Lung and heart allocation in the United States

Lung and heart allocation in the United States has evolved over the past 20-30 years to better serve transplant candidates and improve organ utilization. The current lung allocation policy, based on the Lung Allocation Score, attempts to take into account risk of death on the waiting list and chance of survival posttransplant. This policy is flexible and can be adjusted to improve the predictive ability of the score. Similarly, in response to the changing clinical phenotype of heart transplant candidates, heart allocation policies have evolved to a multitiered algorithm that attempts to prioritize organs to the most infirm, a designation that fluctuates with trends in therapy. The Organ Procurement and Transplantation Network and its committees have been responsive, as demonstrated by recent modifications to pediatric heart allocation and mechanical circulatory support policies and by ongoing efforts to ensure that heart allocation policies are equitable and current. Here we examine the development of US lung and heart allocation policy, evaluate the application of the current policy on clinical practice and explore future directions for lung and heart allocation.

Kidney function and risk of cardiovascular disease and mortality in kidney transplant recipients: the FAVORIT trial

In kidney transplant recipients, cardiovascular disease (CVD) is the leading cause of death. The relationship of kidney function with CVD outcomes in transplant recipients remains uncertain. We performed a post hoc analysis of the Folic Acid for Vascular Outcome Reduction in Transplantation (FAVORIT) Trial to assess risk factors for CVD and mortality in kidney transplant recipients. Following adjustment for demographic, clinical and transplant characteristics, and traditional CVD risk factors, proportional hazards models were used to explore the association of estimated GFR with incident CVD and all-cause mortality. In 4016 participants, mean age was 52 years and 20% had prior CVD. Mean eGFR was 49 ± 18 mL/min/1.73 m(2) . In 3676 participants with complete data, there were 527 CVD events over a median of 3.8 years. Following adjustment, each 5 mL/min/1.73 m(2) higher eGFR at levels below 45 mL/min/1.73 m(2) was associated with a 15% lower risk of both CVD [HR = 0.85 (0.80, 0.90)] and death [HR = 0.85 (0.79, 0.90)], while there was no association between eGFR and outcomes at levels above 45 mL/min/1.73 m(2) . In conclusion, in stable kidney transplant recipients, lower eGFR is independently associated with adverse events, suggesting that reduced kidney function itself rather than preexisting comorbidity may lead to CVD.

Report of a consensus conference on transplant program quality and surveillance

Public reports of organ transplant program outcomes by the US Scientific Registry of Transplant Recipients have been both groundbreaking and controversial. The reports are used by regulatory agencies, private insurance providers, transplant centers and patients. Failure to adequately adjust outcomes for risk may cause programs to avoid performing transplants involving suitable but high-risk candidates and donors. At a consensus conference of stakeholders held February 13-15, 2012, the participants recommended that program-specific reports be better designed to address the needs of all users. Additional comorbidity variables should be collected, but innovation should also be protected by excluding patients who are in approved protocols from statistical models that identify underperforming centers. The potential benefits of hierarchical and mixed-effects statistical methods should be studied. Transplant centers should be provided with tools to facilitate quality assessment and performance improvement. Additional statistical methods to assess outcomes at small-volume transplant programs should be developed. More data on waiting list risk and outcomes should be provided. Monitoring and reporting of short-term living donor outcomes should be enhanced. Overall, there was broad consensus that substantial improvement in reporting outcomes of transplant programs in the United States could and should be made in a cost-effective manner.

Clinical diagnosis of metabolic syndrome: predicting new-onset diabetes, coronary heart disease, and allograft failure late after kidney transplant

Metabolic syndrome is associated with coronary heart disease (CHD) and new-onset diabetes after kidney transplant (NODAT). Using data collected from transplant centers worldwide for the Patient Outcomes in Renal Transplantation study, we examined associations of metabolic syndrome (n = 2253 excluding recipients with diabetes pretransplant), CHD (n = 2253), and NODAT (n = 1840 further excluding recipients with diabetes in the first year post-transplant), with the primary outcome of allograft failure. We assessed risk factors associated with secondary outcomes of metabolic syndrome, NODAT, and CHD after adjusting for type of baseline immunosuppression and transplant center effects. Metabolic syndrome prevalence was 39.8% at 12-24 months post-transplant and 35.4% at 36-48 months. Metabolic syndrome was independently associated with NODAT (hazard ratio 3.46, 95% confidence interval 2.40-4.98, P < 0.0001), CHD (2.03, 1.16-3.52, P = 0.013), and allograft failure (1.36, 1.03-1.79, P = 0.028). Allograft failure occurred in 218 patients (14.6%). After adjustment for metabolic syndrome, NODAT (1.63, 1.18-2.24, P = 0.003) and CHD (5.48, 3.27-9.20, P < 0.0001) remained strongly associated with increased risk of allograft failure. Metabolic syndrome, NODAT, and CHD are risk factors for allograft failure. NODAT and CHD are risk factors for allograft failure, independent of metabolic syndrome.

Clinical diagnosis of metabolic syndrome: predicting new-onset diabetes, coronary heart disease, and allograft failure late after kidney transplant

Metabolic syndrome is associated with coronary heart disease (CHD) and new-onset diabetes after kidney transplant (NODAT). Using data collected from transplant centers worldwide for the Patient Outcomes in Renal Transplantation study, we examined associations of metabolic syndrome (n = 2253 excluding recipients with diabetes pretransplant), CHD (n = 2253), and NODAT (n = 1840 further excluding recipients with diabetes in the first year post-transplant), with the primary outcome of allograft failure. We assessed risk factors associated with secondary outcomes of metabolic syndrome, NODAT, and CHD after adjusting for type of baseline immunosuppression and transplant center effects. Metabolic syndrome prevalence was 39.8% at 12-24 months post-transplant and 35.4% at 36-48 months. Metabolic syndrome was independently associated with NODAT (hazard ratio 3.46, 95% confidence interval 2.40-4.98, P < 0.0001), CHD (2.03, 1.16-3.52, P = 0.013), and allograft failure (1.36, 1.03-1.79, P = 0.028). Allograft failure occurred in 218 patients (14.6%). After adjustment for metabolic syndrome, NODAT (1.63, 1.18-2.24, P = 0.003) and CHD (5.48, 3.27-9.20, P < 0.0001) remained strongly associated with increased risk of allograft failure. Metabolic syndrome, NODAT, and CHD are risk factors for allograft failure. NODAT and CHD are risk factors for allograft failure, independent of metabolic syndrome.

Troponin I levels and postoperative myocardial infarction following renal transplantation

BACKGROUND

The relationship of routine postoperative troponin I (TnI) monitoring in kidney transplant recipients and in-hospital myocardial infarction (MI) is not known.

METHODS

This observational study evaluated the prevalence of abnormal postoperative TnI (Ortho Clinical Diagnostics assay) in 376 consecutive kidney or kidney/pancreas transplant recipients. In-hospital MI was adjudicated using the universal definition. Rates of death and coronary revascularizations at 1 year were studied. Logistic regression analysis was performed to identify independent predictors of abnormal TnI.

RESULTS

Ninety-five (25%) recipients had abnormal TnI (>0.04 ng/ml) following transplantation. Abnormal TnI levels were more common in older (mean age: 52.2 ± 13.4 vs. 48.3 ± 13.2 years, p = 0.01), diabetic (57.9 vs. 45.6%, p = 0.04), and prior coronary artery disease (31.6 vs. 20.3%, p = 0.02) patients. In-hospital MI occurred in 6 patients (1.6%). All subsequent in-hospital cardiovascular events occurred in the abnormal postoperative TnI group; most in those with TnI levels >1 ng/ml. Previous coronary artery disease was the only independent predictor of a postoperative TnI level >1 ng/ml in multivariate analysis (odds ratio 4.61, 95% confidence interval 1.49-14.32). At 1 year there was no significant difference in death (3.2 vs. 1.8%, p = 0.42) and borderline significant difference in coronary revascularization (5.3 vs. 1.4%, p = 0.049) in abnormal versus normal TnI groups.

CONCLUSIONS

In-hospital MI was infrequent, but abnormal TnI highly prevalent following renal transplantation. Normal TnI levels following renal transplantation had a high negative predictive value in excluding patients likely to develop subsequent postoperative MI. The role of a higher TnI cut-off for screening for postoperative MI in high-risk subgroups deserves future prospective evaluation.

Spectrum of cancer risk among US solid organ transplant recipients

CONTEXT

Solid organ transplant recipients have elevated cancer risk due to immunosuppression and oncogenic viral infections. Because most prior research has concerned kidney recipients, large studies that include recipients of differing organs can inform cancer etiology.

OBJECTIVE

To describe the overall pattern of cancer following solid organ transplantation.

DESIGN, SETTING, AND PARTICIPANTS

Cohort study using linked data on solid organ transplant recipients from the US Scientific Registry of Transplant Recipients (1987-2008) and 13 state and regional cancer registries.

MAIN OUTCOME MEASURES

Standardized incidence ratios (SIRs) and excess absolute risks (EARs) assessing relative and absolute cancer risk in transplant recipients compared with the general population.

RESULTS

The registry linkages yielded data on 175,732 solid organ transplants (58.4% for kidney, 21.6% for liver, 10.0% for heart, and 4.0% for lung). The overall cancer risk was elevated with 10,656 cases and an incidence of 1375 per 100,000 person-years (SIR, 2.10 [95% CI, 2.06-2.14]; EAR, 719.3 [95% CI, 693.3-745.6] per 100,000 person-years). Risk was increased for 32 different malignancies, some related to known infections (eg, anal cancer, Kaposi sarcoma) and others unrelated (eg, melanoma, thyroid and lip cancers). The most common malignancies with elevated risk were non-Hodgkin lymphoma (n = 1504; incidence: 194.0 per 100,000 person-years; SIR, 7.54 [95% CI, 7.17-7.93]; EAR, 168.3 [95% CI, 158.6-178.4] per 100,000 person-years) and cancers of the lung (n = 1344; incidence: 173.4 per 100,000 person-years; SIR, 1.97 [95% CI, 1.86-2.08]; EAR, 85.3 [95% CI, 76.2-94.8] per 100,000 person-years), liver (n = 930; incidence: 120.0 per 100,000 person-years; SIR, 11.56 [95% CI, 10.83-12.33]; EAR, 109.6 [95% CI, 102.0-117.6] per 100,000 person-years), and kidney (n = 752; incidence: 97.0 per 100,000 person-years; SIR, 4.65 [95% CI, 4.32-4.99]; EAR, 76.1 [95% CI, 69.3-83.3] per 100,000 person-years). Lung cancer risk was most elevated in lung recipients (SIR, 6.13 [95% CI, 5.18-7.21]) but also increased among other recipients (kidney: SIR, 1.46 [95% CI, 1.34-1.59]; liver: SIR, 1.95 [95% CI, 1.74-2.19]; and heart: SIR, 2.67 [95% CI, 2.40-2.95]). Liver cancer risk was elevated only among liver recipients (SIR, 43.83 [95% CI, 40.90-46.91]), who manifested exceptional risk in the first 6 months (SIR, 508.97 [95% CI, 474.16-545.66]) and a 2-fold excess risk for 10 to 15 years thereafter (SIR, 2.22 [95% CI, 1.57-3.04]). Among kidney recipients, kidney cancer risk was elevated (SIR, 6.66 [95% CI, 6.12-7.23]) and bimodal in onset time. Kidney cancer risk also was increased in liver recipients (SIR, 1.80 [95% CI, 1.40-2.29]) and heart recipients (SIR, 2.90 [95% CI, 2.32-3.59]).

CONCLUSION

Compared with the general population, recipients of a kidney, liver, heart, or lung transplant have an increased risk for diverse infection-related and unrelated cancers.

Lymphoproliferative disorders after adult kidney transplant: epidemiology and comparison of registry report with claims-based diagnoses

BACKGROUND

Posttransplant lymphoproliferative disorder (PTLD) is a major complication of kidney transplant.

STUDY DESIGN

Retrospective cohort study comparing PTLD incidence rates using US Medicare claims and Organ Procurement and Transplantation Network (OPTN) data, examining risk factors for PTLD in OPTN data, and studying recipient and graft survival after PTLD diagnosis.

SETTING & PARTICIPANTS

All adult first-transplant patients who underwent deceased or living donor kidney-only transplants in 2000-2006 (n = 89,485) followed up through 3 years posttransplant.

PREDICTORS

Recipient and donor characteristics, HLA mismatches, viral serologic test results, and initial immunosuppression.

OUTCOMES

OPTN-reported or Medicare claims-based PTLD diagnosis, recipient and graft survival after OPTN-reported PTLD diagnosis.

MEASUREMENTS

Adjusted HRs for PTLD diagnosis estimated using a Cox proportional hazards model; probability of survival free of all-cause graft failure estimated using the Kaplan-Meier method.

RESULTS

The incidence rate of PTLD during the first posttransplant year was 2-fold higher in Medicare claims (0.46/100 patient-years; 95% CI, 0.39-0.53) than in OPTN data (0.22/100 patient-years; 95% CI, 0.17-0.27). Factors associated with increased rates of PTLD included older age, white race (vs African American), induction with T-cell-depleting antibodies, Epstein-Barr virus seronegativity at the time of transplant, and cytomegalovirus seronegativity at the time of transplant. The adjusted risk of death with graft function was 17.5 (95% CI, 14.3-21.4) times higher after a report of PTLD, and the risk of death-censored graft failure was 5.5 (95% CI, 3.9-7.7) times higher.

LIMITATIONS

Shortcomings inherent in large databases, including inconsistencies in patient follow-up, reporting, and coding practices by transplant centers; insufficient registry data to analyze acute rejection episodes and antirejection treatment; no available data for potential effects of different types of PTLD treatment on patient outcomes.

CONCLUSIONS

Despite the limitations of data collected by registries, PTLD clearly is an important complication; both mortality and death-censored graft failure increase after PTLD.

Cardiovascular disease in chronic kidney disease. A clinical update from Kidney Disease: Improving Global Outcomes (KDIGO)

Cardiovascular morbidity and mortality in patients with chronic kidney disease (CKD) is high, and the presence of CKD worsens outcomes of cardiovascular disease (CVD). CKD is associated with specific risk factors. Emerging evidence indicates that the pathology and manifestation of CVD differ in the presence of CKD. During a clinical update conference convened by the Kidney Disease: Improving Global Outcomes (KDIGO), an international group of experts defined the current state of knowledge and the implications for patient care in important topic areas, including coronary artery disease and myocardial infarction, congestive heart failure, cerebrovascular disease, atrial fibrillation, peripheral arterial disease, and sudden cardiac death. Although optimal strategies for prevention, diagnosis, and management of these complications likely should be modified in the presence of CKD, the evidence base for decision making is limited. Trials targeting CVD in patients with CKD have a large potential to improve outcomes.

Lower estimated glomerular filtration rate and higher albuminuria are associated with mortality and end-stage renal disease. A collaborative meta-analysis of kidney disease population cohorts

We studied here the independent associations of estimated glomerular filtration rate (eGFR) and albuminuria with mortality and end-stage renal disease (ESRD) in individuals with chronic kidney disease (CKD). We performed a collaborative meta-analysis of 13 studies totaling 21,688 patients selected for CKD of diverse etiology. After adjustment for potential confounders and albuminuria, we found that a 15 ml/min per 1.73 m² lower eGFR below a threshold of 45 ml/min per 1.73 m² was significantly associated with mortality and ESRD (pooled hazard ratios (HRs) of 1.47 and 6.24, respectively). There was significant heterogeneity between studies for both HR estimates. After adjustment for risk factors and eGFR, an eightfold higher albumin- or protein-to-creatinine ratio was significantly associated with mortality (pooled HR 1.40) without evidence of significant heterogeneity and with ESRD (pooled HR 3.04), with significant heterogeneity between HR estimates. Lower eGFR and more severe albuminuria independently predict mortality and ESRD among individuals selected for CKD, with the associations stronger for ESRD than for mortality. Thus, these relationships are consistent with CKD stage classifications based on eGFR and suggest that albuminuria provides additional prognostic information among individuals with CKD.

Design considerations and feasibility for a clinical trial to examine coronary screening before kidney transplantation (COST)

BACKGROUND

It is unclear whether benefits outweigh harms for routine screening and prophylactic revascularization to prevent coronary artery disease (CAD) in asymptomatic kidney transplant candidates.

STUDY DESIGN

Pilot feasibility study with prospective observational data collection and patient interviews.

SETTING & PARTICIPANTS

Consecutive patients referred for kidney and/or pancreas transplant at 26 major transplant centers in the United States.

PREDICTORS

Older age, diabetes, prior cardiovascular disease, and multiple traditional CAD risk factors.

OUTCOMES

Eligibility and willingness to participate in a randomized controlled trial (RCT) to study the effect of CAD screening on major adverse cardiac events.

MEASUREMENTS

Patients who would be candidates for a hypothetical RCT of CAD screening were interviewed and asked if they would participate in such a trial. Sample size for the trial was estimated using data for Medicare patients in the US Renal Data System with major adverse cardiac events as the primary end point.

RESULTS

Of consecutive eligible patients, CAD evaluation was not indicated in 398 (24%), already completed before referral in 602 (36%), and pending (and hence eligible for an RCT) in 665 (40%). Of 241 interviewed, 73% indicated they would be willing to participate in an RCT. We estimated that ~4,000 would need to be enrolled to detect a 20% decrease in major adverse cardiac events at >80% power at P < 0.05.

LIMITATIONS

Willingness to participate in an actual clinical trial may be different from indicated in an interview.

CONCLUSION

An RCT to compare the effects of routine screening for CAD versus no screening on major adverse cardiac events is feasible.

Lower estimated glomerular filtration rate and higher albuminuria are associated with all-cause and cardiovascular mortality. A collaborative meta-analysis of high-risk population cohorts

Screening for chronic kidney disease is recommended in people at high risk, but data on the independent and combined associations of estimated glomerular filtration rate (eGFR) and albuminuria with all-cause and cardiovascular mortality are limited. To clarify this, we performed a collaborative meta-analysis of 10 cohorts with 266,975 patients selected because of increased risk for chronic kidney disease, defined as a history of hypertension, diabetes, or cardiovascular disease. Risk for all-cause mortality was not associated with eGFR between 60-105 ml/min per 1.73 m², but increased at lower levels. Hazard ratios at eGFRs of 60, 45, and 15 ml/min per 1.73 m² were 1.03, 1.38 and 3.11, respectively, compared to an eGFR of 95, after adjustment for albuminuria and cardiovascular risk factors. Log albuminuria was linearly associated with log risk for all-cause mortality without thresholds. Adjusted hazard ratios at albumin-to-creatinine ratios of 10, 30 and 300 mg/g were 1.08, 1.38, and 2.16, respectively compared to a ratio of five. Albuminuria and eGFR were multiplicatively associated with all-cause mortality, without evidence for interaction. Similar associations were observed for cardiovascular mortality. Findings in cohorts with dipstick data were generally comparable to those in cohorts measuring albumin-to-creatinine ratios. Thus, lower eGFR and higher albuminuria are risk factors for all-cause and cardiovascular mortality in high-risk populations, independent of each other and of cardiovascular risk factors.

The relationship between kidney function and long-term graft survival after kidney transplant

BACKGROUND

Whether chronic kidney disease (CKD) staging provides a useful framework for predicting outcomes after kidney transplant is unclear.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

We used data from the Patient Outcomes in Renal Transplantation (PORT) Study, including 13,671 transplants from 12 centers during 10 years of follow-up.

PREDICTOR

Estimated glomerular filtration rate (eGFR; in milliliters per minute per 1.73 m(2)) at 12 months posttransplant.

OUTCOMES

All-cause graft failure (a composite end point consisting of return to dialysis therapy, pre-emptive retransplant, or death with function), death-censored graft failure, and death with a functioning graft.

MEASUREMENTS

The relationship between 12-month eGFR and subsequent graft outcomes through 10 years posttransplant was assessed using Cox proportional hazards analyses.

RESULTS

Stage 3 included 63% of patients and was subdivided into stages 3a (eGFR, 45-59 mL/min/1.73 m(2); 34%) and 3b (eGFR, 30-44 mL/min/1.73 m(2); 29%). Compared with stage 2 (eGFR, 60-89 mL/min/1.73 m(2); 24%), adjusted Cox proportional HRs for graft failure were 1.12 (95% CI, 1.01-1.24; P = 0.04) for stage 3a, 1.50 (95% CI, 1.35-1.66; P < 0.001) for stage 3b, 2.86 (95% CI, 2.53-3.22; P < 0.001) for stage 4 (eGFR, 15-29 mL/min/1.73 m(2); 9%), and 13.2 (95% CI, 10.7-16.4; P < 0.001) for stage 5 (eGFR <15 mL/min/1.73 m(2); 1%). For stage 1 (eGFR ≥ 90 mL/min/1.73 m(2); 3%), risk of graft failure was increased (1.41 [95% CI, 1.13-1.75]; P < 0.001), likely due to serum creatinine associations independent of kidney function. Similar associations were seen between CKD stages and mortality.

LIMITATIONS

Retrospective study; lack of gold-standard measurements of true GFR; lack of measures of comorbidity, inflammation, muscle mass, proteinuria, and other noncreatinine markers of eGFR.

CONCLUSIONS

CKD stages validated in the general population provide a useful framework for predicting outcomes after kidney transplant.

Donor exchange programs in kidney transplantation: rationale and operational details from the north central donor exchange cooperative

The increasing need for kidney transplants has led to innovations such as donor exchange programs. These programs offer transplant recipients with incompatible donors an opportunity to receive a compatible kidney. They also provide an alternative to costly desensitization protocols that have unproven long-term outcomes. Donor exchange programs have multiple options, including simple 2-pair exchanges, more complicated domino exchanges, or chain donations. The United States currently is limited by regional programs that provide for kidney donor exchanges. However, with the increasing public interest in and need for kidney transplants, general nephrologists will be approached with questions about these donor exchange programs. The goal of this review is to discuss donor exchange programs, including their role in expanding the donor pool, various types of exchanges, regional centers that provide these programs, and the process involved in patient enrollment. General knowledge of donor exchange programs will help providers in discussing options with patients approaching end-stage kidney disease and transplant.

Predicting coronary heart disease after kidney transplantation: Patient Outcomes in Renal Transplantation (PORT) Study

Traditional risk factors do not adequately explain coronary heart disease (CHD) risk after kidney transplantation. We used a large, multicenter database to compare traditional and nontraditional CHD risk factors, and to develop risk-prediction equations for kidney transplant patients in standard clinical practice. We retrospectively assessed risk factors for CHD (acute myocardial infarction, coronary artery revascularization or sudden death) in 23,575 adult kidney transplant patients from 14 transplant centers worldwide. The CHD cumulative incidence was 3.1%, 5.2% and 7.6%, at 1, 3 and 5 years posttransplant, respectively. In separate Cox proportional hazards analyses of CHD in the first posttransplant year (predicted at time of transplant), and predicted within 3 years after a clinic visit occurring in posttransplant years 1-5, important risk factors included pretransplant diabetes, new onset posttransplant diabetes, prior pre- and posttransplant cardiovascular disease events, estimated glomerular filtration rate, delayed graft function, acute rejection, age, sex, race and duration of pretransplant end-stage kidney disease. The risk-prediction equations performed well, with the time-dependent c-statistic greater than 0.75. Traditional risk factors (e.g. hypertension, dyslipidemia and cigarette smoking) added little additional predictive value. Thus, transplant-related risk factors, particularly those linked to graft function, explain much of the variation in CHD after kidney transplantation.

Subgroup analyses in randomized controlled trials: the need for risk stratification in kidney transplantation

Although randomized controlled trials (RCT) are the gold standard for establishing causation in clinical research, their aggregated results can be misleading when applied to individual patients. A treatment may be beneficial in some patients, but its harms may outweigh benefits in others. While conventional one-variable-at-a-time subgroup analyses have well-known limitations, multivariable risk-based analyses can help uncover clinically significant heterogeneity in treatment effects that may be otherwise obscured. Trials in kidney transplantation have yielded the finding that a reduction in acute rejection does not translate into a similar benefit in prolonging graft survival and improving graft function. This paradox might be explained by the variation in risk for acute rejection among included kidney transplant recipients varying the likelihood of benefit or harm from intense immunosuppressive regimens. Analyses that stratify patients by their immunological risk may resolve these otherwise puzzling results. Reliable risk models should be developed to investigate benefits and harms in rationally designed risk-based subgroups of patients in existing RCT data sets. These risk strata would need to be validated in future prospective clinical trials examining long-term effects on patient and graft survival. This approach may allow better individualized treatment choices for kidney transplant recipients.

Who is caring for kidney transplant patients? Variation by region, transplant center, and patient characteristics

BACKGROUND/AIMS

Despite implications for long-term care, little is known about outpatient care for kidney transplant patients.

METHODS

In this retrospective observational cohort study, outpatient claims were examined for 42,078 Medicare kidney transplant patients using United States Renal Data System data to ascertain location and timing of outpatient visits and type of physician seen. Logistic regression with generalized estimating equations was used to determine the odds and clinical correlates of visits in 4 post-transplant time periods.

RESULTS

In months 1-3, 88% of patients visited their transplant centers, but this declined to 69% in months 25-36. In the adjusted analysis, Native Americans (odds ratio 0.56, 95% confidence interval 0.48-0.65) and Hispanics (OR 0.86, 95% CI 0.80-0.92) were less likely than whites to visit their transplant centers. Centers performing 18-34 (OR 1.44, 95% CI 1.30-1.59) and 35-61 transplants per year (OR 1.30, 95% CI 1.18-1.43) were more likely to see patients than centers performing <18 or >61. Almost 80% of patients saw nephrologists in months 1-3 after transplant. African-Americans (OR 0.85, 95% CI 0.80-0.90), Asians (OR 0.87, 95% CI 0.77-0.97), and Native Americans (OR 0.63, 95% CI 0.53-0.75) were less likely than whites to see nephrologists, as were Hispanics (OR 0.78, 95% CI 0.72-0.84) compared with non-Hispanics.

CONCLUSION

Frequency of visits to transplant centers varied by center and region; most visits were to nephrologists. Patients from minority groups were less likely to visit transplant centers and nephrologists, with possibly significant public health implications.

Use of cardioprotective medications in kidney transplant recipients

Death with function causes half of late kidney transplant failures, and cardiovascular disease (CVD) is the most common cause of death in these patients. We examined the use of potentially cardioprotective medications in a prospective observational study at seven transplant centers in the United States and Canada. Among 935 patients, 87% received antihypertensive medications at both 1 and 6 months after transplantation. Similar antihypertensive regimens were used for patients with and without diabetes and CVD, but with wide variability among centers. In contrast, while 44% of patients were on angiotensin converting enzyme inhibitors (ACEI) or angiotensin receptor blockers (ARB) at the time of transplantation, the proportion taking these agents dropped to 12% at month 1, then increased to 24% at 6 months. Fewer than 30% with CVD or diabetes received ACEI/ARB therapy 6 months posttransplant. Aspirin use was uncommon (<40% of patients). Even among those with diabetes and/or CVD, fewer than 60% received aspirin and only half received a statin at 1 and 6 months. This study demonstrates marked variability in the use of cardioprotective medications in kidney transplant recipients, a finding that may reflect, among several possible explanations, clinical uncertainty due the lack of randomized trials for these medications in this population.