The IX t h Makassed Medical Congress - American University of Beirut

More documents

Recommendations

Info

T h e I X t h M a k a s e d M e d i c a l C o n g r e s s Transcatheter Aortic Valve Implantation Samir R. Kapadia, MD E. Murat Tuzcu, MD Corresponding author E. Murat Tuzcu, MD Department of Medicine, Cleveland Clinic, 9500 Euclid Avenue, J2-3, Cleveland, OH 44195, USA. E-mail: Tuzcue@ccf.org Current Treatment Options in Cardiovascular Medicine 2009, 11:467–475 Current Medicine Group LLC ISSN 1092-8464 Copyright © 2009 by Current Medicine Group LLC Opinion statement Aortic stenosis is the most important valvular heart disease affecting the elderly population. Surgical aortic valve replacement is the mainstay of treatment, although a substantial number of patients are considered high risk for surgery. Many of these patients do not undergo surgery and have poor outcomes from medically treated symptomatic, severe aortic stenosis. Transcatheter aortic valve implantation (TAVI) provides a promising treatment option for some of these patients. Several devices are under investigation. The Edwards Sapien valve (Edwards Lifesciences, Irvine, CA) and the CoreValve (Medtronic, Minneapolis, MN) have the largest human experience to date. Initial data suggest that these devices have an acceptable safety profi le and provide excellent hemodynamic relief of aortic stenosis. The Edwards Sapien valve is currently under investigation in the United States in the PARTNER (Placement of Aortic Transcatheter Valve) trial in high-risk surgical or inoperable patients; TAVI is available for clinical use in both Canada and Europe. TAVI is not used in low- or intermediate-risk surgical patients; however, future studies may prove its applicability in these subsets. The major complications of TAVI include access site–related problems and device malpositioning/migration. There are several newgeneration prosthetic valves and delivery systems designed to be low profi le and repositionable. Technical advances and refi nement of the implantation methods may make TAVI even safer and ultimately a better treatment option, not only for patients with high surgical risk but also for those with moderate or low risk. Introduction Valvular heart disease has a signifi cant impact on cardiovascular mortality and morbidity [1–3]. Aortic stenosis (AS) is the most common valvular lesion in the aging population, with a prevalence of 4.6% in adults ≥ 75 years of age [2–4]. The advancing age of the population, combined with the lack of pharmacologic therapies to prevent, halt, or effectively slow the progression of AS, has led to an even greater burden of this disease in developed countries [1–3]. Surgical aortic valve replacement (SAVR) is the recommended treatment for patients with symptoms [5]. After the onset of symptoms, average survival may be as brief as 1 to 3 years without SAVR [5–9]. Within the United States, more than 50,000 aortic valve replacements (AVRs) are performed annually for severe AS. Many patients with severe symptomatic AS do not 82 undergo surgery for various reasons. Some are not referred for surgery because of comorbidities or patient preference; others are deemed inoperable by the surgeon because of the presence of coexisting illnesses. This issue is particularly the case with the elderly. In the Euro Heart Survey on valvular heart disease, 33% of patients with severe symptomatic AS did not undergo surgery [10]. Other studies similarly have shown that 27% to 41% of patients with severe symptomatic AS do not undergo SAVR [9,11–13]. The advent of transcatheter aortic valve implantation (TAVI) provides a unique treatment option for some of these patients [14–19,20•,21]. SAVR remains the gold standard of treatment for patients with low and intermediate surgical risk. However, the surgical risk is diffi cult to judge at times because several subjective variables may play critical roles in
468 Valvular, Myocardial, Pericardial, and Cardiopulmonary Disease decision making. The classic risk calculators include the traditional European System for Cardiac Operative Risk Evaluation (EuroSCORE), the logistic EuroSCORE, and the Society of Thoracic Surgeons (STS) score. Typically, the EuroSCORE overestimates and the STS score underestimates the true mortality. Several important variables are not captured in these scoring systems. Many inoperable patients may be ignored because the scores are derived Treatment Devices • Percutaneous AVR was fi rst performed in a closed-chested pig model by Andersen in 1992 [22]. Since then, several different prostheses have been developed and implanted using different transcatheter approaches. Currently, the most data are available from studies involving the two valves approved for clinical use in Europe under the CE (European Conformity) mark: the Edwards Sapien valve (Edwards Lifesciences, Irvine, CA) and the CoreValve (Medtronic, Minneapolis, MN). Several other second-generation valves have been tested in humans in initial feasibility studies. These valves are repositionable and are potentially deployable via smaller delivery systems. Some examples of these newer valves are the Direct Flow (Direct Flow Medical, Santa Rosa, CA), AORTex, and Lotus (Sadra Medical, Los Gatos, CA) valves. The details of these valves are beyond the scope of this review. • The Edwards Sapien valve is a trileafl et bovine valve attached to a stainless steel frame, constituting a balloon-expandable stent. The proximal portion of the stent is covered by a fabric skirt on its outer perimeter to minimize paravalvular leak. The valve is available in two sizes. The 23-mm valve is mounted inside a 14.5 mm–long stent, whereas the 26mm valve requires a 16-mm stent. About 4 or 5 mm of the distal part of the stent is not covered by the skirt. The newer-generation Edwards valve, the Sapien XT, has a lower crimped profi le because it is a cobaltchromium stent with thinner struts and a more open design, without compromise of its radial strength. Bovine pericardial leafl ets are matched for thickness and elasticity and incorporate treatment with ThermaFix anticalcifi cation (Edwards Lifesciences) [23]. The scalloped geometry and attachment method of the leafl ets have been modifi ed to achieve a naturally closed design. The 23-mm Sapien valve can be introduced via a 22F sheath, whereas the 26-mm valve needs a 22F to 24F sheath, depending on the type of catheter on which the stent is mounted. The Sapien XT valve has a signifi cantly lower profi le. • The CoreValve ReValving system consists of a self-expandable nitinol stent with a trileafl et porcine pericardial valve. The stent is carefully designed with three contiguous leaves of structure and function. The upper third of the frame has low radial force and sits within the ascending aorta to orient the prosthesis in the aortic root. The middle third of the frame has high hoop force; the valve leafl ets are attached to this portion of the stent. The lower third of the frame exerts high radial force and sits within the left ventricular outfl ow tract. A skirt of pericardium borders the lower portion of the valve to create a seal and prevent paravalvular aortic regurgitation. This valve design is such that although the prosthesis is anchored within the annulus, its function is supra-annular. This valve also is available in two sizes: 26 and 29 mm. The 26-mm valve sits within a 55-mm stent; the 23-mm valve is deployed within a 53-mm stent. The skirt height is 12 mm for both valve sizes. 83 from patients who underwent AVR. Ascending aortic calcifi cation, previous radiation exposure, the anatomy of cardiac structures in relation to the sternum, and general frailty are some important examples of the factors that affect outcomes but are not included in the risk-scoring systems. Patient preference and physicians’ comfort levels also vary tremendously. These issues have to be carefully considered when managing a complex patient.
Page 1 and 2:
The IX th Makassed Medical Congress
Page 3 and 4:
CONGRESS PRESIDENT Said Sayegh, MD,
Page 5 and 6:
GENERAL INFORMATION
Page 7 and 8:
• Target Audience: Physicians, Pr
Page 9 and 10:
Durriya Sinno, MD Pediatrics Americ
Page 11 and 12:
Moderators
Page 13 and 14:
PEDIATRICS Bassem Abou Merhi, MD Pe
Page 15 and 16:
Maroun Sokhn, MD Pediatrics Saint G
Page 17 and 18:
Scientific Program
Page 19 and 20:
Session 3: Intensive Care Neonatolo
Page 21 and 22:
Session 1: Pediatric Intensive Care
Page 23 and 24:
8:00 - 8:05 08:05 - 08:10 Welcome r
Page 25 and 26:
Cardiology Session III: Interventio
Page 27 and 28:
Cardiology Session VI: Intervention
Page 29:
Cardiology Symposia (NON-CME) Frida
Page 32 and 33: T h e I X t h M a k a s e d M e d i
show all

The IX t h Makassed Medical Congress - American University of Beirut

Create successful ePaper yourself

Delete template?

Save as template?