Latissimus dorsi dynamic cardiomyoplasty: role of combined ICD implantation

Dynamic cardiomyoplasty as a therapeutic alternative: current status

Dynamic cardiomyoplasty was proposed as an alternative surgical treatment for severe cardiomyopathies and has been performed worldwide in more than 1,000 patients. Patients indicated for this procedure are specifically those with dilated or ischemic cardiomyopathies. The ventricular function improvement observed after dynamic cardiomyoplasty derived from the direct action of synchronized skeletal muscle flap contraction and from a girdling effect that helps to reverse chamber remodeling and to decrease ventricular wall stress. Although long-term benefits of this procedure may be limited by skeletal muscle flap ischemic compromise, technological advances incorporated in the new myostimulators will possibly decrease this complication incidence. Clinical improvement has been reported as a consistent finding in cardiomyoplasty follow-up and the overall 5-year survival after this procedure ranges from 39 % to 54 %. On the other hand, the mortality after cardiomyoplasty has been significantly higher for patients in persistent New York Heart Association functional class IV, showing that this procedure needs to be indicated earlier than the heart transplantation. In this regard, only the results of an ongoing randomized trial will potentially define cardiomyoplasty influence on the survival of patients with severe heart failure. In the meantime, however, there are clearly several functional class III patients whose quality of life and exercise capacity have worsened despite the use of maximum medical therapy, justifying dynamic cardiomyoplasty indication.

Surgical approaches to dilated cardiomyopathy

Heart failure is one of the leading causes of hospitalization in the United States today. Congestive heart failure is a chronic progressive disease with the common central element being the remodeling of the cardiac chamber associated with ventricular dilation. Secondary mitral regurgitation is a complication of end-stage cardiomyopathy and is associated with a poor prognosis. Historically, these patients were not considered operative candidates due to the high morbidity and mortality in this patient population. Heart transplantation is now considered the standard of treatment for select patients with end-stage heart disease, however, it is only applicable to a small number of patients. In an effort to address this problem, newer and alternative surgical approaches are evolving, including mitral valve annuloplasty, the Batista myoplasty, and cardiomyoplasty. When these operative techniques that alter the shape of the left ventricle are utilized, in combination with optimal medical management for heart failure, survival is improved and patients can avoid or postpone transplantation.

Cardiomyoplasty after implantation of a pacemaker and cardioverter/defibrillator

Presently, a combination of two surgical methods improves the survival of patients with advanced ventricular dysfunction: implantable cardioverter/defibrillator implantation (which prevents sudden cardiac death) and cardiomyoplasty (which prevents further dilatation of the heart and provides additional cardiac assistance). We report the clinical course of a patient who had cardiomyoplasty after cardioverter/defibrillator implantation and pacemaker insertion. It is a rare case in which three different devices cardioverter/defibrillator, pacemaker, and cardiomyostimulator) are functioning together without crosstalk.

Surgical alternatives in the treatment of heart failure

Heart failure continues to plague a large population worldwide, and its incidence is increasing annually as a result of an aging population. It is associated with lengthy hospital stays, multiple hospital readmissions, and decreased quality of life because of its clinical manifestations. Although cardiac transplantation has become the therapy of choice for patients with heart failure, scarcity of donor hearts and age limitations prohibit its widespread use. Despite major advances in medical management, researchers continue to explore alternative surgical therapies to help augment cardiac function. This article explores surgical interventions in the management of heart failure, many of which are still experimental or in clinical trials. Coronary artery bypass surgery, dynamic cardiomyoplasty, and partial left ventriculectomy for the management of heart failure are discussed in detail. Descriptions of each surgical procedure, special care needs, and clinical outcomes are presented. However, because readers are familiar with the coronary artery bypass procedure and postoperative patient care, the discussion will focus on issues related to coronary artery bypass grafting in the presence of ischemic cardiomyopathy.

Cardiomyoplasty and implantable cardioverter defibrillator: efficacy and safety of concomitant device implantation: sudden death and cardiomyoplasty

Sudden death represents a common event in the natural history of patients affected by chronic heart failure. Such an outcome also has been shown to characterize the follow-up of the cardiomyoplasty procedure. We report two cases of patients who had cardiomyoplasty and experienced witnessed episodes of ventricular arrhythmia at variable times after surgery (2 years and 2 months, respectively). In the first case, an implantable cardioverter defibrillator (ICD) was implanted subsequent to the arrhythmic episode, whereas the second patient had a combined cardiomyoplasty and ICD implantation procedure. In particular, this patient underwent a modified wrapping technique, herein described, because of a large left ventricular dilatation. In both cases, ventricular defibrillation did not affect the correct functioning of the implanted cardiomyostimulator. Our article confirms that ventricular arrhythmia is common in cardiomyoplasty patients. The combined use of a skeletal muscle stimulator and implantable defibrillator may therefore be effective in preventing arrhythmia-related sudden death without any concurrent effect on the correct functioning of the wrapped muscle/heart circuit, with likely benefit on long-term cardiomyoplasty patient survival.

Dynamic cardiomyoplasty in the treatment of dilated cardiomyopathy: current results and perspectives

BACKGROUND

The purpose of this article is to provide an overview of the current indications, results, and perspectives of dynamic cardiomyoplasty in the treatment of patients with dilated cardiomyopathy. Particular emphasis is placed on the clinical experience with 36 patients operated at the São Paulo Heart Institute between 1988 and 1995.

METHODS

Based on several clinical reports, the mechanisms of action of dynamic cardiomyoplasty in these patients include the enhancement of left ventricular systolic function, by the direct action of synchronized skeletal muscle flap contraction and the reversion of chamber remodeling. Moreover, both mechanisms seem to be responsible for improved diastolic function properties and for the decrease of ventricular wall stress. Besides the acceptable hospital mortality observed for patients with dilated cardiomyopathy ranging from 0% to 8% with this surgical procedure, clinical improvement after dynamic cardiomyoplasty has been demonstrated as a prevailing and significant outcome.

RESULTS

Nevertheless, the 1-year survival for these patients ranges from 82% to 86% and the 5-year survival on the order of 41% to 49%. In addition, the analysis of factors influencing the outcome showed that cardiomyoplasty long-term survival was significantly affected by the severity of preoperative clinical compromise and cardiac function impairment. On the other hand, patients with dilated cardiomyopathy who were operated in functional Class III or intermittent Class IV and with pulmonary vascular resistance below 4 Wood units, present survival rates on the order of 79% at 2 years and of 64% at 5 years of follow-up, which are similar to those reported after cardiac transplantation.

CONCLUSIONS

Furthermore, technological advances incorporated in the new cardiomyostimulators may ameliorate skeletal muscle flap performance at long term. Other developments are also discussed in this field.