Biomedical subjects

H G Fieguth

Publications and source records attributed to H G Fieguth.

78 records · Page 5Linked to original sources

PubMedDate not supplied

Treatment of rejection after heart transplantation: what dosage of pulsed steroids is necessary?

Histologically proved rejection after heart transplantation is commonly treated with intravenous steroids, 1 gm/day for 3 days. This regimen may result in severe side effects, however, both metabolic and infectious. In a total of 663 rejection episodes, we treated 397 with conventional steroid therapy, 1000 mg per day for 3 days (group 1), 199 with 500 mg/day for 3 days (group 2), and 67 with 250 mg/day for 3 days (group 3). Response to treatment was assessed by control biopsy after 1 week and graded as ongoing, resolving, or resolved rejection. The efficacy of the three regimens showed no significant differences between the groups as determined by the results of the subsequent biopsy. Ongoing rejection, resolving rejection, and resolved rejection, respectively: group 1-3.3%, 66.5%, 30.2%; group 2-8.0%, 66.8%, 25.2%; group 3-4.5%, 73.1%, 22.4%. We conclude that comparable effects, even with a considerable reduction of pulsed steroids, may be obtained in the treatment of cardiac allograft rejection, if triple-drug immunosuppression is used for maintenance therapy. It seems likely that steroid side effects may be decreased without jeopardizing the graft.

Adult↗

PubMedDate not supplied

Early graft failure after heart transplantation: management by extracorporeal circulatory assist and retransplantation.

Early graft failure represents a serious complication after orthotopic heart transplantation. Various modes of extracorporeal mechanical circulatory assistance, however, allow for "bridging" to heart retransplantation in these instances. We report a case of bridging to heart transplantation by means of intraaortic balloon counterpulsation. After transplantation a right ventricular assist device was required because of early graft failure while the intraaortic balloon pump was left in place. A retransplantation was successful, and 13 months after the operation the patient is in New York Heart Association functional class I. The cause of early graft failure, especially the tendency toward failure of the right ventricle, is not well understood and seems to be multifactorial, which suggests that an elevated pulmonary vascular resistance in the recipient possibly represents a considerable risk factor. Bridging to heart retransplantation with the use of extracorporeal blood pumps can be performed effectively.

Assisted Circulation↗

PubMedDate not supplied

Flush perfusion using Euro-Collins solution vs cooling by means of extracorporeal circulation in heart-lung preservation.

Single-flush perfusion using modified Euro-Collins solution and donor cooling by extracorporeal circulation represent two concepts of lung preservation currently in use for on-site heart-lung transplantation. The question of which technique is better for safe clinical application of heart-lung transplantation, including extended periods of ischemia and distant organ procurement, currently remains undetermined. Eighteen mongrel dogs, divided in three groups, underwent left lung, heterotopic heart transplantation, leaving the right lung and heart of the recipient in place. Donor organs were obtained from size-matched dogs. In all groups, myocardial preservation was achieved using 10 ml/kg cold potassium cardioplegia. Following flush perfusion of the lung (Euro-Collins solution, 60 ml/kg), six dogs were immediately transplanted (group I). Using the same preservation, organs were stored for 6 hours at 4 degrees C in group II. In group III, organs were cooled using extracorporeal circulation until reaching a rectal temperature of 16 degrees C, harvested, and thereafter stored as in group II. After transplantation, blood supply of the donor heart was assured by selective drainage of the superior vena cava into the right side of the donor heart. Outflow was obtained by end-to-side anastomosis of donor and recipient aorta. The dogs were kept anesthetized, and both lungs were ventilated selectively with an FiO2 of 0.4 for 20 hours or until death. During the postoperative course, the donor heart pumped about one third of the entire cardiac output in all groups. The lowest pulmonary vascular resistance of the transplanted lung was observed in group III. Oxygenation of the transplanted lung revealed no impairment in group I compared with the pretransplant values. By contrast, groups II and III showed a slight decrease of oxygenation within acceptable limits. We therefore conclude that both methods of cardiopulmonary preservation evaluated may allow for an extended ischemic time of up to 6 hours before heart-lung transplantation. Pulmonary vascular resistance was significantly lower in the group preserved by extracorporeal circulation, possibly reflecting superior preservation of lung function by this method.

Animals↗

PubMedDate not supplied

Cytoimmunologic monitoring in early and late acute cardiac rejection.

The absolute concentration of circulating lymphoblasts and prelymphoblasts has been shown repeatedly to closely correlate with acute cardiac rejection in heart transplant recipients. Little information, however, is available with respect to the reliability of this measurement in the late postoperative course. Fifty-two heart transplant recipient operated on from October 1985 through September 1986 were studied with cytoimmunologic monitoring for lymphocyte activation in peripheral blood. Immunosuppressive therapy consisted of azathioprine, cyclosporine, and steroids. Endomyocardial biopsies were obtained at regular intervals. Cytoimmunologic monitoring was performed daily during hospitalization and together with endomyocardial biopsy at outpatient visits. A total of 768 endomyocardial biopsies and 1077 mononuclear concentrates for study of lymphocyte activation were obtained. Concentration of activated cells showed a significant increase during acute rejection. Cytoimmunologic monitoring had an overall sensitivity of 76% and a specificity of 79%. Within 90 days after transplantation cytoimmunologic monitoring showed a sensitivity of 84%, which decreased to 71% beyond 3 months. We therefore conclude that cytoimmunologic monitoring, a noninvasive adjunct for diagnosis of acute allograft rejection, cannot replace routine endomyocardial biopsy, particularly in view of a significant loss in sensitivity in the late postoperative course.

Adolescent↗

PubMedDate not supplied

Changes of the intramyocardial electrogram after orthotopic heart transplantation.

Heart transplantation, including conventional immunosuppression, has allowed the use of the surface electrocardiogram to detect allograft rejection. With the use of cyclosporine this parameter is no longer sensitive, but voltage of the intramyocardial electrogram has correlated repeatedly with rejection. From July 1983 through February 1986, 98 patients had heart transplantation; 13 of those patients had a telemetry pacemaker simultaneously implanted. In previous studies, daytime dependent variabilities of the sum voltage of the surface electrocardiogram were reported. Therefore intramyocardial electrogram was measured at 7, 10, 13, 16, and 20 hours. In addition, the influence of exercise on intramyocardial electrogram voltage was studied in all patients. Analysis of the diurnal intramyocardial electrogram revealed substantial atrial and ventricular variability of both voltage measurements (p less than 0.05). Also, intramyocardial electrogram voltage was influenced by exercise, as demonstrated by a significant decrease after physical work at 25 W (-8%) and 50 W (-12%); p less than 0.05. Therefore we conclude that a high variability of intramyocardial electrogram may be found diurnally and on exercise testing after heart transplantation in humans. If intramyocardial electrogram is used to detect rejection, it should be applied at comparable hours and with the patients in a controlled resting state.

Adolescent↗

PubMedDate not supplied

Preventive treatment of coronary vasculopathy in heart transplantation by inhibition of smooth muscle cell proliferation with angiopeptin.

BACKGROUND: The underlying mechanism of accelerated coronary vasculopathy in cardiac allografts still remains unclear. Our hypothesis was that inhibition of smooth muscle cell proliferation with the somatostatine analogue Angiopeptin may reduce vasculopathy. METHODS: Fifty-four patients received Angiopeptin injections (1500 micrograms x three times daily subcutaneously) for 21 days after the operation and three additional injections with every rejection treatment. Angiography was performed yearly, and data were compared with a matched historic control group. RESULTS: Actuarial survival was 85% at 1 year and 80% at 2 years, comparable with our results in general (80%/77%). Forty-six long-term survivors could be followed by coronary angiography. At 1 year, vasculopathy was assessed in nine patients (17%). Of the 18 patients investigated at 2 years thus far, an additional three patients were found to have vasculopathy. In the control group vasculopathy was comparable, being 13% after 1 year and 20% after 2 years. A significantly lower incidence of rejections and lower creatinine values were found in the study group within the entire observation period (p < 0.05). CONCLUSIONS: We conclude that Angiopeptin treatment appears to be safe without significant side effects; it may reduce the number of acute rejections, at least during the first year after heart transplantation. However, the results of the 2-year follow-up in the remaining patients would have to be included in assessing the effect of Angiopeptin. Long-term follow-up will be necessary to decide whether Angiopeptin will be helpful in reducing the incidence of transplant vasculopathy.

Actuarial Analysis↗