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Biomedical subjects

David C Naftel

Publications and source records attributed to David C Naftel.

18 recordsLinked to original sources
PubMed2006

Hyperlipidemia in children after heart transplantation.

BACKGROUND: Long-term outcome after cardiac transplantation is limited by graft coronary vasculopathy (GCV). Hyperlipidemia may contribute to the development and progression of GCV. The purpose of this study was to determine the distribution of lipid levels in children after heart transplantation and to determine the incidence and risk factors for hyperlipidemia. METHODS: We compared the distribution of lipid values 1 year after heart transplantation in children participating in Pediatric Heart Transplant Study to those of normal U.S. children and then performed a multivariable analysis to identify risk factors for hyperlipidemia. RESULTS: The median values of total and LDL-cholesterol in heart transplant patients were similar to those of normal U.S. pediatric population. However, total cholesterol level was >200 mg/dl in 14% and >170 mg/dl in 33% of transplant patients. LDL-cholesterol was >130 mg/dl in 12%, >110 mg/dl in 27% and >100 mg/dl (greater than "optimal" levels) in 39% of transplant patients. The distribution curve for serum triglycerides was shifted to the right and that for HDL-cholesterol levels was shifted to the left of the normal U.S. pediatric curve. As a result, triglyceride levels were >75th centile of U.S. normal distribution in 59% of the transplant patients. HDL-cholesterol level was <25th centile of U.S. normal distribution in 61% of the transplant patients. Independent risk factors for elevated levels of total and LDL-cholesterol were patient age and use of cyclosporine and prednisone. CONCLUSIONS: Lipid levels considered to be in the intervention range in adults at high risk of coronary artery disease are a common finding after cardiac transplantation in children.

Adolescent↗
PubMed2006

Outcomes of children bridged to heart transplantation with ventricular assist devices: a multi-institutional study.

BACKGROUND: Current ventricular assist devices (VADs) in the United States are designed primarily for adult use. Data on VADs as a bridge to transplantation in children are limited. METHODS AND RESULTS: A multi-institutional, prospectively maintained database of outcomes in children after listing for heart transplantation (n=2375) was used to analyze outcomes of VAD patients (n=99, 4%) listed between January 1993 and December 2003. Median age at VAD implantation was 13.3 years (range, 2 days to 17.9 years); diagnoses were cardiomyopathy (78%) and congenital heart disease (22%). Mean duration of support was 57 days (range, 1 to 465 days). Seventy-three percent were supported with a long-term device, with 39% requiring biventricular support. Seventy-seven patients (77%) survived to transplantation, 5 patients were successfully weaned from support and recovered, and 17 patients (17%) died on support. In the recent era (2000 to 2003), successful bridge to transplantation with VAD was achieved in 86% of patients. Peak hazard for death while waiting was the first 2 weeks after VAD placement. Risk factors for death while awaiting a transplant included earlier era of implantation (P=0.05), female gender (P=0.02), and congenital disease diagnosis (P=0.05). There was no difference in 5-year survival after transplantation for patients on VAD at time of transplantation as compared with those not requiring VAD. CONCLUSIONS: VAD support in children successfully bridged 77% of patients to transplantation, with posttransplantation outcomes comparable to those not requiring VAD. These encouraging results emphasize the need to further understand patient selection and to delineate the impact of VAD technology for children.

Adolescent↗
PubMed2006

Lymphoproliferative disorders after paediatric heart transplantation: a multi-institutional study.

BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD) are an important cause of morbidity and mortality after organ transplantation. We sought to better define the prevalence, pathology, current therapeutic approaches, and outcomes of PTLD in a large group of children who had received heart transplants. METHODS: We assessed data on patients followed up at 19 centres in the Pediatric Heart Transplant Study (PHTS) from 1993 to 2002. Probability of freedom from PTLD was assessed along with details of presentation, pathology, treatment, and outcomes. Risk factors for survival and event-free survival were investigated. FINDINGS: Of 1184 primary transplant recipients, 56 (5%) developed PTLD. Probability of freedom from PTLD was 98% at 1 year, 94% at 3 years, and 92% at 5 years. Mean time to PTLD was 23.8 months. Most common sites of disease were gastrointestinal tract (n=22, 39%) and respiratory system (n=14, 25%). Histology was polymorphic in 35 (65%) and monomorphic in 19 (35%). 47 of 48 cases were of B-cell origin, 39 of 45 (87%) were Epstein-Barr virus positive. Probability of survival was 75% at 1 year, 68% at 3 years, and 67% at 5 years after diagnosis. Death from graft loss was as frequent as death from PTLD. INTERPRETATION: About 5% of paediatric heart-transplant recipients develop PTLD, almost always of B-cell lineage and driven by Epstein-Barr virus. Although many achieve satisfactory outcomes, mortality remains substantial with death due to progressive disease and allograft loss. Advances in management should focus on strategies to protect the allograft as well as improved therapies for PTLD.

Adolescent↗
PubMed2006

Usefulness of live/real time three-dimensional transthoracic echocardiography in the identification of individual segment/scallop prolapse of the mitral valve.

In this report, we present 34 patients in whom surgical intervention was undertaken for severe mitral insufficiency due to mitral valve prolapse (MVP). Location and severity of MVP and regurgitation were assessed preoperatively by live/real time three-dimensional transthoracic echocardiography and closely agreed with the surgical findings.

Adult↗
PubMed2005

Predictors of physical functional disability at 5 to 6 years after heart transplantation.

BACKGROUND: Few reports were found in the literature that examined predictors of physical functional disability after heart transplantation. Therefore, the purpose of this study was to (1) describe physical functional disability, (2) identify differences in physical functional disability by demographic and clinical variables, and (3) identify predictors of physical functional disability at 5 to 6 years after heart transplantation. METHODS: A nonrandom sample of 311 patients (approximately 60 years of age, 78% male, and 90% Caucasian) who were 5 to 6 years post-heart transplantation were investigated. Patients completed 8 reliable and valid quality-of-life instruments via self-report. Data analyses included descriptive statistics, chi-square, independent t-tests, correlations, and stepwise multiple regression. Level of significance was set at p = 0.05. RESULTS: The level of physical functional disability was low at 5 to 6 years after heart transplantation, yet 59% of patients reported having physical disability. Women experienced more functional disability than men, and patients with comorbidities (i.e., diabetes mellitus and orthopedic problems) experienced more functional disability than patients without these comorbidities. At 5 to 6 years after heart transplantation, 70% of variance in physical functional disability was explained by activities of daily living, symptoms, comorbidities, psychologic status, and resource utilization variables. CONCLUSIONS: At 5 to 6 years after heart transplantation, most patients experienced low levels of physical functional disability. Differences in physical functional disability were identified by both demographic characteristics and clinical variables. Predictors of physical functional disability included activities of daily living and symptoms, and clinical, psychologic, and resource utilization variables. Knowledge of factors related to physical disability long-term after heart transplantation provides direction for the development of strategies to assist patients to reduce their level of disability or function adequately despite their disability.

Activities of Daily Living↗
PubMed2005

The intensive care unit oxygen challenge should not be used for donor lung function decision-making.

BACKGROUND: The intensive care unit oxygen challenge is a routine screening test for donor lung function. An arterial PO2 of <300 mm Hg is generally considered evidence of inadequate pulmonary function that contraindicates the use of the lungs for transplantation. METHODS: Between December 1, 2001 and January 24, 2004, the intensive care unit oxygen challenge was compared with the PO2 in samples drawn from each pulmonary vein confluence in the operating room in 91 donors (182 donor lungs) after the lungs were fully inflated (FIO2 1.0). There were 62 males and 29 females, with a median age of 27.5 years (13.6 to 55.4 years). RESULTS: In 40 lungs, the pulmonary vein PO2 was >300 mm Hg, whereas the PO2 was <300 mm Hg on the last intensive care unit O2 challenge. The difference between the intensive care unit PO2 and the operating room pulmonary vein PO2 was greatest for donors with the lowest intensive care unit PO2. Of these 40 lungs, 8 were transplanted, all of whom had excellent graft function with a median intubation of 14.2 hours (6.1 to 23.8 hours). No patient sustained primary graft failure or an airway complication. CONCLUSIONS: The intensive care unit PO2 is an unreliable screening test for donor lung function, particularly when one lung is clear and the other is unclear radiographically. In this setting, intraoperative surgical assessment and pulmonary venous PO2 should be the basis for determining donor lung suitability. This strategy may provide an opportunity to increase donor lung availability.

Adolescent↗
PubMed2005

Multi-organ transplantation: is there a protective effect against acute and chronic rejection?

BACKGROUND: Heart-lung transplantation (Tx) is known to offer a protective effect against acute cardiac rejection. This study was undertaken to evaluate acute and chronic heart and/or lung rejection in the setting of multiple-transplanted organs from the same donor compared with single-organ transplantation. METHODS: Acute (treated rejection episodes of heart or lungs) and chronic (allograft vasculopathy in hearts and bronchiolitis obliterans syndrome [BOS] in lungs) rejection events were analyzed in 348 heart transplant (H) recipients, 24 heart-lung (HL) recipients, 82 double-lung (L) recipients and 8 heart-kidney (HK) recipients >18 years of age, who were transplanted between 1990 and 2002. RESULTS: Survival at 3 years differed among groups as follows: HK, 100%; H, 82%; HL, 74%; and L, 70%. The probability of acute rejection within the first 3 months was higher in H recipients than in HL (81% vs 22%; p < 0.0001) or HK (81% vs 12%; p = 0.00009) recipients. Acute cardiac rejection occurred more frequently during the first 2 years in isolated H recipients compared with HL (2.8 vs 0.27 episodes; p < 0.0001) and HK (2.8 vs 0.54; p < 0.001) recipients. Acute lung rejection occurred more frequently in the first 2 years in L than HL (2.4 vs 1.0 episodes; p = 0.02) recipients. Chronic cardiac rejection (allograft vasculopathy) was more likely within 3 years after H compared with HL (32% vs 16%; p = 0.04) or HK (32% vs 0%; p = 0.14). The onset of chronic lung rejection (BOS) within 3 years was similar in HL and L recipients (39% vs 40%; p = 0.9). CONCLUSIONS: Recipients of multiple organs from a single donor undergo less acute rejection of the heart or lungs compared with isolated heart or lung transplant recipients. Cardiac allograft vasculopathy is decreased significantly when cardiac transplantation is combined with a lung allograft. A lower incidence of cardiac allograft vasculopathy is observed when cardiac transplantation is combined with a renal allograft, and may prove statistically significant when more cases have been accumulated. These phenomena may result from immune modulation of the recipient by simultaneous transplant of disparate tissues or introduction of immune-modulating hematopoietic elements.

Acute Disease↗
PubMed2005

The case for selective re-issuance of medical certificates to allow pilots who have received a heart transplant to resume flying.

BACKGROUND: Cardiac transplant recipients have been regarded as not medically fit to fly an airplane. Recently, the Federal Aviation Administration decided to re-examine this policy and, in response, this study was undertaken to determine the risk of death from any cause and sudden-onset death in heart transplant recipients during the 12 months after an annual evaluation. METHODS: Of 6,510 patients undergoing primary orthotopic cardiac transplantation enrolled in the Cardiac Transplant Research Database (CTRD), 4,978 patients survived for at least 1 year and formed the basis of this study. Risk factors for death from any causes and sudden-onset death (a composite of causes of death that could conceivably result in a pilot's incapacitation) were determined during the 12-month period after an anniversary evaluation. Patients were re-entered into the analysis at each evaluation, resulting in a total of 23,575 anniversary evaluations. RESULTS: The presence of coronary allograft vasculopathy (CAV), left ventricular systolic dysfunction, history of rejection, malignancy, infection and pre-transplant insulin-dependent diabetes were associated with an increased risk of death from any cause and sudden-onset death during the 12-month period after an evaluation. Based on the absence of these risk factors, a group of heart transplant recipients could be defined with a 12-month risk of death from any cause of 1.0% and of sudden-onset death of 0.3% (which is identical to the mortality rate of a matched population from the U.S. life-table). CONCLUSION: Using these identified risk factors, a group of heart transplant recipients can be defined that are potentially medically certifiable to fly without compromising aviation safety.

Adolescent↗
PubMed2005

The impact and outcome of transplant coronary artery disease in a pediatric population: a 9-year multi-institutional study.

BACKGROUND: Transplant coronary artery disease (TCAD) limits survival in heart transplant recipients; however, its incidence in children is unknown. The purpose of this study was to determine the angiographic incidence of TCAD, potential risk factors, and outcomes in a large pediatric cohort. METHODS: From January 1993 to December 1, a total of 1,222 children, aged newborn to 17 years, underwent primary cardiac transplantation at 20 institutions. A total of 2,049 coronary angiograms were performed in 751 patients. All angiograms were graded for coronary disease and results were submitted to the Pediatric Heart Transplant Study database. We analyzed time-related freedom from graded severity and events from coronary disease, and we examined risk factors. RESULTS: The incidence of angiographic abnormalities at 1, 3, and 5 years was 2%, 9%, and 17%, respectively; however, moderate-to-severe disease occurred in only 6% at 5 years, compared with 15% in the adult transplant database (p <0.0001). The major risk factors were older recipient and donor age. Two or more episodes of rejection in the 1st year correlated with coronary disease (p = 0.05). Overall freedom from graft loss caused by primary TCAD was 99%, 96%, and 91% at 1, 5, and 9 years after heart transplantation, respectively. Death or graft loss occurred within 2 years of diagnosis in patients with severe disease; 24% of patients with any coronary disease died within 2 years. CONCLUSIONS: The incidence of TCAD in children is smaller than the incidence in adults, but increases with age. Graft loss is infrequent in children; however, severe coronary disease correlates with poor prognosis.

Adolescent↗
PubMed2005

Predictors of quality of life at 5 to 6 years after heart transplantation.

BACKGROUND: Only a few researchers have examined quality of life (QOL) outcomes more than 5 years after heart transplantation. Therefore, the purpose of this study was to describe QOL (overall, satisfaction with, and perceived importance); identify differences in QOL by age, sex, and race; and identify predictors of QOL at 5 to 6 years after heart transplantation. METHODS: A nonrandom sample of 231 patients (60 years of age, 76% men, 90% white, 79% married, and fairly well educated) who were 5 to 6 years after heart transplantation were investigated. Patients completed 12 QOL instruments via self-report. Data analyses included descriptive statistics, chi2, independent t-tests, correlations, and stepwise multiple regression. Level of significance was set at 0.05. RESULTS: Patient satisfaction with all areas of life was high at 5 to 6 years after heart transplantation. Similarly, patients believed that these same areas of life were very important. Yet areas of QOL with lower levels of satisfaction were identified. Patients who were > or =60 years were more satisfied with their QOL than patients <60 years. At 5 to 6 years after heart transplantation, almost 80% of variance in QOL was explained by psychological, physical, social, clinical, and demographic variables. CONCLUSIONS: At 5 to 6 years after heart transplantation, patients were very satisfied with their QOL, although differences in level of satisfaction were identified by demographic variables, and areas of QOL with lower levels of satisfaction were identified. Understanding those variables that contribute to QOL in the long term after heart transplantation provides direction for assisting patients to improve their QOL.

Adult↗
PubMed2004

Cardiac surgery risk models: a position article.

Differences in medical outcomes may result from disease severity, treatment effectiveness, or chance. Because most outcome studies are observational rather than randomized, risk adjustment is necessary to account for case mix. This has usually been accomplished through the use of standard logistic regression models, although Bayesian models, hierarchical linear models, and machine-learning techniques such as neural networks have also been used. Many factors are essential to insuring the accuracy and usefulness of such models, including selection of an appropriate clinical database, inclusion of critical core variables, precise definitions for predictor variables and endpoints, proper model development, validation, and audit. Risk models may be used to assess the impact of specific predictors on outcome, to aid in patient counseling and treatment selection, to profile provider quality, and to serve as the basis of continuous quality improvement activities.

Bayes Theorem↗
PubMed2004

Risk factors for recurrent rejection in pediatric heart transplantation: a multicenter experience.

BACKGROUND: Cardiac allograft rejection remains as a primary cause of death in the first 3 years after pediatric heart transplantation. Multiple episode of acute rejection in adult heart transplant recipients may accelerate the development of graft vasculopathy. We sought to quantify the time-related probability of recurrent rejection and identify risk factors for the development of recurrent rejection. METHODS: We analyzed data from 847 pediatric recipients who underwent transplantation between January 1, 1993 and December 31, 1998 at 22 centers in the Pediatric Heart Transplant Study (PHTS). Recurrent rejection and risk factors were evaluated using univariate and multivariate analyses. RESULTS: Five hundred fifty two patients had 1,072 rejection events and were the subject of the analyses. The highest risk of recurrent rejection occurs within 1 month after resolution of a previous rejection episode. Risk factors for recurrent rejection include the number of previous rejection events, the elapsed time since a previous rejection episode, and subjects of either Hispanic or African-American descent. Rejection associated with hemodynamic compromise and late rejection is associated with higher mortality. CONCLUSIONS: Recurrent rejection is a risk factor for mortality, especially in the presence of hemodynamic compromise. This association appears independent of the time post-transplantation. Use of surveillance biopsies appears warranted throughout the life of the transplant individual. Retransplantation should be considered among these subjects with recurrent rejection.

Adult↗
PubMed2003

Retransplantation in 7,290 primary transplant patients: a 10-year multi-institutional study.

BACKGROUND: Cardiac retransplantation is a controversial procedure due to the disparity between donor heart demand and supply. METHODS: Of 7,290 patients undergoing primary cardiac transplantation between January 1990 and December 1999 at 42 institutions contributing to the Cardiac Transplant Research Database (CTRD), 106 patients later underwent a second and 1 patient a third cardiac transplant procedure. RESULTS: The actuarial freedom from retransplantation was 99.2% and 96.8% at 1 and 10 years, respectively. Reasons for retransplantation included early graft failure (n = 34), acute cardiac rejection (n = 15), coronary allograft vasculopathy (CAV, n = 39), non-specific graft failure (n = 7), and miscellaneous (n = 10). The only risk factor associated with retransplantation was younger age, reflecting the policy of preferential retransplantation of younger patients. Survival after retransplantation was inferior to that after primary transplantation (56% and 38% at 1 and 5 years, respectively). Risk factors associated with death after retransplantation included retransplantation for acute rejection (p = 0.0005), retransplantation for early graft failure (p = 0.03), and use of a female donor (p = 0.005). Survival after retransplantation for acute rejection was poorest (32% and 8% at 1 and 5 years, respectively) followed by retransplantation for early graft failure (50% and 39% at 1 and 5 years, respectively). Survival after retransplantation for CAV has steadily improved with successive eras. CONCLUSIONS: The results of retransplantation for acute rejection and early graft failure are poor enough to suggest that this option is not advisable. However, retransplantation for CAV is currently associated with satisfactory survival and should continue to be offered to selected patients.

Actuarial Analysis↗
PubMed2003

Late rejection episodes more than 1 year after pediatric heart transplantation: risk factors and outcomes.

BACKGROUND: Little is known about late rejection episodes after pediatric heart transplantation. We determined the frequency of late rejection episodes (>1 year) after pediatric heart transplantation, defined risk factors for its occurrence, and evaluated outcome after late rejection. METHODS: We analyzed data from 685 pediatric recipients (<18 years at transplantation) who underwent transplantation between January 1, 1993, and December 31, 1997, at 18 centers in the Pediatric Heart Transplant Study (PHTS). Probability of freedom from late rejection was determined and risk factors for late rejection and for death after late rejection were sought using univariate and multivariate analyses. RESULTS: We followed 431 patients for >1 year (median follow-up, 32.9 months) of whom 106 (24.6%) experienced 1 or more late rejection episodes (total of 178 episodes, 27 with severe hemodynamic compromise). Probability of freedom from first late rejection was 73% at 3 years and 66% at 4 years after transplantation. Risk factors (multivariate analysis) for first late rejection were >1 episode of rejection in the first year (p = 0.009), recipient black race (p = 0.0002), and older age at transplantation (p = 0.0003). Only 4 of 325 (1.2%) children who survived beyond 1 year without late rejection died compared with 26 of 106 (24.6%) with late rejection (p < 0.0001). Nine of these 26 died within 1 month of the first late rejection episode, and 17 died subsequently: 5 of acute rejection, 3 of sudden unexplained deaths, 3 of documented coronary artery disease, and 6 of other causes. Severe hemodynamic compromise with late rejection was identified as a risk factor for death among children with 1 or more episodes of late rejection. CONCLUSIONS: Approximately 25% of pediatric recipients in the PHTS who survived beyond 1 year experienced late rejection episodes. Late rejection is associated with poor survival, especially when associated with hemodynamic compromise. Absence of late rejection episodes is associated with very low risk of death during medium-term follow-up after pediatric heart transplantation. Determining the risk factors for late rejection will help to identify a cohort of patients who may benefit from enhanced rejection surveillance and treatment.

Age Factors↗
PubMed2003

A multicenter controlled clinical trial of open versus endovascular treatment of abdominal aortic aneurysm.

OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of a novel endovascular graft for elective treatment of infrarenal abdominal aortic aneurysm. The device is a modular bifurcated system with nitinol/expanded polytetrafluoroethylene components and a smaller profile than currently approved devices. METHODS: In a multicenter, concurrent controlled phase II trial, 334 patients underwent treatment with the Excluder bifurcated endoprosthesis (test, n = 235; W. L. Gore & Associates, Inc, Sunnyvale, Calif) or with standard open repair (control, n = 99). Preoperative characteristics, perioperative variables, follow-up clinical evaluations, and radiographic examination results through the first 2 years were analyzed with univariable and multivariable statistics. RESULTS: Patients in the test group had less blood loss (310 +/- 19 mL versus 1590 +/- 124 mL; P <.0001), fewer homologous transfusions (6% versus 32%; P <.0001), and shorter lengths of stay (2.0 +/- 0.1 days versus 9.8 +/- 1.4 days; P <.0001). Early major adverse events were markedly reduced in the test group (14% versus 57%; P <.0001), and this difference persisted at 2 years. No difference was seen in survival rate (P =.13). In the first 2 years, no deployment failure, early conversion, or aneurysm rupture occurred. At the 2-year timepoint, core laboratory read trunk migration in 1%, limb migration in 1%, limb narrowing in 1%, endoleak in 20%, and aneurysm growth in 14%. One wire discontinuity (0.6%) was identified in a discharge film. A 7% annual reintervention rate was seen in the test group in the first 2 years. SUMMARY: The test device is a safe and effective treatment compared with open surgical repair for infrarenal abdominal aortic aneurysm. The most striking benefits are reduced blood loss, fewer complications, and faster recovery. Two-year survival rate was similar.

Aged↗