Treatment of left ventricular thrombi with a low molecular weight heparin

Echocardiographic risk factors of left ventricular thrombus in patients with acute anterior myocardial infarction

AIMS

This study aimed to identify echocardiographic determinants of left ventricular thrombus (LVT) formation after acute anterior myocardial infarction (MI).

METHODS AND RESULTS

This case-control study comprised 55 acute anterior MI patients with LVT as cases and 55 acute anterior MI patients without LVT as controls, who were selected from a cohort of consecutive patients with ischemic heart failure in our hospital. The cases and controls were matched for age, sex, and left ventricular ejection fraction. LVT was detected by routine/contrast echocardiography or cardiac magnetic resonance imaging during the first 3 months following MI. Formation of apical aneurysm after MI was independently associated with LVT formation [72.0% vs. 43.5%, odds ratio (OR) = 5.06, 95% confidence interval (CI) 1.65-15.48, P = 0.005]. Echocardiographic risk factors associated with LVT formation included reduced mitral annular plane systolic excursion (<7 mm, OR = 4.69, 95% CI 1.84-11.95, P = 0.001), moderate-severe diastolic dysfunction (OR = 2.71, 95% CI 1.11-6.57, P = 0.028), and right ventricular (RV) dysfunction [reduced tricuspid annular plane systolic excursion < 17 mm (OR = 5.48, 95% CI 2.12-14.13, P < 0.001), reduced RV fractional area change < 0.35 (OR = 3.32, 95% CI 1.20-9.18, P = 0.021), and enlarged RV mid diameter (per 5 mm increase OR = 1.62, 95% CI 1.12-2.34, P = 0.010)]. Reduced tricuspid annular plane systolic excursion (<17 mm) significantly associated with increased risk of LVT in anterior MI patients (OR = 3.84, 95% CI 1.37-10.75, P = 0.010), especially in those patients without apical aneurysm (OR = 5.12, 95% CI 1.45-18.08, P = 0.011), independent of body mass index, hypertension, anaemia, mitral annular plane systolic excursion, and moderate-severe diastolic dysfunction.

CONCLUSIONS

Right ventricular dysfunction as determined by reduced TAPSE or RV fractional area change is independently associated with LVT formation in acute anterior MI patients, especially in the setting of MI patients without the formation of an apical aneurysm. This study suggests that besides assessment of left ventricular abnormalities, assessment of concomitant RV dysfunction is of importance on risk stratification of LVT formation in patients with acute anterior MI.

Diagnosis and Treatment of Intracardiac Thrombus

ABSTRACT

Intracardiac thrombi can occur in a variety of locations and are frequently encountered in clinical practice. Yet evidence-based guidance for clinicians managing patients with intracardiac thrombi is often limited. This review summarizes what is known regarding the prevalence of intracardiac thrombus, diagnostic strategies, clinical relevance, and treatment options, focusing on four specific types of thrombus for which recent research has shifted clinical understanding and treatment decisions: (1) left atrial appendage thrombus, (2) cardiac implantable electronic device lead thrombus, (3) bioprosthetic aortic valve thrombus, and (4) left ventricular thrombus. Additional studies, ideally prospective, randomized, and head-to-head in design, are needed to better inform best practices in patients with intracardiac thrombi.

Management of left ventricular thrombus: a narrative review

Left ventricular thrombus (LVT) is a serious complication of acute myocardial infarction (MI) and also non-ischemic cardiomyopathies. We performed a narrative literature review, manual-search of reference lists of included articles and relevant reviews. Our literature review indicates that the incidence of LVT following acute MI has decreased, probably due to improvement in patient care as a result of better and earlier reperfusion techniques. Predictors of LVT include anterior MI, involvement of left ventricular (LV) apex (regardless of the coronary territory affected), LV akinesis or dyskinesis, reduced LV ejection fraction (LVEF), severe diastolic dysfunction and large infarct size. LVT is associated with increased risk of systemic embolism, stroke, cardiovascular events and death, and there is evidence that anticoagulant therapy for at least 3 months can reduce the risk of these events. Cardiac magnetic resonance (CMR) has the highest diagnostic accuracy for LVT, followed by echocardiography with the use of echocardiographic contrast agents (ECAs). Although current guidelines suggest use of vitamin K antagonist (VKA) for a minimum of 3 to 6 months, there is growing evidence of the benefits of direct acting oral anticoagulants in treatment of LVT. Embolic events appear to occur even after resolution of LVT suggesting that anticoagulant therapy needs to be considered for a longer period in some cases. Recommendations for the use of triple therapy in the presence of the LVT are mostly based on extrapolation from outcome data in patients with atrial fibrillation (AF) and MI. We conclude that the presence of LVT is more likely in patients with anterior ST-segment elevation MI (STEMI) (involving the apex) and reduced ejection fraction (EF). LVT should be considered a marker of increased long-term thrombotic risk that may persist even after thrombus resolution. Ongoing clinical trials are expected to elucidate the best management strategies for patients with LVT.

Off-label Use of Direct Oral Anticoagulants Compared With Warfarin for Left Ventricular Thrombi

Importance

Left ventricular (LV) thrombi can arise in patients with ischemic and nonischemic cardiomyopathies. Anticoagulation is thought to reduce the risk of stroke or systemic embolism (SSE), but there are no high-quality data on the effectiveness of direct oral anticoagulants (DOACs) for this indication.

Objective

To compare the outcomes associated with DOAC use and warfarin use for the treatment of LV thrombi.

Design, Setting, and Participants

A cohort study was performed at 3 tertiary care academic medical centers among 514 eligible patients with echocardiographically diagnosed LV thrombi between October 1, 2013, and March 31, 2019. Follow-up was performed through the end of the study period.

Exposures

Type and duration of anticoagulant use.

Main Outcomes and Measures

Clinically apparent SSE.

Results

A total of 514 patients (379 men; mean [SD] age, 58.4 [14.8] years) with LV thrombi were identified, including 300 who received warfarin and 185 who received a DOAC (64 patients switched treatment between these groups). The median follow-up across the patient cohort was 351 days (interquartile range, 51-866 days). On unadjusted analysis, DOAC treatment vs warfarin use (hazard ratio [HR], 2.71; 95% CI, 1.31-5.57; P = .01) and prior SSE (HR, 2.13; 95% CI, 1.22-3.72; P = .01) were associated with SSE. On multivariable analysis, anticoagulation with DOAC vs warfarin (HR, 2.64; 95% CI, 1.28-5.43; P = .01) and prior SSE (HR, 2.07; 95% CI, 1.17-3.66; P = .01) remained significantly associated with SSE.

Conclusions and Relevance

In this multicenter cohort study of anticoagulation strategies for LV thrombi, DOAC treatment was associated with a higher risk of SSE compared with warfarin use, even after adjustment for other factors. These results challenge the assumption of DOAC equivalence with warfarin for LV thrombi and highlight the need for prospective randomized clinical trials to determine the most effective treatment strategies for LV thrombi.

Post-Procedural Anticoagulation After Primary Percutaneous Coronary Intervention for Anterior Acute Myocardial Infarction With Severe Left Ventricular Dysfunction

BACKGROUND

Patients with anterior acute myocardial infarction (AMI) and left ventricular (LV) dysfunction have an increased risk of LV thrombus (LVT). In the thrombolytic era, short-term anticoagulation using low-molecular-weight heparin during hospitalization proved to significantly reduce LVT formation, but, the effect of this prophylactic approach remains unclear in the current era. Therefore, we conducted a study to evaluate the effects of post-procedural anticoagulation (PPAC) using enoxaparin in addition to dual antiplatelet therapy (DAPT) after primary percutaneous coronary intervention (PCI) in such patients.

METHODS AND RESULTS

A total of 426 anterior AMI patients with LV ejection fraction ≤40% were retrospectively enrolled and classified into 2 groups based on whether they received PPAC (enoxaparin SC for at least 7 days). All patients received primary PCI and DAPT. The primary endpoint was definite LVT at 30 days diagnosed by echocardiography. The secondary endpoints were 30-day mortality, embolic events, and major bleeding events. PPAC was independently associated with a lower incidence of LVT (odds ratio 0.139, 95% confidence interval 0.032-0.606, P=0.009). The 30-day mortality, embolic events, and major bleeding events were not statistically different between groups.

CONCLUSIONS

Short-term PPAC using enoxaparin after primary PCI may be an effective and safe way to prevent LVT in patients with anterior AMI and LV dysfunction.

Complete Resolution of the Left Ventricular Pedunculated Thrombus with Tirofiban Infusion in a Patient with Severe Left Ventricular Dysfunction

A 28-year-old man was admitted with symptoms of heart failure. Echocardiography revealed severe left ventricular dysfunction, apical aneurysm, and a 40 × 11 mm sized mobile thrombus attached to apical septum with a narrow stalk. The patient had anterior myocardial infarction two years ago. Heparin infusion was started at 1000 IU/hour for 48 hours. There was no detected change on the size of the thrombus. Surgery recommended to the patient was refused by him because of the procedural risks. Tirofiban infusion was started. Repeat echocardiography showed significant reduction in thrombus size after 24 hours, and complete resolution of the thrombus after 48 hours. To our knowledge, this is the first case with left ventricular mobile thrombus treated successfully with tirofiban infusion.

Penetrating Cardiac Injury Managed Without Surgery but with Systemic Heparinisation

A 36-year-old woman presented to hospital after a penetrating chest injury. She was haemodynamically stable. Echocardiography revealed left ventricular thrombus, with minimal pericardial effusion and no associated cardiac injuries. Intravenous anticoagulation was commenced for her intracardiac thrombus and her pericardial effusion was monitored with serial echocardiography. She remained well, was converted to warfarin and discharged home day 12 post admission, with cautious follow-up given her risk of late effusion and tamponade. Follow-up imaging revealed resolution of her intracardiac thrombus. She remains well to date.

Incidence, diagnostic methods, and evolution of left ventricular thrombus in patients with anterior myocardial infarction and low left ventricular ejection fraction: a prospective multicenter study

BACKGROUND AND OBJECTIVES

We aimed to assess the incidence and evolution of left ventricular (LV) thrombi in a high-risk population of patients with LV systolic dysfunction after anterior myocardial infarction (ant-MI). We also compared the accuracy of transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging with contrast-delayed enhancement (CMR-DE) in detecting LV thrombi.

METHODS

We prospectively included 100 consecutive patients with LV ejection fraction (LVEF) <45% at the first TTE performed <7 days after ant-MI. A second evaluation with TTE and CMR-DE (by blinded examiners) was performed at 30 days. A third TTE and assessment of clinical status were performed between 6 and 12 months after ant-MI.

RESULTS

Patients (males 71%; mean age 59.1 ± 12.1 years; mean LVEF 33.5% ± 6.0%) were included at a median of 5.5 days (interquartile range 25th-75th percentile 4.25-6.0 days) after ant-MI. Thrombi were detected among 26 (26%) patients at a median of 12.0 days after ant-MI (7 patients at 1-7 days after MI; 15 at 8-30 days; and 4 after day 30). Sensitivity and specificity for LV thrombi detection were 94.7% and 98.5%, respectively, for TTE as compared with CMR-DE. Most thrombi (n = 24; 92.3%) disappeared after triple antithrombotic therapy (vitamin K antagonist in addition to dual antiplatelet therapy).

CONCLUSION

Left ventricular thrombus is a frequent complication after ant-MI with systolic dysfunction. When a search for thrombus is prespecified, the accuracy of TTE is high as compared with CMR-DE. The best antithrombotic strategy is not known.

Comparison of the usefulness of enoxaparin versus warfarin for prevention of left ventricular mural thrombus after anterior wall acute myocardial infarction

Left ventricular (LV) thrombus is one of the most common complications in patients with anterior acute myocardial infarction (AMI) and LV dysfunction. Although anticoagulation is frequently prescribed, data regarding the appropriate drug, duration, risks, and effect on echocardiographic indices of thrombus are lacking. Moreover, given the difficulty in obtaining adequate anticoagulation with warfarin, it is possible that short-term treatment with a more predictable agent would be effective. We randomized 60 patients at high risk of developing LV mural thrombus (anterior acute myocardial infarction with Q waves and ejection fraction≤40%) to receive either enoxaparin 1 mg/kg (maximum 100 mg) subcutaneously every 12 hours for 30 days or traditional anticoagulation (intravenous heparin followed by oral warfarin for 3 months). Clinical evaluations and transthoracic echocardiograms were obtained at baseline, in-hospital, and at 3.5 months. There were no differences between the groups regarding baseline demographics, acute echocardiographic findings, and in-hospital outcomes. The length of hospital stay tended to be shorter for the enoxaparin group (4.6 vs 5.6; p=0.066) and the corresponding hospital costs ($25,837 vs $34,666; p=0.18). At 3 months, bleeding and thromboembolic events were rare and similar between enoxaparin and warfarin groups. Although more patients had probable mural thrombus in the enoxaparin group compared with warfarin at 3.5 months (15% vs 4%; p=0.35), this was not significantly different. In conclusion, the use of enoxaparin tends to shorten hospitalization and lower cost of care. However, at 3.5 months, there appears to be numerically higher (but statistically insignificant) rates of LV thrombus in the enoxaparin group.

Intracardiac thrombus: diagnosis, complications and management

Intracardiac thrombus is a condition of increasing clinical significance not only because of its potential complications but also because of the lack of clinical evidence to guide clinicians in selecting optimal therapies. Thus, 2 recent cases encountered at the Vanderbilt University Medical Center illustrate the clinical challenges one may encounter in patients with intracardiac thrombus. A careful review of the diagnostic challenges, potential complications and current recommendations for management are presented.

Mobile left ventricular thrombus in left ventricular dysfunction: case report and review of literature

INTRODUCTION

Left ventricular (LV) thrombi carry a high risk of embolization. Therapeutic recommendations like treatment with low molecular heparin and intravenous unfractionated heparin (UFH), thrombolysis or surgical thrombectomy have failed to reach a consensus.

CASE DESCRIPTION

A 56-year-old female patient presented in cardiogenic shock to the emergency department. Echocardiography demonstrated a dilated LV with a severely depressed global systolic function and a large LV apical thrombus. Treatment with UFH was initiated as well as a treatment with catecholamines for stabilizing the patient's hemodynamic situation. On the follow-up echocardiographic examination, extensive free-floating parts of the thrombus could be documented. Given the high risk of embolization in a now hemodynamically stable situation, emergency surgical embolectomy was performed.

DISCUSSION

A conservative procedure might be useful for bridging till surgical treatment is available and/or the risk due to surgery is acceptable.

CONCLUSION

In absence of evidence-based guidelines for the treatment of LV thrombi, individualized management options concerning surgical, embolization and bleeding risk must be taken into account.

Treatment of massive cardiac thrombi in a patient with protein C and protein S deficiency

Myocarditis and dilated cardiomyopathy is characterized by dilatation of all four cardiac chambers and decreased systolic function of the heart, especially in the left ventricle. In this report we presented a patient with myocarditis or dilated cardiomyopathy and deficiency of protein C and protein S with biventricular multiple intracardiac thrombi. Standard heparin infusion and acetyl salicylic acid was begun. On the 10th day of hospitalization the right ventricular thrombus disappeared, and on the 24th day all thrombi in the left ventricle disappeared. During the treatment we did not observe any complication such as hemorrhagia or embolism. We think that patients with dilated cardiomyopathy or myocarditis should be evaluated for hemostatic disorders, and should be anticoagulated if any of these disorders are presented.

Fibrinolytic treatment in left ventricular mobile thrombi with low ejection fraction: results and follow-up of seven cases

BACKGROUND

Left ventricular mobile thrombi carry high risk of embolism and need early treatment in which the appropriate treatment is still controversial. Because most patients with mobile thrombi have low ejection fraction and also accompanying heart failure symptoms, decision of surgical treatment is not always easy and thus effective medical treatment is crucial.

METHOD

In this paper we present, treatment and follow-up of seven patients with mobile thrombi who underwent fibrinolytic treatment between 2002 and 2006.

RESULTS

In four cases, mobile thrombi disappeared completely while echocardiographically regressed to lower size with decreased mobility in the other three patients. On 6th month follow-up, complete lysis of the thrombi in six patients was observed with warfarin treatment. No major complications were seen in the patients.

CONCLUSION

In case of mobile left ventricular thrombi with concomitant low ejection fraction and heart failure fibrinolytic treatment might be a therapeutic option.