Haytham Elgharably

Current Hypotheses in Cardiac Surgery: Biofilm in Infective Endocarditis

Despite recent advances in diagnostics and treatments, infective endocarditis is still associated with substantial morbidity and mortality. Even prolonged courses of broad-spectrum antimicrobials often fail to eradicate the infection, making surgical intervention necessary in many cases. In this review, we present recent advances in molecular microbiology techniques that have uncovered a plausible explanation for this resistance to treatment: the recently discovered social behavior of some microbes, in which colonies form a nearly impenetrable barrier around themselves called a biofilm. These biofilm structures isolate the colony from the body׳s immune response and antimicrobial drugs. We also present current thinking about possible ways biofilms can be destroyed.

First-in-Human Implantations of the NaviGate Bioprosthesis in a Severely Dilated Tricuspid Annulus and in a Failed Tricuspid Annuloplasty Ring

Based on an old misconception that the tricuspid valve is not important for cardiac performance, functional tricuspid regurgitation (TR) has been historically ignored. As a consequence, an increasing number of patients present in the current era with severe TR associated with right heart failure that is refractory to medical treatment. Traditional or redotricuspid valve surgery in that setting has been shown to have high mortality (up to 35% at 30 days).1–3 Thereby, transcatheter valve implantation technology seems as an attractive alternative. Herein, we report the first-in-human successful implantation of the NaviGate valved-stent (NaviGate Cardiac Structures, Inc, NCSI, Lake Forest, CA) in 2 patients with severe TR and prohibitive risk for conventional surgery, for which they received Food and Drug Administration and institutional review board approvals for compassionate use (Figure 1). Figure 1. The NaviGate valved-stent. A , Ventricular view. B , Lateral view. A 64-year-old woman presented after multiple admissions for refractory right heart failure with severe functional TR secondary to annular dilatation, severe right ventricular (RV) dysfunction, severe pulmonary hypertension (systolic pressure, 75 mm Hg), and moderate ischemic mitral regurgitation (Figure 2A). Other comorbidities included chronic kidney dysfunction, chest radiation for breast cancer, atrial fibrillation, obstructive lung disease, and coronary bypass surgery with patent grafts. The patient was deemed high risk for conventional open-heart surgery by the Multidisciplinary Heart Team and was found a candidate for compassionate use of a first-in-human NaviGate valved-stent implantation. Preoperative sizing included a focused 4-dimensional computed tomography that was used to develop a 3-dimensional printing model of the …

Tricuspid Regurgitation Associated With Ischemic Mitral Regurgitation: Characterization, Evolution After Mitral Surgery, and Value of Tricuspid Repair.

BACKGROUND Tricuspid regurgitation (TR) often accompanies ischemic mitral regurgitation and is generally assumed to be a secondary consequence of altered hemodynamics of the left-sided regurgitation. We hypothesized that it may also be a direct consequence of right-sided ischemic disease. Therefore, our objectives were to (1) characterize the nature of this TR and (2) describe its time course after mitral valve surgery for ischemic mitral regurgitation, with or without concomitant tricuspid valve repair. METHODS From 2001 to 2011, 568 patients with ischemic mitral regurgitation underwent mitral valve surgery. They had varying degrees of TR and altered right-side heart morphology and function; 131 had concomitant tricuspid valve repair. Postoperatively, 1,395 echocardiograms were available to assess residual and recurrent TR. RESULTS Greater severity of preoperative TR was accompanied by larger tricuspid valve diameter, greater leaflet tethering, worse right ventricular function, and higher right ventricular pressure (all p [trend] ≤ 0.002). Without tricuspid valve repair, 31% of patients with no preoperative TR had moderate or greater TR by 5 years, as did 62% with moderate TR. With tricuspid valve repair, 25% with moderate preoperative TR remained in that grade at 5 years, but 11% had severe TR. CONCLUSIONS Tricuspid regurgitation accompanying ischemic mitral regurgitation is associated with right-side heart remodeling and dysfunction often mirroring that occurring in the left side of the heart-ischemic TR. Tricuspid valve repair is effective initially, but as with mitral valve repair, TR progressively returns. Therefore, when the severity of TR and right-sided remodeling reaches the point of irreversibility, it may be an indication to eliminate the TR by replacing the tricuspid valve.

Transcatheter Tricuspid Valve Implantation of NaviGate Bioprosthesis in a Preclinical Model

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Third time mitral valve replacement-lessons learned

We report the management of three iatrogenic injuries involving the aortic valve, left circumflex artery, and left ventricular outflow tract, that occurred during a re‐operative mitral valve replacement.

Pitfalls and Pearls for 3-Dimensional Printing of the Tricuspid Valve in the Procedural Planning of Percutaneous Transcatheter Therapies

There is a recent rise in percutaneous therapies for the tricuspid valve. Due to the innovative nature of these procedures and the complex anatomy of the tricuspid valve, procedural planning often relies on 3-dimensional (3D) printing. Whereas contrast-enhanced 4-dimensional (4D) computed tomography

Early mitral bioprosthetic failure secondary to strut entrapment by suture loop causing severe valve incompetence: Early Mitral Bioprosthetic Failure Secondary to strut

1Department of Thoracic and Cardiovascular Surgery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio 2Department of Cardiothoracic Anesthesia, Heart and Vascular Institute, Cleveland Clinic, Cleveland, Ohio Correspondence José L. Navia MD, Department of Thoracic and Cardiovascular Surgery, Cleveland Clinic, 9500 Euclid Avenue/Desk J4-1, Cleveland, OH 44143. Email: naviaj@ccf.org Funding information None

Transcatheter mitral valve replacement with the NaviGate stent in a preclinical model

AIMS The aim of this study was to test the feasibility of transcatheter mitral valve implantation of the NaviGate device in acute and chronic preclinical models. METHODS AND RESULTS We evaluated NaviGate valved stent implantation in the mitral position in an acute swine model (n=24, ≤5 days) through three different approaches - transatrial, transapical, and transseptal - and in a chronic swine model (n=12, >10 days) through a transatrial approach. The NaviGate implantation procedures were successful in 83% of the acute model studies (n=20) and 83% of the chronic model studies (n=10). Echocardiographic assessment showed low gradient across the valved stent (mean gradient <3 mmHg) and the left ventricular outflow tract (mean gradient <6 mmHg). Post implantation, there was no mitral regurgitation (MR) in 75% (n=15) of the acute studies and mild MR in 25% (n=5). In the chronic model, there was no MR in 60% (n=6) and mild MR in 40% (n=4). The implantation procedure was aborted in four acute studies due to inferior vena cava injury and in two chronic studies due to prosthesis-annulus mismatch. CONCLUSIONS In preparation for clinical application, transcatheter mitral implantation of the NaviGate valved stent was proved feasible in acute and chronic preclinical models. The three featured delivery approaches are of particular value for high-risk patients with functional MR and challenging vascular access.

Biofilm in Infective Endocarditis and Clinical Implications

There has been a growing recognition of the concept that biofilm formation is important in the pathogenesis of infective endocarditis (IE). Microbes causing IE have the ability to colonize the cardiac structures and develop biofilms, thereby protecting themselves against antibiotics and host defenses, facilitating invasion and tissue destruction and resulting in persistent and relapsing infections. In this review, we present the available evidence and clinical implications of biofilm role in IE.

Devices for ex vivo heart and lung perfusion

ABSTRACT Introduction: The number of organs available for heart and lung transplantation is far short of the number that is needed to meet demand. Perfusion and ventilation of donor organs after procurement has led to exciting advances in the field of cardiothoracic transplantation. The clinical implications of this technology allows for techniques to evaluate the quality of an organ, active rehabilitation of organs after procurement and prior to implantation, and increased time between organ procurement and implantation. This ex-vivo perfusion technique has also been referred to in the lay press as the ‘heart in a box’ or ‘lung in a box.’ Areas covered: This review includes information from case reports, case series, and clinical trials on ex vivo heart and lung perfusion. The focus is on the devices, ventilation and perfusion techniques, outcomes, and application of the technology. Expert commentary: Ex vivo perfusion of donor hearts and lungs prior to transplantation has proven to be a viable alternative to standard cold-preservation strategies. Its use has allowed for ongoing expansion of the donor pool. The biggest barriers to expansion of this technology are access, cost, and lack of evidence which clearly supports superior outcomes.