THE ROLE OF SURGERY IN HEART FAILURE - PART 4 ppt

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THE ROLE OF SURGERY IN HEART FAILURE - PART 4 ppt

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Valve Pathology in Heart Failure: Which Valves Can Be Fixed? Martinus T. Spoor, MD y , Steven F. Bolling, MD * University of Michigan, Ann Arbor, MI, USA Congestive heart failure (CHF) is a significant health burden whose impact is increasing around the world. As our population ages, medical advances that have extended our average life expectancy have also left more people living with chronic cardiac disease than ever before. In the United States alone, there are nearly 4.9 million suffering with heart failure with over 500,000 new patients diagnosed each year. Despite the signif- icant improvements with medical management, patients who have CHF are repeatedly readmitted for inpatient care, and the vast majority will die within 3 years of diagnosis [1]. Heart transplanta- tion has evolved to become the gold standard treatment for patients who have symptoms of severe congestive heart failure associated with end-stage heart disease. From an epidemiologic perspective, this treatment is ‘‘trivial’’ because less than 2800 patients in the United States are offered transplantation due to limitations of age, comorbid conditions, and donor availability. New surgical strategies to manage patients with severe end-stage heart disease have therefore evolved to cope with the donor shortage in heart transplantation and have included high-risk coro- nary artery revascularization [2–9], cardiomyo- plasty [10,11], and high-risk valvular repair or replacement [12]. Surgical treatment of mitral valve disease Geometric mitral reconstruction Functional mitral regurgitation (MR) is a sig- nificant complication of end-stage cardiomyopathy and it may affect almost all patients who have heart failure as a preterminal or terminal event. Its presence in these patients is associated with pro- gressive ventricular dilatation, an escalation of CHF symptomatology, and significant reductions in long-term survival estimated between only 6 and 24 months [2]. A firm understanding of the functional anat- omy of the mitral valve is fundamental to the management of MR in heart failure. The mitral valve apparatus consists of the annulus, leaflets, chordae tendineae, and papillary muscles as well as the entire left ventricle (LV). Thus the mainte- nance of chordal, annular, and subvalvular conti- nuity is essential for the preservation of mitral geometric relationships and overall ventricular function. As the ventricle fails, the progressive di- latation of the LV gives rise to MR, which begets more MR and further ventricular dilatation (Fig. 1). With postinfarction remodeling and lat- eral wall dysfunction, similar processes combine to result in ischemic mitral regurgitation. Left un- corrected, the end result of progressive MR and global ventricular remodeling is similar regardless of the etiology of cardiomyopathy. Incomplete leaflet coaptation, loss of the zone of coaptation, and regurgitation develop secondary to alter- ations in the annular–ventricular apparatus and ventricular geometry [3,4]. As the mitral valve an- nulus increases in size, an increasing amount of re- dundant mitral leaflet tissue, associated with a reduction of the size of the area of coaptation y Formerly from the Section of Cardiac Surgery, University of Michigan, Ann Arbor, Michigan. * Corresponding author. Section of Cardiac Surgery, University of Michigan, 1500 East Medical Center Drive, Ann Arbor, MI 48103. E-mail address: sbolling@umich.edu (S.F. Bolling). 1551-7136/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.hfc.2007.04.008 heartfailure.theclinics.com Heart Failure Clin 3 (2007) 289–298 Patients who Have Dilated Cardiomyopathy Must Have a Trial of Bridge to Recovery (Pro) Johannes Mueller, MD a, * , Gerd Wallukat, PhD b a Berlin Heart, Berlin, Germany b Max Delbrueck Center, Berlin, Germany Healing of idiopathic dilated cardiomyopathy (IDC) by drug therapy has not yet been successful. Mechanical unloading of the heart by an assist device is the only available measure that allows the heart a period of relative rest in which functional improvement may be achieved by interrupting the vicious circle of increasing wall tension and functional impairment. The hearts of a subset of patients who have IDC improve to normal or near-normal function when supported by a device. It is believed that under unloading conditions, special medical supplementation may enhance the process of improvement [1–9]. End-stage heart failure in patients who have dilated cardiomyopathy is characterized by vol- ume and pressure overload of the left and/or right ventricle. The ventricular wall and the interven- tricular septum are stretched and therefore thinned. The myocardial structure is severely disturbed by a collagen composition of the extra- cellular matrix that is out of balance [10–12]. Arrhythmia and conductance disturbances are the consequence. Finally, because of the inability of the heart to pump a sufficient volume of blood to the end organs, a globally impaired supply with oxygen is the result. Medically, these patients are treated with full antifailure medication, which, after a time of improvement, cannot avoid a trend toward further deteriora- tion in most patients [13,14]. Likewise the appli- cation of devices with biventricular pacing capability postpones the process of deterioration but does not lead to long-term sustained improve- ment of cardiac function. At this stage, cardiac transplantation is the logical next step to keep the patient alive. However, if a donor heart is not avail- able, the ultima ratio is the implantation of a me- chanical cardiac assist system, which leads to an immediate improvement of the overall oxygen sup- ply and of end-organ function [15,16]. Because the number of donor organs is limited and indeed has even decreased within the past years, there is growing significance attached to the application of mechanical assist devices as a method to save the lives of patients who are facing imminent death [17]. The development of cardiac assist devices has made much progress within the last 10 years. In the 1980s, mainly paracorporeal devices were available; however, in the 1990s, the partly implantable and fully implantable pulsatile car- diac support systems emerged and played an increasing role (Fig. 1) [18,19]. Then, in 1998, the first rotary blood pump was implanted [20]. Rotary pumps are significantly smaller, free of noise, and have lower power consumption than the pulsatile devices (Fig. 2). Most of these devices are placed above the diaphragm and do not need a pocket between two abdominal muscle layers [21–23]. With these new devices, the assist device technology has reached a status whereby the sur- gical implantation procedure is easier than with the former systems, and infection done of the crit- ical problems related to the size of the devicesdno longer plays a prominent role. The remaining problem with these pumps alludes to throm- boembolic events and potentially long-term effects caused by the reduced pulsatility of the blood * Corresponding author. Berlin Heart, Wiesenweg 10, 12247 Berlin, Germany. E-mail address: johannes.mueller@berlinheart.de (J. Mueller). 1551-7136/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.hfc.2007.05.006 heartfailure.theclinics.com Heart Failure Clin 3 (2007) 299–315 . an- nulus increases in size, an increasing amount of re- dundant mitral leaflet tissue, associated with a reduction of the size of the area of coaptation y Formerly from the Section of Cardiac Surgery, University. the functional anat- omy of the mitral valve is fundamental to the management of MR in heart failure. The mitral valve apparatus consists of the annulus, leaflets, chordae tendineae, and papillary. sbolling@umich.edu (S.F. Bolling). 155 1-7 136/07/$ - see front matter Ó 2007 Elsevier Inc. All rights reserved. doi:10.1016/j.hfc.2007. 04. 008 heartfailure.theclinics.com Heart Failure Clin 3 (2007) 289–298 Patients

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