Left ventricular mural thrombi secondary to acute myocardial infarction: predisposing factors and embolic phenomenon

C-Reactive protein as a risk factor for left ventricular thrombus in patients with acute myocardial infarction

BACKGROUND

Elevated C-reactive protein (CRP) has been found to correlate with higher risk for cardiac events in patients with acute myocardial infarction (AMI). It has been suggested that CRP may be involved in initiation process of coagulation; however, the role of CRP level in the formation of left ventricular (LV) thrombus has not been studied.

HYPOTHESIS

This study investigated whether CRP is a risk factor for LV thrombus in patients with AMI.

METHODS

Clinical, echocardiographic, and biochemical data were analyzed in 141 consecutive patients (aged 57 +/- 13 years; 33 women) with first anterior AMI. Two-dimensional and Doppler echocardiographic examinations were performed on Days 1, 3, 7, 15, and 30. Blood samples were obtained every day during hospitalization. Serum CRP concentrations were measured by an ultrasensitive immunonephelometry method.

RESULTS

Left ventricular thrombus was detected in 33 (23.4%) patients. Univariate analysis showed that patients with LV thrombus had a higher peak creatine kinase (CK) level (2,879 +/- 742 vs. 1,693 +/- 1,210 I/U, p = 0.001), higher peak CRP level (14.9 +/- 7.1 vs. 9.2 +/- 6.8 mg/dl, p = 0.001), higher wall motion score index (1.8 +/- 0.2 vs. 1.5 +/- 0.3, p = 0.002), higher apical wall motion score index (2.35 +/- 0.72 vs. 2.07 +/- 0.70, p = 0.001), larger end-diastolic volume (145.2 +/- 43.7 vs. 116.5 +/- 44.2 ml, p = 0.002), larger end-systolic volume (85.4 +/- 37.2 vs. 62.9 +/- 31.6 ml, p = 0.003), and lower ejection fraction (42.1 +/- 12 vs. 47.3 +/- 13, p = 0.04). In multivariate analyses, only peak CK level (p = 0.0001), LV apical wall motion score index (p = 0.001), and CRP levels (p = 0.001) were independent predictors of LV thrombus formation.

CONCLUSIONS

These results suggest that CRP is a risk factor for LV thrombus in patients with AMI.

Cardioversion in Patients with Left Ventricular Thrombus Is Not Associated with Increased Thromboembolic Risk

OBJECTIVES

The purpose of the study was to define the incidence of systemic embolism after cardioversion in patients with left ventricular (LV) thrombus.

BACKGROUND

The risk of systemic embolization after cardioversion in patients with an atrial thrombus is well known. However, data on thromboembolic events after cardioversion in patients with LV thrombus are limited because of hesitance to perform cardioversion in this population.

METHODS

Transthoracic and transesophageal echocardiograms acquired between January 1996 and October 2001 at our institution were reviewed for presence of LV thrombus in two orthogonal apical views. A total of 413 patients had echocardiographic evidence of LV thrombus. Medical records were reviewed for cardioversion performed within 3 weeks of the echocardiogram.

RESULTS

A total of 21 patients, age 66 +/- 10 years and ejection fraction 22 +/- 10% were identified. Cardioversion was indicated for atrial fibrillation in 8 (38%) and ventricular tachyarrhythmia in 13 (62%) patients, and was performed emergently in 5 (24%), electively in 8 (38%), and during electrophysiology study in 8 (38%) patients. The time interval between diagnostic echocardiographic study and cardioversion was 6 +/- 5 (range 1-18) days. All thrombi were located in the apical LV and were described as laminated (71%) and protruding (29%), and measured 0.7 +/- 0.4 x 1.6 +/- 0.8 cm. Before cardioversion, 17 (81%) patients were anticoagulated with warfarin or heparin. During clinical follow-up of up to 1 year (153 +/- 150 days) anticoagulation with warfarin was given to 15 (71%) patients. No patient had clinically apparent embolic event, including stroke, during hospitalization or during outpatient follow-up.

CONCLUSIONS

Embolism after cardioversion in patients with echocardiographic evidence of LV thrombus was not observed. Cardioversion seems to be safe and further prospective studies are needed to address this.

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.

Pulsed wave tissue Doppler-derived myocardial performance index for the assessment of left ventricular thrombus formation risk after acute myocardial infarction

BACKGROUND

Assessment of left ventricular (LV) thrombosis risk after acute myocardial infarction (AMI) is important because of potential embolic sequelae that are reduced by oral anticoagulant agents. The goal of this study was to investigate whether early assessment of LV systolic and diastolic performance with pulsed wave tissue Doppler ultrasound scanning (PWTD) predicts LV thrombosis after AMI.

METHODS

Two-dimensional and Doppler ultrasound scanning echocardiographic examinations were performed in 92 consecutive patients (age, 58 +/- 10 years; 11 women) with first anterior AMI within 24 hours after arrival to the coronary care unit. From the apical 4-chamber view, the mitral annular velocities were recorded at the lateral corner of the mitral annulus with PWTD. The myocardial performance index (MPI), which combines parameters of both systolic and diastolic ventricular function, was calculated from the PWTD recordings. To analyze LV thrombus formation, the 2-dimensional echocardiographic examination was repeated on days 3, 7, 15, and 30. The patients were divided in 2 groups according to LV thrombus formation.

RESULTS

LV thrombus was found in 32 of 92 patients (35%; group 1) and was not found in 60 patients (65%; group 2). The MPI was significantly higher in group 1 than in group 2 (0.73 +/- 0.20 vs 0.53 +/- 0.14; P <.001). When an MPI >0.6 was used as the cutoff, LV thrombus formation could be predicted with a sensitivity rate of 81%, a specificity rate of 73%, a positive predictive value of 62%, and a negative predictive value of 88%. In multivariate analyses, only MPI and LV wall motion score index were independent predictors of LV thrombus formation (P = .038 and P = .047, respectively).

CONCLUSIONS

The MPI derived with PWTD soon after admission appears to be a useful parameter for assessing the risk of LV thrombosis after AMI. Patients with an MPI >0.6 after AMI seem to be at a higher risk for thrombus formation.

Increased plasma fibronectin levels in patients with acute myocardial infarction complicated with left ventricular thrombus

Fibronectin is a polymorphic and multifunctional glycoprotein that plays a wide-ranging role in hemostasis. In this study, it was aimed to determine plasma fibronectin levels and evaluate its possible role in left ventricular (LV) thrombus formation following acute myocardial infarction (AMI). We have determined clinical, echocardiographic, and biochemical parameters in 97 consecutive patients (aged 59 +/- 13; 87 men/10 women) with first anterior AMI. Two-dimensional echocardiography was performed on Days 1, 3, 7, 15, and 30. Blood samples were obtained within 24-48 h after the onset of symptoms. The study also included 30 healthy control subjects. Plasma fibronectin levels were significantly higher in patients with AMI than control subjects (38 +/- 13 vs. 25.2 +/- 8.7 mg/dl, P=.0001). LV thrombus was detected in 20 (20.6%) of 97 patients. Plasma fibronectin levels were significantly higher in patients with LV thrombus (Group 2) than in patients without LV thrombus (Group 1) (44.5 +/- 11 vs. 36.1 +/-13.4 mg/dl, P=.01). Although univariate analysis showed that plasma fibronectin levels were higher in patients with thrombus, multivariate analysis showed that plasma fibronectin levels were not an independent predictor of LV thrombus formation (P=.059). In multivariate analyses, only peak creatine phosphokinase (CPK) level and LV wall motion score index (WMSI) were independent predictors of thrombus formation (P=.007 and P=.0001, respectively). These results suggest the increased plasma fibronectin levels may be one of the risk factors for LV thrombus formation after AMI. However, further studies concerning the relation between plasma fibronectin levels and LV thrombus formation are necessary.

Serum lipoprotein(a) and its relation to left ventricular thrombus in patients with acute myocardial infarction

It is well known that the incidence of left ventricular (LV) thrombosis is high in patients with acute myocardial infarction (AMI). Due to the high degree of structural homology with plasminogen, lipoprotein(a) may produce thrombogenic effects by modulating the fibrinolytic system. However, the role of Lp(a) level in the formation of LV thrombus has not been studied. This study sought to determine whether Lp(a) is a risk factor for LV thrombus in patients with AMI. We have analyzed clinical, echocardiographic and biochemical data in 102 consecutive patients (aged 58+/-12 years, 92 men / 10 women) with first anterior AMI. Two-dimensional examination was performed on days 1, 3, 7, 15, and 30. Blood samples were obtained within 12 h after the onset of symptoms and before beginning the therapy. Plasma levels of fibrinogen and Lp(a) were measured using enzyme-linked immunosorbent assay and immunonephelometric methods, respectively. LV thrombus was detected in 20 (20.3%) patients. No significant difference was found for admission Lp(a) levels between patients with or without thrombus (30.5+/-17.2 vs 32.3+/-22.4 mg/dl, p = 0.7). Univariate analysis showed that patients with LV thrombus had a higher wall motion score index (1.8+/-0.3 vs 1.4+/-0.3, p = 0.002), a higher peak creatine kinase level (2945+/-898 vs 1805+/-1336, I / U p = 0.004), a larger end-diastolic volume (139.7+/-38.6 vs 114.1+/-41.8 ml, p = 0.04), a larger end-systolic volume (83.1+/-34.3 vs 59.2+/-30.6 ml, p = 0.02 ), and a lower ejection fraction (38+/-12 vs 47+/-11, p = 0.04). In multivariate analyses, only peak creatine kinase level (p = 0.04) and LV wall motion score index (p = 0.002) were independent predictors of left ventricular thrombus formation. These results suggest that Lp (a) is not a risk factor for LV thrombus in patients with AMI. Our data demonstrate that the best predictors of LV thrombus formation after AMI are a high peak creatine kinase level and a high LV wall motion score index.

Doppler-derived mitral deceleration time as an early predictor of left ventricular thrombus after first anterior acute myocardial infarction

BACKGROUND

The relation between left ventricular (LV) diastolic function and LV thrombus has not yet been fully investigated. The aim of this study was to determine whether early assessment of Doppler-derived mitral deceleration time (DT), a measure of LV compliance and filling, may predict LV thrombus formation after acute myocardial infarction.

METHODS AND RESULTS

Two-dimensional and Doppler echocardiographic examinations were performed in 98 consecutive patients (aged 57 +/- 12 years; 8 women) with first acute myocardial infarction. The patients were studied within 24 hours and at days 3, 7, 15, and 30 after arrival to the coronary care unit. Mitral flow velocities were obtained from the apical 4-chamber view with pulsed Doppler. LV thrombus was detected in 20 of 98 patients. Patients were divided into 2 groups according to LV thrombus formation: group 1 (n = 20) with thrombus and group 2 (n = 78) without thrombus. Mitral E-wave DT was significantly shorter in group 1 than group 2 (134 ms vs 175 ms; P <.001). Patients in group 1 had significantly larger LV end-diastolic and end-systolic volumes and a higher wall motion score index than patients in group 2 (133 +/- 39 mL vs 112 +/- 41 mL, P =.03; 83 +/- 34 mL vs 59 +/- 30 mL, P =.003; and 1.8 +/- 0.3 mL vs 1.5 +/- 0.3 mL, P =.007, respectively). The LV ejection fraction was significantly lower in group 1 than in group 2 (39% +/- 13% vs 48% +/- 12%; P =.004). In a multivariate regression analysis, mitral E-wave DT was identified as an independent variable related to development of LV thrombus (P =.04).

CONCLUSIONS

Doppler-derived mitral DT is superior to conventional clinical and 2-dimensional echocardiographic assessment in estimating the risk of left ventricular thrombosis after myocardial infarction.

Refractory Left Ventricular Failure Due to Large Left Ventricular Thrombus

Mural thrombi are common in patients with acute myocardial infarction and can cause refractory left ventricular failure as a rare complication. We report a case of large postinfarction ventricular thrombus resulting in left ventricular failure resistant to medical therapy. After echocardiographic diagnosis, thrombectomy and coronary bypass grafting were performed and the symptoms subsided.

Doppler left ventricular flow pattern versus conventional predictors of left ventricular thrombus after acute myocardial infarction

OBJECTIVES

The value of Doppler-derived left ventricular spatial flow patterns in predicting left ventricular thrombus formation after myocardial infarction was compared with that of conventional clinical and echocardiographic variables.

BACKGROUND

Assessment of left ventricular thrombosis risk after myocardial infarction is important because of potential embolic sequelae that are reduced by oral anticoagulant agents.

METHODS

Clinical, two-dimensional and Doppler echocardiographic data were prospectively obtained in 104 patients with acute myocardial infarction within 48 h of admission. Ventricular flow was assessed by Doppler echocardiography and considered normal when brisk ventricular inflow with simultaneous onset at the mitral valve and apical levels was present, together with alternating directions of apical flow throughout the cardiac cycle. In addition to normal flow, two abnormal flow patterns were recognized: apical rotating flow and vortex ring formation. Oral anticoagulant agents were prescribed only to patients with abnormal flow at admission. The incidence of left ventricular thrombosis was assessed by echocardiography during 9 months of follow-up.

RESULTS

Abnormal flow pattern had a positive predictive value of 63% and a negative predictive value of 99%. On stepwise logistic regression analysis, only abnormal flow pattern had an independent relation to left ventricular thrombus (odds ratio 92).

CONCLUSIONS

Left ventricular flow pattern derived by Doppler echocardiography soon after admission is superior to conventional clinical and two-dimensional echocardiographic assessment in estimating the risk of left ventricular thrombosis after myocardial infarction.

The natural history of left ventricular thrombus in myocardial infarction: a rationale in support of masterly inactivity

One hundred five unselected and consecutive patients were prospectively studies after acute transmural myocardial infarction to assess the incidence of mural thrombus formation and to relate the presence of thrombus to patient outcome in terms of systemic embolic events, functional class and survival. In 87 patients, optimal quality two-dimensional echocardiographic studies were obtained and were repeated at daily intervals to detect mural thrombus formation. The site of infarction was anterior in 53 patients and inferior in 34. On admission, all patients received subcutaneous heparin and antiplatelet agents (aspirin, dipyridamole); none received full anticoagulant therapy. Left ventricular mural thrombus was visualized between 2 and 11 days (median 6) after the clinical onset of infarction in 21 (40%) of the 53 patients with anterior infarction. No patients with inferior infarction had echocardiographic evidence of thrombus formation. During follow-up of 22 to 51 months (mean 39), none of the 21 patients with mural thrombus had clinical evidence of systemic embolism. One patient with inferior and one with anterior infarction had a cerebral embolus 7 days and 9 months, respectively, after the acute event, but neither of these patients had echocardiographic evidence of left ventricular thrombus at any stage. Echocardiography performed at 1 and 2 years of follow-up showed persistent evidence of thrombus in only 8 (31%) and 5 (24%) of the 21 patients, respectively. On admission, the functional class of patients with anterior myocardial infarction and thrombus was similar to that of patients without ventricular thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular thrombus incidence and behavior studied by serial two-dimensional echocardiography in acute anterior myocardial infarction: left ventricular wall motion, systemic embolism and oral anticoagulation

Serial two-dimensional echocardiography was performed to detect left ventricular thrombus in 92 consecutive patients with a confirmed first acute anterior myocardial infarction. Thirty left ventricular thrombi were diagnosed in these 92 patients. The cumulative percent of identified thrombus in each echocardiographic examination in the surviving patients was 27% at less than 24 h; 57% at 48 to 72 h; 75% at 1 week and 96% at 2 weeks. The thrombus shape was defined as mural in 53% and protruding in 47% of patients. Systemic embolism (stroke) was noted during hospitalization in two patients with a protruding thrombus. At 12 weeks of follow-up, patients with thrombus had poorer (and almost unchanged from baseline) global left ventricular function as expressed by wall motion score compared with that of patients without thrombus, who exhibited significant improvement. Global left ventricular wall motion in patients with persisting or resolved thrombus was similar during follow-up. Apical wall motion worsened in 70% of the patients with persisting thrombus and in 25% of the patients with resolved thrombus (p less than 0.1). In the 22 surviving patients with thrombus, resolution or change in thrombus shape or size was noted in 14 of the 15 patients receiving anticoagulant therapy and in 4 of the 7 untreated patients. Six of the 18 patients with an early- (48 to 72 h) and none of the 12 patients with a later-formed thrombus died. Maximal serum enzyme levels, percent with Killip functional class III to IV and left ventricular wall motion score were higher in the patients with an early- than in those with a later-formed thrombus.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebrovascular accidents in acute myocardial infarction

Cerebral ischemia was recorded in 1.9% of 1277 patients with myocardial infarction. In most cases ischemia involved the carotid artery system, usually causing a hemiparesis or hemiplegia. Patients were mostly elderly, and the ischemic episode worsened their prognosis. The pathogenesis was surely often of embolic origin but several facts suggest that other mechanisms were also involved. Anticoagulant therapy, at least in the form in which it was used in these patients, i.e. subcutaneous administration of calcium heparin 5000 I.U. b.i.d. for thrombophlebitis prophylaxis, does not seem to prevent these complications.

Prophylactic anticoagulation for left ventricular thrombi after acute myocardial infarction: a prospective randomized trial

Thirty patients with a first episode of an anterior acute myocardial infarction (AMI) without a history of cardiac disease were prospectively randomized into a prophylactic heparin-treated group (group I) and a control nonanticoagulated group (group II) within 12 hours of the onset of chest pain to determine the effectiveness of anticoagulation for preventing left ventricular (LV) thrombi. Serial two-dimensional echocardiograms were performed during the hospital stay and patients were followed clinically for systemic emboli for 1 month after discharge from the hospital. Thirty-one percent of patients in group I (4/13) and 35% of patients in group II (6/17) developed LV thrombi on two-dimensional echocardiograms. There was no statistical difference in the incidence of LV thrombi between the two groups (p greater than 0.05). Infarct size as determined by creatine phosphokinase isoenzymes (2,386 +/- 1,568 vs 2,083 +/- 1,462 IU for groups I and II, respectively; p greater than 0.05), wall motion score (12.7 +/- 5 vs 10.7 +/- 5 for groups I and II, respectively; p greater than 0.05) and wall motion index (1.8 +/- 0.6 vs 1.8 +/- 0.56 for groups I and II, respectively; p greater than 0.05) were not statistically different between the two groups of patients. One patient in both groups had an embolic event. In conclusion, prophylactic anticoagulation in high-risk AMI patients for LV thrombus development does not prevent LV thrombus formation during the acute and subacute stages of an AMI. The results also suggest that anticoagulation may not prevent systemic embolization.

Thrombosis and embolism from cardiac chambers and infected valves

In a number of cardiac conditions (acute myocardial infarction, chronic left ventricular aneurysm, dilated cardiomyopathy, infective endocarditis and atrial fibrillation in the absence of valvular disease), the risk of embolism gives cause for concern. Although anticoagulation with warfarin (Coumadin)-derivatives has been shown to be effective in some of these situations, there is no evidence regarding the role of antiplatelet agents. The common factor in the thromboembolic potential of acute myocardial infarction, chronic left ventricular aneurysm and dilated cardiomyopathy is mural thrombus. This can be detected by two-dimensional echocardiography and indium-111 platelet scintigraphy. Although of value in elucidating the natural history of mural thrombus, in most cases, management is not substantially aided by these investigations. In patients with extensive myocardial infarction, particularly anterior infarction, moderate intensity anticoagulation started soon after hospital admission reduces the rate of embolism. After 8 to 12 weeks, embolic risk is low so that anticoagulants can usually be discontinued. Patients with chronic left ventricular aneurysm have a low incidence of embolism; anticoagulation is, therefore, inappropriate. Dilated cardiomyopathy is associated with a high risk of embolism; moderate intensity anticoagulation may be advisable in many such cases. Little information is available regarding the incidence of thromboembolism or the role of antithrombotic therapy in the patient with a diffusely dilated left ventricle due to ischemic heart disease. In native valve infective endocarditis, the risk of hemorrhage is high, and the efficacy of conventional anticoagulants unclear; thus, anticoagulation should not be instituted for the cardiac condition as such. However, in prosthetic valve endocarditis, the risk of embolism seems to be very high, and anticoagulant therapy should be continued, but with great care because there is a substantial risk of cerebral hemorrhage. Atrial fibrillation in patients with valvular heart disease is dealt with in a previous review. Patients with nonvalvular atrial fibrillation are at varying risk of embolism, depending on the etiology of the arrhythmia; trials of antithrombotic therapy are needed for the various subsets of patients. In most elderly patients, the etiology is not known, and their stroke risk is high. The risk of embolism in younger patients with idiopathic atrial fibrillation is so low as to make any antithrombotic therapy unnecessary.(ABSTRACT TRUNCATED AT 400 WORDS)

Detection of ventricular thrombosis in acute myocardial infarction: value of indium-111 platelet scintigraphy in relation to two-dimensional echocardiography and clinical course

In order to detect left ventricular (LV) thrombosis, 111In-platelet scintigraphy and two-dimensional echocardiography were performed in 40 patients 15 days +/- 6 days after acute myocardial infarction. A dual isotope subtraction method, using 111In-platelet scintigraphy and 99mTc-blood pool scintigraphy, was used to assess LV platelet deposition expressed as LV counts per pixel. Seven patients (group A) had a positive 111In-platelet scintigram and 33 patients (group B) had a negative 111In-platelet scintigram (LV counts per pixel: 0.56 +/- 0.23 and 0.28 +/- 0.19, respectively, P less than 0.05). Three group A patients but no group B patients had a positive echocardiogram. Arterial embolism was noted in four patients, of whom two showed both positive echocardiogram and platelet scintigram. LV counts per pixel were 0.57 +/- 0.13 and 0.31 +/- 0.21, respectively (P less than 0.02) in patients with and without arterial embolism. Thus, both 111In-platelet scintigraphy and two-dimensional echocardiography can detect LV thrombosis. 111In-platelet scintigraphy may help to define patients at risk for embolization and may be used in conjunction with echocardiography to study the effect of antithrombotic therapy.