Faculty Bibliography

The technique of mechanical circulatory support or the site of cannulation may affect transvalvular flow. We describe early failure of a mitral bioprosthesis in a patient with temporary left ventricular assist device support, likely from thrombosis. Salvage with transcatheter mitral valve replacement was attempted. Temporary mechanical circulatory support strategies that maximize flow across a new bioprosthesis should be sought to avoid early valvular thrombosis.

Purpose of Review: Atrial fibrillation (AF) is the most common arrhythmia in humans. It is a major cause of morbidity and mortality as it impairs cardiac function and is a major risk of embolic stroke. Traditionally, thromboembolic risk of AF has been treated with system anticoagulation with intravenous, intramuscular, or oral anticoagulants. Although the novel oral anticoagulants (NOACs) have revolutionized stroke risk reduction in AF patients, they are associated with a significant risk of bleeding and may be contraindicated in certain patients. Embolic events in AF typically originate from thrombi that form within the left atrial appendage (LAA), especially in nonvalvular AF. Both surgical and percutaneous LAA closure techniques have been devised as alternatives to systemic anticoagulation. As surgical LAA closure is typically performed as an adjunct to other cardiac surgeries, the amount of eligible patients for this type of therapy may be limited. Recent Findings: Excluding the LAA from the systemic circulation may reduce the risk of thromboembolism in AF. Recent technologic advances have led to the development of several percutaneously delivered devices that can occlude or exclude the LAA from systemic circulation. These devices may be purely endocardially delivered such as the Watchman (Boston Scientific, Maple Grove, MN) and Amulet (St. Jude Medical, Minneapolis, MN), or both endocardially and pericardially delivered such as the Lariat (Sentre-HEART, Palo Alto, CA). During Amulet and Watchman procedures, a transseptally delivered device composed of nitinol is placed in the LAA orifice, subsequently excluding the LAA from the systemic circulation. In the Lariat procedure, a magnet link is created between a transseptally delivered endocardial wire and epicardially delivered pericardial wire, followed by epicardial suture ligation of the LAA. Their use is steadily increasing in worldwide either through routine clinical use of approved devices or within clinical trials. Summary: In this review, we describe the various devices available for percutaneous LAA closure, and the indispensable role of real-time transesophageal echocardiography in the periprocedural assessment and intraprocedural guidance of percutaneous LAA occlusion procedures.

This paper provides a comprehensive overview of 3D transesophageal echocardiography still images and movies of mechanical mitral valves, mitral bioprostheses, and mitral valve repairs. Alongside these visual descriptions, the historical overview of surgical and percutaneous mitral valve intervention is described with the special emphasis on the incremental value of 3D transesophageal echocardiography (3DTEE). For each mitral valve intervention, 2D echocardiography, chest x-ray, and fluoroscopy images corresponding to 3DTEE are given. In addition, key references on echocardiographic imaging of individual valves and procedures are enumerated in accompanying figures and tables.

Background: Patients with severe aortic stenosis in the setting of low gradient and preserved left ventricular ejection fraction (LVEF) remain an area of clinical uncertainty. Methods: Retrospective chart review identified 209 patients who underwent transcatheter aortic valve replacement (TAVR) between September 2014 and September 2015. Of these patients, 3 (1.4%) were excluded due to procedural indication other than severe aortic stenosis and 41 (20%) were excluded due to reduced LVEF (<50%). Of the remaining 165 patients with aortic valve area <1 cm2, 77 (47%) had either a peak velocity <4.0 m2 or mean gradient <40 mmHg (LG group) and 88 (53%) had both peak velocity >4.0 m2 and mean gradient >40 mmHg (HG group) across the AV. Outcomes were defined by the valve academic research consortium 2 criteria when applicable and compared between the LG and HG groups via Fisher's exact test. Median follow-up was 367 days. Continuous data are shown as median [interquartile range] and categorical data are shown as proportions. Results: The 30-day mortality risk as assessed by Society of Thoracic Surgery score was not significantly different between the LG and HG groups (5.9% [3.5-8.1] vs 6.2% [4.4-7.6], p=0.45). There were no significant differences in outcomes (Table). Conclusion: In a high-volume center, patients undergoing TAVR for severe AS with LG preserved LVEF have no significant difference in adverse outcomes, both in-hospital and on 1-year follow-up, when compared to patients with HG preserved LVEF. (Figure Presented)

Aortic root thrombus is an uncommon complication of continuous-flow left ventricular assist devices (LVAD). We present the case of a 71-year-old man with ischemic cardiomyopathy who underwent destination therapy HeartMate II LVAD placement. Eighteen months later, he presented with a cerebrovascular accident followed by myocardial infarction. Transesophageal echocardiography revealed an aortic root thrombus spanning the left and noncoronary cusps and obliterating the left main coronary artery. We discuss the incidence, risk factors, and management of aortic root thrombus in LVAD patients. To our knowledge, this is the first report of three-dimensional echocardiography used to characterize an LVAD-associated aortic root thrombus.

PURPOSE OF REVIEW: Functional mitral regurgitation (FMR) is a common complication of left ventricular dysfunction. It is now recognized as an important clinical entity and an independent predictor of poor prognosis in cardiomyopathy patients. In this review, we provide a comprehensive summary of the pathophysiology, latest imaging modalities, and diagnostic criteria for FMR. Additionally, we discuss the recent literature on the continuously evolving surgical and percutaneous treatment options. RECENT FINDINGS: The criteria for quantification of FMR on echocardiography were updated and are distinct from organic mitral regurgitation in the most recent American College of Cardiology/American Heart Association 2014 valve guidelines. Furthermore, the evolving role of MitraClip for potential treatment of FMR offers exciting prospects to treat high-risk symptomatic patients. SUMMARY: Our review serves to consolidate the current diagnostic and treatment modalities for FMR and provide a contemporary resource for clinicians while treating patients. Additionally, we identify the gaps present in our knowledge of FMR to guide further clinical investigation.