Effect of a Novel Multicomponent Intervention to Improve Patient Access to Kidney Transplant and Living Kidney Donation: The EnAKT LKD Cluster Randomized Clinical Trial

Importance

Patients with advanced chronic kidney disease (CKD) have the best chance for a longer and healthier life if they receive a kidney transplant. However, many barriers prevent patients from receiving a transplant.

Objectives

To evaluate the effect of a multicomponent intervention designed to target several barriers that prevent eligible patients from completing key steps toward receiving a kidney transplant.

Design, Setting, and Participants

This pragmatic, 2-arm, parallel-group, open-label, registry-based, superiority, cluster randomized clinical trial included all 26 CKD programs in Ontario, Canada, from November 1, 2017, to December 31, 2021. These programs provide care for patients with advanced CKD (patients approaching the need for dialysis or receiving maintenance dialysis).

Interventions

Using stratified, covariate-constrained randomization, allocation of the CKD programs at a 1:1 ratio was used to compare the multicomponent intervention vs usual care for 4.2 years. The intervention had 4 main components, (1) administrative support to establish local quality improvement teams; (2) transplant educational resources; (3) an initiative for transplant recipients and living donors to share stories and experiences; and (4) program-level performance reports and oversight by administrative leaders.

Main Outcomes and Measures

The primary outcome was the rate of steps completed toward receiving a kidney transplant. Each patient could complete up to 4 steps: step 1, referred to a transplant center for evaluation; step 2, had a potential living donor contact a transplant center for evaluation; step 3, added to the deceased donor waitlist; and step 4, received a transplant from a living or deceased donor.

Results

The 26 CKD programs (13 intervention, 13 usual care) during the trial period included 20 375 potentially transplant-eligible patients with advanced CKD (intervention group [n = 9780 patients], usual-care group [n = 10 595 patients]). Despite evidence of intervention uptake, the step completion rate did not significantly differ between the intervention vs usual-care groups: 5334 vs 5638 steps; 24.8 vs 24.1 steps per 100 patient-years; adjusted hazard ratio, 1.00 (95% CI, 0.87-1.15).

Conclusions and Relevance

This novel multicomponent intervention did not significantly increase the rate of completed steps toward receiving a kidney transplant. Improving access to transplantation remains a global priority that requires substantial effort.

Trial Registration

ClinicalTrials.gov Identifier: NCT03329521.

Enhance Access to Kidney Transplantation and Living Kidney Donation (EnAKT LKD): Statistical Analysis Plan of a Registry-Based, Cluster-Randomized Clinical Trial

BACKGROUND

Enhance Access to Kidney Transplantation and Living Kidney Donation (EnAKT LKD) is a quality improvement intervention designed to enhance access to kidney transplantation and living kidney donation. We conducted a cluster-randomized clinical trial to evaluate the effect of the intervention versus usual care on completing key steps toward receiving a kidney transplant.

OBJECTIVE

To prespecify the statistical analysis plan for the EnAKT LKD trial.

DESIGN

The EnAKT LKD trial is a pragmatic, 2-arm, parallel-group, registry-based, open-label, cluster-randomized, superiority, clinical trial. Randomization was performed at the level of the chronic kidney disease (CKD) programs (the "clusters").

SETTING

Twenty-six CKD programs in Ontario, Canada.

PARTICIPANTS

More than 10 000 patients with advanced CKD (ie, patients approaching the need for dialysis or receiving maintenance dialysis) with no recorded contraindication to receiving a kidney transplant.

METHODS

The trial data (including patient characteristics and outcomes) will be obtained from linked administrative health care databases (the "registry"). Stratified covariate-constrained randomization was used to allocate the 26 CKD programs (1:1) to provide the intervention or usual care from November 1, 2017, to December 31, 2021 (4.17 years). CKD programs in the intervention arm received the following: (1) support for local quality improvement teams and administrative needs; (2) tailored education and resources for staff, patients, and living kidney donor candidates; (3) support from kidney transplant recipients and living kidney donors; and (4) program-level performance reports and oversight by program leaders.

OUTCOMES

The primary outcome is completing key steps toward receiving a kidney transplant, where up to 4 unique steps per patient will be considered: (1) patient referred to a transplant center for evaluation, (2) a potential living kidney donor begins their evaluation at a transplant center to donate a kidney to the patient, (3) patient added to the deceased donor transplant waitlist, and (4) patient receives a kidney transplant from a living or deceased donor.

ANALYSIS PLAN

Using an intent-to-treat approach, the primary outcome will be analyzed using a patient-level constrained multistate model adjusting for the clustering in CKD programs.

TRIAL STATUS

The EnAKT LKD trial period is November 1, 2017, to December 31, 2021. We expect to analyze and report the results once the data for the trial period is available in linked administrative health care databases.

TRIAL REGISTRATION

The EnAKT LKD trial is registered with the U.S. National Institute of Health at clincaltrials.gov (NCT03329521 available at https://clinicaltrials.gov/ct2/show/NCT03329521).

STATISTICAL ANALYTIC PLAN

Version 1.0 August 26, 2022.

Retrospective Analysis of Tacrolimus Intrapatient Variability as a Measure of Medication Adherence

Background:

Increased intrapatient variability (IPV) in tacrolimus levels is associated with graft rejection, de novo donor-specific antibodies, and graft loss. Medication nonadherence may be a significant contributor to high IPV.

Objective:

The objective of this study is to determine the utility of tacrolimus IPV in detecting nonadherence by examining the relationship between self-reported adherence and tacrolimus coefficient of variability (COV), a measure of IPV.

Design:

Retrospective cohort study.

Setting:

St. Michael’s Hospital, Toronto, Ontario.

Patients:

All patients who were at least 1-year post-kidney transplant as of March 31, 2019, prescribed tacrolimus as an immunosuppressant and had a self-reported adherence status. Patients were excluded from the primary analysis of examining the correlation between COV and self-reported adherence if they lacked a calculatable COV.

Measurements:

Self-reported adherence, COV, demographic data, transplant, and medication history.

Methods:

A modified Basel Assessment of Adherence to Immunosuppressive Medications Scale (BAASIS) administered by healthcare professionals to assess self-reported adherence was used. The COV of tacrolimus trough levels was calculated and its correlation to BAASIS response was noted. The median COV was used as a cutoff to examine the characteristics of patients deemed “high COV” and “low COV.”

Results:

A total of 591 patients fit the initial criteria; however, only 525 had a recent calculatable COV. Overall, 92.38% of the population were adherent by self-report. Primary analysis identified a COV of 25.2% and 29.6% in self-reported adherent and nonadherent patients, respectively, though the result was not significant (P = .2). Secondary analyses showed a significant correlation between younger age at transplant and at the time of adherence self-reporting with nonadherence (P = .01). In addition, there was a strong correlation between those nonadherent with routine post-transplant blood work and younger age (P < .01).

Limitations:

The limitations included modified nonvalidated BAASIS questionnaire, social desirability bias, BAASIS only administered in English, and patients with graft failure not active in clinic not being captured.

Conclusions:

The COV should not be used as the sole method for determining medication adherence. However, COV may have some utility in capturing individuals who are not adherent to their blood work or patients who are having a poor response to tacrolimus and should be switched to another medication.

A Quality Improvement Intervention to Enhance Access to Kidney Transplantation and Living Kidney Donation (EnAKT LKD) in Patients With Chronic Kidney Disease: Clinical Research Protocol of a Cluster-Randomized Clinical Trial

Background:

Many patients with kidney failure will live longer and healthier lives if they receive a kidney transplant rather than dialysis. However, multiple barriers prevent patients from accessing this treatment option.

Objective:

To determine if a quality improvement intervention provided in chronic kidney disease (CKD) programs (vs. usual care) enables more patients with no recorded contraindications to kidney transplant to complete more steps toward receiving a kidney transplant.

Design:

This protocol describes a pragmatic 2-arm, parallel-group, open-label, registry-based, cluster-randomized clinical trial—the Enhance Access to Kidney Transplantation and Living Kidney Donation (EnAKT LKD) trial.

Setting:

All 26 CKD programs in Ontario, Canada, with a trial start date of November 1, 2017. The original end date of March 31, 2021 (3.4 years) has been extended to December 31, 2021 (4.1 years) due to the COVID-19 pandemic.

Participants:

During the trial, the 26 CKD programs are expected to care for more than 10 000 adult patients with CKD (including patients approaching the need for dialysis and patients receiving dialysis) with no recorded contraindications to a kidney transplant.

Intervention:

Programs were randomly allocated to provide a quality improvement intervention or usual care. The intervention has 4 main components: (1) local quality improvement teams and administrative support; (2) tailored education and resources for staff, patients, and living kidney donor candidates; (3) support from kidney transplant recipients and living kidney donors; and (4) program-level performance reports and oversight by program leaders.

Primary Outcome:

The primary outcome is the number of key steps completed toward receiving a kidney transplant analyzed at the cluster level (CKD program). The following 4 unique steps per patient will be counted: (1) patient referred to a transplant center for evaluation, (2) at least one living kidney donor candidate contacts a transplant center for an intended recipient and completes a health history questionnaire to begin their evaluation, (3) patient added to the deceased donor transplant wait list, and (4) patient receives a kidney transplant from a living or deceased donor.

Planned Primary Analysis:

Study data will be obtained from Ontario’s linked administrative healthcare databases. An intent-to-treat analysis will be conducted comparing the primary outcome between randomized groups using a 2-stage approach. First stage: residuals are obtained from fitting a regression model to individual-level variables ignoring intervention and clustering effects. Second stage: residuals from the first stage are aggregated at the cluster level as the outcome.

Limitations:

It may not be possible to isolate independent effects of each intervention component, the usual care group could adopt intervention components leading to contamination bias, and the relatively small number of clusters could mean the 2 arms are not balanced on all baseline prognostic factors.

Conclusions:

The EnAKT LKD trial will provide high-quality evidence on whether a multi-component quality improvement intervention helps patients complete more steps toward receiving a kidney transplant.

Trial registration:

Clinicaltrials.gov; identifier: NCT03329521.

COVID-19 Outbreak in an Urban Hemodialysis Unit

RATIONALE & OBJECTIVE

Hemodialysis patients are at increased risk for coronavirus disease 2019 (COVID-19) transmission due in part to difficulty maintaining physical distancing. Our hemodialysis unit experienced a COVID-19 outbreak despite following symptom-based screening guidelines. We describe the course of the COVID-19 outbreak and the infection control measures taken for mitigation.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

237 maintenance hemodialysis patients and 93 hemodialysis staff at a single hemodialysis center in Toronto, Canada.

EXPOSURE

Universal screening of patients and staff for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

OUTCOMES

The primary outcome was detection of SARS-CoV-2 in nasopharyngeal samples from patients and staff using reverse transcriptase-polymerase chain reaction (RT-PCR).

ANALYTICAL APPROACH

Descriptive statistics were used for clinical characteristics and the primary outcome.

RESULTS

11 of 237 (4.6%) hemodialysis patients and 11 of 93 (12%) staff members had a positive RT-PCR test result for SARS-CoV-2. Among individuals testing positive, 12 of 22 (55%) were asymptomatic at time of testing and 7 of 22 (32%) were asymptomatic for the duration of follow-up. One patient was hospitalized at the time of SARS-CoV-2 infection and 4 additional patients with positive test results were subsequently hospitalized. 2 (18%) patients required admission to the intensive care unit. After 30 days' follow-up, no patients had died or required mechanical ventilation. No hemodialysis staff required hospitalization. Universal droplet and contact precautions were implemented during the outbreak. Hemodialysis staff with SARS-CoV-2 infection were placed on home quarantine regardless of symptom status. Patients with SARS-CoV-2 infection, including asymptomatic individuals, were treated with droplet and contact precautions until confirmation of negative SARS-CoV-2 RT-PCR test results. Analysis of the outbreak identified 2 index cases with subsequent nosocomial transmission within the dialysis unit and in shared shuttle buses to the hemodialysis unit.

LIMITATIONS

Single-center study.

CONCLUSIONS

Universal SARS-CoV-2 testing and universal droplet and contact precautions in the setting of an outbreak appeared to be effective in preventing further transmission.

The First North American Experience Using Glycosorb Immunoadsorption Columns for Blood Group-Incompatible Kidney Transplantation

Background:

Blood group incompatibility (ABOi) is the most common barrier to living donor kidney transplantation. Options for such recipients include kidney paired donation (KPD) or desensitization methodology to reduce blood antibody response.

Objective:

The objective of this study is to report on the first North America experience in ABOi living donor kidney transplantation using Glycosorb ABO immunoadsorption columns.

Design:

Retrospective observational cohort study.

Setting:

Renal transplant program at St. Michael’s Hospital, Unity Health Toronto, University of Toronto.

Patients:

Twenty-six ABOi living donor transplants from August 2011 through February 2020 were undertaken at our center.

Measurements:

Renal allograft and patient survival postdesensitization for ABOi living donor transplants and isohemagglutinin titer reduction.

Methods:

Preoperative immunosuppressive regimen consisted of a single dose of Rituximab 375 mg/m² IV on day −28; tacrolimus, mycophenolic acid, and prednisone to start on day −7. Immunoadsorption treatments with Glycosorb A or B columns were performed on day −7 through day −1 based on anti-A or anti-B titers on Spectra Optia Apheresis System. Immunosuppression included basiliximab, solumedrol followed by oral prednisone, once-daily tacrolimus, and mycophenolic acid. The mean follow-up was 53 months (3-96 months).

Results:

A total of 26 individuals underwent an attempt at desensitization of whom 24 patients underwent immediate transplant. One patient had a rebound in titers and subsequently was transplanted from a blood group compatible living donor. A second patient had an unrelated medical issue and desensitization was discontinued. Five-year patient survival was 96% and death censored allograft survival was 92%. Posttransplant anti-A or anti-B titers were monitored daily for the first 7 days posttransplant and every 2 days from days 7 to 14. There were no acute rejections seen in this cohort of transplant recipients.

Limitations:

As our protocol was first initiated as proof of concept, a few recipients had low initial isohemagglutinin titers. This may have contributed to improved clinical outcomes.

Conclusions:

ABO column immunoadsorption with specific columns is a safe and effective method for ABOi living donor kidney transplantation, and an option when KPD is less than ideal.

Trial not registered as this was a retrospective cohort review.

Projecting the Number of Posttransplant Clinic Visits With a Rise in the Number of Kidney Transplants: A Case Study From Ontario, Canada

Background:

In Ontario, kidney transplants have risen by 4% annually in recent years. An understanding of how this will affect the future annual number of posttransplant follow-up visits informs how to organize and deliver care.

Objective:

We projected the required number of annual posttransplant follow-up nephrology visits to inform posttransplant care delivery.

Design:

Population-based retrospective cohort study.

Setting:

Linked databases from Ontario, Canada (population 14 million).

Patients:

Incident kidney transplant recipients from years 2008 to 2013.

Measurements:

Frequency, distance traveled, and current and projected visits for posttransplant follow-up.

Methods:

Assuming a graft survival of 13 years and using the mean number of posttransplant clinic visits in years 1, 2, and 3, we forecasted the number of clinic visits needed in the year 2027.

Results:

Using data from 2443 recipients, the mean (SD) number of clinic visits per recipient was 14.0 (9.2) in the first year after transplant, and 3.9 (6.2) and 3.0 (5.3) in the second and third year, respectively. If transplant rates rise by 4% per year until 2027, the estimated annual visits number will increase from 30 622 to 43 948. The median (25th, 75th percentile) distance between transplant center and patient’s home was 30 (13, 65) km. The median round-trip travel distance for these visits in the first year after transplantation was 603 km per recipient, and median driving cost was Can$344 (2017).

Limitations:

Regarding patient expense, limitations include that distances traveled were calculated orthodromically, and we did not account for patient cost of follow-up beyond that of vehicular travel. Regarding follow-up projections, limitations include the assumption that graft life span will not change, follow-up patterns do not differ between donor kidney type, and we did not survey stakeholders as to their preferred method of follow-up.

Conclusion:

We quantified the increase in posttransplant visits when regional annual rates of transplantation rise. Strategies recognizing the burden of these visits may enhance patient-centered care, as it is unclear how some patients manage costs, nor how the current health care system will manage the demand.

Ten years of Israel's organ transplant law: is it on the right track?

The Israeli organ donor law was established in 2008. In the ensuing 10 years there have been some improvements in deceased donation and living donor rates and a reduction in the unethical practice of transplant tourism. There is, however, controversy regarding increased access to transplant for those who have been living donors, who are family members of deceased donors, or who have registered their intent to donate. The issue of routine retrieval versus obtaining consent for organ donation has also been raised. This commentary will address these issue, and propose some steps for improvement of the current Israeli organ donation system.

Effect of organ donation after circulatory determination of death on number of organ transplants from donors with neurologic determination of death

BACKGROUND

To increase the available pool of organ donors, Ontario introduced donation after circulatory determination of death (DCD) in 2006. Other jurisdictions have reported a decrease in donations involving neurologic determination of death (NDD) after implementation of DCD, with a drop in organ yield and quality. In this study, we examined the effect of DCD on overall transplant activity in Ontario.

METHODS

We examined deceased donor and organ transplant activity during 3 distinct 4-year eras: pre-DCD (2002/03 to 2005/06), early DCD (2006/07 to 2009/10) and recent DCD (2010/11 to 2013/14). We compared these donor groups by categorical characteristics.

RESULTS

Donation increased by 57%, from 578 donors in the pre-DCD era to 905 donors in the recent DCD era, with a 21% proportion (190/905) of DCD donors in the recent DCD era. However, overall NDD donation also increased. The mean length of hospital stay before declaration for NDD was 2.7 days versus 6.0 days before withdrawal of life support and subsequent asystole in cases of DCD. The average organ yield was 3.73 with NDD donation versus 2.58 with DCD (p < 0.001). Apart from hearts, all organs from DCD donors were successfully transplanted. From the pre-DCD era to the recent DCD era, transplant activity in each era increased for all solid-organ recipients, including heart (from 158 to 216), kidney (from 821 to 1321), liver (from 477 to 657) and lung (from 160 to 305).

INTERPRETATION

Implementation of DCD in Ontario led to increased transplant activity for all solid-organ recipients. There was no evidence that the use of DCD was pre-empting potential NDD donation. In contrast to groups receiving other organs, heart transplant candidates have not yet benefited from DCD.

The role of thrombectomy and diffusion-weighted imaging with MRI in post-transplant renal vein thrombosis: a case report

Background

Surgical thrombectomy in the context of acute renal vein thrombosis (RVT) post-transplantation has had limited success, with considerable variation in the surgical techniques used. Unfortunately, it is usually followed by allograft nephrectomy within a few days if rapid allograft recovery does not ensue. We report a case of acute RVT in which nephrectomy was not performed despite a prolonged requirement for dialysis post-thrombectomy, but with recovery of renal function 2 weeks later. We also report the findings of serial MRI with diffusion-weighted imaging (DW-MRI) throughout the patient’s recovery, which provided novel insights into allograft microvascular perfusion changes post-thrombectomy.

Case presentation

A 65-year old patient underwent living-unrelated kidney transplantation complicated by acute RVT. Surgical thrombectomy and irrigation led to a delayed, but significant, recovery of renal function. Serial non-contrast DW-MRI scanning was used to non-invasively assess microvascular renal blood flow post-operatively. Unlike standard Doppler ultrasonography, DW-MRI documented reduced microvascular perfusion initially, with gradual but incomplete recovery that mirrored the partial improvement in renal function.

Conclusions

Our findings suggest that surgical thrombectomy may be more effective than previously described if followed by careful patient observation. Moreover, diffusion-weighted MRI appears to provide important insights into the pathophysiology of delayed graft function and deserves further investigation.

Study of Cardiovascular Outcomes in Renal Transplantation: A Prospective, Multicenter Study to Determine the Incidence of Cardiovascular Events in Renal Transplant Recipients in Ontario, Canada

Background:

Renal transplant recipients (RTRs) are at significantly higher risk for morbidity and mortality compared with the general population, largely attributed to cardiovascular disease (CVD). Previous estimates of CVD events have come from health care databases and retrospective studies.

Objective:

The objective of this study was to prospectively determine the prevalence of risk factors and incidence of CVD events in a Canadian cohort of RTRs.

Design:

Study of Cardiovascular Outcomes in Renal Transplantation (SCORe) was a prospective, longitudinal, multicenter observational study.

Setting:

Adult RTRs were recruited from 6 participating transplant sites in Ontario, Canada.

Patients:

Eligible patients were those receiving a living or deceased donor renal transplant. Patients who received simultaneous transplant of any other organ were excluded.

Measurements:

Primary outcomes included myocardial infarction (MI) defined by American College of Cardiology (ACC-MI) criteria, and major adverse cardiac events (MACE), defined as cardiovascular (CV) death, ACC-MI, coronary revascularization, and nonhemorrhagic stroke. CV events were adjudicated by a single, independent cardiologist.

Methods:

CV and transplant-specific risk factors that predict MACE and ACC-MI were identified by stepwise regression analysis using the Cox proportional hazards model.

Results:

A total of 1303 patients enrolled across 6 transplant centers were followed for 4.5 ± 1.6 years (mean ± SD). Incidence of MACE was 7.0%, with significant independent predictors/risk factors including age, diabetes, coronary revascularization, nonhemorrhagic stroke, and renal replacement therapy (RRT). ACC-MI incidence was 4.0%, with significant independent predictors/risk factors including age, coronary revascularization, and duration of RRT in excess of the median value (2.91 years).

Limitations:

Patients were recruited from a single province, so may not reflect the experience of RTRs in other areas of Canada.

Conclusions:

Using a prospective design and rigorous methodology, this study found that the incidence of CV events after renal transplantation was elevated relative to the general Canadian population and was comparable with that reported in patient registries, thus helping validate the utility of retrospective analysis in this field. SCORe highlights the importance of monitoring RTRs for traditional cardiac and transplant-specific CV risk factors to help prevent CV morbidity and mortality. Further research is needed to investigate a broader range of potential risk factors and their combined effects on incident CV events.

Two Years Postconversion From a Prograf-Based Regimen to a Once-Daily Tacrolimus Extended-Release Formulation in Stable Kidney Transplant Recipients

Tacrolimus extended-release (XL) is a once-daily formulation recently developed to reduce the frequency of dosing for patients currently using the twice-a-day formulation of tacrolimus (TAC). As reported previously, 67 kidney transplant recipients were safely converted (1:1 mg basis, total daily dose) from TAC twice-a-day to XL once-daily in the morning and were maintained on an am dosing regimen of XL using the same therapeutic monitoring and patient care techniques currently employed with TAC. The 2-year postconversion patient (100%) and graft (98.5%) survival, incidence of biopsy-confirmed acute rejection (6.0%), incidence of multiple rejections (1.5%), and safety profile (posttransplant diabetes, hyperlipidemia, hypertension, infections, renal dysfunction, hepatic dysfunction, and malignancies) were consistent with or more favorable than those previously reported for TAC twice-a-day.

Impact of kidney transplantation on sleep apnoea in patients with end-stage renal disease

BACKGROUND

Sleep apnoea is common in patients with end-stage renal disease. Although individual case reports have described an improvement in sleep apnoea following kidney transplantation, there have been no longitudinal studies of a case series to determine what proportion of patients with sleep apnoea improve.

METHODS

Dialysis-dependent patients awaiting kidney transplantation and pre-dialysis patients with an identified living donor kidney had overnight polysomnography, which was repeated several months after successful kidney transplantation. Patients were divided into apnoeic and non-apnoeic groups based on an apneoa-hypopnoea index (AHI) > 10/h during pre-transplant polysomnography and, following transplantation, apnoeic patients were further divided into responders and non-responders based on >50% reduction in AHI and/or AHI < 10/h.

RESULTS

Eighteen patients (11 men, 7 women), aged 27-65, were studied. Pre-transplant sleep apnoea was present in 11 of 18 (61%) patients. Although transplantation was associated with a significant reduction in blood urea nitrogen and serum creatinine, there were no significant changes in AHI (pre vs post: 20.2 +/- 15.1 vs 23.5 +/- 21.3). Among the 11 apnoeic patients, only three met the criteria for a significant improvement ('responder'). There were no patient characteristics, sleep apnoea indices or renal function changes that distinguished responders from non-responders.

CONCLUSIONS

Sleep apnoea improves in a minority of patients with end-stage renal disease following successful kidney transplantation. Specific determinants of improvement were not identified.

Treatment and one-year outcome of patients with renal dysfunction across the broad spectrum of acute coronary syndromes

BACKGROUND

There are limited data on the treatment and long-term outcome of patients with renal dysfunction across the broad spectrum of acute coronary syndromes (ACS) in Canada.

OBJECTIVES

To examine the treatment patterns and outcome of ACS patients with renal dysfunction.

METHODS

In the prospective, multicentre, Canadian ACS Registry, 3510 patients hospitalized for ACS (including unstable angina, ST and non-ST elevation myocardial infarction) were categorized into four groups: normal renal function (creatinine clearance [CrCl] 90 mL/min or greater; n=1152), mild renal dysfunction (CrCl 60 mL/min to 89 mL/min; n=1253), moderate renal dysfunction (CrCl 30 mL/min to 59 mL/min; n=944) and severe renal dysfunction (CrCl less than 30 mL/min; n=161). Multivariable logistic regression analysis was performed to examine the independent prognostic value of renal dysfunction, and the association of various therapies with one-year survival.

RESULTS

All-cause mortality at one year was 2.8%, 6.4%, 14.5% and 40.9% in patients with normal renal function, and mild, moderate and severe renal dysfunction, respectively (P for trend<0.001). After adjusting for other prognosticators, moderate (OR 1.82, 95% CI 1.08 to 3.08) and severe (OR 6.29, 95% CI 3.37 to 11.77) renal dysfunction remained independent predictors of one-year death. Patients with renal dysfunction were less likely to receive fibrinolytic therapy, to undergo coronary angiography and revascularization in hospital, and to be treated with acetylsalicylic acid, beta-blockers and lipid-lowering therapy at discharge and at one-year follow-up. The association of in-hospital revascularization, and discharge use of acetylsalicylic acid and beta-blockers with better one-year survival was similar among patients with normal and impaired renal function.

CONCLUSIONS

Renal dysfunction is prevalent and independently predicts higher mortality in patients with ACS. The current underutilization of effective therapies may contribute to the poor outcome. There remains an important opportunity to improve care in this high-risk population.

Conversion of stable kidney transplant recipients from a twice daily Prograf-based regimen to a once daily modified release tacrolimus-based regimen

Modified release (MR) tacrolimus is an extended release formulation administered once daily (qD). The purpose of this pharmacokinetic (PK) study was to evaluate tacrolimus exposure in stable kidney transplant recipients converted from Prograf twice a day to MR tacrolimus qD.

METHODS

This was an open-label, multicenter study with a crossover design. Eligible patients were 18 to 65 years of age, more than 6 months posttransplant with stable renal function, and received stable Prograf doses more than 2 weeks prior to enrollment. Patients received Prograf twice a day through day 7; 24-hour PK profiles were obtained on days 1 and 7. Patients were converted to the same milligram-for-milligram daily dose of MR tacrolimus qD in the morning on day 8; 24-hour PK profiles were obtained for MR tacrolimus on days 8, 14, and 21. Laboratory and safety parameters were also evaluated.

RESULTS

Most patients (67 of 70) completed all 5 PK profiles. The 90% confidence intervals (CI) for the MR tacrolimus vs Prograf comparison at steady state (days 14 and 21 vs days 1 and 7) were 90.7 and 99.4 for AUC0-24 and 82.7 and 91.9 for Cmin. MR tacrolimus was well tolerated with a safety profile comparable to that of Prograf. AUC0-24 was highly correlated to Cmin for Prograf (day 1, r = 0.80; day 7, r = 0.84) and MR tacrolimus (day 14, r = 0.92; day 21, r = 0.86). Renal function remained stable after conversion to MR tacrolimus.

CONCLUSION

The steady state PK of MR tacrolimus are equivalent to Prograf after a milligram-for-milligram conversion in stable kidney transplant recipients. The results provide evidence to support a safe 1:1 conversion from Prograf twice a day to MR tacrolimus.

Diltiazem use in tacrolimus-treated renal transplant recipients

BACKGROUND

Calcium channel blockers are widely used in the treatment of post-transplant hypertension but have the potential for drug interaction with calcineurin inhibitors. Renal allograft outcomes when diltiazem is used with cyclosporine have been reported, but similar data with tacrolimus are not available.

METHODS

We performed a retrospective analysis of all our renal transplant recipients from March 1997 to March 2002 who were given tacrolimus, mycophenolate mofetil and prednisone. Patients were divided into two groups based on whether diltiazem was started in the first postoperative week. Outcome measures included renal function up to 2 years post-transplant, blood pressure (BP) control, tacrolimus exposure, and costs related to tacrolimus monitoring.

RESULTS

Sixty-four patients constituted the diltiazem group and 32 the control group. Their baseline characteristics were similar. The mean average daily dose of diltiazem used was 213.95 mg/day. There was no difference in renal function, graft survival, or patient survival over 2 years. BP control was similar although the diltiazem group required more medication. Diltiazem was discontinued in four patients due to side-effects. There was no difference in tacrolimus-related side-effects between the two groups. There was also no difference in tacrolimus exposure, cost related to tacrolimus monitoring, or combined costs when the expense of diltiazem was added.

CONCLUSION

Diltiazem use is acceptably safe and efficacious in renal transplant recipients treated with tacrolimus-based immunosuppressive therapy. It can be considered as a first-line antihypertensive in these patients and is cost neutral for tacrolimus use.

Review of clinical outcomes in nocturnal haemodialysis patients after renal transplantation

BACKGROUND

Nocturnal haemodialysis (NHD) is a novel form of haemodialysis therapy that is associated with improved blood pressure control when compared to conventional haemodialysis (CHD). Current studies suggest that NHD lowers blood pressure through a decrease in peripheral resistance. The graft and blood pressure outcomes of NHD patients who undergo renal transplantation are unknown.

METHODS

We reviewed the renal allograft and blood pressure outcomes of 15 NHD patients who underwent renal transplantation. An age and vintage matched cohort of 29 CHD patients was used as controls.

RESULTS

The rate of delayed graft function (DGF) tended to be higher in the NHD group compared to the CHD group (64 vs 41%, P = 0.15), however the 1-year graft function (53+/-6 vs 59+/-5 ml/min, P = 0.426) and graft survival (92 vs 95%, P = 0.751) were similar. Intra-operatively, NHD patients had lower minimum systolic (92+/-5 vs 109+/-4, P = 0.03) and diastolic (48+/-3 vs 64+/-2, P = 0.02) blood pressures in comparison to the CHD cohort. Pathologically, acute tubular necrosis accounted for 100% of DGF in the NHD group in contrast to 75% in the CHD population (P = 0.01). Pre-transplant mean systolic BP (sBP) was significantly lower in the NHD group compared to the CHD group (113+/-6 vs 145+/-10 mmHg, P<0.001). At 12 months post-transplant, mean sBP increased from baseline in the NHD group ( triangle up sBP 22+/-7 mmHg, P = 0.009) while in the CHD group mean sBP fell (Delta sBP -14+/-5 mmHg, P = 0.014). Mean arterial and diastolic BP exhibited similar changes. These trends persisted after 24 months of post-transplant follow-up.

CONCLUSIONS

One-year graft outcomes and blood pressures are similar for NHD and CHD patients who undergo renal transplantation. Unlike CHD patients, NHD patients experienced a significant fall in their intra-operative blood pressures, which likely contributed towards the delayed graft function in this cohort of patients. Further prospective studies are needed to examine the underlying differences in haemodynamics and long-term graft survival between the two renal replacement modalities.

A pilot study of steroid-free immunosuppression in the prevention of acute rejection in renal allograft recipients

BACKGROUND

Corticosteroids have been a mainstay of rejection prophylaxis for several decades, despite the multiple adverse effects of long-term use, including weight gain, hyperlipidemia, diabetes, hypertension, and bone disease. The detrimental effect of steroids on the metabolic profile begins in the early posttransplantation period, and the complete avoidance of steroids in transplantation would therefore be optimal. We hypothesized that the addition of mycophenolate mofetil (MMF) and a humanized monoclonal anti-CD25 antibody (daclizumab) to a cyclosporine (CsA microemulsion)-based immunosuppression protocol would permit transplantation without steroids.

METHODS

Steroid-free renal transplantation was attempted in 57 patients treated with daclizumab, MMF, and CsA. Twenty-eight patients received kidneys from living donors; the remaining 29 received cadaveric grafts.

RESULTS

At 1 year, patient and graft survival were 95% and 89%, respectively. Fourteen patients (25%) experienced rejections, of which 13 were readily reversed with steroids; 1 patient required OKT3. Mean serum creatinine at 12 months for patients not experiencing rejection was 149+/-58 micromol/L, compared with 158+/-102 micromol/L for those experiencing rejection. Five patients required hospitalization for infection; no patients developed lymphoproliferative disease. At baseline, 17 patients required 3 or more antihypertensive medications, compared with 2 patients at 1 year. Three of 43 nondiabetic patients developed diabetes during the study. There was no significant reduction in lumbar or femoral bone density.

CONCLUSIONS

On the basis of these positive results, we believe steroid avoidance with this immunosuppressive regimen merits further study.

Outcome of kidney transplantation from high-risk donors is determined by both structure and function

METHOD

Despite the need to expand the donor pool, it is unclear what parameters should be used. The value of donor renal pathology and calculated creatinine clearance (CrCl) in determining recipient outcome was assessed in 57 kidney transplants from 34 donors in whom pretransplant renal biopsies were performed because of age > or =60, hypertension, and/or vascular disease. We retrospectively compared clinical outcomes in these recipients and 57 control recipients selected to have the same baseline demographics but receiving transplants from low risk donors who were significantly younger (32+/-13.9 vs. 61+/-7.3 years) and lighter weight (71+/-18.1 vs. 84+/-20.2 kg) than the high-risk donors (P<.001 for both).

RESULTS

Recipients of high-risk kidneys had a higher incidence of delayed graft function, defined by a <10% fall in serum creatinine (Cr) in the first 24 hr, (56% vs. 30%, P<.01), a higher incidence of rejection (60% vs. 37%, P = .02) and a higher Cr level (197+/-64 vs. 144+/-54 micromol/L at 18 months, P<.005). Graft and patient survival were similar; 12% and 5% vs. 91% and 9% in high-risk vs. control groups, respectively (P = NS). Donor renal pathology was scored 0-3 (none to severe disease) in four areas: glomerulosclerosis, interstitial fibrosis, tubular atrophy, and vascular disease. A donor vessel score of 3/3 was associated with a 100% incidence of delayed graft function and a mean 1-year Cr level of 275+106 micromol/L (compared with 43% and 192+54 micromol/L in those with lower vessel scores, P<.05). Calculated donor CrCl <100 ml/min was associated with higher recipient Cr levels at 1 year, 240+/-95 micromol/L vs. 180+/-54 micromol/L in recipients of kidneys from donors with CrCl levels >100 ml/min (P<.05). The mean 1-year Cr level was 320+/-102 micromol/L in recipients with both a vascular score of 3/3 and a donor CrCl <100 ml/min and 184+/-63 micromol/L in those with neither factor (P = .001).

CONCLUSION

Calculated donor CrCl and donor vascular pathology predict recipient graft function and may be helpful in selecting high-risk donors for single kidney transplantation.

Safety and tolerability of cyclosporine and cyclosporine microemulsion during 18 months of follow-up in stable renal transplant recipients: a report of the Canadian Neoral Renal Study Group

BACKGROUND

There has been concern that the increased drug exposure associated with treatment with cyclosporine microemulsion (CsA-ME) would lead to an increase in adverse events.

METHODS

The long-term safety and tolerability of conventional cyclosporine (CsA) and CsA-ME were compared in a randomized, multicenter, pharmacoepidemiologic study involving 1097 stable renal transplant patients after 18 months of follow-up.

RESULTS

No significant difference was seen in change in serum creatinine or calculated creatinine clearance between the two groups. Episodes of deterioration in renal function (change in serum creatinine > or = 20%) were categorized with the following results for CsA-ME versus CsA, respectively: acute rejection, 4.5% vs. 4.5%; chronic rejection, 8% vs. 11%; CsA nephrotoxicity, 12% vs. 7% (P=0.008); transient changes, 17% vs. 12%; other causes, 4% vs. 6%. During the first 6 months of the study, a transient increase in the incidence of gastrointestinal and neurological adverse events was seen in the CsA-ME group compared with the CsA group. Up to 18 months, patients in the CsA group reported significantly fewer hearing and vestibular disorders, but more cardiovascular problems than those in the CsA-ME group (P=0.035).

CONCLUSIONS

Tolerance to CsA and CsA-ME was similar. Renal function over 18 months was not adversely affected by the increased drug exposure with CsA-ME, although there was a transient increase in nephrotoxicity. The frequency of acute and chronic rejection did not change.

Thrombotic microangiopathy in renal transplant recipients treated with cyclosporin A

Thrombotic microangiopathy is an uncommon but well described complication of renal transplantation. This study is a review of the case records of 18 patients with biopsy proven post transplant thrombotic microangiopathy, without cellular rejection. There was no single characteristic underlying cause of renal failure in native kidneys. Although only two (11%) patients had undergone previous transplantation, 16 (89%) had panel reactive antibodies (PRA). All patients received prophylactic antilymphocyte globulin, a single patient had cyclosporin A (CSA) at the time of transplant and in 16 patients CSA was introduced when graft function was established. On this protocol 16 (89%) patients had early graft function. All patients developed acute renal failure and 16 (89%) required dialysis. Nine (50%) patients developed hematological abnormalities. All patients were treated aggressively with anti-rejection therapy, CSA was temporarily withdrawn, and 2 (11%) patients received plasmapheresis. Seven (39%) patients lost their grafts. Renal function in the remaining patients recovered to serum creatinine levels ranging from 104 mumol/l to 430 mumol/l (1.2 mg% to 4.8 mg%). All patients with surviving grafts had CSA successfully reintroduced. This study indicates that there is an association between patients who develop posttransplant thrombotic microangiopathy after CSA administration and high PRA levels. The condition appears to respond to anti-rejection therapy and stopping CSA in the majority of cases. The safe reintroduction of CSA suggests that endothelial cell damage in the posttransplant period may be multifactorial and not solely due to CSA therapy.

alpha-smooth muscle actin and collagen deposition in dysfunctional renal transplants

In normal kidneys, alpha-smooth muscle actin and collagen type III expression is restricted to vascular smooth muscle cells and perivascular fibrous tissues, respectively, but in pathological conditions their expression or deposition is more extensive. Using immunohistochemistry, we examined the expression of alpha-smooth muscle actin and type III collagen in 31 human renal transplant biopsy specimens obtained from patients with graft dysfunction. We found that dysfunctional renal transplants have increased alpha-smooth muscle actin and collagen III expression in the glomerulus and interstitium, but only glomerular alpha-smooth muscle actin expression correlates with graft function and prognosis.

A randomized, prospective multicenter pharmacoepidemiologic study of cyclosporine microemulsion in stable renal graft recipients. Report of the Canadian Neoral Renal Transplantation Study Group

BACKGROUND

The safety, tolerability, and pharmacokinetics of conventional cyclosporine (ConCsA) and cyclosporine microemulsion (MeCsA) were compared under conditions of normal clinical practice in a prospective, randomized, concentration-controlled, pharmacoepidemiologic study.

METHODS

Between September 1994 and March 1995, 1097 stable renal transplant recipients in 14 Canadian centers were randomized 2:1 to treatment with MeCsA or ConCsA. Patients were commenced on each study drug at a dose equal to their previous therapy with ConCsA, and the dose was adjusted to maintain predose whole blood cyclosporine concentrations within the therapeutic range established for each center. Prednisone and azathioprine were continued unless dose adjustment was required for clinical reasons.

RESULTS

The mean cyclosporine concentration was comparable in both treatment groups at all time points throughout the 6 months of follow-up. The mean dose of cyclosporine was 3.6 mg/kg/day in both treatment groups at entry to the study, and declined by 0.3% and by 2.8% in patients receiving ConCsA and MeCsA, respectively. The nature and severity of adverse events were similar in both treatment groups, but there was a transient increase in neurological and gastrointestinal complications in the group receiving MeCsA within the first month after conversion (P<0.05). Serum creatinine and creatinine clearance did not change in either treatment group throughout the study. Biopsy-proven acute rejection occurred in three patients (0.8%) receiving ConCsA and in seven patients (0.9%) receiving MeCsA, with non-histologically proven acute rejection in an additional three patients (0.8%) receiving ConCsA and five patients (0.6%) receiving MeCsA (P=NS). Serum creatinine rose transiently in 35 patients (9.8%) receiving ConCsA and 138 patients (18.7%) receiving MeCsA (P<0.05) and resolved either spontaneously or after a reduction in the cyclosporine dose. One graft was lost in the MeCsA group due to irreversible rejection, and seven patients died, three in the group receiving ConCsA and four of those receiving MeCsA (P=NS). Absorption of cyclosporine was more rapid and complete from MeCsA than from ConCsA during the first 4 hr of the dosing interval, resulting in almost 40% greater exposure to the drug (P<0.001). There was close correlation between area under the time-concentration curve (AUC) over the first 4 hr of the 12-hr dosage interval and AUC over the entire 12-hr dosage interval for both formulations, making AUC over the first 4 hr a good predictor of total cyclosporine exposure. Using this parameter, patients with low absorption randomized to receive MeCsA showed a marked increase in drug exposure by months 3 and 6, whereas there was no change in those who continued on ConCsA. A limited sampling strategy utilizing samples at the predose and postdose trough levels provided an excellent correlation with drug exposure, particularly for patients receiving MeCsA (r2=0.94 MeCsA vs. r2=0.89 ConCsA).

CONCLUSIONS

MeCsA appears to be a safe and effective therapy in stable renal transplant patients and provides superior and more consistent absorption of cyclosporine when compared with ConCsA. Transient toxicity after conversion to MeCsA occurs in some patients, and may reflect the increased exposure to cyclosporine. Use of a limited sampling approach combining trough and 2-hr postdose concentrations may provide an effective way to monitor this exposure.

Sustained vasoconstriction associated with daily cyclosporine dose in heart and lung transplant recipients: potential pathophysiologic role of endothelin

Transient decreases in glomerular filtration rate (GFR) and renal plasma flow (RPF) have been associated with each daily dose of cyclosporine (CYA) in patients with renal allografts. We examined the differential dose effects of CYA on native renal function in 24 recipients of heart or lung transplants (treated with 7.3 +/- 0.5 mg/kg/day [mean +/- SEM]) and in seven patients with psoriasis (treated with 4.2 +/- 0.7 mg/kg/day). GFR and RPF were measured by urinary inulin and para-aminohippuric acid clearances 2 hours before the morning CYA dose and for 6 hours after. The age of heart and lung transplant recipients at renal study (2 months after transplantation) was 47 +/- 2.0 years. Their serum creatinine levels rose from 80 +/- 4.0 mumol/L during the first week after transplantation to 120 +/- 4.0 mumol/L at renal study (p < 0.0001). Their GFR and RPF were decreased before the CYA dose at 64 +/- 2.4 and 340 +/- 16 ml/min per 1.73 m2 and did not vary during the study. In comparison, the age of patients with psoriasis was 51 +/- 4.6 years at renal study (24 +/- 4.0 months after CYA treatment). Their serum creatinine levels rose from 80 +/- 4.0 mumol/L before treatment to 100 +/- 10 mumol/L at renal study (p = 0.07). Transient decreases of their baseline GFR and RPF (85 +/- 7.4 and 380 ml/min per 1.73 m2) with a nadir occurring during the first 2 hours of CYA ingestion were observed together with the recovery of these parameters toward baseline by the end of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Safety and efficacy of recombinant human erythropoietin in correcting the anemia of patients with chronic renal allograft dysfunction

Recombinant human erythropoietin (rHuEPO) is effective in correcting anemia in hemodialysis, peritoneal dialysis, and predialysis patients. Limited studies in patients with failing renal allografts suggest a similar efficacy but provide little information concerning benefits, dose requirements, or adverse events. This study examined these considerations in a group of 40 patients (18 men; 22 women) aged 40.3 +/- 13.8 yr with stable, chronic renal allograft failure. All patients had a hemoglobin < 95 g/L and a serum creatinine > 250 mumol/L at baseline. Patients received rHuEPO (50 U/kg sc) three times weekly for 24 wk along with iron po if serum ferritin was < 100 micrograms/L. Mean hemoglobin rose from 78.9 +/- 10.4 to 102.6 +/- 18.4 g/L after 24 wk. Mean rHuEPO dose at 24 wk was 129.8 +/- 81.9 U/kg per week. With oral iron supplementation only, serum ferritin fell throughout the 24 wk, whereas serum iron, transferrin saturation, and total iron-binding capacity remained stable. Quality of life was assessed by use of the general Sickness Impact Profile and the disease-specific Transplant Disease Questionnaire measures at baseline and every 8 wk during rHuEPO therapy. Significant improvement was noted in global Sickness Impact Profile scores and in four of five dimensions of the Transplant Disease Questionnaire. Serious adverse events were infrequent. No change in mean systolic or diastolic blood pressure was noted, although there was a significantly increased need for antihypertensive drugs in 18 patients (P = 0.0002). A significant inverse correlation was noted between baseline renal function and maintenance rHuEPO dose (r = -0.45; P < 0.05). Twelve patients returned to dialysis during the study.(ABSTRACT TRUNCATED AT 250 WORDS)