of left ventricular thrombus formation.

CONCLUSION

Our results suggest that; diabetes mellitus, higher wall motion score index and hyperhomocysteinemia independently increases the risk for the development of left ventricular thrombus formation in patients with acute anterior myocardial infarction following thrombolytic therapy.

Determinants of left ventricular thrombus formation after primary percutaneous coronary intervention for anterior wall myocardial infarction

Previous studies have reported that left ventricular (LV) thrombus is a complication in 10-56% of ST-segment elevation acute anterior wall myocardial infarctions (AWMI). Data suggest that changes in acute myocardial infarction management such as early anticoagulation, thrombolysis, and most recently, primary percutaneous coronary intervention (PCI), may decrease thrombus occurrence. Early time to reperfusion has been shown to decrease mortality and improve LV function recovery. To determine if door-to-balloon time (DTBT) affects the incidence of LV thrombus, we retrospectively analyzed data on 43 consecutive patients who underwent successful PCI of a primary acute ST-segment elevation AWMI. Transthoracic echocardiography was performed for detecting LV thrombus and measuring LV ejection fraction (EF) within 5 days on all patients (average time: 2.17 days post event). Nineteen patients underwent PCI within 2 h of arrival to the Emergency Department (Group A, average 88 min) and 24 patients underwent PCI with DTBT of more than 2 h (Group B, average 193 min). Clinically significant LV thrombus was detected in 35% of all patients. The incidence of LV thrombus formation in Group A was not significantly different from that in Group B (42.1% vs. 29.0%, respectively; P = 0.52). The risk of LV thrombus was independent of in-hospital anticoagulation and medical management, peak enzyme levels, and LVEF but did relate to age (odds ratio = 1.96, 95% CI 1.03-3.73, P = 0.04 per decade). No embolic events in hospital were observed (average hospital stay 9.2 days). We conclude that the incidence of LV thrombus remains high despite PCI. Also, we find that DTBT in patients presenting with an ST-segment elevation AWMI does not affect the incidence of LV thrombus formation. Increased age, however, does appear to increase the risk of LV thrombus development.

Improved detection of left ventricular thrombi and spontaneous echocontrast by tissue harmonic imaging in patients with myocardial infarction

BACKGROUND

Tissue harmonic imaging (THI) reduces near-field and side-lobe artifacts. This could improve recognition of cardiac masses, including thrombi and spontaneous echocontrast (SEC), a known thromboembolic risk factor.

OBJECTIVES

We tested the hypothesis that THI improves detection of left ventricular (LV) thrombi and SEC compared with transthoracic fundamental imaging in patients with recent myocardial infarction.

METHODS

In all, 118 consecutive patients with recent myocardial infarction were studied at predischarge. The echocardiographic examination was performed in both fundamental imaging and THI modality and evaluated by 3 skilled and 3 nonexperienced observers for recognition of LV thrombosis and SEC.

RESULTS

THI increased LV thrombi diagnosis by 25% by skilled observers and by 50% by nonexperienced readers, reducing the number of false-positive diagnoses by 67%. Also, compared with fundamental imaging, THI improved recognition of LV SEC by both experienced and nonexperienced observers by 56% and 62%, respectively.

CONCLUSIONS

The improved recognition of LV thrombosis and SEC by THI in patients with myocardial infarction is clinically relevant allowing appropriate treatment and prognostic stratification. Therefore, routine use of THI should be recommended when studying such patients in clinical practice.

Clinical, imaging, and pathological characteristics of left ventricular thrombus: a comparison of contrast-enhanced magnetic resonance imaging, transthoracic echocardiography, and transesophageal echocardiography with surgical or pathological validation

BACKGROUND

Left ventricular (LV) thrombus is a frequent and potentially dangerous complication of ischemic heart disease (IHD). We evaluated the clinical, imaging, and pathology characteristics of confirmed LV thrombus and compared the diagnostic value of contrast-enhanced magnetic resonance imaging (MRI) with transthoracic (TTE) and transesophageal echocardiography (TEE) for the diagnosis of LV thrombi.

METHODS

Between November 1997 and December 2003, 361 patients with IHD had surgical and/or pathological confirmation of presence or absence of LV thrombus. Clinical information and preoperative imaging study reports were retrospectively reviewed regarding detection of thrombus. Comparisons were made between clinical and imaging characteristics of patients with and without confirmed thrombus.

RESULTS

Left ventricular thrombus was present in 106 (29%) of 361 patients in this study. Patients with thrombus had a higher incidence of recent embolic events (6.1% vs 0.8%, P < .005). In 160 patients with all 3 imaging modalities performed within 30 days of surgical or pathological confirmation, contrast-enhanced MRI showed the highest sensitivity and specificity (88% +/- 9% and 99% +/- 2%, respectively) compared with TTE (23% +/- 12% and 96% +/- 3.6%, respectively) and TEE (40% +/- 14% and 96% +/- 3.6%, respectively) for thrombus detection.

CONCLUSIONS

Left ventricular thrombus occurs frequently in patients with IHD and is associated with risk of systemic embolization. Contrast-enhanced MRI provided the highest sensitivity and specificity for LV thrombus when compared to TTE and TEE, and should be considered in the care of patients at high risk of LV thrombus formation.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

The incidence of LV thrombus formation after acute MI, in the current era of rapid reperfusion, is lower than what has been historically reported.

Left ventricular mural thrombus after anterior ST-segment-elevation acute myocardial infarction in the era of aggressive reperfusion therapy ??? still a frequent complication

BACKGROUND

Left ventricular mural thrombus (LVMT) is a well-known complication of anterior ST-elevation acute myocardial infraction (AMI). It remains unknown how modern therapies have impacted on its occurrence.

OBJECTIVES

To define the frequency of LVMT among contemporary patients with anterior ST-elevation AMI, the clinical and echocardiographic predictors of LVMT formation, and the intermediate-term outcomes of patients with LVMT.

METHODS

We retrospectively analysed patients (in the years 1997-2002) with a diagnosis of anterior ST-elevation AMI and no prior AMI, and who underwent a thorough echocardiographic assessment within 72 h of admission. Stepwise logistic regression analysis was used to define predictors of LVMT formation. Survival was calculated by the Kaplan-Meier product-limit method.

RESULTS

Of the 153 patients with complete data, LVMT was detected in 36 (23.5%). There were no significant differences in baseline demographic and clinical variables between LVMT and non-LVMT patients, or in treatments (all patients received reperfusion treatment). The mean wall motion score index was higher in LVMT than non-LVMT patients (0.88+/-1.79 versus 0.65+/-0.36, respectively; P=0.01), indicating worse cardiac systolic function. LVMT patients were treated with warfarin for 3-6 months. The incidence of death was similar between the groups (11.1% for LVMT patients versus 12.8% for non-LVMT patients, P=0.79) over a mean follow-up of 71-72 months. The only independent predictor found for LVMT occurrence was worse regional wall motion of the apex (odds ratio, 2.04, 95% confidence interval, 1.39-3.03; P<0.001).

CONCLUSIONS

In the contemporary 'real-world scenario', despite aggressive reperfusion treatment and anti-aggregant use, the incidence of LVMT remained high after anterior ST-elevation AMI. LVMT was not related to increased intermediate-term mortality when patients were treated with warfarin, and the only predictor of LVMT occurrence was regional function of the apex.

Assessment of Mitral Annular Velocities by Doppler Tissue Imaging in Predicting Left Ventricular Thrombus Formation after First Anterior Acute Myocardial Infarction

The aim of this study was to determine whether early assessment of left ventricular (LV) systolic and diastolic functions by pulsed wave Doppler tissue imaging predicts LV thrombus formation after acute anterior myocardial infarction. Echocardiography was performed in 87 consecutive patients with first acute anterior myocardial infarction within 24 hours after arrival to the coronary care department. Mitral inflow velocities and early diastolic (Em), late diastolic (Am), and peak systolic (SM) mitral annular velocities were measured. Em/Am and the ratio of early diastolic mitral inflow velocity to Em (E/Em), which is a reasonably good index for predicting elevated LV filling pressure, were calculated. To detect LV thrombus, 2-dimensional echocardiography was repeated on days 3, 7, 15, and 30. Patients were divided into two groups according to LV thrombus formation: group 1 (n = 29; aged 59 +/- 11 years; 4 women) with thrombus; and group 2 (n = 58; aged 57 +/- 9 years; 6 women) without thrombus. Members of group 1 had significantly lower Em, a lower SM, a lower peak systolic mitral annular velocity, and a lower Em/Am than those in group 2 (6.4 +/- 2.0 cm/s vs 8.9 +/- 2.7 cm/s, P < .001; 7.3 +/- 1.6 cm/s vs 8.6 +/- 1.7 cm/s, P = .001; 0.65 +/- 0.25 cm/s vs 0.89 +/- 0.27 cm/s, P < .001, respectively). The E/Em was significantly higher in group 1 than in group 2 (12.5 +/- 5.0 vs 7.2 +/- 2.8, P < .001). The sensitivity of an E/Em ratio greater than 9 in predicting LV thrombus formation was 69%, the specificity 79%, the positive predictive value 63%, and the negative predictive value 84%. Mitral annular velocities derived by pulsed wave Doppler tissue imaging are simple to obtain even in technically suboptimal studies, and can be used for predicting LV thrombus formation after myocardial infarction.

[An elderly patients with ventricular aneurysm, thrombus in the aneurysm, and cerebral infarction 10 years after myocardial infarction]

A 75-year-old man had a 26-year history of hypertension and an 18-year history of effort angina pectoris. He suffered acute myocardial infarction at age 61. According to serial echocardiography, the initially hypokinetic segment of the left ventricular apex was transformed to an apical aneurysm over the course of 10 years (at age 71). Ten months later, a transient ischemic attack occurred, despite the administration of aspirin. At age 72, echocardiography revealed a hyperechoic lesion that was suspected to be a thrombus within the aneurysmal cavity. Cerebral infarction (right occipital lobe) occurred 13 years after myocardial infarction, at age 73. After warfarin therapy for 3 months, the thrombus-like echo in the left ventricular aneurysm disappeared.

Relation between early mitral regurgitation and left ventricular thrombus formation after acute myocardial infarction: results of the GISSI-3 echo substudy

OBJECTIVE

To evaluate the prevalence and correlates of left ventricular thrombosis in patients with acute myocardial infarction, and whether the occurrence of early mitral regurgitation has a protective effect against the formation of left ventricular thrombus.

DESIGN AND SETTING

Multicentre clinical trial carried out in 47 Italian coronary care units.

PATIENTS AND METHODS

757 patients from the GISSI-3 echo substudy population with their first acute myocardial infarct were studied by echocardiography at 24-48 hours from symptom onset (S1), at discharge (S2), at six weeks (S3), and at six months (S4). The diagnosis of left ventricular thrombosis was based on the detection of an echo dense mass with defined margins visible throughout the cardiac cycle in at least two orthogonal views.

RESULTS

In 64 patients (8%), left ventricular thrombosis was detected in one or more examinations. Compared with the remaining 693 patients, subjects with left ventricular thrombosis were older (mean (SD) age: 64.6 (13.0) v 59.8 (11.7) years, p < 0.005), and had larger infarcts (extent of wall motion asynergy: 40.9 (11.5)% v 24.9 (14)%, p < 0.001), greater depression of left ventricular ejection fraction at S1 (43.3 (6.9)% v 48.1 (6.8)%, p < 0.001), and greater left ventricular volumes at S1 (end diastolic volume: 87 (22) v 78 (18) ml/m(2), p < 0.001; end systolic volume: 50 (17) v 41 (14) ml/m(2), p < 0.001). The prevalence of moderate to severe mitral regurgitation on colour Doppler at S1 was greater in patients who had left ventricular thrombosis at any time (10.2% v 4.2%, p < 0.05). On stepwise multiple logistic regression analysis the only independent variables related to the presence of left ventricular thrombosis were the extent of wall motion asynergy and anterior site of infarction.

CONCLUSIONS

Left ventricular thrombosis is not reduced, and may even be increased, by early moderate to severe mitral regurgitation after acute myocardial infarction. The only independent determinant of left ventricular thrombosis is the extent of the akinetic-dyskinetic area detected on echocardiography between 24-48 hours from symptom onset.

Role of echocardiography in the assessment of left ventricular thrombus embolic potential after anterior acute myocardial infarction

The contribution of cardiac ultrasound in assessment of the embolic potential of left ventricular thrombi after anterior acute myocardial infarction was verified in a prospective study of serial echocardiograms (mean, 18.9 examinations per patient) obtained over a long-term period (1-72 months; mean, 38±12). The study population comprised 222 patients (162 men; age, 64±11 years) with a first anterior acute myocardial infarction, treated with thrombolysis (group A) or receiving no antithrombolic therapy (group B). Embolism occurred in a total of 12 patients (11 with a left ventricular thrombus; p<0.005) and was more frequent in group B (10 patients; p<0.04). Predictors of embolism were the absence of thrombolysis, detection of a left ventricular thrombus, protrusion or mobility of the thrombus, and morphologic changes in the thrombus over time. Patients in group A had a lower incidence of each of these predictors, and a higher thrombus resolution rate. An appropriate echocardiographic protocol is crucial to assessment of the embolic potential of left ventricular thrombi after anterior acute myocardial infarction and may help to identify candidates for aggressive antithrombotic therapy (c)2001 CHF, Inc.

Prevalence of early left ventricular thrombus after primary coronary intervention for acute myocardial infarction

The prevalence of left ventricular (LV) thrombus after acute myocardial infarction (AMI) has been reported high at 20-60%. Current reperfusion therapies such as thrombolysis have shown a trend toward reducing the incidence of LV thrombosis. However, the prevalence of LV thrombus after primary percutaneous coronary intervention (PCI) for AMI has not been systematically studied. At Massachusetts General Hospital 71 consecutive patients who underwent primary PCI for acute ST elevation MI were reviewed for the prevalence of LV thrombus evaluated by echocardiography. Echocardiography was performed within 5 days of infarction. PCI was successful in all patients. The time delay from symptom onset to intervention was 191 minutes. Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was achieved in more than 80% of cases. Only 3 patients (4%) had echocardiographic evidence of LV thrombus. All 3 patients had anterior infarctions. The incidence among patients with anterior MI was 10% (3 of 30 patients). The prevalence of LV thrombus in patients treated with primary PCI for AMI is low (4%).

Long-term prospective assessment of left ventricular thrombus in anterior wall acute myocardial infarction and implications for a rational approach to embolic risk

To prospectively assess the predictive value of left ventricular (LV) thrombus anatomy for defining the embolic risk after acute myocardial infarction (AMI), 2 comparable groups of patients with a first anterior AMI (group A, 97 thrombolysed patients; group B, 125 patients untreated with antithrombotic drugs [total 222]) underwent prospective serial echocardiography (follow-up 39 +/- 13 months) at different time periods. LV thrombi were detected in 26 patients in group A (27%) and in 71 in group B (57%; p <0.005). Embolism occurred in 12 patients (5.4%; 1 in group A [1%] vs 11% in group B [9%], p < 0.04). At multivariate analysis, thrombus morphologic changes were the most powerful predictor of embolism (p <0.001), followed by protruding shape (p <0.01) and mobility (p <0.02). In patients untreated with thrombolysis, a higher occurrence of thrombus morphologic changes (48% vs 8%, p <0.002) and protruding shape (69% vs 31%, p <0.002) were observed, whereas thrombus mobility was similar in the 2 groups (18% vs 8%, p = NS). Thrombus resolution occurred more frequently in thrombolysed patients (85% vs 56%, p <0.002). Thus, after anterior AMI, changes in LV thrombus anatomy frequently occur and appear the most powerful predictor of embolization. A minor prevalence of thrombus, a more favorable thrombus anatomy, and a higher resolution rate may contribute to reduce embolic risk after thrombolysis.

Left ventricular thrombus formation and resolution in acute myocardial infarction

Left ventricular thrombus formation and resolution were studied by serial echocardiography in 38 patients with acute anterior myocardial infarction. Twenty (52.6%) patients developed thrombus. Cumulative rates were: 12/20 (60%) at 24 h (+/-24 h), 17/20 (85%) at 72 h (+/-24 h), and 19/20 (95%) at 120 h (+/-24 h). Early thrombus formation was associated with worse left ventricular wall motion relative to those with delayed thrombus development (P=0.00016). In patients with initially normal echocardiograms, subsequent thrombus formation was associated with wall motion deterioration (P=0.016). A thrombus occurred in 16/28 (57.1%) patients given streptokinase. Heparin and warfarin were given in case of thrombus formation. Among survivors with thrombus, resolution occurred with a cumulative rate of 1/18 (5.6%) at 72 h (+/-24 h), 2/18 (11.1%) at 120 h (+/-24 h), 10/18 (55.6%) at 3 months (+/-1 week) and 16/18 (88.9%) at 6 months (+/-1 week). No embolic events occurred. Left ventricular thrombus formation occurs often and early after acute anterior myocardial infarction, even when streptokinase is given. Delayed thrombus formation is associated with wall motion deterioration. Thrombus resolution occurs frequently during anticoagulation and seems not associated with increased embolic risk.

Predischarge two-dimensional echocardiographic evaluation of left ventricular thrombosis after acute myocardial infarction in the GISSI-3 study

Left ventricular (LV) thrombosis can be found in patients with acute myocardial infarction (AMI). No wide multicenter trial on AMI has provided information about LV thrombosis until now. The protocol of the GISSI-3 study included the search for the presence of LV thrombosis in patients from 200 coronary care units that did not specifically focus on LV thrombosis. We examined the GISSI-3 database results related to 8,326 patients at low to medium risk for LV thrombi in which a predischarge echocardiogram (9 +/- 5 days) was available. LV thrombosis was found in 427 patients (5.1%): 292 of 2,544 patients (11.5%) with anterior AMI and in 135 of 5,782 patients (2.3%) with AMI in other sites (p <0.0001). The incidence of LV thrombosis was higher in patients with ejection fraction < or = 40% (151 of 1,432 [10.5%] vs 276 of 6,894 [4%]; p <0.0001) both in the total population and in the subgroup with anterior AMI (106 of 597 [17.8%] vs 186 of 1,947 [9.6%]; p <0.0001). Multivariate analysis showed that only the Killip class > I and early intravenous beta-blocker administration were independently associated with higher LV thrombosis risk in the subgroup of patients with anterior AMI (odds ratio 1.75, 95% confidence interval 1.28 to 2.39; odds ratio 1.32, 95% confidence interval 1.02 to 1.72, respectively). In patients with anterior AMI, oral beta-blocker therapy given or not given after early intravenous beta-blocker administration does not influence the occurrence of LV thrombosis. The rate of LV thrombosis was similar in patients treated or not treated with nitrates and lisinopril both in the total population and in patients with anterior and nonanterior AMI. In conclusion, in the GISSI-3 population at low to medium risk for LV thrombi, the highest rate of occurrence of LV thrombosis was found among patients with anterior AMI and an ejection fraction < 40%. Killip class > I and the early intravenous beta-blocker administration were the only variables independently associated with a higher predischarge incidence of LV thrombosis after anterior AMI.

Randomized trial of low molecular weight heparin (dalteparin) in prevention of left ventricular thrombus formation and arterial embolism after acute anterior myocardial infarction: the Fragmin in Acute Myocardial Infarction (FRAMI) Study

OBJECTIVES

The present trial investigated the efficacy and safety of dalteparin in the prevention of arterial thromboembolism after an acute anterior myocardial infarction (MI).

BACKGROUND

Left ventricular (LV) thrombus formation is associated with increased risk of arterial embolism in patients with an acute MI. Thrombolytic and antiplatelet therapy do not prevent thrombus formation.

METHODS

A total of 776 patients were enrolled in a multicenter, randomized, double-blind, placebo-controlled trial of subcutaneous dalteparin (150 IU/kg body weight every 12 h during the hospital period). Thrombolytic therapy and aspirin were administered in 91.5% and 97.6% of patients, respectively. The primary study end point was the composite of thrombus formation diagnosed by echocardiography and arterial embolism on day 9 +/- 2.

RESULTS

Of 517 patients with echocardiographic recordings available for end point analysis, thrombus formation or embolism, or both, was found in 59 (21.9%) of 270 patients (59 with thrombus, none with embolism) in the placebo group and 35 (14.2%) of 247 patients (34 with thrombus, 1 with embolism) in the dalteparin group (p = 0.03). The risk reduction of thrombus formation associated with dalteparin treatment was 0.63 (95% confidence interval 0.43 to 0.92, p = 0.02). Analyses of all randomized patients (388 in each group) revealed no significant difference between the placebo and dalteparin groups with respect to arterial embolism (6 vs. 5 patients), reinfarction (8 vs. 6 patients) and mortality rates (23 vs. 23 patients, p = NS for all). Dalteparin was associated with an increased risk of hemorrhage: major in 11 dalteparin group patients (2.9%) verus 1 placebo group patient (0.3%, p = 0.006); minor in 52 dalteparin group patients (14.8%) versus 8 placebo group patients (1.8%, p < 0.001).

CONCLUSIONS

Dalteparin treatment significantly reduces LV thrombus formation in acute anterior MI but is associated with increased hemorrhagic risk.

Incidence and natural history of left ventricular thrombus following anterior wall acute myocardial infarction

Previous studies have reported left ventricular (LV) thrombus in 20% to 56% of patients after anterior wall acute myocardial infarction (AMI). The Healing and Early Afterload Reducing Therapy (HEART) study was a prospective study comparing effects of early (24 hours) or delayed (14 days) initiation of ramipril, an angiotensin-converting enzyme inhibitor, on LV function after anterior wall AMI. This ancillary study assessed prevalence of LV thrombus. Two-dimensional echocardiography was performed on days 1, 14, and 90 after myocardial infarction. The cohort consisted of 309 patients. Q-wave anterior wall AMI occurred in 78%; 87% received reperfusion therapy. The prevalence of LV thrombus was 2 of 309 (0.6%) at day 1, 11 of 295 (3.7%) at day 14, and 7 of 283 (2.5%) at day 90. One patient had thrombus at 2 examinations. The day 1 echocardiogram was not correlated with thrombus development. LV size increased more in patients with thrombus than in those without thrombus. Patients with thrombus had more wall motion abnormality after day 1 than patients without thrombus (p = 0.03). Thus, the current prevalence of LV thrombus in anterior wall AMI is lower than previously reported, possibly due to changes in AMI management. Preservation of LV function is likely to be an important mechanism. Most thrombi are seen by 2 weeks after AMI. Resolution documented by echocardiography is frequent.

Ventricular dysfunction and the risk of stroke after myocardial infarction

BACKGROUND

In patients who have had a myocardial infarction, the long-term risk of stroke and its relation to the extent of left ventricular dysfunction have not been determined. We studied whether a reduced left ventricular ejection fraction is associated with an increased risk of stroke after myocardial infarction and whether other factors such as older age and therapy with anticoagulants, thrombolytic agents, or captopril affect long-term rates of stroke.

METHODS

We performed an observational analysis of prospectively collected data on 2231 patients who had left ventricular dysfunction after acute myocardial infarction who were enrolled in the Survival and Ventricular Enlargement trial. The mean follow-up was 42 months. Risk factors for stroke were assessed by both univariate and multivariate Cox proportional-hazards analysis.

RESULTS

Among these patients, 103 (4.6 percent) had fatal or nonfatal strokes during the study (rate of stroke per year of follow-up, 1.5 percent). The estimated five-year rate of stroke in all the patients was 8.1 percent. As compared with patients without stroke, patients with stroke were older (mean [+/-SD] age, 63+/-9 years vs. 59+/-11 years; P<0.001) and had lower ejection fractions (29+/-7 percent vs. 31+/-7 percent, P=0.01). Independent risk factors for stroke included a lower ejection fraction (for every decrease of 5 percentage points in the ejection fraction there was an 18 percent increase in the risk of stroke), older age, and the absence of aspirin or anticoagulant therapy. Patients with ejection fractions of < or = 28 percent after myocardial infarction had a relative risk of stroke of 1.86, as compared with patients with ejection fractions of more than 35 percent (P=0.01). The use of thrombolytic agents and captopril had no significant effect on the risk of stroke.

CONCLUSIONS

During the five years after myocardial infarction, patients have a substantial risk of stroke. A decreased ejection fraction and older age are both independent predictors of an increased risk of stroke. Anticoagulant therapy appears to have a protective effect against stroke after myocardial infarction.

Role of transoesophageal echocardiography in determining the source of peripheral arterial embolism

Thirty patients with peripheral arterial embolism underwent conventional transthoracic echocardiography. Transoesophageal echocardiography was also performed in ten of the same patients. The detection rate of cardiac abnormalities considered responsible for embolism was five of 20 in patients who received only transthoracic echocardiography and eight of ten in those who underwent transoesophageal echocardiography. One abnormality was detected by transthoracic echocardiography in the ten patients who received both tests, while eight cardiac or aortic abnormalities were discovered by transoesophageal echocardiography (P < 0.05). Transoesophageal echocardiography is significantly better than conventional transthoracic echocardiography at detecting cardiac sources of peripheral arterial embolism.

Echocardiography in the evaluation of cardiac sources of emboli: the role of transthoracic echocardiography

Cardioembolism is responsible for a significant number of systemic emboli including approximately 15% of all ischemic strokes. Transthoracic echocardiography has contributed to the understanding of cardioembolism and has been used to detect specific and potential cardiac sources of systemic emboli and risk stratify patients with specific clinical findings for subsequent cardiovascular events. Findings from transthoracic echocardiography indicate that stasis is an important prerequisite for intracardiac thrombosis while reversal of stasis and thrombolysis appear operative in embolism of existing thrombus. Transthoracic echocardiography allows a sensitive and specific noninvasive means to detect left ventricular thrombus, valvular vegetation, and intracardiac tumor, lesions that are directly responsible for cardioembolism. Transthoracic echocardiography can also detect lesions that could potentially contribute to cardioembolism but are not specific causes. Examples of these potential lesions include mitral valve prolapse, patent foramen ovale, and interatrial septal aneurysm. Finally, population-based studies and prospective clinical trials have indicated that the results of transthoracic echocardiography have predictive value for subsequent cardiovascular events and hence provide a means for stratification of patients at risk for cardioembolism. The latter is most notable for the group of patients with nonvalvular atrial fibrillation where left ventricular dysfunction and increased left atrial size are independent predictors for subsequent stroke.

Disappearing intracardiac thrombi in both atria after mumps in a patient with Turner syndrome

A girl with Turner syndrome was admitted with an acute cerebrovascular occlusive disease 15 days after mumps infection. Imaging techniques such as Doppler echocardiography, computed tomography and angiography of the heart revealed the existence of masses in both atria. Eight days after the last radiologic study the patient had an operation, but no masses were found in either atrium. It was thought that atrial thrombi, probably formed after viral infection, had broken down to form emboli and disappeared. It is proposed that the patients with congenital cardiopathy should be regularly examined after viral infections for possible intracardiac thrombus formation. If such a mass is found and the decision is to operate, the existence of the mass must be confirmed even in the operating room just before intervention.

Use of echocardiography in detecting cardiac sources of embolus

Up to 20% of all ischemic strokes are felt to be the result of emboli from the heart. High resolution transthoracic (TTE) and transesophageal (TEE) echocardiography have been the principal diagnostic tools for detecting associated cardiac abnormalities and for guiding medical and surgical approaches to these patients. In addition to identifying the precise location and morphological characteristics of intracardiac masses, echocardiography has improved our ability to predict embolic potential of these masses. Specific cardiac lesions that are predisposed to stroke and are readily identifiable by echocardiography include: cardiac thrombi, valvular vegetations, cardiac tumors, aortic atheroma, atrial septal aneurysm, and regional left ventricular wall abnormalities. Careful interrogation of patients with cerebrovascular accidents has identified a potential cardiac source of embolus in approximately 30%. This is largely due to the advent of TEE, which has provided much better assessment of posterior cardiac chambers including left atrium and left atrial appendage. Use of TEE in identifying a cardiac source of embolus is indicated in patients with stroke who are young, have no apparent cerebrovascular disease, or have recurrent embolic events. Echocardiography is an essential diagnostic tool in evaluating patients with a suspected cardiac source of embolus. TTE and TEE provide invaluable information regarding the majority of cardiac sources of embolus.

Usefulness of transesophageal echocardiography in identifying small left ventricular apical thrombus

OBJECTIVES

The aim of this study was to determine whether transesophageal echocardiography could clarify the nature of equivocal echodense structures in the left ventricular apical region frequently found on transthoracic echocardiography by directing the ultrasound beam from the left ventricular base to the apex and achieving better image quality.

BACKGROUND

Transthoracic echocardiography often reveals an echogenic structure suggesting thrombus in the left ventricular apical region because of limited near-field resolution and echo vibration artifact in apical views.

METHODS

Thirty-six patients with coronary artery disease or dilated cardiomyopathy who had apical wall motion abnormalities and equivocal transthoracic echodense structures were studied with transesophageal echocardiography using special manipulation of the transesophageal probe for adequate imaging of the apical region. Left ventricular thrombus was defined when echogenic structures with a clearly delineated margin adjacent to but distinct from the endocardium were observed in at least two different tomographic views in the four-chamber and left ventricular long-axis views during both systole and diastole.

RESULTS

Left ventricular thrombus (mean size 1.3 +/- 0.7 cm2) was defined by transesophageal echocardiography in 19 (53%) of 36 patients with suspected thrombus on transthoracic echocardiography in the four-chamber or left ventricular long-axis view. Heavy trabeculation or extremely high echo reflection, or both, was observed in the apical region in 12 patients (33%). No extra structures in the apical region were found in five patients. In 19 patients with transesophageal echocardiographically defined thrombus, 6 patients (31%) experienced arterial embolic events before the transesophageal procedure. In contrast, none of 17 patients without transesophageal echocardiographically defined thrombi had systemic embolism (p < 0.03).

CONCLUSIONS

1) Transesophageal echocardiography is useful in identifying left ventricular apical thrombus in patients with unclear echogenic structures on transthoracic apical images; and 2) the high incidence of arterial embolism in patients with transesophageal echocardiographically detected left ventricular thrombus indicates the clinical importance of such thrombus.

From swirling to a mobile, pedunculated mass--the evolution of left ventricular thrombus despite full anticoagulation. Echocardiographic demonstration

We describe the unusual evolution of a left ventricular thrombus following acute anterior myocardial infarction despite adequate anticoagulation. Serial echocardiographic examinations demonstrated the evolution from swirling in the left ventricle through a solid apical mass gradually dislodging into a mobile, pedunculated mass that was removed surgically to prevent embolization. This report emphasizes the need to follow echocardiographically left ventricular thrombi during treatment with anticoagulants, and to identify morphologic changes that may predict embolization. This case suggests that left ventricular thrombectomy should be considered in selected patients in whom a very high-risk thrombus morphology is detected.

Ischemic stroke and intracranial hemorrhage following thrombolytic therapy for acute myocardial infarction: a risk-benefit analysis

Stroke is a potentially serious complication of acute myocardial infarction (AMI). In the prethrombolytic era, most strokes were attributed to cerebral embolism. On the basis of available information, the occurrence of stroke in the thrombolytic era appears to be less than in the prethrombolytic era. In the thrombolytic era, the occurrence of various forms of intracranial hemorrhage has increasingly been documented in addition to cerebral embolism, with intriguing features. In general, however, the delineation of specific stroke subtypes has been imprecise and must take into account factors that are unique to this setting. Age is a risk factor for both ischemic and hemorrhagic stroke. Potential risk factors for intracranial hemorrhage include hypertension, dosage of fibrinolytic agents, and prior neurologic disease. Potential causes of intracranial hemorrhage include combined fibrinolytic/adjunctive therapies, various cerebrovascular lesions, and head trauma. Existing data suggest that mortality related to stroke complicating AMI is on the decline as well. More research is needed in order to quantify precisely the occurrence and proportions of stroke subtypes, risk factors, and causes in order to define mechanisms and preventive measures.

Echocardiography. Basics for the primary care physician

Echocardiography is commonly performed to assess aortic stenosis, mitral valve prolapse, pericardial effusion and cardiac tamponade, myocardial infarction, endocarditis, and valvular regurgitation. We have found that the more defined and appropriate a request for an echocardiogram is, the better the technician and interpreter can relate observations to the requesting physician. Thus, thorough understanding of the indications and limitations of echocardiography by the primary care physician will result in improved patient care.

Natural history of left ventricular thrombi: their appearance and resolution in the posthospitalization period of acute myocardial infarction

A series of 198 consecutive patients with acute myocardial infarction were prospectively studied before hospital discharge and during 24.0 +/- 8.6 months of follow-up. A predischarge thrombus was found in 38 (31%) of 124 patients with anterior infarction but in none of 74 patients with inferior infarction (p less than 0.001). Early thrombolytic therapy in 34 patients did not decrease the rate of thrombus occurrence. Acute anterior infarction, ejection fraction less than or equal to 35% and apical dyskinesia or aneurysm (but not akinesia) were significantly related to the appearance of thrombus during hospitalization by stepwise logistic regression analysis. Echocardiographic follow-up of 159 patients for at least 6 months (mean 26.6 +/- 8.4) revealed that thrombus disappeared in 14 (48%) of 29. Disappearance of thrombus was related to predischarge apical akinesia (but not dyskinesia) and to warfarin therapy during the follow-up period. A new thrombus first appeared after hospital discharge in 13 of 130 patients, and in 7 of the 13 it resolved during further follow-up. Thus, 30% (13 of 42) of thrombi in these patients appeared after discharge from the hospital. Three factors were related to occurrence of new thrombi during the follow-up period: deterioration in left ventricular ejection fraction, predischarge ejection fraction less than or equal to 35% and ventricular aneurysm or dyskinesia. Systemic embolism occurred in six patients, all with a predischarge thrombus (p less than 0.001). Mobility of the thrombus was the only variable significantly related to subsequent embolic events (p = 0.001) by logistic regression analysis. Thus, the predischarge echocardiogram identifies patients with thrombus and those at highest risk of embolic events. It can indicate patients who are likely to have thrombus resolution and those at risk of developing a new thrombus after hospital discharge. Follow-up echocardiograms may help in guiding the length of long-term anticoagulant therapy. Four additional patients with a predischarge apical mobile thrombus (not part of the consecutive series) received thrombolytic therapy. In two of the four, lysis of thrombus was achieved without complications, but systemic embolism occurred in the other two, and proved fatal in one.

Prediction of apical thrombus formation in acute myocardial infarction based on left ventricular spatial flow pattern

The predictive value of the left ventricular spatial flow pattern for thrombus formation was determined in 62 patients with acute myocardial infarction. A normal flow pattern by pulsed Doppler echocardiography was characterized by 1) simultaneous onset of blood motion at the mitral valve and apical level, and 2) a discontinuous Doppler signal along the lateral wall and interventricular septum. The flow pattern was assessed by these criteria, within 24 h after the onset of complaints and after 6 and 12 weeks. In 46 of the 62 patients, a normal flow pattern was found at the first examination; none of these 46 patients developed a thrombus during the study period. An abnormal flow pattern was seen at the first examination in 16 patients; this pattern normalized during follow-up in 6 patients, none of whom developed a thrombus. In the other 10 patients the abnormal flow pattern persisted, and 7 of these developed a thrombus. These findings suggest that a normal left ventricular flow pattern in the setting of acute myocardial infarction is not associated with subsequent thrombus formation. This observation may be of importance if anticoagulation is considered.

Decision analysis concerning the application of echocardiography to the diagnosis and treatment of mural thrombi after anterior wall acute myocardial infarction

The diagnostic and therapeutic approach to the problem of mural thrombi after acute myocardial infarction is uncertain. It is clear that the main therapeutic goal is the prevention of embolic strokes. Although it is known that the incidence of thrombi is greatest after anterior wall infarctions, there is uncertainty concerning (1) the probability of a mural thrombus; (2) the sensitivity and specificity of echocardiography in making the diagnosis; (3) the probability that a thrombus will embolize and result in a cerebrovascular accident (CVA); (4) the efficacy of warfarin in preventing embolization; and (5) the probability of bleeding with and without warfarin. To study this problem in patients who have had an anterior wall myocardial infarction, a model was created in which reasonable estimates for the unknown parameters were determined from published medical studies. The model was designed to consider patients if they were or were not treated during the initial hospitalization with heparin. The probability of thrombus was estimated at 0.30, sensitivity and specificity of echocardiography at 0.85 and 0.85, probability that a thrombus will embolize at 0.15, efficacy of anticoagulation of 0.75, probability of bleeding with warfarin at 0.03 and probability of bleeding without warfarin at 0.005. Probabilities of a CVA and of bleeding with and without warfarin were determined if all patients were anticoagulated, if patients with positive echocardiographic results were treated, if patients with negative echocardiographic results were treated and if echocardiographically guided therapy was instituted in which patients with positive echocardiographic results are treated and patients with negative results are not treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of thrombolytic treatment followed by full dose anticoagulation on the frequency of left ventricular thrombi in acute myocardial infarction

This study evaluated the influence of thrombolysis followed by full anticoagulation on the frequency of left ventricular (LV) thrombi after acute myocardial infarction (AMI). Nineteen consecutive patients with a first anterior wall AMI who received 1,500,000 IU of streptokinase within 3 hours of symptom onset, followed by full anticoagulation, underwent echocardiographic studies within 24 hours of symptoms, and then on days 2, 3, 5, 7, 12, 30 and 90. Forty-four patients, with comparable clinical features and echocardiographic protocol but without antithrombotic therapy, served as the control group. LV thrombi developed in 4 of 19 (21%) treated patients and in 23 of 44 (52%) control subjects (p = 0.02). LV aneurysm or major wall motion abnormalities were noted in 8 of 19 (42%) treated patients and in 30 of 44 (68%) control subjects (p less than 0.05). No significant difference was found between treated and untreated patients when comparing the incidence of thrombi in the subgroups of patients with aneurysm or major wall motion abnormalities (3 of 8 vs 21 of 30) and in the subgroups with less extensive LV dysfunction. Thrombi disappeared during hospitalization in 3 of 4 treated patients, but in none of the controls. Fewer patients treated with intravenous streptokinase followed by full anticoagulation developed LV thrombi compared to patients treated with conventional therapy. This difference may be related to a reduced occurrence of major LV wall motion abnormalities. Resolution of thrombi frequently occurs in the hospital phase of AMI; therefore, only frequent echocardiographic examinations can assess the true frequency of LV thrombi.