Surgical outcome in 85 patients with primary cardiac tumors

BACKGROUND

We present a large, single institution experience with adult cardiac tumors and address factors affecting outcome.

METHODS

A retrospective review was made of all patients who underwent surgery for primary cardiac tumors from April 1975 through August 2002.

RESULTS

Eighty-five patients (33 male and 52 female) with a mean age of 54 years were identified with follow-up available for 80 (94%) patients. There were 68 (80%) benign tumors and 17 (20%) malignant tumors. Three tumors recurred and were resected giving a total of 88 surgeries. All benign tumors were grossly resected and the extent of resection for malignant disease ranged from 14 (78%) gross resections and 3 (17%) debulkings to 1 (5%) biopsy. There were 4 (5%) early hospital deaths. Median survival was 9.6 months and 322 months for patients with malignant and benign diseases, respectively. Significant predictors of long-term mortality were malignant disease (P <0.0001) and New York Heart Association class (P <0.03).

CONCLUSIONS

Surgical resection provides excellent outcome in patients with benign cardiac tumors. Malignant tumors continue to pose a challenge with good local tumor control but limited survival owing to metastatic disease.

End-stage heart failure with multiple intracardiac thrombi: a rescue strategy

The use of ventricular assist devices as a bridge to transplantation has become a widely used option for patients with end-stage heart failure. In contrast to total artificial hearts, ventricular assist devices support the failing heart by bypassing one or both ventricles. In certain cases (myocardial tumors, graft failure, transplant rejection, endocarditis, intracardiac thrombus formation), however, it may be advantageous to excise the heart and replace it with an artificial device. Total artificial hearts are intracorporeal devices designed for this purpose. Unfortunately, some patients are too small or are, for other reasons, ineligible for a total artificial heart. We describe the case of a 55-year-old woman who had ischemic cardiomyopathy and thrombus formation in all 4 cardiac chambers. To reduce the risk of thromboembolic events, we elected to replace her heart completely with 2 extracorporeal ventricular assist devices. The heart was excised via a median stemotomy approach, and the outflow cannulae (from device to patient) were connected to both atrial remnants. The 2 inflow cannulae (from patient to device) were anastomosed end-to-end to the aorta and the pulmonary artery, respectively. After attaining a flow of more than 5 L, the 2 extracorporeal assist devices effectively and efficiently performed the work of the native heart. Thus re-established, organ perfusion was improved by this mechanically driven circulation, as signified by an initial decrease in creatinine and blood urea nitrogen levels. The patient, however, did not recover from postoperative neurological dysfunction and died of respiratory insufficiency and multiple-organ failure on the 26th postoperative day.

Evidence of improved right ventricular structure after LVAD support in patients with end-stage cardiomyopathy

BACKGROUND

Although many reports demonstrate the hemodynamic benefits of left ventricular assist devices (LVAD) in right-sided circulation, it is not known whether the right ventricular myocardium goes through reverse remodeling after left ventricular mechanical circulatory support. Accordingly, the purposes of our studies were 1). to investigate the right ventricular changes that occur in fibrosis, in cellular hypertrophy, and in intra-myocardial tumor necrosis factor alpha (TNF-alpha) levels in patients receiving LVAD support; and 2). to determine whether the type of LVAD used influences right ventricular myocardial changes.

METHODS AND RESULTS

We measured myocyte size, total collagen content, and TNF-alpha levels using semi-quantitative immunohistochemical analysis of myocardial samples from the right and left ventricles of control and failing myocardia, either supported by 1 of 2 distinct forms of LVADs or without support. We found that when compared with control, although myocyte size was not increased in the right ventricle of failing myocardia (p = not significant), total collagen content and myocardial TNF-alpha levels were decreased in the right ventricle compared with controls (p < 0.01 and p < 0.001, respectively).

CONCLUSION

These data demonstrate that chronic left ventricular unloading with either pulsatile or continuous-flow devices decreases right ventricular total collagen and myocardial TNF-alpha content. We suggest that the decreased fibrosis and normalization of cytokine milieu observed may in part contribute to the recovery of right-sided cardiac function associated with chronic mechanical circulatory support.

New surgical therapies for heart failure

A growing number of patients present with heart failure. Some of them may qualify for surgical correction of their cardiac condition. Since heart transplantation will always be available to only a small number of patients, several new surgical techniques have been developed for approval in heart failure patients. Classic interventions such as revascularization, valve repair, or valve replacement have been improved and modified to meet the need of heart failure patients. Several of these techniques are currently under investigation in large clinical trials. These trials will definitely have an impact on the development of surgical treatment of patients with heart failure.

Patient selection for assist devices: bridge to transplant

Patients in severely progressed states of heart failure can be bridged to successful heart transplantation with mechanical assist devices. Experience has demonstrated that patient selection and timing of device implantation are crucial for obtaining acceptable results when using this expensive technology. The degree of irreversible secondary organ dysfunction before re-establishing adequate cardiac output determines the chance of reaching transplantation. Patients who recover during support from all sequelae of end stage heart failure have an excellent outcome after heart transplantation.

First Turkish experience with the MicroMed DeBakey VAD

Mechanical bridging to cardiac transplantation with a ventricular assist device may be a life-saving procedure for patients with end-stage heart failure. Here we report our 3 cases of patients implanted with the MicroMed DeBakey VAD (ventricular assist device). Three male patients, aged 37, 41, and 40, had end-stage left heart failure due to idiopathic cardiomyopathy and were listed for cardiac transplantation. They had progressive hemodynamic deterioration. Although Patient 1 underwent surgery, after device implantation, for bowel necrosis caused by thromboemboli of unknown origin, heart transplantation was performed 70 days after implantation. Pump thrombosis occurred in Patient 2 on the 120th day. Outflow graft ligation was performed because the patient refused a pump exchange. This patient died on the 25th day after ligation and the 145th day after ventricular assist device implantation. A heparin-coated version of the device was implanted in Patient 3, whose preoperative profound biventricular failure had been improved by inotropic medication and intra-aortic balloon pump support. Successful heart transplantation was performed 161 days after implantation. These are the 1st implantations of a left ventricular assist device in Turkey. From these cases, we have learned that the DeBakey VAD supplies adequate blood flow during the bridging period and, due to its simplicity, portability, and low infection rate, enables discharge of the patient from the hospital. However, preoperative psychological evaluation and postoperative psychological support are important for a successful bridging procedure, as is close observation of coagulation and of pump operation.

Molecular remodelling of dystrophin in patients with end-stage cardiomyopathies and reversal in patients on assistance-device therapy

BACKGROUND

Mutations that lead to disruption of cytoskeletal proteins have been recorded in patients with familial dilated cardiomyopathy. We postulated that changes in cytoskeletal and sarcolemmal proteins provide a final common pathway for dilation and contractile dysfunction in dilated cardiomyopathy. In this study, we investigated the integrity of dystrophin in the myocardium of patients with end-stage heart failure due to ischaemic or dilated cardiomyopathy, and the response to treatment with left-ventricular assistance devices (LVAD).

METHODS

We assessed the expression and integrity of dystrophin in myocardial biopsy samples by immunohistochemistry and western-blot analysis using antibodies against the amino-terminal, carboxyl-terminal, and midrod domains. We took samples from the myocardia of ten controls, ten patients with dilated cardiomyopathy, ten with ischaemic heart disease, and six with dilated cardiomyopathy who underwent placement of a left-ventricular assistance device for progressive refractory heart failure.

FINDINGS

Immunohistochemical staining identified a disruption to the amino-terminus of dystrophin in 18 of 20 patients with end-stage cardiomyopathy (dilated or ischaemic), whereas staining with antibodies against other domains of dystrophin was normal. Western-blot analysis confirmed these observations, suggesting that remodelling of dystrophin is a common pathway for dysfunction of failing cardiomyocytes. Furthermore, this disruption was reversible in four patients after LVAD support.

INTERPRETATION

Dystrophin remodelling is a useful indicator of left-ventricular function in patients with dilated and ischaemic cardiomyopathy. Our results lend support to the hypothesis that changes in cytoskeletal proteins and, in particular, dystrophin might provide a final common pathway for contractile dysfunction in heart failure and these changes might be reversible by reduction of mechanical stress.

Use of a donor heart that had undergone previous cardiac surgery for ASD closure

We report the use of a heart from a 19-year-old female donor who had undergone open heart surgery for closure of an atrial septal defect at the age of 12. The explantation procedure was modified to prevent hemodynamic instability. The recipient, a 59-year-old male with increased pulmonary vascular resistance had an uneventful recovery after transplantation.

Postoperative course of S-100B protein and neuron-specific enolase in patients after implantation of continuous and pulsatile flow LVADs

BACKGROUND

In the early post-operative period after implantation of a continuous flow left ventricular assist device (LVAD) a non-pulsatile flow occurs. We compared the post-operative time-courses of protein S-100B (S100B) and neuron-specific enolase (NSE) as biochemical markers of brain injury in patients after implantation of a continuous flow LVAD and patients receiving a pulsatile flow LVAD.

METHODS

Since 1998 the continuous flow DeBakey VAD has been implanted in 8 patients at our institution. For comparison purposes, a group of 7 consecutive patients in whom a pulsatile Novacor N100 LVAD was implanted were investigated. In both groups cardiopulmonary bypass (CPB) with cardiotomy suction was used. S100B and NSE were measured in serum pre-operatively, 4 hours after CPB, and on days 1, 3, 7, and 14 after implantation of the LVAD. A neurologic examination was performed pre-operatively and post-operatively on days 3 and 14.

RESULTS

No differences were found between groups in pre-operative characteristics. The analysis of variance with repeated measurements for S-100B and NSE showed significant time effects (p = 0.004, p = 0.009, respectively) but no group effects (p = 0.06, p = 0.26, respectively) and no interaction between groups and time (p = 0.12, p = 0.48, respectively). The pre-operative serum level of S100B was significantly higher (p = 0.03) in the DeBakey VAD group. The pre-operative serum level of NSE was similar in the 2 groups (p = 0.7). In both groups there was a significant increase of S100B and NSE immediately after surgery (S100B: p = 0.006, p = 0.019; NSE: p = 0.01, p = 0.001). The values returned to pre-operative levels in the DeBakey VAD group on day 1 after implantation and in the Novacor group for S100B on day 3 and NSE on day 1. Post-operatively the mean values of S100B and NSE in the DeBakey VAD group compared with the Novacor group were significantly elevated only on day 3 (p = 0.005, p = 0.023).No neurologic complications were noted in patients with a continuous flow LVAD, whereas in the pulsatile LVAD group 2 patients presented neurologic abnormalities during the study period.

CONCLUSIONS

The similar course of biochemical markers of brain damage in both groups may indicate that the non-pulsatile flow in the early post-operative period does not lead to increased brain injury or permeability of the brain blood barrier.Elevated levels of S100B and NSE in the post-operative period can be used as diagnostic markers of brain injury in patients after implantation of both types of LVAD.

Cardiac hypertrophy after transplantation is associated with persistent expression of tumor necrosis factor-alpha

BACKGROUND

The mechanisms that contribute to cardiac allograft hypertrophy are not known; however, the rapid progression and severity of hypertrophy suggest that nonhemodynamic factors may play a contributory role. Tumor necrosis factor-alpha (TNF-alpha) is a cytokine produced in cardiac allografts and capable of producing hypertrophy and fibrosis; therefore, we suggest that TNF-alpha may play a contributory role. Accordingly, the aims of our study were to define the role of systemic hypertension in the development of hypertrophy, characterize the histological determinants of hypertrophy, and characterize the expression of myocardial TNF-alpha after heart transplantation.

METHODS AND RESULTS

To separate the effect of hypertension from immune injury in the development of cardiac allograft hypertrophy, we measured the gain in left ventricular mass by 2D echocardiography in heart transplant recipients and lung transplant recipients who developed similar rates of systemic hypertension. The gain in left ventricular mass was 73% in heart transplant recipients and 7% in lung transplant recipients (P<0.0001). By comparing myocardial samples obtained during the first week after transplant and at 1 year, we found that there was a significant increase in total collagen content (P<0.0001), collagen I (P<0.0001), collagen III (P<0.0001), and myocyte size (P<0.0001). These changes were associated with persistent myocardial TNF-alpha expression.

CONCLUSIONS

We suggest that the contribution of hypertension to cardiac allograft hypertrophy is minimal and that persistent intracardiac expression of TNF-alpha may contribute to the development of cardiac allograft hypertrophy.

Transcranial Detection of Microembolic Signals in Patients with a Novel Nonpulsatile Implantable LVAD

Mechanical ventricular assist devices (VAD) have become an accepted therapy for the support of patients in severe heart failure. With the devices presently available, the incidence of thromboembolic complications is high. Since November 1998, we have used the DeBakey VAD (MicroMed, Inc., Woodlands, TX). To detect the effect of this VAD on the appearance of microthrombi or bubbles from cavitation, we measured Microembolic Signals (MES) with transcranial Doppler in patients after the implantation of the DeBakey VAD. Transcranial Doppler studies were performed with the MULTI-DOP X4 device with two 2 MHz probes (for the left and right middle cranial arteries [MCA]) in five patients preoperatively and during 10 weeks after VAD implantation. Both MCAs were monitored simultaneously for 60 minutes in 10 sessions in each patient. The detection and analysis of MES was performed in accordance with the technique and criteria described by the international consensus group. No MES were noted during the study period in four patients. In one patient with preoperatively noted MES the prevalence of MES postoperatively was 50%. The high speed rotating impeller of the DeBakey VAD did not produce any detectable microthrombi or bubbles from cavitation effects.

Complications Common to Ventricular Assist Device Support Are Rare with 90 Days of DeBakey VAD® Support in Calves

The DeBakey VAD is a miniaturized, electromagnetically driven axial flow pump intended for long-term ventricular assist. Safety and performance data from six calves implanted with the complete DeBakey VAD system are reported elsewhere; here we describe complications and necropsy findings for these same six animals, all of which survived 90 days. The study was conducted according to a uniform protocol, which included anticoagulation and antibiotic prophylaxis. Clinical complications tracked included bleeding, cardiovascular abnormalities (e.g., arrhythmias, tachycardia unrelated to pain, bradycardia), hemolysis, hepatic dysfunction, renal dysfunction, thromboembolism (neurologic or peripheral), or infection. Each adverse event was retrospectively categorized with regard to severity (mild, moderate, severe) and relationship to device. Clinical findings were confirmed by necropsy. There was no evidence of systemic infection, thromboembolism, hemolysis, or renal or hepatic dysfunction in these six animals during the study period. A single adverse event was noted in each of two of the calves. Both events were considered mild according to the predefined criteria. Bleeding related to the surgical implantation procedure and requiring reoperation occurred in one animal. The other animal had evidence of a superficial infection at the exit site of the cables on the left lateral thoracic wall; the infection did not extend into the thoracic cavity. Chronic, healed small renal infarct scars were present in several animals. Mild valvular endocardiosis was observed in two calves and mild fibroelastosis was present in the endocardium at the site of the inflow cannula in three calves; however, these lesions were not considered clinically significant. No other gross or histologic abnormalities were noted at necropsy. In conclusion, calves implanted with the complete DeBakey VAD for 90 days demonstrated few complications and had no significant necropsy findings. Complications common to ventricular assist device (VAD) support (i.e., hemolysis, infection, bleeding, thromboembolism) were rare during long-term support (90 days) with the DeBakey VAD.

Inflammatory Response after Implantation of a Left Ventricular Assist Device: Comparison between the Axial Flow MicroMed DeBakey VAD and the Pulsatile Novacor Device

The implantation of a ventricular assist device (VAD) is associated with a stimulation of the inflammatory system. We compared changes in the inflammatory response after implantation of a pulsatile Novacor left (L) VAD and the axial flow MicroMed DeBakey VAD. Six consecutive patients after implantation of a Novacor LVAD (NC) and six patients after implantation of a MicroMed DeBakey VAD (MD) were included in the investigation. Patients received LVADs for medically non treatable end-stage heart failure. Tumor necrosis factor alpha (TNF), C3a, C5a, interleukin 6 (IL-6), and neutrophil elastase were measured twice a week over a period of 3 months after implantation of the device. All tests were performed with an enzyme-linked immunosorbent assay. There was no significant difference in the clinical course of the two groups. All inflammatory parameters were elevated in both groups during the entire period of the investigation. There was no difference in TNF, polynuclear leukocyte elastase, or C3a levels between the two groups; however, IL-6 (NC: 23.6+/-37.6 pg/ml vs. MD: 63+/-114 pg/ml, p < 0.001) and C5a (NC: 708+/-352 microg/L vs. MD: 1,745+/-1,305 microg/L, p < 0.001) were increased significantly more in patients following implantation of the axial flow MicroMed DeBakey VAD. Compared with the pulsatile Novacor device, the implantation of the axial flow MicroMed DeBakey LVAD seems to be associated with an increased stimulation of one part of the inflammatory system. Further investigations are necessary for evaluation of the pathophysiologic mechanism and clinical implications of these findings.

New strategies for the management of acute decompensated heart failure

Acute heart failure in adults is the unfolding of heart failure in minutes, hours or a few days. Low output heart failure describes a form of heart failure in which the heart pumps blood at a rate at rest or with exertion that is below the physiological range and the metabolizing tissues extract their required oxygen from blood at a lower rate, causing a proportionately smaller oxygen amount remaining in the blood. Therefore, a widened arterial-venous oxygen difference occurs. High output heart failure is characterized by pumping blood with a rate above the physiological range at rest or during exertion, resulting in an arterial-venous oxygen difference, which is normal or low. This may be caused by peripheral vasodilatation during sepsis or thyrotoxicosis, blood shunting, or reduced blood oxygen content/viscosity (Fig. 1). The differentiation between low output heart failure versus high output heart failure is of highest importance for the choice of therapy and therefore the information and the monitoring of the systemic vascular resistance. Patients who present with acute heart failure suffer from a severe complication of different cardiac disorders. Most often they have an acute injury that affects their myocardial performance (eg, myocardial infarction) or valvular/chamber integrity (mitral regurgitation, ventricular septal rupture), which leads to an acute rise in left-ventricular filling pressures resulting in pulmonary edema.

Regression of fibrosis and hypertrophy in failing myocardium following mechanical circulatory support

BACKGROUND

The cellular and structural changes that occur during long-term ventricular unloading leading to cardiac recovery are poorly understood. However, we have previously demonstrated that left ventricular assist device (LVAD) support leads to a significant decrease in intracardiac tumor necrosis factor-alpha (TNF-alpha), a protein capable of producing hypertrophy and fibrosis.

METHODS

To further define the beneficial effects of long-term ventricular unloading on cardiac function, we determined the effect of mechanical circulatory support on fibrosis and hypertrophy in paired myocardial samples of 18 patients with end-stage cardiomyopathy obtained at the time of LVAD implantation and removal.

RESULTS

We determined total collagen as well as collagen I and III by a semiquantitative analysis of positive immune-stained areas in pre- and post-LVAD myocardial samples. We found that total collagen content was reduced by 72% (p < 0.001), whereas collagen I content decreased by 66% (p < 0.001) and collagen III content was reduced by 62% (p < 0.001). Next, we determined myocyte size by direct analysis of cellular dimensions utilizing a computerized edge detection system in pre- and post-LVAD myocardial samples. We found that myocyte size decreased in all patients studied for an average reduction of 26% (33.1 +/- 1.32 to 24.4 +/- 1.64 microm, p < 0.001).

CONCLUSION

These data demonstrate that long-term mechanical circulatory support significantly reduces collagen content and decreases myocyte size. We suggest that the reduction of fibrosis and hypertrophy observed may in part contribute to the recovery of cardiac function associated with long-term mechanical circulatory support.

Clinical experience with the MicroMed DeBakey ventricular assist device

BACKGROUND

The MicroMed DeBakey ventricular assist device (VAD) (MicroMed Technology, Inc, Houston, TX) is the first long-term axial flow circulatory assist device to be introduced into clinical trials as a bridge to transplantation. Clinical trials began in Europe in November 1998 and in the United States in June 2000.

METHODS

To qualify for the study, the patients must be listed for cardiac transplantation and must have demonstrated profound cardiac failure. There were no exclusions to the MicroMed DeBakey VAD implant other than those patients who would typically be excluded from cardiac transplantation.

RESULTS

As of September 2000, 51 patients have been implanted with the MicroMed DeBakey VAD. A detailed evaluation of the first 32 patients has been completed. With current data, the probability of survival at 30 days after VAD implant is 81%.

CONCLUSIONS

The clinical trial demonstrated that the MicroMed DeBakey VAD is capable of providing adequate circulatory support in patients with severe heart failure, sufficient to recover and return to normal activities while awaiting a heart transplantation. Much has been learned about the function of the device and its continuous flow in humans.