Incidence of left-ventricular thrombosis after acute transmural myocardial infarction. Serial evaluation by two-dimensional echocardiography

Echocardiographic Detection of Left Ventricular Thrombus in Patients Undergoing Heartmate II Left Ventricular Assist Device Implantation

Purpose

Transthoracic (TTE) and transesophageal echocardiograms (TEE) are considered accurate in detecting the presence of left ventricular (LV) thrombus. A persistent LV thrombus poses risks of pump thrombosis and stroke in LVAD recipients. The relationship between pre-operative echocardiography and intraoperative findings at LVAD implantation has not previously been studied.

Methods

A retrospective review examined all patients undergoing LVAD placement or exchange from October 2011 to March 2014. Pre-Operative TTE and TEE data were validated with presence of LV thrombus during the direct inspection at the time of LVAD placement, and the findings were analyzed quantitatively.

Results

Between October 2011 and March 2014, 99 patients underwent a total of 107 LVAD implants. Pre-Operative TTE was available in 93 (86.9%) cases, while pre-operative TEE was available in 37 cases (34.6%). On pre-operative TTE, LV thrombus was correctly identified in only two cases, while on pre-operative TEE no cases of LV thrombus were identified correctly, and there were 2 false positive reports. Intraoperative inspection revealed presence of LV thrombus in 14 cases. The sensitivity of pre-operative TTE was 16.7% and the specificity 100% in detecting LVT, compared to 0% and 93.8%, respectively, for TEE.

Conclusions

Pre-Operative echocardiogram offers low accuracy for presence of LV thrombus. Overall, the sensitivity is too low to reliably exclude thrombus. This could have significant implications in planning off-pump LVAD exchange as thrombus could be missed. More data are necessary to determine whether this could have significant effects on thromboembolic complications and survival.

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.

Echocardiographic Algorithm for Post-Myocardial Infarction LV Thrombus: A Gatekeeper for Thrombus Evaluation by Delayed Enhancement CMR

OBJECTIVES

The goal of this study was to determine the prevalence of post-myocardial infarction (MI) left ventricular (LV) thrombus in the current era and to develop an effective algorithm (predicated on echocardiography [echo]) to discern patients warranting further testing for thrombus via delayed enhancement (DE) cardiac magnetic resonance (CMR).

BACKGROUND

LV thrombus affects post-MI management. DE-CMR provides thrombus tissue characterization and is a well-validated but an impractical screening modality for all patients after an MI.

METHODS

A same-day echo and CMR were performed according to a tailored protocol, which entailed uniform echo contrast (irrespective of image quality) and dedicated DE-CMR for thrombus tissue characterization.

RESULTS

A total of 201 patients were studied; 8% had thrombus according to DE-CMR. All thrombi were apically located; 94% of thrombi occurred in the context of a left anterior descending (LAD) infarct-related artery. Although patients with thrombus had more prolonged chest pain and larger MI (p ≤ 0.01), only 18% had aneurysm on echo (cine-CMR 24%). Noncontrast (35%) and contrast (64%) echo yielded limited sensitivity for thrombus on DE-CMR. Thrombus was associated with stepwise increments in basal → apical contractile dysfunction on echo and quantitative cine-CMR; the echo-measured apical wall motion score was higher among patients with thrombus (p < 0.001) and paralleled cine-CMR decrements in apical ejection fraction and peak ejection rates (both p < 0.005). Thrombus-associated decrements in apical contractile dysfunction were significant even among patients with LAD infarction (p < 0.05). The echo-based apical wall motion score improved overall performance (area under the curve 0.89 ± 0.44) for thrombus compared with ejection fraction (area under the curve 0.80 ± 0.61; p = 0.01). Apical wall motion partitions would have enabled all patients with LV thrombus to be appropriately referred for DE-CMR testing (100% sensitivity and negative predictive value), while avoiding further testing in more than one-half (56% to 63%) of patients.

CONCLUSIONS

LV thrombus remains common, especially after LAD MI, and can occur even in the absence of aneurysm. Although DE-CMR yielded improved overall thrombus detection, apical wall motion on a noncontrast echocardiogram can be an effective stratification tool to identify patients in whom DE-CMR thrombus assessment is most warranted. (Diagnostic Utility of Contrast Echocardiography for Detection of LV Thrombi Post ST Elevation Myocardial Infarction; NCT00539045).

Dual antiplatelet compared to triple antithrombotic therapy in anterior wall acute myocardial infarction complicated by depressed left ventricular ejection fraction

Current guidelines recommend triple antithrombotic therapy (TT) consisting of warfarin, aspirin, and a P2Y12 inhibitor following an anterior ST elevation myocardial infarction (STEMI) complicated by extensive wall motion abnormalities. This recommendation, however, is based on data collected before percutaneous coronary intervention (PCI) became the standard of care for the treatment of STEMI. We designed a retrospective study of patients who received PCI for anterior STEMI over an 8-year period to compare rates of thromboembolic and bleeding events between patients receiving dual antiplatelet therapy (DAPT) and those receiving TT, including warfarin. Patients were included if the predischarge echocardiogram showed extensive wall motion abnormality and an ejection fraction ≤35%. Patients with known left ventricular thrombus were excluded. A total of 124 patients met the criteria, with 80 patients in the DAPT group and 44 in the TT group. The median age was 58 years in the TT group and 64 years in the DAPT group (P < 0.04), with an average ejection fraction of 31%. Thromboembolic events occurred in 4 patients (5%) in the DAPT group compared with 3 patients (6.8%) in the TT group (P = 0.70). Bleeding occurred in 2 patients in the DAPT group and 4 patients in the TT group (2.5% in DAPT vs. 9.1% in TT group, P = 0.18). No differences in rates of clinical embolism or left ventricular thrombus were found. Our data support recent findings that warfarin may not be indicated for patients following PCI for anterior STEMI, even when significant wall motion abnormalities and reduced ejection fraction ≤35% are present.

Myocardial infarct associated with a partial thickness left atrial tear in a dog with mitral insufficiency

A 10-year-old male neutered cavalier King Charles Spaniel with a 1-year history of degenerative mitral valve disease presented for dyspnea and severe weakness. He was diagnosed with congestive heart failure, systolic dysfunction, presumptive myocardial infarction and a left atrial thrombus based on thoracic radiographs, electrocardiogram and echocardiographic findings. Clinical signs also suggested right foreleg embolism. The dog was euthanized due to the grave prognosis and a postmortem evaluation was performed. The postmortem examination confirmed myocardial infarction and was thought to be due to embolic showering from the thrombus attached to a partial thickness left atrial endocardial tear.

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.

Left ventricular thrombus in a patient with cutaneous T-cell lymphoma, hypereosinophilia and Mycoplasma pneumoniae infection - a challenging diagnosis: a case report

Differential diagnoses of cardiac masses include primary benign and malignant neoplasms, secondary neoplasms, and non-neoplastic masses, such as thrombi. Owing to different therapeutic approaches and the way these affect the prognosis, the early and correct diagnostic determination of the etiology of a cardiac mass is of utmost importance and essential for the appropriate management of patients.

We report a case of a 52-year-old woman with a left ventricular mass in the setting of a recent Mycoplasma pneumoniae infection and a medical history of cutaneous T-cell lymphoma and hypereosinophilia. Imaging findings were consistent with both an infiltrative process of the lymphoma and a cardiac thrombus. An estimated very high risk for embolization led to the indication for open-heart surgery for the removal of the cardiac mass. Histopathological examination confirmed the presence of a thrombus; there were no signs of malignancy. The patient was discharged 11 days after surgery in good general condition and is now in outpatient care for follow-up and further management.

This case highlights possible challenges in the diagnostic assessment of cardiac masses and their management in a patient with several underlying diseases and a complex medical history.

Delayed left ventricular apical thrombus formation following discontinuation of dual anti-platelet therapy

Delayed de novo left ventricular apical thrombus following a distant antero-apical myocardial infarction has to our knowledge not been previously reported. Herein we describe a patient who developed an apical thrombus 18 months after his initial infarct following cessation of dual anti-platelet therapy for a traumatic subdural haematoma requiring surgical evacuation.

Contrast echocardiography for assessment of left ventricular thrombi

The diagnosis of intracardiac thrombi remains clinically relevant, with associated risks of systemic embolization and implications for antithrombotic management. Intravenously injected ultrasound contrast agents, composed of microbubbles smaller than red blood cells, have become established essential adjunctive tools for performance of state-of-the-art echocardiography, providing important information on cardiac structure and function. Despite advances in other imaging modalities, echocardiography remains the initial tool for diagnosis and risk stratification in patients predisposed to developing cardiac thrombi. Ultrasound contrast agents are approved for left ventricular (LV) opacification and endocardial border definition. Additionally, the use of contrast echocardiography facilitates LV thrombus detection by providing contrast opacification within the cardiac chambers to clearly show the "filling defect" of an intracardiac thrombus. Furthermore, contrast perfusion echocardiography can provide an assessment of the tissue characteristics of LV masses suspicious for intracardiac thrombi and, by differentiating an avascular thrombus from a tumor, results in improved diagnostic performance of echocardiography. This article presents a clinical vignette highlighting the sound judgment of using contrast echocardiography to aid in the diagnosis of LV thrombi and will review recent advances in imaging modalities for intracardiac thrombus detection.

Hemodynamic Consequences of Hypertrophic Cardiomyopathy with Midventricular Obstruction: Apical Aneurysm and Thrombus Formation

Background

Hypertrophic cardiomyopathy (HCM) with midventricular hypertrophy is an uncommon phenotypic variant of the disease. Midventricular hypertrophy predisposes to intracavitary obstruction and downstream hemodynamic sequelae.

Case report

We present a case of HCM with midventricular hypertrophy and obstruction diagnosed after a CT scan of the abdomen incidentally revealed a filling defect in the left ventricular apex. Transthoracic echocardiography demonstrated mid left ventricular hypertrophy and obstruction, as well as an aneurysmal apex containing a large thrombus. Cardiovascular MRI showed a spade-shaped left ventricle with midcavitary obliteration, an infarcted apex and regions of myocardial fibrosis. Due to the risk of embolization and a relative contraindication to anticoagulation, the patient underwent surgery including thrombectomy, septal myectomy and aneurysmal ligation.

Conclusions

Hypertrophic cardiomyopathy with midventricular hypertrophy leads to cavity obstruction, increased apical wall tension, ischemia and ultimately fibrosis. Over time, patchy apical fibrosis can develop into a confluent scar resembling a transmural myocardial infarction in the left anterior descending coronary artery distribution. Aneurysmal remodeling of the left ventricular apex potentiates thrombus formation and risk of cardioembolism. For these reasons, hypertrophic cardiomyopathy with midventricular obstruction portends a particularly poor prognosis and should be recognized early in the disease process.

Left ventricular ball-like thrombus after acute myocardial infarction with essential thrombocythemia

Left ventricular (LV) thrombus after acute myocardial infarction (AMI) is a frequent complication that is associated with a risk of systemic embolism. Essential thrombocythemia (ET) has opposing tendencies towards hemorrhage and thrombogenesis and it can cause AMI via thrombogenesis. Ball-like LV thrombus is associated with a high risk of systemic embolism. We describe surgical resection of LV ball-like thrombus from a patient with ET. A 60-year-old woman presented at our hospital with transient ischemic attack accompanied by transient hemiplegia. Ultrasonic cardiography revealed a mobile ball-like thrombus in the LV after transmural AMI of the anterior wall. We performed emergency LV thrombectomy because of the mobile LV thrombus with embolism. Platelet aberrations and pathological bone marrow findings were consistent with a diagnosis of ET. We administered the patient with anti-coagulation drugs and the DNA replication inhibitor hydroxycarbamide to decrease the platelet count. She continues to survive and is doing well without major postoperative complications. .

Guidelines for the prevention of stroke in patients with stroke and transient ischemic attack: a guideline for healthcare professionals from the American Heart Association/American Stroke Association

The aim of this updated guideline is to provide comprehensive and timely evidence-based recommendations on the prevention of future stroke among survivors of ischemic stroke or transient ischemic attack. The guideline is addressed to all clinicians who manage secondary prevention for these patients. Evidence-based recommendations are provided for control of risk factors, intervention for vascular obstruction, antithrombotic therapy for cardioembolism, and antiplatelet therapy for noncardioembolic stroke. Recommendations are also provided for the prevention of recurrent stroke in a variety of specific circumstances, including aortic arch atherosclerosis, arterial dissection, patent foramen ovale, hyperhomocysteinemia, hypercoagulable states, antiphospholipid antibody syndrome, sickle cell disease, cerebral venous sinus thrombosis, and pregnancy. Special sections address use of antithrombotic and anticoagulation therapy after an intracranial hemorrhage and implementation of guidelines.

Left ventricular thrombus development during ventricular fibrillation and resolution during resuscitation in a swine model of sudden cardiac arrest

BACKGROUND

Intracardiac thrombus is a well-known complication of low-flow cardiac states including acute myocardial infarction and atrial fibrillation. Little is known, however, about the formation of intracardiac (left ventricular [LV]) thrombus during the extreme low-flow state of cardiac arrest.

OBJECTIVE

Using a swine model of sudden cardiac arrest, we examined the sonographic development of LV thrombus over time after induction of ventricular fibrillation (VF) and resolution of thrombus with cardiopulmonary resuscitation (CPR).

METHODS

This observational study was IACUC approved. Forty-five Yorkshire swine were sedated, intubated, and instrumented under general anesthesia before VF was electrically induced. Sonographic data was collected immediately after VF induction and at 2-min intervals thereafter. Following 12min of untreated VF, resuscitation was initiated with closed chest compressions using an oxygen-powered mechanical resuscitation device. Observations were continued during attempted resuscitation. At the end of the experiment, the animals were euthanized while still at a surgical depth of anesthesia. The data was analyzed descriptively.

RESULTS

Sonographic evidence of LV thrombus was observed in 43/45 animals (95.6% [95%CI: 85.2%, 98.8%]). Thrombus was detected within 6min in 39/45 (86.7% [95%CI: 73.8%, 93.8%]) animals that developed thrombus. Thrombus resolved within 2min after initiation of chest compressions in 31/43 (72.1% [95%CI: 57.3%, 83.3%]) animals.

CONCLUSION

Similar to other low-flow cardiac states, LV thrombus develops early in the natural history of VF arrest and resolves quickly once forward flow is re-established by chest compressions. Institutional protocol number: 154600-8.

Neurologic complications of myocardial infarction

Cardiac disease, in particular coronary artery disease, is the leading cause of mortality in developed nations. Strokes can complicate cardiac disease - either as result of left ventricular dysfunction and associated thrombus formation or of therapy for the cardiac disease. Antiplatelet drugs and anticoagulants routinely used to treat cardiac disease increase the risk for hemorrhagic stroke.

Prevalence and Aetiology of Left Ventricular Thrombus in Patients Undergoing Transthoracic Echocardiography at the University of Maiduguri Teaching Hospital

Objectives. We sought to determine the prevalence and aetiology of LVT among patients undergoing echocardiography. Methods. We reviewed case notes and echocardiographic data of patient diagnosed with LVT using noncontrast transthoracic echocardiography. Definition of various conditions was made using standard guidelines. Mean ± SD were derived for continuous variables and comparison was made using Student's t-test. Results. Total of 1302 transthoracic echocardiograms were performed out of which 949 adult echocardiograms were considered eligible. Mean age of all subjects with abnormal echocardiograms was 44.73 (16.73) years. Abnormalities associated with LVT were observed in 782/949 (82.40%) subjects among whom 84/782 (8.85%) had LVT. The highest prevalence of 39.29% (33/84) was observed in patients with dilated cardiomyopathy, followed by myocardial infarction with a prevalence of 29.76% (25/84). Peripartum cardiomyopathy accounted for 18/84 (21.43%) cases with some having multiple thrombi, whereas hypertensive heart disease was responsible for 6/84 (7.14%) cases. The lowest prevalence of 2.38% (2/84) was observed in those with rheumatic heart disease. Left ventricular EF of <35% was recorded in 55/84 (65.48%). Conclusions. Left ventricular thrombus is common among patients undergoing echo, with dilated cardiomyopathy being the most common underlying aetiology followed by myocardial infarction. Multiple LVTs were documented in peripartum cardiomyopathy.

Comparison of C-reactive protein and fibrinogen levels in patients having anterior wall ST-Segment elevation myocardial infarction with versus without left ventricular thrombus (from a primary percutaneous coronary intervention cohort)

We tested the hypothesis that admission serum inflammatory biomarkers may predict risk of early left ventricular (LV) thrombus formation in patients with first-ever anterior wall ST-segment elevation myocardial infarction (STEMI). Medical records of 207 patients admitted to our department between January 2006 and April 2012 for first-ever diagnosed anterior wall STEMI and treated with primary percutaneous coronary intervention (PPCI) were reviewed. Serum C-reactive protein (CRP) and fibrinogen levels were determined from blood samples taken before PPCI. Patients underwent an initial cardiac echocardiography on days 1 or 2 of admission and a second echocardiography on days 5 to 7 of hospitalization. An early LV thrombus was detected on the second echocardiogram in 11 patients (11 of 207, 5%), 6 of whom had also displayed an LV thrombus already during their first echocardiogram. Patients with an LV thrombus had significantly higher mean serum CRP levels than those without an LV thrombus (48 mg/L vs 8.4 mg/L, p = 0.001), and a trend for higher fibrinogen levels was also observed (398 ± 135 mg/dl vs 312 ± 82 mg/dl, p = 0.063). Following adjustment to other variables and the performance of multiple logistic regression, the CRP (relative risk 4.63, p = 0.004) and fibrinogen (relative risk 1.006, p = 0.033) levels were independent predictors of LV thrombus formation. We conclude that admission serum CRP and fibrinogen levels are independent predictors for early LV thrombus formation complicating a first-ever anterior wall STEMI.

Frequency and correlates of early left ventricular thrombus formation following anterior wall acute myocardial infarction treated with primary percutaneous coronary intervention

The introduction of primary percutaneous coronary intervention (PPCI) for the treatment of patients with acute ST-segment elevation myocardial infarctions has resulted in a significant decrease in the prevalence of diagnosed left ventricular (LV) thrombus. However, reported rates are still as high as 10% to 20% in patients when followed up to 30 days. The aim of this study was to assess the frequency and predictors of early (<7 days after admission) LV thrombus formation in patients with acute anterior ST-segment elevation myocardial infarctions treated with PPCI. The cohort included 429 consecutive patients with documented acute anterior ST-segment elevation myocardial infarctions, who were treated with PPCI from January 2006 to July 2012. All patients underwent cardiac echocardiography on the first or second day of admission and repeat echocardiography 5 to 7 days after admission. Correlates of LV thrombus were estimated using a logistic multivariate regression model. LV thrombus formations were found in 18 of 429 patients (4%) during hospitalization. The first echocardiographic study diagnosed 11 of 18 LV thrombus formations. Patients with identified LV thrombus had significantly lower LV ejection fractions than those without LV thrombus at admission (p = 0.005) and at discharge (p <0.001). Lower admission LV ejection fractions, Thrombolysis In Myocardial Infarction (TIMI) flow grade ≤1 before angioplasty, and a longer time from symptom onset to PPCI were independent predictors of early LV thrombus formation. In conclusion, late reperfusion, a lower LV ejection fraction, and a lower TIMI score significantly increased the risk for early LV thrombus formations, even in the era of PPCI. Early echocardiographic assessment is warranted when admission test results identify at-risk patients.

Successful medical management of a left ventricular thrombus and aneurysm following failed thrombolysis in myocardial infarction

We report the case of a patient with an extensive anterior myocardial infarction complicated by left ventricular systolic dysfunction, left ventricular apical thrombus and an apical left ventricular aneurysm following failed thrombolysis. We obtained serial two-dimensional echocardiograms at short intervals in the acute phase and also during the months of recovery and follow up. The patient was successfully and exclusively medically managed.

SYNTAX Score Predicts the Left Ventricle Thrombus Development in Patients Undergoing Primary Percutaneous Coronary Intervention for First Anterior Myocardial Infarction

Objectives:

The aim of this study is to investigate the relationship between left ventricular thrombus (LVT) developments and the SYNTAX score (SS) in patients undergoing primary percutaneous coronary intervention (PPCI) for first anterior wall ST-segment elevation myocardial infarction (STEMI).

Methods:

We enrolled 160 patients. All participants were evaluated by serial transthoracic echocardiography. Baseline clinical, echocardiographic, and procedural features of PPCI were analyzed to find predictors of LVT development.

Results:

The LVT was detected in 32 (20%) patients. Left ventricular ejection fraction (LVEF) and SS-I were found to be independent predictors of LVT development. Receiver–operating characteristic curve analysis revealed a cutoff value >19.5 for SS-I (area under the curve: 0.697, 95% confidence interval 0.620-0.767, P < .001) with a specificity of 45.3% and a sensitivity of 84.3%.

Conclusion:

High SS which was obtained through diagnostic angiogram of PPCI may be associated with LVT development in patients with first anterior wall STEMI.

Prothrombotic markers in patients with acute myocardial infarction and left ventricular thrombus formation treated with pci and dual antiplatelet therapy

Background

The aim of the present study was to compare circulating levels of selected prothrombotic markers in patients suffering acute myocardial infarction (AMI) with and without left ventricular (LV) thrombus.

Methods

One hundred patients with AMI treated with PCI on the LAD and dual antiplatelet therapy were included. LV thrombus formation was detected by echocardiography and/or MRI in 15 patients. Fasting blood samples were drawn 4–5 days (baseline), 6–7 days, 8–9 days, 2–3 weeks and 3 months after the AMI for determination of haemostatic markers.

Results

We found higher levels of soluble tissue factor (TF) and D-dimer in the LV thrombus group 4–5 days, 8–9 days and 3 months (only TF) after the AMI compared to the patients without thrombus formation (p<0.05). Patients with TF in the upper quartile at baseline had significantly higher risk for LV thrombus (OR 4.2; 95% CI 1.2 -14.5; p=0.02, adjusted for infarct size).

The levels of prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were significantly lower in the thrombus group after 8–9 days (only ETP), 2–3 weeks and 3 months. The levels of plasminogen activator inhibitor 1 activity and tissue plasminogen activator antigen did not differ between the groups.

Conclusion

In the acute phase of AMI, we found higher levels of TF and D-dimer in the LV thrombus group, indicating hypercoagulability of possible importance for the generation of mural thrombus. Lower levels of F1+2, ETP and D-dimer in the thrombus group late during follow-up are probably induced by the initiated anticoagulation therapy.

Rapid progression of left ventricular thrombus with left ventricular dysfunction detected by preoperative transthoracic echocardiography

We report a successfully treated case of rapid progressive left ventricular (LV) thrombus with ischemic cardiomyopathy. Initially, the patient was scheduled to undergo only coronary artery bypass grafting. After two months, preoperative echocardiography revealed a previously undetected ball-like thrombus in the LV cavity. Surgical revascularization and thrombectomy were performed. No systemic embolism was associated with surgical manipulation during the perioperative period. Repeated preoperative evaluation for the presence of thrombus by transthoracic or transesophageal echocardiography is essential in cases of ischemic cardiomyopathy.

Monocytes/macrophages prevent healing defects and left ventricular thrombus formation after myocardial infarction

Myocardial infarction (MI) leads to rapid necrosis of cardiac myocytes. To achieve tissue integrity and function, inflammatory cells are activated, including monocytes/macrophages. However, the effect of monocyte/macrophage recruitment after MI remains poorly defined. After experimental MI, monocytes and macrophages were depleted through serial injections of clodronate-containing liposomes. Monocyte/macrophage infiltration was reduced in the myocardium after MI by active treatment. Mortality was increased due to thromboembolic events in monocyte- and macrophage-depleted animals (92 vs. 33%; P<0.01). Left ventricular thrombi were detectable as early as 24 h after MI; this was reproduced in a genetic model of monocyte/macrophage ablation. A general prothrombotic state, increased infarct expansion, and deficient neovascularization were not observed. Severely compromised extracellular matrix remodeling (collagen I, placebo liposome vs. clodronate liposome, 2.4 ± 0.2 vs. 0.8 ± 0.2 arbitrary units; P<0.001) and locally lost integrity of the endocardium after MI are potential mechanisms. Patients with a left ventricular thrombus had a relative decrease of CD14CD16 monocyte/macrophage subsets in the peripheral blood after MI (no thrombus vs. thrombus, 14.2 ± 0.9 vs. 7.80 ± 0.4%; P<0.05). In summary, monocytes/macrophages are of central importance for healing after MI. Impaired monocyte/macrophage function appears to be an unrecognized new pathophysiological mechanism for left ventricular thrombus development after MI.

Left ventricular thrombus and subsequent thromboembolism, comparison of anticoagulation, surgical removal, and antiplatelet agents

Left ventricular (LV) thrombus is one of the risk factors for systemic thromboembolism. The aims of this study were to compare the long-term clinical outcomes of LV thrombus using current therapeutics, anticoagulation, operative treatment, and antiplatelet agents and to identify independent predictors of systemic thromboembolism.

METHODS

We screened 86,374 patients for intracardiac thrombus in the electronic medical records and imaging databases. Records of 62 patients with LV thrombus, diagnosed between May 2003 to November 2011, were comprehensively reviewed regarding baseline characteristics, imaging data and thrombus outcomes, thromboembolic events and treatment complications by treatment group.

RESULTS

The majority (80.6%) had ischemic etiology. Systemic thromboembolism developed in 18 patients; 8 (45%) were post-treatment thromboembolisms while 10 events occurred before treatment began. No post-treatment thromboembolism occurred in the operative treatment group; in contrast, 7 post-treatment thromboembolisms occurred in anticoagulation group (17%) (Log rank p= 0.175). Independent predictors of post-treatment thromboembolism were dilated cardiomyopathy (HR 61.30, p= 0.001), previous cerebrovascular events (HR 7.06, p= 0.042), female gender (HR 7.11, p= 0.031), and echocardiographic left ventricular end-diastolic diameter (HR 1.15, p= 0.047).

CONCLUSIONS

In this study, the rate of post-treatment thromboembolism was not significantly different among the treatment groups; however, operative treatment tended towards less post-treatment thromboembolism than other treatment groups.

Primary and secondary prevention of cardiovascular disease: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

This guideline focuses on long-term administration of antithrombotic drugs designed for primary and secondary prevention of cardiovascular disease, including two new antiplatelet therapies.

METHODS

The methods of this guideline follow those described in Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We present 23 recommendations for pertinent clinical questions. For primary prevention of cardiovascular disease, we suggest low-dose aspirin (75-100 mg/d) in patients aged > 50 years over no aspirin therapy (Grade 2B). For patients with established coronary artery disease, defined as patients 1-year post-acute coronary syndrome, with prior revascularization, coronary stenoses > 50% by coronary angiogram, and/or evidence for cardiac ischemia on diagnostic testing, we recommend long-term low-dose aspirin or clopidogrel (75 mg/d) (Grade 1A). For patients with acute coronary syndromes who undergo percutaneous coronary intervention (PCI) with stent placement, we recommend for the first year dual antiplatelet therapy with low-dose aspirin in combination with ticagrelor 90 mg bid, clopidogrel 75 mg/d, or prasugrel 10 mg/d over single antiplatelet therapy (Grade 1B). For patients undergoing elective PCI with stent placement, we recommend aspirin (75-325 mg/d) and clopidogrel for a minimum duration of 1 month (bare-metal stents) or 3 to 6 months (drug-eluting stents) (Grade 1A). We suggest continuing low-dose aspirin plus clopidogrel for 12 months for all stents (Grade 2C). Thereafter, we recommend single antiplatelet therapy over continuation of dual antiplatelet therapy (Grade 1B).

CONCLUSIONS

Recommendations continue to favor single antiplatelet therapy for patients with established coronary artery disease. For patients with acute coronary syndromes or undergoing elective PCI with stent placement, dual antiplatelet therapy for up to 1 year is warranted.

Mean Platelet Volume in Patients With Dilated Cardiomyopathy

We assessed the clinical echocardiograhic, hematological, and biochemical parameters in patients with dilated cardiomyopathy (DCMP) and control individuals mainly focusing on the mean platelet volume (MPV) in terms of DCMP and left ventricle (LV) thrombus formation. Consecutive patients (n = 251) with DCMP and 266 patients without DCMP were studied. Mean platelet volume was significantly greater in patients with DCMP than in control patients ( P < .05 for all comparisons). Comparing DCMP patients with LV thrombus (19 patients, 8%) and without LV thrombus (232 patients, 92%) showed that the prevalence of smokers was significantly higher and ejection fraction was significantly lower in patients with LV thrombus. We have shown that patients with DCMP have significantly higher MPV suggesting more platelet activation and the MPV of patients with DCMP and LV thrombus is comparable to those of patients without LV thrombus.

Left ventricular thrombus attenuation characterization in cardiac computed tomography angiography

BACKGROUND

Because of their similar visual appearance, differentiation of left ventricular thrombotic material and myocardial wall can be difficult in contrast-enhanced coronary computed tomography (CT) angiography.

OBJECTIVE

We identified typical thrombi attenuation of left ventricular thrombi with the use of CT measurement.

METHODS

Over a time period of 6 years, we retrospectively identified 31 patients who showed a left ventricular thrombus in CT angiography datasets. Patients underwent routine contrast cardiac CT to investigate coronary artery disease. CT attenuation of each thrombus was assessed in the 4-chamber view. CT densities were also determined in the ascending aorta, left ventricle, and myocardial wall both in the mid-septal and mid-lateral segments. The mean CT attenuation of thrombi and the difference between attenuation in thrombi, left ventricular cavity, and myocardial wall were determined. The ratio of attenuation values in thrombus versus aorta and myocardium versus aorta were also determined.

RESULTS

Mean (±SD) CT attenuation of all left ventricular thrombi in 31 patients was 43.2 ± 15.3 HU (range, 25-80 HU). Mean CT densities of septal and lateral myocardial wall were 102.9 ± 23.1 HU (range, 63-155 HU) and 99.3 ± 28.7 HU (range, 72-191 HU), respectively, and were thus significantly higher than the CT attenuation of thrombi (P < 0.001). A threshold of 65 HU yielded a sensitivity, specificity, and positive and negative predictive values of 94%, 97%, 94%, and 97%, respectively, to differentiate thrombus from the myocardial wall. The mean ratio between CT attenuation of thrombus and CT attenuation within the ascending aorta was 0.11 ± 0.05 (range, 0.04-0.23), which was significantly lower compared with the mean ratio between CT attenuation of the myocardial wall and the CT attenuation within the ascending aorta.

CONCLUSION

CT attenuation within left ventricular thrombi was significantly lower than myocardial attenuation in CT angiography datasets. Assessment of CT attenuation may contribute to the differentiation of thrombi.

LV thrombus detection by routine echocardiography: insights into performance characteristics using delayed enhancement CMR

OBJECTIVES

This study sought to evaluate performance characteristics of routine echo for left ventricular thrombus (LVT).

BACKGROUND

Although the utility of dedicated echocardiography (echo) for LVT is established, echo is widely used as a general test for which LVT is rarely the primary indication. We used delayed-enhancement cardiac magnetic resonance (DE-CMR) as a reference to evaluate LVT detection by routine echo.

METHODS

Dedicated LVT assessment using DE-CMR was prospectively performed in patients with left ventricular systolic dysfunction. Echoes were done as part of routine clinical care. Echo and CMR were independently read for LVT and related indexes of LVT size, shape, and image quality/diagnostic confidence. Follow-up was done for embolic events and pathology validation of LVT.

RESULTS

In this study, 243 patients had routine clinical echo and dedicated CMR within 1 week without intervening events. Follow-up supported DE-CMR as a reference standard, with >5-fold difference in endpoints between patients with versus without LVT by DE-CMR (p = 0.02). LVT prevalence was 10% by DE-CMR. Echo contrast was used in 4% of patients. Echo sensitivity and specificity were 33% and 91%, with positive and negative predictive values of 29% and 93%. Among patients with possible LVT as the clinical indication for echo, sensitivity and positive predictive value were markedly higher (60%, 75%). Regarding sensitivity, echo performance related to LVT morphology and mirrored cine-CMR, with protuberant thrombus typically missed when small (p ≤ 0.02). There was also a strong trend to miss mural thrombus irrespective of size (p = 0.06). Concerning positive predictive value, echo performance related to image quality, with lower diagnostic confidence scores for echoes read positive for LVT in discordance with DE-CMR compared with echoes concordant with DE-CMR (p < 0.02).

CONCLUSIONS

Routine echo with rare contrast use can yield misleading results concerning LVT. Echo performance is improved when large protuberant thrombus is present and when the clinical indication is specifically for LVT assessment.

Frequency of left ventricular thrombus in patients with anterior wall acute myocardial infarction treated with percutaneous coronary intervention and dual antiplatelet therapy

The aim of the present study was to investigate the prevalence of left ventricular (LV) thrombus formation and important determinants in patients with acute ST elevation myocardial infarction localized to the anterior wall treated with percutaneous coronary intervention (PCI) and dual-antiplatelet therapy. One hundred selected patients with ST elevation myocardial infarctions revascularized with PCI in the left anterior descending coronary artery were included. The patients participated in the Autologous Stem Cell Transplantation in Acute Myocardial Infarction (ASTAMI) trial. All were treated with aspirin 75 mg/day and clopidogrel 75 mg/day and underwent serial echocardiography and magnetic resonance imaging during the first 3 months after PCI. After 4 to 5 days, the ejection fraction and infarct size in percentage of the left anterior descending coronary artery area were assessed using single photon-emission computed tomography in addition to the ejection fraction by echocardiography. LV thrombi were detected in 15 patients during the first 3 months, 2/3 of them within the first week. No differences in baseline characteristics between the groups with and without LV thrombi were shown. However, in the thrombus group, significantly higher peak creatine kinase levels (6,128 vs 2,197 U/L, p <0.01), larger infarct sizes (82.5% vs 63.8%, p <0.01), and lower ejection fractions on single photon-emission computed tomography (35.5% vs 40.0%, p = 0.03) and on echocardiography (43.0% vs 46.0%, p = 0.03) were found compared to patients without LV thrombi. In conclusion, LV thrombus formation is a frequent finding in patients with anterior wall ST elevation myocardial infarction treated acutely with PCI and dual-antiplatelet therapy and should be assessed by echocardiography within the first week.

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.

Anticoagulation after anterior myocardial infarction and the risk of stroke

Background

Survivors of anterior MI are at increased risk for stroke with predilection to form ventricular thrombus. Commonly patients are discharged on dual antiplatelet therapy. Given the frequency of early coronary reperfusion and risk of bleeding, it remains uncertain whether anticoagulation offers additional utility. We examined the effectiveness of anticoagulation therapy for the prevention of stroke after anterior MI.

Methods and Findings

We performed a population-based cohort analysis of 10,383 patients who survived hospitalization for an acute MI in Ontario, Canada from April 1, 1999 to March 31, 2001. The primary outcome was four-year ischemic stroke rates compared between anterior and non-anterior MI patients. Risk factors for stroke were assessed by multivariate Cox proportional-hazards analysis. Warfarin use was determined at discharge and followed for 90 days among a subset of patients aged 66 and older (n = 1483). Among the 10,383 patients studied, 2,942 patients survived hospitalization for an anterior MI and 20% were discharged on anticoagulation therapy. Within 4 years, 169 patients (5.7%) were admitted with an ischemic stroke, half of which occurred within 1-year post-MI. There was no significant difference in stroke rate between anterior and non-anterior MI patients. The use of warfarin up to 90 days was not associated with stroke protection after anterior MI (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.37–1.26). The use of angiotensin-converting-enzyme inhibitors (HR, 0.65; 95% CI, 0.44–0.95) and beta-blockers (HR, 0.60; 95% CI, 0.41–0.87) were associated with a significant decrease in stroke risk. There was no significant difference in bleeding-related hospitalizations in patients who used warfarin for up to 90 days post-MI.

Conclusion

Many practitioners still consider a large anterior-wall MI as high risk for potential LV thrombus formation and stroke. Among a cohort of elderly patients who survived an anterior MI there was no benefit from the use of warfarin up to 90 days post-MI to prevent ischemic stroke. Our data suggests that routine anticoagulation of patients with anterior-wall MI may not be indicated. Prospective randomized trials are needed to determine the optimal antithrombin strategy for preventing this common and serious adverse outcome.

Contrast-enhanced anatomic imaging as compared to contrast-enhanced tissue characterization for detection of left ventricular thrombus

OBJECTIVES

This study sought to compare contrast-enhanced anatomic imaging and contrast-enhanced tissue characterization (delayed-enhancement cardiac magnetic resonance [DE-CMR]) for left ventricular (LV) thrombus detection.

BACKGROUND

Contrast echocardiography (echo) detects LV thrombus based on anatomic appearance, whereas DE-CMR imaging detects thrombus based on tissue characteristics. Although DE-CMR has been validated as an accurate technique for thrombus, its utility compared with contrast echo is unknown.

METHODS

Multimodality imaging was performed in 121 patients at high risk for thrombus due to myocardial infarction or heart failure. Imaging included 3 anatomic imaging techniques for thrombus detection (contrast echo, noncontrast echo, cine-CMR) and a reference of DE-CMR tissue characterization. LV structural parameters were quantified to identify markers for thrombus and predictors of additive utility of contrast-enhanced thrombus imaging.

RESULTS

Twenty-four patients had thrombus by DE-CMR. Patients with thrombus had larger infarcts (by DE-CMR), more aneurysms, and lower LV ejection fraction (by CMR and echo) than those without thrombus. Contrast echo nearly doubled sensitivity (61% vs. 33%, p < 0.05) and yielded improved accuracy (92% vs. 82%, p < 0.01) versus noncontrast echo. Patients who derived incremental diagnostic utility from DE-CMR had lower LV ejection fraction versus those in whom noncontrast echo alone accurately assessed thrombus (35 +/- 9% vs. 42 +/- 14%, p < 0.01), with a similar trend for patients who derived incremental benefit from contrast echo (p = 0.08). Contrast echo and cine-CMR closely agreed on the diagnosis of thrombus (kappa = 0.79, p < 0.001). Thrombus prevalence was lower by contrast echo than DE-CMR (p < 0.05). Thrombus detected by DE-CMR but not by contrast echo was more likely to be mural in shape or, when apical, small in volume (p < 0.05).

CONCLUSIONS

Echo contrast in high-risk patients markedly improves detection of LV thrombus, but does not detect a substantial number of thrombi identified by DE-CMR tissue characterization. Thrombi detected by DE-CMR but not by contrast echo are typically mural in shape or small in volume.