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Background: Systemic barriers to posttransplant care, including access to immunosuppressant medications, contribute to higher rates of kidney transplant failure in racial minorities. Matching donor and recipient HLA alleles reduce allorecognition, easing reliance on immunosuppression. We hypothesize that 0-antigen mismatch transplants may provide stronger protection against graft loss in racial minorities. Methods: We compared adult, single-organ, deceased-donor kidney transplants in the United States from 2007 to 2016 by degree of HLA mismatch (0- versus ≥1-antigen mismatch). We examined time-to-allograft failure, with death as a competing event, using multivariable Weibull models, stratified by recipient race (White versus non-White), and evaluated the interaction between mismatch and recipient race. We used Kaplan-Meier imputation to account for competing risk of death. Results: We analyzed 102 114 transplants (median follow-up, 5.6 y; 16 862 graft losses, 18 994 deaths). Zero-antigen mismatch was associated with improved allograft survival (adjusted subdistribution hazard ratio [sHR] 0.80; 95% confidence interval [CI], 0.75-0.85). When stratified by recipient race, the effect of 0-antigen mismatch was more pronounced in White (unadjusted sHR 0.78; 95% CI, 0.72-0.83) versus non-White recipients (sHR 0.88; 95% CI, 0.79-0.99; interaction P = 0.04). The differential effect was attenuated after adjusting for covariates (sHR 0.78; 95% CI, 0.73-0.84 versus sHR 0.87; 95% CI, 0.77-0.98; interaction P = 0.10). Conclusions: Zero-antigen mismatch transplants conferred a 20% risk reduction in allograft loss, which was similar between non-White and White recipients. This may reflect an increased degree of mismatch at other HLA alleles and non-HLA alleles in non-White recipients or because of the extent of systemic barriers to healthcare borne by minority recipients.
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BACKGROUND: Recent efforts to increase access to kidney transplant (KTx) in the United States include increasing referrals to transplant programs, leading to more pretransplant services. Transplant programs reconcile the costs of these services through the Organ Acquisition Cost Center (OACC). OBJECTIVE: The aim of this study was to determine the costs associated with pretransplant services by applying microeconomic methods to OACC costs reported by transplant hospitals. RESEARCH DESIGN, SUBJECTS, AND MEASURES: For all US adult kidney transplant hospitals from 2013 through 2018 (n=193), we crosslinked the total OACC costs (at the hospital-fiscal year level) to proxy measures of volumes of pretransplant services. We used a multiple-output cost function, regressing total OACC costs against proxy measures for volumes of pretransplant services and adjusting for patient characteristics, to calculate the marginal cost of each pretransplant service. RESULTS: Over 1015 adult hospital-years, median OACC costs attributable to the pretransplant services were $5 million. Marginal costs for the pretransplant services were: initial transplant evaluation, $9k per waitlist addition; waitlist management, $2k per patient-year on the waitlist; deceased donor offer management, $1k per offer; living donor evaluation, procurement and follow-up: $26k per living donor. Longer time on dialysis among patients added to the waitlist was associated with higher OACC costs at the transplant hospital. CONCLUSIONS: To achieve the policy goals of more access to KTx, sufficient funding is needed to support the increase in volume of pretransplant services. Future studies should assess the relative value of each service and explore ways to enhance efficiency.
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Trasplante de Riñón , Listas de Espera , Humanos , Trasplante de Riñón/economía , Trasplante de Riñón/estadística & datos numéricos , Estados Unidos , Masculino , Femenino , Persona de Mediana Edad , Determinación de la Elegibilidad , Adulto , Obtención de Tejidos y Órganos/economía , Costos de la Atención en Salud/estadística & datos numéricosRESUMEN
Advocates for improved equity in kidney transplants in the United States have recently focused their efforts on initiatives to increase referral for transplant evaluation. However, because donor kidneys remain scarce, increased referrals are likely to result in an increasing number of patients proceeding through the evaluation process without ultimately receiving a kidney. Unfortunately, the process of referral and evaluation can be highly resource-intensive for patients, families, transplant programs, and payers. Patients and families may incur out-of-pocket expenses and be required to complete testing and treatments that they might not have chosen in the course of routine clinical care. Kidney transplant programs may struggle with insufficient capacity, inefficient workflow, and challenging programmatic finances, and payers will need to absorb the increased expenses of upfront pretransplant costs. Increased referral in isolation may risk simply transmitting system stress and resulting disparities to downstream processes in this complex system. We argue that success in efforts to improve access through increased referrals hinges on adaptations to the pretransplant process more broadly. We call for an urgent re-evaluation and redesign at multiple levels of the pretransplant system in order to achieve the aim of equitable access to kidney transplantation for all patients with kidney failure.
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Donantes de Tejidos , Obtención de Tejidos y Órganos , Humanos , Riñón , Supervivencia de InjertoRESUMEN
Although heart transplantation is the preferred therapy for appropriate patients with advanced heart failure, the presence of concomitant renal or hepatic dysfunction can pose a barrier to isolated heart transplantation. Because donor organ supply limits the availability of organ transplantation, appropriate allocation of this scarce resource is essential; thus, clear guidance for simultaneous heart-kidney transplantation and simultaneous heart-liver transplantation is urgently required. The purposes of this scientific statement are (1) to describe the impact of pretransplantation renal and hepatic dysfunction on posttransplantation outcomes; (2) to discuss the assessment of pretransplantation renal and hepatic dysfunction; (3) to provide an approach to patient selection for simultaneous heart-kidney transplantation and simultaneous heart-liver transplantation and posttransplantation management; and (4) to explore the ethics of multiorgan transplantation.
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Standard eligibility criteria for simultaneous liver-kidney transplantation (SLK) are in place in the United States. We hypothesize that the benefit associated with SLK over liver transplant alone differs by patient, depending on the specific SLK criteria met. We analyzed a retrospective US cohort of 5446 adult liver transplant or SLK recipients between January 1, 2015, and December 31, 2018, who are potentially qualified for SLK. Exposure was a receipt of SLK. We tested effect modification by the specific SLK eligibility criteria met (end-stage kidney disease, acute kidney injury, chronic kidney disease, or unknown). The primary outcome was death within 1 year of a liver transplant. We used a modified Cox regression analysis containing an interaction term of SLK * time from transplant. Two hundred ten (9%) SLK recipients and 351 (11%) liver-alone recipients died in 1 year. In the overall population, SLK was associated with a mortality benefit over liver transplant on the day of the transplant, without adjustment [HR: 0.59 (95% CI, 0.46-0.76)] and with adjustment [aHR: 0.50 (95% CI, 0.35-0.71)]. However, when SLK eligibility criteria were included, only in patients with end-stage kidney disease was SLK associated with a sustained survival benefit at day 0 [HR: 0.17 (0.08-0.35)] up to 288 (95% CI, 120-649) days post-transplant. Benefit within the first year post-transplant associated with SLK over liver-alone transplantation was only pronounced in patients with end-stage kidney disease but not present in patients meeting other criteria for SLK. A "strict SLK liberal Safety Net" strategy may warrant consideration at the national policy level.
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Fallo Renal Crónico , Trasplante de Riñón , Trasplante de Hígado , Adulto , Humanos , Estados Unidos/epidemiología , Trasplante de Riñón/efectos adversos , Trasplante de Hígado/efectos adversos , Estudios Retrospectivos , Fallo Renal Crónico/cirugía , HígadoRESUMEN
BACKGROUND: Kidney stone disease is common and can lead to complications such as AKI, urinary tract obstruction, and urosepsis. In kidney transplant recipients, complications from kidney stone events can also lead to rejection and allograft failure. There is limited information on the incidence of kidney stone events in transplant recipients. METHODS: We identified 83,535 patients from the United States Renal Data System who received their first kidney transplant between January 1, 2007, and December 31, 2018. We examined the incidence of kidney stone events and identified risk factors associated with a kidney stone event in the first 3 years after transplantation. RESULTS: We found 1436 patients (1.7%) who were diagnosed with a kidney stone in the 3 years after kidney transplant. The unadjusted incidence rate for a kidney stone event was 7.8 per 1000 person-years. The median time from transplant to a kidney stone diagnosis was 0.61 (25%-75% range 0.19-1.46) years. Patients with a history of kidney stones were at greatest risk of a kidney stone event after transplant (hazard ratio [HR], 4.65; 95% confidence interval [CI], 3.82 to 5.65). Other notable risk factors included a diagnosis of gout (HR, 1.53; 95% CI, 1.31 to 1.80), hypertension (HR, 1.29; 95% CI, 1.00 to 1.66), and a dialysis of vintage of ≥9 years (HR, 1.48; 95% CI, 1.18 to 1.86; ref vintage ≤2.5 years). CONCLUSIONS: Approximately 2% of kidney transplant recipients were diagnosed with a kidney stone in the 3 years after kidney transplant. Risk factors of a kidney stone event include a history of kidney stones and longer dialysis vintage.
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Cálculos Renales , Trasplante de Riñón , Humanos , Estados Unidos/epidemiología , Trasplante de Riñón/efectos adversos , Cálculos Renales/epidemiología , Cálculos Renales/etiología , Trasplante Homólogo , Factores de Riesgo , Diálisis RenalRESUMEN
Importance: Testing for coronary heart disease (CHD) in asymptomatic kidney transplant candidates before transplant is widespread and endorsed by various professional societies, but its association with perioperative outcomes is unclear. Objective: To estimate the association of pretransplant CHD testing with rates of death and myocardial infarction (MI). Design, Setting, and Participants: This retrospective cohort study included all adult, first-time kidney transplant recipients from January 2000 through December 2014 in the US Renal Data System with at least 1 year of Medicare enrollment before and after transplant. An instrumental variable (IV) analysis was used, with the program-level CHD testing rate in the year of the transplant as the IV. Analyses were stratified by study period, as the rate of CHD testing varied over time. A combination of US Renal Data System variables and Medicare claims was used to ascertain exposure, IV, covariates, and outcomes. Exposures: Receipt of nonurgent invasive or noninvasive CHD testing during the 12 months preceding kidney transplant. Main Outcomes and Measures: The primary outcome was a composite of death or acute MI within 30 days of after kidney transplant. Results: The cohort comprised 79â¯334 adult, first-time kidney transplant recipients (30â¯147 women [38%]; 25â¯387 [21%] Black and 48â¯394 [61%] White individuals; mean [SD] age of 56 [14] years during 2012 to 2014). The primary outcome occurred in 4604 patients (244 [5.3%]; 120 [2.6%] death, 134 [2.9%] acute MI). During the most recent study period (2012-2014), the CHD testing rate was 56% in patients in the most test-intensive transplant programs (fifth IV quintile) and 24% in patients at the least test-intensive transplant program (first IV quintile, P < .001); this pattern was similar across other study periods. In the main IV analysis, compared with no testing, CHD testing was not associated with a change in the rate of primary outcome (rate difference, 1.9%; 95% CI, 0%-3.5%). The results were similar across study periods, except for 2000 to 2003, during which CHD testing was associated with a higher event rate (rate difference, 6.8%; 95% CI, 1.8%-12.0%). Conclusions and Relevance: The results of this cohort study suggest that pretransplant CHD testing was not associated with a reduction in early posttransplant death or acute MI. The study findings potentially challenge the ubiquity of CHD testing before kidney transplant and should be confirmed in interventional studies.
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Enfermedad Coronaria , Trasplante de Riñón , Infarto del Miocardio , Adulto , Humanos , Femenino , Anciano , Estados Unidos/epidemiología , Adolescente , Trasplante de Riñón/efectos adversos , Estudios Retrospectivos , Estudios de Cohortes , Medicare , Enfermedad Coronaria/diagnóstico , Enfermedad Coronaria/epidemiología , Enfermedad Coronaria/cirugía , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/epidemiología , Infarto del Miocardio/etiologíaRESUMEN
Coronary heart disease is an important source of mortality and morbidity among kidney transplantation and liver transplantation candidates and recipients and is driven by traditional and nontraditional risk factors related to end-stage organ disease. In this scientific statement, we review evidence from the past decade related to coronary heart disease screening and management for kidney and liver transplantation candidates. Coronary heart disease screening in asymptomatic kidney and liver transplantation candidates has not been demonstrated to improve outcomes but is common in practice. Risk stratification algorithms based on the presence or absence of clinical risk factors and physical performance have been proposed, but a high proportion of candidates still meet criteria for screening tests. We suggest new approaches to pretransplantation evaluation grounded on the presence or absence of known coronary heart disease and cardiac symptoms and emphasize multidisciplinary engagement, including involvement of a dedicated cardiologist. Noninvasive functional screening methods such as stress echocardiography and myocardial perfusion scintigraphy have limited accuracy, and newer noninvasive modalities, especially cardiac computed tomography-based tests, are promising alternatives. Emerging evidence such as results of the 2020 International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease trial emphasizes the vital importance of guideline-directed medical therapy in managing diagnosed coronary heart disease and further questions the value of revascularization among asymptomatic kidney transplantation candidates. Optimizing strategies to disseminate and implement best practices for medical management in the broader end-stage organ disease population should be prioritized to improve cardiovascular outcomes in these populations.
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Enfermedad de la Arteria Coronaria , Tamizaje Masivo , Humanos , American Heart Association , Enfermedad de la Arteria Coronaria/diagnóstico , Trasplante de Riñón , Trasplante de Hígado , Estados Unidos , Ensayos Clínicos como AsuntoRESUMEN
Background: Coronary artery disease (CAD) screening in asymptomatic kidney transplant candidates is widespread but not well supported by contemporary cardiology literature. In this study we describe temporal trends in CAD screening before kidney transplant in the United States. Methods: Using the United States Renal Data System, we examined Medicare-insured adults who received a first kidney transplant from 2000 through 2015. We stratified analysis on the basis of whether the patient's comorbidity burden met guideline definitions of high risk for CAD. We examined temporal trends in nonurgent CAD tests within the year before transplant and the composite of death and nonfatal myocardial infarction in the 30 days after transplant. Results: Of 94,832 kidney transplant recipients, 37,139 (39%) underwent at least one nonurgent CAD test in the 1 year before transplant. From 2000 to 2015, the transplant program waitlist volume had increased as transplant volume stayed constant, whereas patients in the later eras had a slightly higher comorbidity burden (older, longer dialysis vintage, and a higher prevalence of diabetes mellitus and CAD). The likelihood of CAD test in the year before transplant increased from 2000 through 2003 and remained relatively stable thereafter. When stratified by CAD risk status, test rates decreased modestly in patients who were high risk but remained constant in patients who were low risk after 2008. Death or nonfatal myocardial infarction within 30 days after transplant decreased from 3% in 2000 to 2% in 2015. Nuclear perfusion scan was the most frequent modality of testing throughout the examined time periods. Conclusions: CAD testing rates before kidney transplantation have remained constant from 2000 through 2015, despite widespread changes in cardiology guidelines and practice.
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Enfermedad de la Arteria Coronaria , Trasplante de Riñón , Infarto del Miocardio , Adulto , Anciano , Enfermedad de la Arteria Coronaria/diagnóstico , Humanos , Trasplante de Riñón/efectos adversos , Medicare , Infarto del Miocardio/diagnóstico , Diálisis Renal , Estados Unidos/epidemiologíaRESUMEN
Importance: While recent policy reforms aim to improve access to kidney transplantation for patients with end-stage kidney disease, the cost implications of kidney waiting list expansion are not well understood. The Organ Acquisition Cost Center (OACC) is the mechanism by which Medicare reimburses kidney transplantation programs, at cost, for costs attributable to kidney transplantation evaluation and waiting list management, but these costs have not been well described to date. Objectives: To describe temporal trends in mean OACC costs per kidney transplantation and to identify factors most associated with cost. Design, Setting, and Participants: This economic evaluation included all kidney transplantation waiting list candidates and recipients in the United States from 2012 to 2017. A population-based study of cost center reports was conducted using data from all Center of Medicare & Medicaid-certified transplantation hospitals. Data analysis was conducted from June to August 2021. Exposures: Year, local price index, transplantation and waiting list volume of transplantation program, and comorbidity burden. Main Outcomes and Measures: Mean OACC costs per kidney transplantation. Results: In 1335 hospital-years from 2012 through 2017, Medicare's share of OACC costs increased from $0.95 billion in 2012 to $1.32 billion in 2017 (3.7% of total Medicare End-Stage Renal Disease program expenditure). Median (IQR) OACC costs per transplantation increased from $81â¯000 ($66â¯000 to $103â¯000) in 2012 to $100â¯000 ($82â¯000 to $125â¯000) in 2017. Kidney organ procurement costs contributed to 36% of mean OACC costs per transplantation throughout the study period. During the study period, transplantation hospitals experienced increases in kidney waiting list volume, kidney waiting list active volume, kidney transplantation volume, and comorbidity burden. For a median-sized transplantation program, mean OACC costs per transplantation decreased with more transplants (-$3500 [95% CI, -$4300 to -$2700] per 10 transplants; P < .001) and increased with year ($4400 [95% CI, $3500 to $5300] per year; P < .001), local price index ($1900 [95% CI, $200 to $3700] per 10-point increase; P = .03), patients listed active on the waiting list ($3100 [95% CI, $1700 to $4600] per 100 patients; P < .001), and patients on the waiting list with high comorbidities ($1500 [9% CI, $600 to $2500] per 1% increase in proportion of waitlisted patients with the highest comorbidity score; P = .002). Conclusions and Relevance: In this study, OACC costs increased at 4% per year from 2012 to 2017 and were not solely attributable to the cost of organ procurement. Expanding the waiting list will likely contribute to further increases in the mean OACC costs per transplantation and substantially increase Medicare liability.
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Fallo Renal Crónico , Trasplante de Riñón , Obtención de Tejidos y Órganos , Anciano , Femenino , Humanos , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/cirugía , Masculino , Medicare , Estados Unidos , Listas de EsperaRESUMEN
There are no established regulations governing patient selection for simultaneous heart-kidney (SHK) transplantation, creating the potential for significant center-level variations in clinical practice. METHODS: Using the United Network for Organ Sharing (UNOS) Standard Transplant Analysis and Research (STAR) file, we examined practice trends and variations in patient selection for SHK at the center level between January 1, 2004 and March 31, 2019. RESULTS: Overall, SHK is becoming more common with most centers performing heart transplants also performing SHK. Among patients who underwent heart transplant who were receiving dialysis, the rate of SHK varied from 22% to 86% at the center level. Among patients not on dialysis, the median estimated glomerular filtration rate (eGFR) of patients receiving SHK varied between 19 and 59 mL/min/1.73 m2 . When adjusting for other factors, the odds of SHK varied 57-fold between the highest and lowest SHK performing centers. CONCLUSION: Variation in SHK at the center level suggests the need for national guidelines around the selection of patients for SHK.
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Trasplante de Corazón , Trasplante de Riñón , Tasa de Filtración Glomerular , Humanos , Riñón , Selección de PacienteRESUMEN
Increasing rates of simultaneous heart-kidney (SHK) transplant in the United States exacerbate the overall shortage of deceased donor kidneys (DDK). Current allocation policy does not impose constraints on SHK eligibility, and how best to do so remains unknown. We apply a decision-analytic model to evaluate options for heart transplant (HT) candidates with comorbid kidney dysfunction. We compare SHK with a "Safety Net" strategy, in which DDK transplant is performed 6 months after HT, only if native kidneys do not recover. We identify patient subsets for whom SHK using a DDK is efficient, considering the quality-adjusted life year (QALY) gains from DDKs instead allocated for kidney transplant-only. For an average-aged candidate with a 50% probability of kidney recovery after HT-only, SHK produces 0.64 more QALYs than Safety Net at a cost of 0.58 more kidneys used. SHK is inefficient in this scenario, producing fewer QALYs per DDK used (1.1) than a DDK allocated for KT-only (2.2). SHK is preferred to Safety Net only for candidates with a lower probability of native kidney recovery (24%-38%, varying by recipient age). This finding favors the implementation of a Safety Net provision and should inform the establishment of objective criteria for SHK transplant eligibility.
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Trasplante de Corazón , Trasplante de Riñón , Obtención de Tejidos y Órganos , Anciano , Análisis Costo-Beneficio , Humanos , Riñón , Selección de Paciente , Donantes de Tejidos , Estados UnidosRESUMEN
BACKGROUND AND OBJECTIVES: In December 2014, the Kidney Allocation System (KAS) was implemented to improve equity in access to transplantation, but preliminary studies in children show mixed results. Thus, we aimed to assess how the 2014 KAS policy change affected racial and ethnic disparities in pediatric kidney transplantation access and related outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a retrospective cohort study of children <18 years of age active on the kidney transplant list from 2008 to 2019 using the Scientific Registry of Transplant Recipients. Log-logistic accelerated failure time models were used to determine the time from first activation on the transplant list and the time on dialysis to deceased donor transplant, each with KAS era or race and ethnicity as the exposure of interest. We used logistic regression to assess odds of delayed graft function. Log-rank tests assessed time to graft loss within racial and ethnic groups across KAS eras. RESULTS: All children experienced longer wait times from activation to transplantation post-KAS. In univariable analysis, Black and Hispanic children and other children of color experienced longer times from activation to transplant compared with White children in both eras; this finding was largely attenuated after multivariable analysis (time ratio, 1.16; 95% confidence interval, 1.01 to 1.32; time ratio, 1.13; 95% confidence interval, 1.00 to 1.28; and time ratio, 1.17; 95% confidence interval, 0.96 to 1.41 post-KAS, respectively). Multivariable analysis also showed that racial and ethnic disparities in time from dialysis initiation to transplantation in the pre-KAS era were mitigated in the post-KAS era. There were no disparities in odds of delayed graft function. Black and Hispanic children experienced longer times with a functioning graft in the post-KAS era. CONCLUSIONS: No racial and ethnic disparities from activation to deceased donor transplantation were seen before or after implementation of the KAS in multivariable analysis, whereas time on dialysis to transplantation and odds of short-term graft loss improved in equity after the implementation of the KAS, without compromising disparities in delayed graft function. PODCAST: This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2021_12_07_CJN06740521.mp3.
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Trasplante de Riñón , Obtención de Tejidos y Órganos , Humanos , Niño , Estados Unidos , Funcionamiento Retardado del Injerto , Estudios Retrospectivos , RiñónRESUMEN
BACKGROUND AND OBJECTIVES: In patients with kidney failure due to IgA nephropathy, IgA deposits can recur in a subsequent kidney transplant. The incidence, effect, and risk factors of IgA nephropathy recurrence is unclear, because most studies have been single center and sample sizes are relatively small. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We performed a multicenter, international, retrospective study to determine the incidence, risk factors, and treatment response of recurrent IgA nephropathy after kidney transplantation. Data were collected from all consecutive patients with biopsy-proven IgA nephropathy transplanted between 2005 and 2015, across 16 "The Post-Transplant Glomerular Disease" study centers in Europe, North America, and South America. RESULTS: Out of 504 transplant recipients with IgA nephropathy, recurrent IgA deposits were identified by kidney biopsy in 82 patients; cumulative incidence of recurrence was 23% at 15 years (95% confidence interval, 14 to 34). Multivariable Cox regression revealed a higher risk for recurrence of IgA deposits in patients with a pre-emptive kidney transplant (hazard ratio, 3.45; 95% confidence interval, 1.31 to 9.17) and in patients with preformed donor-specific antibodies (hazard ratio, 2.59; 95% confidence interval, 1.09 to 6.19). After kidney transplantation, development of de novo donor-specific antibodies was associated with subsequent higher risk of recurrence of IgA nephropathy (hazard ratio, 6.65; 95% confidence interval, 3.33 to 13.27). Immunosuppressive regimen was not associated with recurrent IgA nephropathy in multivariable analysis, including steroid use. Graft loss was higher in patients with recurrence of IgA nephropathy compared with patients without (hazard ratio, 3.69; 95% confidence interval, 2.04 to 6.66), resulting in 32% (95% confidence interval, 50 to 82) graft loss at 8 years after diagnosis of recurrence. CONCLUSIONS: In our international cohort, cumulative risk of IgA nephropathy recurrence increased after transplant and was associated with a 3.7-fold greater risk of graft loss.
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Anticuerpos/sangre , Glomerulonefritis por IGA/epidemiología , Fallo Renal Crónico/etiología , Fallo Renal Crónico/cirugía , Adulto , Aloinjertos/inmunología , Aloinjertos/patología , Biopsia , Brasil/epidemiología , Europa (Continente)/epidemiología , Femenino , Glomerulonefritis por IGA/complicaciones , Glomerulonefritis por IGA/tratamiento farmacológico , Glomerulonefritis por IGA/patología , Supervivencia de Injerto , Humanos , Incidencia , Riñón/patología , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Estados Unidos/epidemiologíaRESUMEN
INTRODUCTION: Current screening algorithms for coronary artery disease (CAD) before kidney transplantation result in many tests but few interventions. OBJECTIVE: The aim of this study was to study the utility of 6-minute walk test (6MWT), an office-based test of cardiorespiratory fitness, for risk stratification in this setting. METHODS: We enrolled 360 patients who are near the top of the kidney transplant waitlist at our institution. All patients underwent CAD evaluation irrespective of 6MWT results. We examined the association between 6MWT and time to CAD-related events (defined as cardiac death, revascularization, nonfatal myocardial infarction, and removal from the waitlist for CAD), treating noncardiac death and waitlist removal for non-CAD reasons as competing events. RESULTS: The 6MWT-based approach designated approximately 45% of patients as "low risk," whereas a risk factor- or symptom-based approach designated 14 and 81% of patients as "low risk," respectively. The 6MWT-based approach was not significantly associated with CAD-related events within 1 year (subproportional hazard ratio [sHR] 1.00 [0.90-1.11] per 50 m) but was significantly associated with competing events (sHR 0.70 [0.66-0.75] per 50 m). In a companion analysis, removing waitlist status from consideration, 6MWT result was associated with the development of CAD-related events (sHR 0.92 [0.84-1.00] per 50 m). CONCLUSIONS: The 6MWT designates fewer patients as high risk and in need of further testing (compared to risk factor-based approaches), but its utility as a pure CAD risk stratification tool is modulated by the background waitlist removal rate. CAD screening before kidney transplant should be tailored according to a patient's actual chance of receiving a transplant.