Mechanical circulatory support in severe heart failure: single-center experience

Ventricular assist devices (VADs) have become important therapeutic tools to treat patients with end-stage cardiac failure. VADs are an essential component of transplantation programs as they successfully bridge individuals who would otherwise die. Recently left ventricular VAD (LVAD) therapy has been proposed as alternative to heart transplantation (HTx) for patients who are not transplant candidates. Other indications have now expanded into areas such as postcardiotomy failure, acute myocarditis, and acute massive myocardial infarction. From 1988 to May 2003, 80 patients received left or biventricular mechanical circulatory support including 78 as a bridge to and two as an alternative to HT. All patients survived the operation. Mean duration of VAD support was 77 +/- 150 days. Fifty-one points (63.8%) underwent heart transplantation; 3 (3.8%) recovered and were weaned from VADs. Major bleeding episodes occurred in 11 patients (13.8%) and major neurologic events occurred in 8 (10%). Sixteen patients (20%) were discharged home while waiting for HTx. Twenty-two patients (27.5%) died on VAD. In conclusion, VAD therapy proved effective in bridging patients with end-stage heart failure to HTx. While on LVAD support patients who were assisted with implantable wearable devices could be discharged at home, improving their quality of life.     

Effect of biventricular pacing therapy in patients with dilated cardiomyopathy with severe congestive heart failure

Objectives: Biventricular pacing (BVP) therapy has recently emerged as an effective treatment for patients with moderate to severe congestive heart failure (CHF) and ventricular asynchrony all over the world. However, this therapy is not yet available in Japan. We evaluated the effects of BVP in patients with severe CHF due to dilated cardiomyopathy (DCM). Subjects: Four patients with medically refractory severe CHF due to DCM in New York Heart Association functional class III or IV heart failure underwent BVP therapy. We combined the implantation of the left ventricular (LV) epicardial lead via small thoracotomy following right atrial and ventricular intravenous leads under general anesthesia. We evaluated to determine whether improvements of ventricular function, ventricular size, mitral regurgitation, functional status, frequency of hospitalization, and quality of life were associated with BVP therapy. Results: BVP improved LV systolic function, decreased LV size and mitral regurgitation, and shortened prolonged QRS interval. The patients’ symptoms, exercise tolerance, frequency of hospitalization, and quality of life were also dramatically improved by BVP. Furthermore, combination of BVP and oral administration of amiodarone significantly prevented recurrence of ventricular tachycardia and paroxysmal atrial fibrillation, and maintained sinus rhythm for a long period. Conclusions: In view of these findings, BVP therapy may contribute to the development of new therapeutic method for patients with severe CHF due to DCM.     

Mechanical support for patients with fulminant acute myocarditis: strategy for biventricular failure and respiratory failure

Abstract   Acute fulminant myocarditis can cause left ventricular dysfunction that predisposes the patients to critical condition. Left ventricular assist device (LVAD) is a useful option for the patient whose condition is resistant to medical therapy. However, when right ventricular dysfunction with hypoxia is complicated with left ventricular dysfunction, it can be difficult to make a prompt decision in order to achieve better outcome. We present our case in which the support on LVAD and extracorporeal membrane oxygenation (ECMO) was effective to treat critically ill patients.     

Mechanical support for biventricular failure using the HeartWare (HVAD) pump

The limited availability of organs for transplant has vastly popularized implantation of left ventricular assist devices. Right ventricular failure is a continued problem with an incidence as high as 44 %, significantly decreasing survival after left ventricular assist devices (LVAD) implantation. Survival is significantly better when LVAD patients at high risk for right ventricular failure (RVF) are converted directly to biventricular assist device (BiVAD) therapy instead of LVAD with subsequent right ventricular assist device (RVAD) implantation. The options available for biventricular assistance entail a total artificial heart (TAH) or additional right-sided placement of a continuous flow/pulsatile device which could be para-corporeal or implantable. The HeartWare HVAD (HeartWare International, Framingham, MA) device in a biventricular configuration is a very attractive option. This report details experiences and techniques for implantation of the HVAD in such a configuration.     

Surgical strategy for severe heart failure

Heart transplantation had been an only effective treatment for severe congestive heart failure secondary to dilated or ischemic cardiomyopathy. Recently, mitral valve repair and left ventricular reconstruction have been introduced to restore their own cardiac function. These operations can be one of treatment options for relatively stable congestive heart failure patients. For those with severer heart failure complicated with cardiogenic shock or end-organ dysfunction, use of mechanical assist device should be included in the treatment strategies. Perioperative problems of implantation of left ventricular assist device include right heart failure, multi-organ failure, infection and anti-coagulation. Implantable LVAS, which provides potent circulatory assist is useful to overcome organ dysfunction and render good QOL during long waiting period for heart transplantation.     

A successful biventricular assist for postoperative patient with severe heart failure and hepatorenal dysfunction after mitral and tricuspid valve surgery

We report a case of successful biventricular assist for severe heart failure after open heart surgery. A 62-year-old man suffering from advanced valvular disease accompanied with hepatorenal dysfunction underwent mitral valve replacement and tricuspid annuloplasty on September 22, 1988. Because of inability of weaning from cardiopulmonary bypass, left heart assisted circulation using a roller pump with heparin-coated tubing system was inserted. Following the left heart assist, an right ventricular assist device (RVAD) was subsequently applied to intractable right ventricular failure. He was successfully weaned from an RVAD after 24 hours, and from left heart assisted circulation after 46 hours. At present, he is doing well without significant complications. Earlier application of biventricular assist might be effective for biventricular failure with hepatorenal dysfunction.     

The use of a biventricular assist device for postcardiotomy profound biventricular failure

A 58-year-old woman who could not be weaned from cardiopulmonary bypass was treated with a biventricular assist device (BVAD) using a centrifugal pump for the left side and a pneumatic pulsatile pump for the right side. At the initiation of the BVAD support, predominant right ventricular failure was recognized and therefore weaning was begun from the left side. The left ventricular assist device was discontinued after 87 h and the patient was finally weaned from the right ventricular assist device after 205 h. Despite the complete recovery of cardiac function, the patient developed renal failure followed by an intractable infection and died of multiple organ failure on the 59th postoperative day (POD).     

Clinical experience of mechanical ventricular support with centrifugal pump for severe ventricular failure after open heart surgery

Five adult patients (pts) with age 15-67 (mean 43) received mechanical circulatory support with centrifugal pump (Biomedicus, BP-80, Sarns centrifugal pump) for postcardiotomy profound shock. Three pts underwent left ventricular support (LVS) alone, and the other 2 required biventricular support (BVS). Duration of the LVS ranged from 33 to 240 hours (mean 126 hours) and the right ventricular support 92, 120 hrs. Pump flow rate was 1.1 to 2.5 (mean 1.9) L/min/m2. Sixteen pumps were used and the pump exchange was performed 9 times in five pts and an average perfusion time per pump was 57 hrs. Two of 3 pts with LVS alone survived and one died of multiorgan failure associated with right heart dysfunction. In two pts with BVS, one survived and the other died of persistent low cardiac output early after pump removal. As the complication during mechanical support, bleeding was seen in 3 pts and cerebral infarction in one. Although centrifugal pump has potential limitation in antithrombogenicity and durability, this device provides a simple and effective mechanical circulatory support.     

Possibilities and limitations of a miniaturized long-term extracorporeal life support system as bridge to transplantation in a case with biventricular heart failure

In cardiac surgery extracorporeal life support systems (ECLS), also known as extracorporeal membrane oxygenation systems (ECMO), are often placed in case of postcardiotomy shock, until the patient's myocardial pump function recovers. Patients under ECLS are typically intubated and immobilized. We present a 57-year-old man suffering from severe ischemic cardiomyopathy in biventricular failure and intractable cardiogenic shock, who was supported with a miniaturized cardiopulmonary bypass system (MECC((R))) installed as venoarterial ECLS for 37 days. The patient was fully awake, spontaneously breathing, and practicing exercise in bed during life support for four weeks. He then required intubation for pneumonia, but later underwent successful transplantation. In conclusion, this case demonstrates that ECLS with miniaturized heart-lung machines offer the possibility of prolonged and safe support, ideal as a bridge to decision in patients with cardiogenic shock. On the other side, this report also indicates that ECLS is not recommended as a bridge to transplantation on a routine basis.     

Surgical regeneration therapy using myoblast sheets for severe heart failure

We have already reported that heart transplantation and left ventricular assist system (LVAS) are the useful surgical treatments for severe heart failure. However, these treatments have several problems such as donor limitation and complications and a novel strategy is desired. The autologous myoblast sheets attenuated the cardiac remodeling in the rat infarcted myocardium and dilated cardiomyopathy hamsters, leading to the improvement of cardiac performance. In this study, we will report the present results of heart transplantation and LVAS and also, report the development of porcine autologous myoblast sheets and hypothesized that autologous myoblast sheets regenerate the porcine infracted myocardium for clinical application. Skeletal myoblast (SM) isolated from leg muscle were cultured and detached from the dishes as single monolayer cell-sheet (tissue) at 20 degrees C using temperature-responsive culture dishes. Echocardiography demonstrated that cardiac systolic performance was significantly improved in SM group 4 weeks after operation rather than the control group. Both diastolic dysfunction and regional delayed relaxation in association with regional systolic function were recovered in the SM group, while the control group were not. Histologically, anterior wall was significantly recovered and dilatation of left ventricle was well attenuated in the SM group, while not in the other groups. SM-sheet implantation improved cardiac function by attenuating the cardiac remodeling and metabolic recovery in the impaired myocardium in the porcine ischemic myocardium, suggesting a promising strategy for clinical myocardial regeneration therapy.     

Univentricular versus biventricular assist device support

Controversy continues over whether patients should receive selective univentricular assist devices (UVADs) or biventricular assist devices (BVADs). Data from 39 patients supported for more than 2 days with Thoratec VADs were analyzed to compare mortality and morbidity between those receiving UVAD versus BVAD. Twenty-three patients received UVADs and 16 BVADs. Age, gender, and duration of support did not differ significantly between the two groups. Morbidity in VAD patients does not differ between UVAD and BVAD support. Survival is determined by the reversibility of pre-VAD myocardial damage or the eligibility for transplantation, rather than by the number of devices used. These data do not support the use of BVAD in all patients; they support a selective approach based on hemodynamic requirements.