Early introduction of HMG-CoA reductase inhibitors could prevent the incidence of transplant coronary artery disease.
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Biomedical subjects
Publications and source records attributed to S A Hunt.
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BACKGROUND: A comminuted, intra-articular distal femur fracture was surgically treated by the authors with a locked, double-plating technique because fixation stability could not be initially achieved by using a standard double-plating technique. The purpose of this study was to determine biomechanically whether a locked double-plate construct would enhance fixation stability compared with a nonlocked double-plate construct. METHODS: Six matched pairs of mildly osteopenic femurs were selected and all had a reproducible intra-articular fracture pattern created. Each pair underwent fixation with either a double-plating construct or a locked, double-plating construct that was randomly assigned. The instrumented femurs were then mechanically tested in several loading modes to determine fixation stability. After initial testing, specimens were cyclically loaded and retested for stability. RESULTS: The locked, double-plating construct provided significantly greater fixation stability than the standard double-plating construct in precycling and postcycling biomechanical testing. CONCLUSION: The technique described is particularly applicable for severely comminuted fractures of the distal femur and fractures in osteopenic bone with poor screw purchase. It offers a simple alternative for enhancing fixation stability, which avoids the potential complications of methylmethacrylate-enhanced screw fixation.
BACKGROUND: Coronary artery disease occurs in an accelerated fashion in the donor heart after heart transplantation (TxCAD), but the cause is poorly understood. The risk of developing TxCAD is increased by cytomegalovirus (CMV) infection and decreased by use of calcium blockers. Our group observed that prophylactic administration of ganciclovir early after heart transplantation inhibited CMV illness, and we now propose to determine whether this therapy also prevents TxCAD. METHODS AND RESULTS: One hundred forty-nine consecutive patients (131 men and 18 women aged 48+/-13 years) were randomized to receive either ganciclovir or placebo during the initial 28 days after heart transplantation. Immunosuppression consisted of muromonab-CD3 (OKT-3) prophylaxis and maintenance with cyclosporine, prednisone, and azathioprine. Mean follow-up time was 4.7+/-1.3 years. In a post hoc analysis of this trial designed to assess efficacy of ganciclovir for prevention of CMV disease, we compared the actuarial incidence of TxCAD, defined by annual angiography as the presence of any stenosis. Because calcium blockers have been shown to prevent TxCAD, we analyzed the results by stratifying patients according to use of calcium blockers. TxCAD could not be evaluated in 28 patients because of early death or limited follow-up. Among the evaluable patients, actuarial incidence of TxCAD at follow-up (mean, 4.7 years) in ganciclovir-treated patients (n=62) compared with placebo (n=59) was 43+/-8% versus 60+/-10% (P<0.1). By Cox multivariate analysis, independent predictors of TxCAD were donor age >40 years (relative risk, 2.7; CI, 1.3 to 5.5; P<0.01) and no ganciclovir (relative risk, 2.1; CI, 1.1 to 5.3; P=0.04). Stratification on the basis of calcium blocker use revealed differences in TxCAD incidence when ganciclovir and placebo were compared: no calcium blockers (n=53), 32+/-11% (n=28) for ganciclovir versus 62+/-16% (n=25) for placebo (P<0.03); calcium blockers (n=68), 50+/-14% (n=33) for ganciclovir versus 45+/-12% (n=35) for placebo (P=NS). CONCLUSIONS: TxCAD incidence appears to be lower in patients treated with ganciclovir who are not treated with calcium blockers. Given the limitations imposed by post hoc analysis, a randomized clinical trial is required to address this issue.
BACKGROUND: The experience with 30 years of cardiac transplantation at Stanford University Medical Center was reviewed. A total of 954 transplants were performed in 885 patients. Patients were divided into 3 groups based on immunosuppression received: group I, no cyclosporine (INN: ciclosporin) (n = 201) (January 1968-November 1980); group II, cyclosporine (n = 248) (December 1980-June 1987); and group III, cyclosporine + OKT3 (n = 436) (July 1987-March 1998). RESULTS: The 1-, 5-, and 10-year actuarial survivals were 68%, 41%, and 24% (group I); 80%, 57%, and 37% (group II); and 85%, 68%, and 46% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from rejection were 8%, 12%, and 14% (group I); 5%, 7%, and 7% (group II); and 2%, 5%, and 5% (group III) (I vs II, P = not significant; I vs III, P <.005; and II vs III, P <.005). The 1-, 5-, and 10-year actuarial death rates from infection were 25%, 43%, and 50% (group I); 8%, 17%, and 29% (group II); and 6%, 11%, and 16% (group III) (I vs II, P <.005; I vs III, P <.005; and II vs III, P <.05). The 1-, 5-, and 10-year actuarial death rates from graft coronary artery disease were 0%, 5%, and 13% (group I); 0%, 12%, and 19% (group II); and 1%, 6%, and 9% (group III) (I vs II, P <.01; I vs III, P <.005; and II vs III, P = not significant). There have been 69 retransplants in 67 patients with 1-, 5-, and 10-year actuarial survivals of 49%, 27%, and 15%, respectively. CONCLUSIONS: The evolution of 3 decades of experience with cardiac transplantation has resulted in improved overall survival. The incidence of rejection and of death from infection and graft coronary artery disease have decreased over time, primarily as a result of improvements in immunosuppression and in the prevention and treatment of infection. Continued advances in perioperative management and the development of more specific, less toxic immunosuppressive agents could further refine this initial experience and improve the survival and quality of life of patients after cardiac transplantation.
Cardiac transplantation, first introduced 30 years ago, has become a widely used and increasingly important procedure for treatment of truly end-stage heart disease. Current use is limited strictly by donor supply, making selection of appropriate recipients an important ethical and societal issue. Survival rates after transplantation rose in the 1980s with the use of cyclosporine and have remained relatively consistent since then, although recipients older than 65 years or younger than 1 year have lower survival rates than recipients of other ages. Although immunosuppressive drugs have helped establish cardiac transplantation as a successful procedure, risks of opportunistic infection and rejection, as well as coronary arteriopathy, have led to development of new immunosuppressive agents currently under study. Future alternatives to the current technology of cardiac allotransplantation may include xenotransplantation and/or nonbiological replacement of the heart with mechanical devices.
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PURPOSE: To evaluate the short and long-term effects of total lymphoid irradiation (TLI) in the treatment of cardiac transplant rejection. METHODS AND MATERIALS: Between 1986 and 1995, 48 courses of TLI were delivered to 47 cardiac transplant patients. In 37 patients, TLI was administered for intractable allograft rejection despite conventional therapy while 10 patients received TLI prophylactically. The prescribed radiation dose was 8 Gy in 0.8 Gy fractions twice weekly to mantle and inverted-Y plus spleen fields. Postirradiation follow-up ranged from 6 months to 9.1 years, with a mean of 3.1 years. RESULTS: The actual mean dose was 7.3 Gy delivered over a mean of 39 days. Fifty-six percent of patients required treatment delay or abbreviation because of thrombocytopenia, leukopenia, infection, or unrelated problems. In patients treated for intractable rejection, rejection rates dropped from 0.46 to 0.14 and to 0.06 episodes/patient/month before, during, and after TLI (p < 0.0001). Rejection rates continued to drop throughout follow-up. Prednisone requirements decreased from 0.41 mg/kg before treatment to 0.21 mg/kg afterward (p < 0.0001). The ratio of helper to cytotoxic-suppressor T-cells decreased during TLI from 1.33 to 0.89, and remained low at 0.44, 2-4 months after treatment. Infection rates were not increased and two patients developed malignancy. Rejection rates were high during prophylactic treatment and this protocol was abandoned. Three-year actuarial survival after irradiation was 60% for patients with intractable rejection and 70% for the prophylactic cohort. CONCLUSION: TLI is an effective treatment for control of intractable cardiac rejection. Episodes of rejection and steroid dosage requirements are decreased for up to 9.1 years. A possible mechanism of action is long term alteration in T-lymphocyte subsets. Patients experience transient bone marrow suppression but no increase in infection or bleeding. Long-term complications of TLI are not appreciably different than conventional immunosuppression.
OBJECTIVES: This study assessed the influence of donor age and preexisting donor coronary disease on the later development of allograft coronary artery disease, ischemic events and overall survival. BACKGROUND: The increasing demand for heart donors has led to a tendency to liberalize age criteria for donor acceptability. METHODS: A total of 233 consecutive heart transplant recipients who had baseline, early postoperative and follow-up coronary angiograms, as well as a subset of 47 patients with baseline intracoronary ultrasound imaging recordings, were analyzed (mean 3.8 years of follow-up). Patients were subclassified according to the presence of donor coronary artery disease on the baseline angiogram and stratified at age 40 years. RESULTS: patients without evidence of preexisting coronary artery disease on a baseline angiogram (n = 219) were significantly less likely to develop new disease than the 14 patients with preexisting coronary artery disease (p = 0.002). Although older donors exhibited earlier coronary artery disease than younger donors at 3 years of follow-up, there was no difference by 5 years (p = 0.25). There was no difference in survival or probability of developing ischemic events between the groups. Baseline ultrasound imaging revealed substantial disease in 7 of 9 older donated hearts, and in only 7 of 38 younger donated hearts (p = 0.002). Preexisting coronary artery disease, nonuse of calcium channel blocking agents, older donor age, posttransplantation cytomegalovirus infection, elevated very low density lipoprotein levels and previous ischemic heart disease in the recipient were significant predictors of allograft coronary artery disease. CONCLUSIONS: Heart donors with angiographic evidence of preexisting coronary artery disease and older donors are more likely to develop new allograft coronary artery disease by 3 years. However, there is no difference in survival or freedom from ischemic events between younger and older donors at a mean follow-up of 3.8 years.
BACKGROUND: Methotrexate and total lymphoid irradiation (TLI) have been used successfully for treatment of recurrent and persistent rejection in orthotopic heart transplant recipients; however, there has been no comparison of these two modalities. METHODS: We retrospectively compared the efficacy of methotrexate (n = 29) versus TLI (n = 28) in heart transplant recipients with recurrent or persistent rejection. All patients received induction therapy (rabbit anti-thymocyte globulin or OKT3) and standard triple immunosuppressive therapy. Methotrexate (7.5 mg to 22.5 mg per wk) or TLI (80 cGy x 10 fractions) was used for the treatment of recurrent or persistent rejection on the basis of clinical indications. Average biopsy scores (International Society of Heart and Lung Transplantation biopsy score/total number of biopsies performed) calculated over 3-month periods, daily maintenance prednisone dose before and after methotrexate or TLI treatment, and actuarial survival and freedom from angiographic coronary artery disease and infection were compared. To control for the general decrease in prednisone with increased time from transplantation, a control group matched for time from transplantation was selected. RESULTS: Recipient sex and age at transplant, donor age, and donor ischemic time were similar in both groups. Days after transplantation to start of therapy was longer in patients receiving methotrexate; however, this did not reach statistical significance. Patients receiving TLI had received more cumulative corticosteroids and OKT3 before the start of TLI therapy (p < 0.001). There were no differences in actuarial freedom from infection or coronary artery disease between the two groups and between the treatment groups and the control group. Actuarial survival was reduced in patients receiving TLI 3 years after transplantation (p < 0.05). Maintenance prednisone doses from 3 months before until 9 months after therapy (mg/kg) were not different between patients receiving TLI and methotrexate and were significantly greater than the prednisone doses in the control group. Four months after treatment initiation, the prednisone dose was significantly reduced in both treatment groups compared with the pretherapy dose (methotrexate 0.28 +/- 0.16 to 0.22 +/- 0.13, p = 0.05; TLI 0.36 +/- 0.16 to 0.22 +/- .07, p < 0.001). The average biopsy score was significantly reduced by both methotrexate and TLI therapy (methotrexate 1.8 +/- 0.7 to 0.83 +/- 0.9, p = 0.0001; TLI 2.1 +/- 0.8 to 1.0 +/- 0.9, p = 0.0001). CONCLUSION: Methotrexate and TLI are both effective for the treatment of recurrent or persistent rejection after heart transplantation, reducing average biopsy scores and daily maintenance prednisone doses. There was a reduction in actuarial survival rates in patients treated with TLI, possibly reflecting the greater rejection therapy received before TLI initiation. Because both agents are effective, the choice of methotrexate or TLI may be based on clinical indications, as well as other issues, such as cost, compliance, and availability.
AIMS: As a consequence of recent advances in heart transplantation, upper age limits for the procedure have been liberalized in many centres. It was the purpose of this study to compare post-transplant mortality, morbidity and quality of life in a consecutive series of 72 patients > 54 years (mean age, 57.6 +/- 2.7 years) with a control group of 72 adult patients < or = 54 years (mean age, 42.4 +/- 9.5 years) transplanted at one centre between 1985 and 1991. METHODS AND RESULTS: Patients were followed for 41 +/- 27 months post-transplant. Actuarial 1-, 5- and 7-year survival rates were 78 +/- 5%, vs 81 +/- 5%, 52 +/- 7% vs 66 +/- 6% and 46 +/- 8% vs 63 +/- 6% in patients > 54 years and < or = 54 years, respectively (P = ns). Causes of death were not significantly different between the groups. Patients > 54 years experienced significantly fewer rejection episodes after the 6th month post-transplant (0.5 +/- 0.9 vs 0.9 +/- 1.0, P < 0.04), and incidence and treatment of rejection episodes as well as incidence of infection was comparable between the groups. Non-lymphoid malignancies, mainly skin cancer, occurred more often in the older age group (27% vs 13%, P < 0.05). Quality of life, as assessed by the Nottingham Health Profile, was better in 5/6 dimensions of social functioning in older patients and the difference reached statistical significance for the dimensions of emotional reactions (P = 0.005) and sleep (P = 0.0005). CONCLUSION: In conclusion, carefully selected patients > 54 years can undergo heart transplantation with mortality and morbidity comparable to younger patients. Quality of life post-transplant seems even to be slightly better in the older age group.
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BACKGROUND: Doppler echocardiographic (DE) diastolic dysfunction has been correlated with rejection after orthotopic cardiac transplantation (Tx). However, the relationship of early diastolic dysfunction to late outcome is unknown. The purpose of this study was to assess the correlation between early DE diastolic dysfunction and outcome after heart Tx. METHODS AND RESULTS: Of 133 patients undergoing heart Tx between October 1990 and April 1994, 83 were identified with > or = 4 routine DE performed during the first 6 months. Assessment of diastolic function included measurement of isovolumic relaxation time (IVRT), pressure half-time (PHT), and peak early mitral inflow velocity (M1). Diastolic dysfunction was defined as a decrease of 15% from baseline (IVRT and PHT) or an increase of 20% (M1). A mean dysfunction score (MDS) was calculated for each patient (number of episodes of dysfunction by Doppler total number of echocardiograms performed). The population diastole MDS was determined and two groups established (group 1, MDS < mean; group 2, MDS > mean). Actuarial survival, rejection, and transplant coronary artery disease (TxCAD) were compared between groups. Actuarial survival was significantly reduced in patients with greater early diastolic dysfunction (P < .05). There were 17 deaths overall: 5 in group 1 (mean, 786 days) and 12 in group 2 (mean, 384 days). There were no significant differences in treated rejection episodes, actuarial freedom from rejection or TxCAD, immunosuppression, sex, donor age, donor ischemic time, or cytomegalovirus between the two groups. CONCLUSIONS: Diastolic dysfunction within 6 months of transplant was associated with an increased late mortality.
BACKGROUND: Accelerated coronary artery disease is a major cause of mortality in heart transplant recipients; however, it does not appear to play a major role in the clinical outcome of heart-lung transplant recipients. The purpose of this study was to determine whether the incidence and severity of transplant coronary artery disease as detected by intracoronary ultrasound in heart-lung transplant recipients are less than those encountered in heart transplant recipients. METHODS AND RESULTS: We studied the left anterior descending coronary artery with the use of intracoronary ultrasound imaging in 22 heart-lung transplant recipients at the time of their routine annual coronary angiogram. Twenty-two heart transplant recipients were case matched for number of years after transplant at ultrasound study, recipient age, donor age, and diagnosis of nonischemic cardiomyopathy. Mean intimal area, intimal index, Stanford class, and incidence of at least moderate disease (Stanford class > or = 3) were measured and calculated in each group and then compared between the two groups. Mean intimal area (1.6 +/- 2.5 versus 3.8 +/- 2.8 mm2), mean intimal index (0.07 +/- 0.10 versus 0.22 +/- 0.14), mean Stanford class (1.7 +/- 1.0 versus 2.7 +/- 1.2), and incidence of Stanford class > or = 3 (14% versus 45%) were significantly lower in the heart-lung transplant recipient group. CONCLUSIONS: The incidence and severity of transplant coronary artery disease are much less in patients receiving heart-lung transplants than in those receiving heart transplants alone.
BACKGROUND: The mechanisms underlying cardiac contractile dysfunction after transplantation remain poorly defined. Previous work has revealed that inducible nitric oxide synthase (iNOS) is expressed in the rat heterotopic cardiac allograft during rejection; resultant overproduction of nitric oxide (NO) might cause cardiac contractile dysfunction via the negative inotropic and cytotoxic actions of NO. In this investigation, we tested the hypothesis that induction of iNOS may occur and be associated with cardiac allograft contractile dysfunction in humans. METHODS AND RESULTS: We prospectively studied 16 patients in the first year after cardiac transplantation at the time of serial surveillance endomyocardial biopsy. Clinical data, the results of biopsy histology, and echocardiographic and Doppler evaluation of left ventricular systolic and diastolic function were recorded. Total RNA was extracted from biopsy specimens, and mRNA for beta-actin, detected by reverse transcription-polymerase chain reaction (RT-PCR) using human specific primers, was used as a constitutive gene control; iNOS mRNA was similarly detected by RT-PCR using human specific primers. iNOS protein was detected in biopsy frozen sections by immunofluorescence. Myocardial cGMP was measured by radioimmunoassay, and serum nitrogen oxide levels (NOx = NO2 + NO3) were measured by chemiluminescence. iNOS mRNA was detected in allograft myocardium at some point in each patient and in 59 of 123 biopsies (48%) overall. In individual patients, iNOS mRNA expression was episodic and time dependent; the frequency of expression was highest during the first 180 days after transplant (P = .0006). iNOS protein associated with iNOS mRNA was detected by immunofluorescence in cardiac myocytes. iNOS mRNA expression was not related to the ISHLT histological grade of rejection or to serum levels of NOx but was associated with increased levels of myocardial cGMP (P = .01) and with both systolic (P = .024) and diastolic (P = .006) left ventricular contractile dysfunction measured by echocardiography and Doppler. CONCLUSIONS: These data support a relation between iNOS mRNA expression and contractile dysfunction in the human cardiac allograft.
This study examined the hypothesis that immunologic factors are the major correlates of coronary artery intimal thickening and luminal stenosis. The study population included 116 adult heart transplant recipients with a mean age of 44.7 +/- 12.0 years (89 men and 27 women) undergoing annual coronary angiography and intracoronary ultrasound 3.4 +/- 2.7 (range, 1.0-14.6) years after transplantation. Mean intimal thickness was obtained from several distinct sites along the left anterior descending and/or left circumflex coronary artery by intracoronary ultrasound. Coronary artery stenosis defined by angiography was classified as mild (< 30% luminal stenosis), moderate (> or = 30-70% luminal stenosis), or severe (> 70% luminal stenosis or diffuse pruning of distal vessels). Prevalence of any transplant coronary artery disease (TxCAD) was 85% by intracoronary ultrasound and 15% by angiography. By multiple regression analysis, only average fasting plasma triglyceride level (P < 0.006) and average weight (P < 0.007) were significantly correlated with severity of intimal thickening (R = 0.54, P < 0.0001). Donor age (P < 0.006) and average fasting plasma triglyceride level (P < 0.009) were significantly correlated with stenosis by angiography. Correlation of multiple immunologic and metabolic factors with intimal thickness by univariate analysis suggests a multifactorial etiology for TxCAD. Among the multiple univariate correlates of TxCAD, higher fasting plasma triglyceride levels and body weight are the only independent correlates of TxCAD. The absence of acute rejection as an independent predictor of intimal thickening suggests that mechanisms beyond those mediating typical cellular rejection should be targeted for advancing our understanding of Tx-CAD.
OBJECTIVES: This study assessed the time of first appearance of angiographic graft coronary artery disease in relation to clinical and laboratory variables and clinical events in heart transplant recipients. BACKGROUND: Graft coronary artery disease is the main factor limiting long-term survival after heart transplantation, and it is important to understand its natural history. METHODS: One hundred thirty-nine consecutive patients who developed angiographic coronary artery disease after heart transplantation were classified according to early (< or = 2 years) versus late (> 2 years) posttransplantation initial detection of coronary artery disease. These subgroups were analyzed for differences in clinical and laboratory demographics, incidence of progression to ischemic events and incidence of antecedent cytomegalovirus infection. RESULTS: The early-onset group (64 patients) had more rapid progression to ischemic events than the late-onset group (75 patients), with 59% of the late group and only 35% of the early group free from ischemic events by 5 years after initial detection (p = 0.02), but there were no significantly correlated clinical or laboratory predictors of ischemic events. The early group had a significantly higher incidence of antecedent cytomegalovirus infection. CONCLUSIONS: We conclude that 1) accelerated graft coronary artery disease develops at variable times after heart transplantation; 2) the early appearance of graft coronary artery disease may be a marker of intrinsically more aggressive disease; 3) cytomegalovirus infection is associated with earlier onset of graft coronary artery disease. Patients with early development of graft coronary artery disease should potentially be given priority for interventional strategies as they are developed.
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