Left ventricular thrombosis and arterial embolism in acute anterior myocardial infarction

The effect of ticagrelor based dual antiplatelet therapy on development of late left ventricular thrombus after acute anterior ST elevation myocardial infarction

AIM

The aim of this study is to investigate the impact of ticagrelor as compared to clopidogrel based dual antiplatelet therapy (DAPT) during post-discharge management on the incidence of left ventricular (LV) thrombus in patients with first acute anterior ST elevation myocardial infarction (STEMI).

METHOD

641 patients who met the inclusion criteria were divided into two groups based on the receipt of either ticagrelor or clopidogrel based DAPT.

RESULT

Left ventricular thrombus was detected in 73 (11.4%) patients at the first month echocardiographic examination. Ticagrelor based DAPT was associated with significantly less incidence of LV thrombus when compared to clopidogrel [20 (7.4%) vs 53 (14.0%) OR: 0.50 (0.29-0.86)]. Penalized maximum likelihood estimation (PMLE) logistic regression analyses were performed to fourteen candidate variables for identifying the independent predictors of LV thrombus, ticagrelor (compared with clopidogrel) [OR: 0.53 (0.28-0.96), p = 0.039], body mass index (BMI) [OR: 0.58 (0.44-0.77), p < 0.001], KILLIP class (I vs II-IV) [OR: 0.35 (0.14-0.83), p = 0.017], age [OR: 1.22 (1.08-1.40), p < 0.001], poor postprocedural myocardial blush grade (MBG) [OR: 3.35 (1.32-8.15), p = 0.012] and LVEF predischarge [OR: 0.79 (0.72-0.86), p < 0.001] were found to be associated with LV thrombus.

CONCLUSION

Our study demonstrated that the incidence of LV trombus was significantly lower with ticagrelor than clopidogrel-based DAPT during postdischarge treatment for anterior STEMI patients.

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.

Left ventricular thrombus in patients with acute myocardial infarction:Case report and Caribbean focused update

Despite the well documented benefit of echocardiography in acute coronary syndromes, its wide-scale use in the Caribbean is limited by access, health literacy and affordability. Because of the limited use of echocardiography in the region, routine complications of acute myocardial infarction (AMI) are not fully appreciated and may go unrecognized, further contributing to increased cardiovascular morbidity and mortality. It is therefore necessary to bring focus to this common clinical condition and highlight the clinical utility of echocardiography in facilitating timely and accurate diagnosis. We report here a case of large left ventricular (LV) thrombus in a patient with AMI. Coronary angiography showed completely occluded left anterior descending artery (LAD) with angiographically normal remaining vessels. Immediate anticoagulation was commenced with heparin and overlapped with warfarin. No Primary Angioplasty (PA) was done based on the evidence from occluded artery trial. LV thrombus was completely resolved on echocardiography at three months. No evidence of thrombo-embolism was found during the resolution of LV thrombus.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Echocardiographic Recognition of Left Ventricular Mural Thrombus

Left ventricular (LV) mural thrombus is a well recognized complication of acute myocardial infarction. In survivors of infarction, its incidence is influenced by the location and magnitude of infarction: it occurs often in patients with large anterior Q wave infarctions, particularly in the presence of LV apical akinesis or dyskinesis. Although radionuclide imaging with indium-111-labeled platelets, computed tomography, and magnetic resonance imaging may be used to identify LV mural thrombus, two-dimensional echocardiography is the technique of choice for assessing its presence, shape, and size, and recent technical advances in echocardiographic methodology, such as high-frequency, short-focal-length transducers, have improved the echocardiographic assessment of LV mural thrombus. In the patient in whom a mural thrombus is identified, acute and chronic anticoagulation (with heparin and warfarin, respectively) is indicated: first, to prevent further thrombus formation and, second, to reduce the incidence of systemic embolization.

Left ventricular thrombus formation and resolution in acute myocardial infarction

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

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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