Showing papers by "Dale G. Renlund published in 1996"

Improved long-term survival after heart transplantation predicted by successful early withdrawal from maintenance corticosteroid therapy.

Abstract: Background : Short-term studies suggest that cardiac transplant immunosuppression without maintenance corticosteroids is feasible in selected patients. However, concern exists as to the long-term effects, specifically the possibility of increased morbidity and mortality because of late allograft rejection and allograft coronary artery disease. Methods : We retrospectively reviewed the records from 441 consecutive heart transplantation procedures done in 416 patients with use of an immunosuppressive protocol that attempted corticosteroid withdrawal within 2 months of transplantation. Forty-two patients died or underwent retransplantation during the first 3 months and were excluded from further analysis. Analysis focused on demographic and long-term outcome variables (including death, rejection, retransplantation, and infection). Results : Thirty percent (111) of eligible patients (374) met the definition of successful early steroid withdrawal. Only male gender independently predicted successful withdrawal. Mortality, both short and long term, was significantly lower in patients in whom successful early withdrawal from corticosteroids was achieved than in patients in whom the early attempts failed (1.7% per year versus 4.7% per year ; p < 0.0001). The prevalence of late acute allograft rejection (more than 1 year after transplantation) was lower in patients successfully withdrawn from steroid therapy early after transplantation (0.07 pt-yr of follow-up versus 0.15 pt-yr ; p = 0.002). Multivariate analysis of the entire group identified incidence of infection (p = 0.001), older age (p = 0.001), failed early steroid withdrawal (p = 0.006), and female gender (p = 0.016) as independent predictors of mortality. Conclusions : Successful early corticosteroid withdrawal identifies a subgroup of immunologically privileged patients with a low risk for long-term mortality and is not associated with an increased prevalence of late rejection or clinically significant coronary artery disease.

Exercise capacity after heart transplantation: influence of donor and recipient characteristics.

Abstract: Background : For incompletely understood reasons, cardiac transplant recipients achieve only 60% to 70% of predicted values for maximal exercise capacity. The objective was to determine the characteristics of cardiac transplant recipients that are predictive of exercise capacity. Methods : One hundred ten patients underwent maximal exercise testing using a modified Naughton protocol 26 ± 1 months after transplantation. Recipient characteristics, resting hemodynamic variables and exercise parameters were compared using univariate and multivariate analyses. Results : The average maximum heart rate was 85% of predicted, and the average peak oxygen consumption (Vo 2 ) was 17.7 ± 0.3 ml/kg/min (64% of predicted). Pretransplant status, etiology of heart failure, ischemic time, degree of HLA disparity, cumulative corticosteroid exposure, and number of rejection episodes failed to correlate with any exercise parameter. Older recipient age and female gender were associated with greater values for the proportion of the predicted peak Vo 2 (p < 0.001 for age ; p = 0.001 for gender). Older donor age was the strongest independent predictor of a decreased chronotropic response (p < 0.001) and was a weak predictor of decreased peak Vo 2 (p = 0.014). Even in the multivariate analysis, maintenance prednisone dose negatively impacts exercise duration (p = 0.05), peak Vo 2 (p = 0.035) and percent of predicted peak Vo 2 (p = 0.032). Of all characteristics tested, pulmonary vascular resistance within 24 hours of exercise most powerfully predicts exercise duration (p = 0.002) and peak Vo 2 (p = 0.001). Conclusions : Female recipients and older recipients have a lower absolute exercise capacity, but achieve a greater proportion of their predicted capacity. Recipients of older donor hearts and those receiving chronic corticosteroids have decreased exercise capacity. Pulmonary vascular resistance is inversely correlated with exercise capacity.

Mycophenolate mofetil (MMF) in heart transplantation: rejection prevention and treatment.

Abstract: Mycophenolate mofetil (MMF), the morpholinoethylester of mycophenolic acid, inhibits the de novo pathway for purine synthesis. Evidence suggests that MMF suppresses lymphocyte function more than that of neutrophils, erythrocytes, and other rapidly dividing cell lines that can utilize salvage pathways for purine synthesis. While rigorous efficacy data await the completion of an ongoing, multicenter, prospectively randomized, placebo-controlled trial, long-term safety data are, however, available from numerous uncontrolled trials in cardiac transplantation. Dose-ranging trials in 49 heart recipients suggest that doses > or = 4000 mg/d are associated with significant, reversible gastrointestinal toxicity when compared with doses or = 1000 mg/d may have fewer rejection episodes. Even in the long term, changing from azathioprine to MMF is associated with increases in hematocrit (p < 0.001), total WBC count (p < 0.005), and absolute neutrophil count (p < 0.005). Successful use of MMF in refractory cardiac allograft rejection suggests an advantage over azathioprine. MMF is safe and appears to be at least as effective as azathioprine for immunosuppression following heart transplantation.

The repetitive histologic pattern of vascular cardiac allograft rejection. Increased incidence associated with longer exposure to prophylactic murine monoclonal anti-CD3 antibody (OKT3).

Abstract: While vascular cardiac allograft rejection increases morbidity and mortality following transplantation, factors predisposing to its development have not been completely elucidated. To evaluate the influence of the duration of early rejection prophylaxis with the murine monoclonal anti-CD3 antibody (OKT3) on the development of a repetitive histologic pattern of vascular cardiac allograft rejection, endomyocardial biopsies from 344 heart transplant recipients were prospectively evaluated. The influence of clinical characteristics was assessed. Eighty-three patients (24%) developed and 261 patients (76%) did not develop a repetitive histologic pattern of vascular cardiac allograft rejection. The vascular rejection pattern was more common in patients with a positive crossmatch (89% versus 11%, P<0.0001) and OKT3 sensitization (73% versus 27%, P<0.0001), and was positively correlated with the duration of OKT3 treatment (P<0.0001). The correlation persists even after excluding patients with a positive crossmatch or OKT3 sensitization. Patients developing a repetitive histologic pattern of vascular cardiac allograft rejection early after transplantation had decreased allograft survival (P=0.0008). The development of a repetitive histologic pattern of vascular cardiac allograft rejection is positively correlated with the duration of OKT3 treatment. Judicious use of OKT3 in early rejection prophylaxis in cardiac transplantation is warranted.

Cyclophosphamide in cardiac transplant recipients with frequent rejection: a six-year retrospective review.

Abstract: Allograft rejection remains a major cause of morbidity and mortality. Cyclophosphamide, a nitrogen mustard, is a potent immunosuppressive agent with effects on both T- and B-lymphocytes, and thus may be effective in preventing further cellular and/or humoral rejection in cardiac transplant recipients with recurrent or recalcitrant rejection. We retrospectively reviewed the records of 320 surviving cardiac transplant recipients. Cyclophosphamide was substituted for azathioprine in 28 patients because of frequent allograft rejection. We then reviewed the rejection history of these 28 patients, specifically looking at rejection frequency, type (cellular, vascular or mixed), and treatment. Cyclophosphamide was substituted for azathioprine at an average of 8.4 +/- 2.8 months after transplantation. Despite a 56.0% reduction in prednisone dose (p < 0.001), at least a threefold reduction in rejection frequency (p < 0.001) was observed, while cyclosporine levels were unchanged. Twenty-eight percent of the patients did not experience even mild rejection after beginning therapy with cyclophosphamide, 55% had 1 or 2 subsequent mild or moderate rejection episodes, and only 17% had more than two subsequent episodes of mild or moderate rejection. Overall, the number of treated rejection episodes decreased from 0.37 episodes per patient month with azathioprine to 0.10 episodes per patient month on therapy with cyclophosphamide. Separating the patients into two groups based on the predominant rejection type (cellular vs. vascular) occurring at the time of cyclophosphamide substitution revealed a similar reduction in cellular and vascular rejection in each respective group. While white blood cell count decreased by 16%, cyclophosphamide was not discontinued in any patient due to leukopenia, and no change was noted in hematocrit. Cyclophosphamide appears to be safe and effective in maintenance immunosuppression and may reduce rejection frequency in some patients with frequently occurring allograft rejection without necessitating the augmentation of either corticosteroids or cyclosporine.

New Pharmacologic Immunosuppressive Agents

Abstract: The wizardry necessary for the management of existing nonselective drug regimens recalls the dances, chants and songs practiced by the Babylonians in accord with their concepts of numerology, astrology and fetishism.