Latif Arusoglu

Novacor left ventricular assist system versus heartmate vented electric left ventricular assist system as a long-term mechanical circulatory support device in bridging patients: A prospective study

OBJECTIVE Long-term mechanical circulatory support as a bridge-to-transplantation procedure and bridge to recovery is of increasing importance. The implantable left ventricular assist devices, Novacor N100 left ventricular assist system (Baxter Healthcare Corporation, Berkeley, Calif) and TCI HeartMate vented electric left ventricular assist system (Thermo Cardiosystems Inc, Woburn, Mass), have proved to be efficient devices in bridge-to-transplantation settings and for prolonged support. The two systems were compared with regard to reliability and morbidity. METHODS Between October 1996 and March 1998, a prospective, single-center study was done that included 40 patients, 20 of whom were treated with the Novacor system and 20 of whom were treated with the HeartMate device. The diseases were mainly dilated cardiomyopathy (13/9) and ischemic cardiomyopathy (6/10). There were no statistically significant differences between the two groups regarding age, sex, preoperative clinical blood chemistry values, hemodynamic data, or risk factors. RESULTS There were no statistically significant differences between the two groups with regard to postoperative hemodynamics, organ recovery, out-of-hospital support, and survival to heart transplantation. Mean duration of support was 235.3 +/- 210 days for the Novacor group and 174.6 +/- 175 days for the HeartMate group and mean out-of-hospital support was 241 +/- 179 days and 166 +/- 152 days for the two groups, respectively. Neurologic complications occurred significantly more often among the Novacor group, whereas the HeartMate group had a higher prevalence of infections and technical problems, which was statistically significant. Survival to transplantation was 65% for the Novacor group and 60% for the HeartMate group. CONCLUSIONS Most patients had organ recovery with left ventricular assist system support, and a considerable number of patients in both groups underwent transplantation. However, both devices need revision to address the current problems, that is, thromboembolism for the Novacor device and infection and reliability for the HeartMate device.

European experience of DuraHeart™ magnetically levitated centrifugal left ventricular assist system

OBJECTIVE The DuraHeart (Terumo Heart, Inc., Ann Arbor, Michigan, USA) is the worlds first approved magnetically levitated centrifugal left ventricular assist system designed for long-term circulatory support. We report the clinical outcomes of 68 patients implanted with the DuraHeart as a bridge to cardiac transplantation in Europe. METHODS Sixty-eight patients with advanced heart failure (six females), who were eligible for cardiac transplantation were implanted with the DuraHeart between January 2004 and July 2008. Median age was 58 (range: 29-74) years with 31% over 65 years. Thirty-three of these patients received the device as a part of the European multi-center clinical trial. Survival analyses were conducted for 68 patients and other safety and performance data were analyzed based on 33 trial patients. RESULTS Mean support duration was 242+/-243 days (range: 19-1148, median: 161) with a cumulative duration of 45 years. Thirty-five patients (51%) remain ongoing, 18 transplanted, 1 explanted, and 14 died during support with a median time to death of 62 days. The Kaplan-Meier survival rate during support was 81% at 6 months and 77% at 1 year. Of the 13 patients (21%) supported for >1 year, 4 supported for >2 years, 1 supported >3 years, 2 transplanted, 2 died, and 9 ongoing with a mean duration of 744+/-216 days (range: 537-1148, median: 651). Major adverse events included driveline/pocket infection, stroke, bleeding, and right heart failure. There was no incidence of pump mechanical failure, pump thrombosis, or hemolysis. CONCLUSIONS The DuraHeart was able to provide safe and reliable long-term circulatory support with an improved survival and an acceptable adverse event rate in advanced heart failure patients who were eligible for transplantation.

Single-center experience with the thoratec ventricular assist device☆☆☆

OBJECTIVE The Thoratec ventricular assist device (Thoratec Laboratories, Pleasanton, Calif) is widely accepted for univentricular and biventricular support in patients with various indications. The aim of this study is to describe our experience with implantation of the Thoratec ventricular assist device in more than 100 patients. METHODS From March 1992 to June 1998, 114 patients (98 men and 16 women; mean age, 47.9 years) received the Thoratec ventricular assist device for a mean duration of 44.9 days. The patients were divided into 3 groups. Group 1 included 84 patients in whom the system was applied as a bridge-to-transplant procedure. Group 2 included 17 patients with postcardiotomy cardiogenic shock, and group 3 included 13 patients with cardiogenic shock of other causes. RESULTS Sixty-eight percent of patients in group 1 survived to transplantation with a posttransplant survival of 88%. The only independent risk factor affecting survival was age more than 60 years. Survivals in groups 2 and 3 were 47% and 31%, respectively. Main complications in all groups were bleeding, multiple organ failure, liver failure, sepsis, and neurologic disorders. CONCLUSIONS The Thoratec ventricular assist device has proved to be a reliable device for bridge to transplantation and postcardiotomy support. Further studies are required on patient selection and on patient and device management to reduce the incidence of complications in these patient populations.

Mechanical circulatory support: The Bad Oeynhausen experience

From September 1987 to February 1994, we treated 147 patients ranging between 11 and 82 years old with different mechanical circulatory support systems. The applied devices were the Bio-Medicus centrifugal pump in 61 patients, the Abiomed BVS System 5000 in 49 patients, the Thoratec ventricular assist device in 42 patients, and the Novacor left ventricular assist device in 7 patients. On the basis of indication for mechanical circulatory support, the patients were divided into three groups: group 1 consisted of 72 patients with postcardiotomy cardiogenic shock; group 2, 50 patients in whom mechanical support was used as a bridge to cardiac transplantation; and group 3 (miscellaneous), 25 patients in cardiogenic shock resulting from acute myocardial infarction (n = 14), acute fulminant myocarditis (n = 3), primary graft failure (n = 2), right heart failure after heart transplantation (n = 3), and acute rejection (n = 3). Time of support ranged from 1 hour to 97 days (mean duration, 10.8 days). Seventy-five patients (51%) were discharged from the hospital. The best survival rate was achieved in group 2 with 72%, followed by group 1 with 44% and then group 3 with 28%. The most frequent complications in group 1 were bleeding (44%), multiple-organ failure (24%), neurologic disorders (18%), and acute renal failure (15%). In group 2, the major complications were bleeding (34%) and cerebrovascular disorders (22%) and in group 3, multiple-organ failure and sepsis (60%) and bleeding (32%).

Predictors of survival in patients bridged to transplantation with the Thoratec VAD device: a single-center retrospective study on more than 100 patients

BACKGROUND Careful patient selection markedly influences the outcome of patients who undergo mechanical circulatory support. Therefore, we tried to evaluate predictors of survival after implantation of the Thoratec ventricular assist device (VAD). METHODS Between October 1992 and January 2000, 104 patients (86 men, 18 women, aged 11 to 69 years) received the Thoratec VAD as a bridge to transplant. A total of 51 patients required left ventricular support (LVAD), 50 patients required biventricular support (BVAD), and 3 patients required total artificial heart implantation. We performed univariate analysis of 25 parameters with regard to their effect on survival and then applied a multivariate analysis to evaluate those factors that turned out to be marginally significant. We performed all analysis for the total collective as well as for the LVAD and BVAD sub-group. RESULTS The BVAD patients tended to have worse outcomes than did LVAD patients. We found no significant predictors of survival in either sub-group. In the total collective, however, we found the following pre-implant conditions were independent risk factors for survival after VAD implantation: patient age > 60 years (odds ratio [OR] 3.87, confidence interval [CI] 1.39 to 10.76), pre-implant ventilation (OR, 6.76; CI 2.42 to 18.84), and increased pre-implant total bilirubin (OR, 1.42; CL, 1.19 to 1.69). CONCLUSIONS Transplant candidates on inotropic support should be considered for bridging to transplant as soon as bilirubin values start to increase or before respiratory function deteriorates and ventilation becomes necessary. In elderly patients, careful patient selection, particularly considering potential risk factors, might favorably affect their outcomes.

Preliminary experience with the lionheart left ventricular assist device in patients with end-stage heart failure

BACKGROUND The Arrow LionHeart LVD 2000 left ventricular assist device is the first fully implantable system designed for destination therapy. We report on 2 years of experience with this device, which we implanted for the first time in October 1999. METHODS Since October 1999, 6 male patients between 55 and 69 years of age (mean 65 +/- 6 years) have received the device at our center; all were in New York Heart Association functional class IV and ineligible for heart transplantation. RESULTS All surgical procedures were uneventful, with a timely extubation in 5 of 6 patients. Duration of support was 17 to 670 (mean 245 +/- 138) days, with a cumulative experience of 4.5 years. Three patients recovered to be discharged from hospital under support and are long-term survivors. Three patients died 17, 31, and 112 days after implantation from multiple organ failure without being discharged to their homes. The survival rate is 50% after 18 months. There were no major system-related problems or any device-related infections, which are otherwise commonly found among vertricular assist device patients. CONCLUSIONS Our preliminary experience demonstrates the reliability and efficacy of the different parts of the system. Nevertheless, further sophistication is needed to reduce the size of its components, which so far still constitutes a limiting factor.

The time course of natriuretic hormones as plasma markers of myocardial recovery in heart transplant candidates during ventricular assist device support reveals differences among device types.

BACKGROUND The natriuretic hormones ANP and BNP are expressed differently in the myocardium. Both hormones have compensatory diuretic activity during heart failure. Mechanical stretch of the myocardial walls induces the expression of these hormones. In failing human myocardium, both ANP and BNP are transcribed in the ventricular myocardium in high amounts. We measured the plasma concentrations of ANP and BNP in patients supported by various ventricular assist devices (VADs) at various times. We analyzed the time courses of ANP and BNP to determine (1) the time scale of their down-regulation as a marker of putative myocardial recovery, (2) their steady-state levels under VAD support and (3) differences caused by various VAD devices. METHODS We analyzed ANP and BNP using commercially available radioimmune assays. We analyzed the time courses of patients supported by Thoratec (THO) LVAD (n = 8), TCI Heartmate (TCI) (n = 6), Novacor (NOV) (n = 7), and Lionheart (LIO) (n = 3). RESULTS Patients supported with NOV and some patients with TCI showed down-regulation of BNP to a steady-state level at 30 to 50 days, following a single exponential decay. In contrast, patients supported by THO or LIO did not reveal a determined time course of the natriuretic hormones. Only a few patients reached normal plasma values during VAD support. CONCLUSION The time courses of ANP and BNP differ among VAD types because of construction and/or driving mode, which might be important when considering patients for weaning from VAD without heart transplant.

Temporary pulsatile ventricular assist devices and biventricular assist devices

BACKGROUND During the past years several systems for mechanical circulatory support have become available. In this study we describe our experience with short-term and mid-term application of the ABIOMED and Thoratec device. METHODS Since 1990 the ABIOMED BVS and since 1992 the Thoratec VAD have been applied to 75 and 103 patients, respectively, with postcardiotomy heart failure, as a bridge-to-transplant procedure, and with different other indications. RESULTS In the ABIOMED collective 25 of 50 patients (50%) with postcardiotomy heart failure and 1 of 4 patients with miscellaneous other indications could be discharged from hospital, 7 of 14 bridge-to-transplant patients (50%) underwent transplantation with a posttransplant survival of 86%. In the Thoratec collective 6 of 10 patients (60%) with postcardiotomy heart failure and 4 of 8 patients (50%) with miscellaneous indications could be discharged from hospital, 48 bridge-to-transplant patients (74%) underwent transplantation with a posttransplant survival of 90%. CONCLUSIONS The results show the versatility of the Thoratec VAD for short-term and mid-term application in patients with postcardiotomy heart failure and as a bridge-to-transplant procedure. The use of the ABIOMED device is not indicated for bridging patients to transplantation. Although in case of postcardiotomy heart failure, Thoratec is also superior to ABIOMED, the high costs of the Thoratec VAD limits its wide acceptance in this patient cohort.

Extended donor criteria: use of cardiac allografts after carbon monoxide poisoning.

BACKGROUND An increasing demand for cardiac allografts for the treatment of end-stage cardiac failure has led to a shift in the traditional views about donor criteria. The use of allografts exposed to high concentrations of carbon monoxide is still under discussion. The current literature on this topic is contradictory. We describe our experience with orthotopic cardiac transplantation, using cardiac allografts after carbon monoxide poisoning. METHODS Between March 13, 1989 and August 1, 1996, 770 orthotopic heart transplantations were performed in our center. Within this period, we accepted five cardiac allografts from brain-dead, carbon monoxide-poisoned donors. Donor history showed carbon monoxide intoxication in all cases. At the time of organ explantation, donor hemodynamic parameters were feeble in all patients. RESULTS The postoperative course was uneventful in three of the five recipients. The overall 3-year survival rate in this small group is 40%. Induction therapy or rescue therapy with mono/polyclonal antibodies was not necessary. Myocardial right-ventricular biopsies did not show any specific signs of carbon monoxide poisoning. CONCLUSIONS In our opinion, cardiac allografts from donors exposed to carbon monoxide can be transplanted successfully in infants and adults, if there are no signs of severe hemodynamic dysfunction in the presence of a normal central venous pressure and low-dose support with catecholamines and there are no electrocardiographic changes in combination with elevated transaminase. With extended donor criteria, the hearts of carbon monoxide-poisoned victims could increase the number of suitable organs and lower the death rate of patients on the United Network for Organ Sharing and Eurotransplant International Foundation waiting lists.

MECHANICAL CIRCULATORY SUPPORT AFTER ORTHOTOPIC HEART TRANSPLANTATION

Frequently the only therapy for primary graft- and right heart failure, as well as low output syndrome from acute of chronic rejection, is implantation of a mechanical circulatory support system, until recompensation or retransplantation. At our institution, mechanical assist devices were implanted in 25 heart recipients for a cute rejection (n=9), primary graft failure (n=7), acute right heart failure (n=7), and chronic rejection with low output syndrome (n=2). Patients (pts) with primary graft failure (n=3) received an intraaortic balloon pump (IABP), one pt an IABP plus Abiomed®-System for left ventricular support, one pt the Thoratec®-System for biventricular support. Patients with right heart failure (RHF) received the Biomedicus® centrifugal pump for right ventricular support. Nine pts suffered from acute rejection. Six pts received an IABP, one the Biomedicus® as femoro-femoral bypass, one the Abiomed®-System for biventricular support, two the Thoratec®-System for biventricular support and two within this group switched from the Biomedicus® pump to the Thoratec®-System for biventricular support. Patients with chronic graft failure (n=2) received the Novacor®-System (LVAD) for left ventricular support, one received a Tojobo®-System and an oxygenator for biventricular support post coronary artery bypass surgery. Support time ranged from 0.5-h to 73 days. Five pts were weaned. Two (8%) of 25 pts were retransplanted, 18 (72%) died in spite of mechanical support from multiple organ failure. The use of a mechanical assist device after heart transplantation is encouraging only in the case of early right heart failure, as well as primary and chronic graft failure. In view of the poor results, the use of mechanical assist devices should not be recommended in the case of heart failure caused by acute rejection.