Echocardiography in the Recognition and Management of Mechanical Complications of Acute Myocardial Infarction

PURPOSE OF REVIEW

Although rare, the development of mechanical complications following an acute myocardial infarction is associated with a high morbidity and mortality. Here, we review the clinical features, diagnostic strategy, and treatment options for each of the mechanical complications, with a focus on the role of echocardiography.

RECENT FINDINGS

The growth of percutaneous structural interventions worldwide has given rise to new non-surgical options for management of mechanical complications. As such, select patients may benefit from a novel use of these established treatment methods. A thorough understanding of the two-dimensional, three-dimensional, color Doppler, and spectral Doppler findings for each mechanical complication is essential in recognizing major causes of hemodynamic decompensation after an acute myocardial infarction. Thereafter, echocardiography can aid in the selection and maintenance of mechanical circulatory support and potentially facilitate the use of a percutaneous intervention.

Left Atrial Appendage Tilt-Up-and-Turn-Left Maneuver: A Novel Three-Dimensional Transesophageal Echocardiography Imaging Maneuver to Characterize the Left Atrial Appendage and to Improve Transcatheter Closure Guidance

•Precise LAA anatomy must be established for LAA occlusion device selection. •We have developed the TUPLE maneuver, an acronym for “tilt up and turn left”. •The TUPLE maneuver facilitates LAA device selection and intraprocedural guidance.

Cysts Around the Heart: Differential Diagnosis and Multimodality Imaging Strategies for Paracardiac Cysts

•Paracardiac cysts (located adjacent to or inside the heart) are rarely detected. •There is a broad differential diagnosis for cysts encountered with echocardiography. •Multimodality imaging is crucial for comprehensively evaluating paracardiac cysts.

Pig-to-human heart xenotransplantation in two recently deceased human recipients

Genetically modified xenografts are one of the most promising solutions to the discrepancy between the numbers of available human organs for transplantation and potential recipients. To date, a porcine heart has been implanted into only one human recipient. Here, using 10-gene-edited pigs, we transplanted porcine hearts into two brain-dead human recipients and monitored xenograft function, hemodynamics and systemic responses over the course of 66 hours. Although both xenografts demonstrated excellent cardiac function immediately after transplantation and continued to function for the duration of the study, cardiac function declined postoperatively in one case, attributed to a size mismatch between the donor pig and the recipient. For both hearts, we confirmed transgene expression and found no evidence of cellular or antibody-mediated rejection, as assessed using histology, flow cytometry and a cytotoxic crossmatch assay. Moreover, we found no evidence of zoonotic transmission from the donor pigs to the human recipients. While substantial additional work will be needed to advance this technology to human trials, these results indicate that pig-to-human heart xenotransplantation can be performed successfully without hyperacute rejection or zoonosis.

Device-Associated Thrombus with Watchman FLX Left Atrial Appendage Closure Device: A Report of Two Cases

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Individual cases of Watchman FLX DAT are scare in literature.

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The Watchman FLX has shown lower rates of DAT than the Watchman 2.0.

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Thrombus formation is still possible in rare instances with the Watchman FLX.

Taking Command of Three-Dimensional Stitching Artifacts: From an Annoyance to an Easy Tool for Navigating Three-Dimensional Transesophageal Echocardiography

Despite many recent advances in three-dimensional (3D) transesophageal echocardiography (TEE) imagining, the process of orienting 3D TEE images is nonintuitive and uses assumptions based on idealized anatomy. Correlating two-dimensional TEE cross-sectional images to 3D reconstructions remains an additional challenge. In this article, we suggest the repurposing of the stitching artifact generated in 2-beat electrocardiogram-gated 3D TEE as a means of exactly orienting 3D images within a patient's unique anatomy. We demonstrate the application of this strategy to assess a normal mitral valve to localize scallops of mitral valve prolapse and to visualize typical left atrial appendage two-dimensional cuts in a 3D space. By taking command of stitching artifacts, cardiac imagers can successfully navigate the complex structures of the heart for optimal, individualized echocardiographic views.

Bacterial endocarditis with AACEK (HACEK) organisms

INTRODUCTION

Gram-negative organisms of the AACEK group, formerly known as HACEK, rarely cause endocarditis.

CASE SERIES

We present three cases of bacterial endocarditis, involving native and prosthetic valves, caused by AACEK organisms. In two patients, Cardiobacterium hominis was the responsible organism, and in a third, Aggregatibacter aphrophilus was implicated. A dental source of infection was identified in two patients, and in all three patients, the presentation of endocarditis was subacute.

DISCUSSION

This case series highlights the indolent nature of infection with the AACEK organisms. It also demonstrates the crucial role of multimodality imaging, especially transesophageal echocardiography, in the diagnosis of AACEk endocarditis of both native and prosthetic valves, and in delineating the extent of abscess in those with prosthetic valve infection.

Multimodality Imaging of Caval and Coronary Sinus Venous Anomalies

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Abnormal fetal development can produce several anomalies of the caval venous system.

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We present multimodality imaging of the most common caval venous anomalies.

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Each imaging modality provides incremental value when identifying these anomalies.

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Even normal variants may impact pacing lead or central venous catheter placement.

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Pathologic variants may lead to intracardiac shunting.

Multimodality Imaging of Sinus Venosus Atrial Septal Defect: A Challenging Diagnosis in Adults

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SVASD should be suspected in cases of unexplained RV volume overload.

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Direct visualization of SVASD with TTE is difficult in adults compared with children.

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TEE is helpful for diagnosing SVASD and associated pulmonary venous abnormalities.

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Multimodal imaging techniques offer incremental value in the workup of SVASD.

Cor Pulmonale from Concomitant Human Immunodeficiency Virus Infection and Methamphetamine Use

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HIV and frequent methamphetamine use are two known risk factors for PAH development.

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HIV and methamphetamine are both associated with higher rates of mortality in PAH.

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Echocardiography is an effective noninvasive modality for assessing PAH severity.

Two cases of acute endocarditis misdiagnosed as COVID-19 infection

The COVID‐19 pandemic has presented countless new challenges for healthcare providers including the challenge of differentiating COVID‐19 infection from other diseases. COVID‐19 infection and acute endocarditis may present similarly, both with shortness of breath and vital sign abnormalities, yet they require very different treatments. Here, we present two cases in which life‐threatening acute endocarditis was initially misdiagnosed as COVID‐19 infection during the height of the pandemic in New York City. The first was a case of Klebsiella pneumoniae mitral valve endocarditis leading to papillary muscle rupture and severe mitral regurgitation, and the second a case of Streptococcus mitis aortic valve endocarditis with heart failure due to severe aortic regurgitation. These cases highlight the importance of careful clinical reasoning and demonstrate how cognitive errors may impact clinical reasoning. They also underscore the limitations of real‐time reverse transcription‐polymerase chain reaction (RT‐PCR) for SARS‐CoV‐2 testing and illustrate the ways in which difficulty interpreting results may also influence clinical reasoning. Accurate diagnosis of acute endocarditis is critical given that surgical intervention can be lifesaving in unstable patients.

Long-term outcomes after transcatheter aortic valve replacement with minimal contrast in chronic kidney disease

BACKGROUND

Patients with renal insufficiency have poor short-term outcomes after transcatheter aortic valve replacement (TAVR).

METHODS

Retrospective chart review identified 575 consecutive patients not on hemodialysis who underwent TAVR between September 2014 and January 2017. Outcomes were defined by VARC-2 criteria. Primary outcome of all-cause mortality was evaluated at a median follow-up of 811 days (interquartile range 125-1,151).

RESULTS

Preprocedural glomerular filtration rate (GFR) was ≥60 ml/min in 51.7%, 30-60 ml/min in 42.1%, and < 30 ml/min in 6.3%. Use of transfemoral access (98.8%) and achieved device success (91.0%) did not differ among groups, but less contrast was used with lower GFR (23 ml [15-33], 24 ml [14-33], 13 ml [8-20]; p < .001). Peri-procedural stroke (0.7%, 2.1%, 11.1%; p < .001) was higher with lower GFR. Core lab analysis of preprocedural computed tomography scans of patients who developed a peri-procedural stroke identified potential anatomic substrate for stroke in three out of four patients with GFR 30-60 ml/min and all three with GFR <30 ml/min (severe atheroma was the most common subtype of anatomical substrate present). Compared to GFR ≥60 ml/min, all-cause mortality was higher with GFR 30-60 ml/min (HR 1.61 [1.00-2.59]; aHR 1.61 [0.91-2.83]) and GFR <30 ml/min (HR 2.41 [1.06-5.48]; aHR 2.34 [0.90-6.09]) but not significant after multivariable adjustment. Follow-up echocardiographic data, available in 63%, demonstrated no difference in structural heart valve deterioration over time among groups.

CONCLUSIONS

Patients with baseline renal insufficiency remain a challenging population with poor long-term outcomes despite procedural optimization with a transfemoral-first and an extremely low-contrast approach.

Photorealistic imaging of left atrial appendage occlusion/exclusion

Recent improvements in 3D TEE post processing rendering techniques referred to as TrueVue (Philips Medical Systems, Andover, MA, USA). It allows for novel photorealistic imaging of cardiac structures including left atrial appendage (LAA) and its closure devices. Here we present TrueVue images of the LAA prior to and after LAA exclusion/occlusion using various percutaneous and surgical techniques. TrueVue may improve delineation of LAA anatomy prior to occlusion as well as visualization of occluder device position within the LAA.

Echocardiographic Guidance of the Novel WaveCrest Left Atrial Appendage Occlusion Device

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The WaveCrest device is a novel LAA occluder with unique features.

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Two-dimensional and 3D TEE and fluoroscopy are essential for successful implantation.

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Air between layers of WaveCrest ePTFE fabric may obscure visualization on TEE.

Apoptosis inhibitor ARC promotes breast tumorigenesis, metastasis, and chemoresistance

Apoptosis repressor with caspase recruitment domain (ARC) inhibits both death receptor- and mitochondrial/ER-mediated pathways of apoptosis. Although expressed mainly in terminally differentiated cells, ARC is markedly upregulated in a variety of human cancers, where its potential contributions have not yet been defined. In this study, we provide evidence of multiple critical pathophysiologic functions for ARC in breast carcinogenesis. In the polyoma middle T-antigen (PyMT) transgenic mouse model of breast cancer, in which endogenous ARC is strongly upregulated, deletion of the ARC-encoding gene nol3 decreased primary tumor burden without affecting tumor onset or multiplicity. More notably, ARC deficiency also limited tumor cell invasion and the number of circulating cancer cells, markedly reducing the number of lung metastases. Conversely, ectopic overexpression of ARC in a PyMT-derived metastatic breast cancer cell line increased invasion in vitro and lung metastasis in vivo. We confirmed these results in a humanized orthotopic model based on MDA-MB-231-derived LM2 metastatic breast cancer cells, in which RNAi-mediated knockdown of ARC levels was shown to reduce tumor volume, local invasion, and lung metastases. Lastly, we found that endogenous levels of ARC conferred chemoresistance in primary tumors and invading cell populations. Our results establish that ARC promotes breast carcinogenesis by driving primary tumor growth, invasion, and metastasis as well as by promoting chemoresistance in invasive cells.

Abstract 4695: Apoptosis inhibitor ARC as a novel mediator of breast tumorigenesis, metastasis and chemoresistance

Apoptosis is critical for normal development and post-natal tissue homeostasis. ARC (Apoptosis Repressor with CARD), is an inhibitor of apoptosis with the unusual property of antagonizing both death receptor and mitochondrial apoptosis pathways. Under normal conditions, ARC is expressed in cardiac and skeletal myocytes and neurons. Suppression of cell death is critical for carcinogenesis and chemoresistance and we previously reported that ARC expression is induced in a wide variety of primary human epithelial cancers, including breast. Herein we present the first data demonstrating critical roles for ARC in several aspects of breast carcinogenesis. To test the hypothesis that ARC plays an important role in the pathogenesis of breast cancer in vivo, ARC-/- mice were bred onto the polyoma middle T-antigen (PyMT) transgenic mouse model of breast cancer. PyMT expression activates many oncogenic pathways common to human breast cancer including the induction of ARC in early and late-stage tumors and invading and metastatic cells. PyMT mice lacking ARC exhibit a 34% decrease in primary tumor burden compared to PyMT mice with ARC, although tumor onset and multiplicity remains unchanged. Unexpectedly, the reduced tumor burden can be accounted for by a novel function of ARC to promote proliferation, while baseline apoptosis remained comparable. The absence of ARC also results in a 44% reduction in the number of lung metastases independent of primary tumor burden. In vivo invasion assays and blood burden intravasation assays demonstrate that PyMT mice lacking ARC have a significant reduction in invading and circulating tumor cells when compared to those with ARC. Conversely, overexpression of ARC in a PyMT-derived metastatic cell line caused a significant increase in basement membrane invasion in vitro and lung metastases when injected into tail veins of mice. To test the function of ARC in a humanized model of breast cancer, ARC was knocked-down in the MDA-MB-231-derived LM2 human metastatic breast cancer cell line which was subsequently transplanted into mammary glands of SCID mice. Diminished ARC expression resulted in a 50% reduction in xenograft tumor volume and a drastic decline in stromal invasion in vivo. We also examined if the presence of ARC in invasive and metastatic cells contributes to chemoresistance. Xenograft LM2 mammary tumors deficient in ARC were sensitized to apoptosis induced by doxorubicin while the control tumors remained resistant. Moreover, deletion of ARC sensitized the invading cell population collected from primary PyMT breast tumors to tamoxifen-induced killing. This study demonstrates that ARC promotes primary tumor growth, improves the efficiency of metastasis at several stages and renders invasive breast cancer cells resistant to chemotherapies. These data implicate ARC as a novel mediator in the pathogenesis of breast cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4695. doi:10.1158/1538-7445.AM2011-4695