Canadian-Australasian Randomised trial of screening kidney transplant candidates for coronary artery disease-A trial protocol for the CARSK study

Kidney Transplant Candidacy: Addressing Common Medical and Psychosocial Barriers to Transplant

Improving access to kidney transplants remains a priority for the transplant community. However, many medical, psychosocial, geographic, and socioeconomic barriers exist that prevent or delay transplantation for candidates with certain conditions. There is a lack of consensus regarding how to best approach many of these issues and barriers, leading to heterogeneity in transplant centers' management and acceptance practices for a variety of pretransplant candidate issues. In this review, we address several of the more common contemporary patient medical and psychosocial barriers frequently encountered by transplant programs. The barriers discussed here include kidney transplant candidates with obesity, older age, prior malignancy, cardiovascular disease, history of nonadherence, and cannabis use. Improving understanding of how to best address these specific issues can empower referring providers, transplant programs, and patients to address these issues as necessary to progress toward eventual successful transplantation.

Coronary Artery Disease Assessment and Cardiovascular Events in Middle-Aged Patients on Hemodialysis

OBJECTIVE

To explore whether, in younger patients on dialysis with longer life expectancy, assessment of coronary artery disease (CAD) could identify individuals at higher risk of events and revascularization might improve outcomes in selected patients contrary to what had been observed in elderly patients.

METHODS

From August 1997 to January 2019, 2265 patients with stage 5 chronic kidney disease were prospectively referred for cardiovascular assessment. For this study, we selected 1374 asymptomatic patients aged between 18 and 64 years. After clinical risk stratification and cardiac scintigraphy by single-photon emission computed tomography, 866 patients underwent coronary angiography. The primary end point was the composite incidence of nonfatal/fatal major adverse cardiovascular events during a follow-up period of 0.1 to 189.7 months (median, 26 months). The secondary end point was all-cause mortality.

RESULTS

The primary end point occurred in 327 (23.8%) patients. Clinically stratified high-risk patients had a 3-fold increased risk of the primary end point. The prevalence of abnormal findings on perfusion scans was 29.2% (n=375), and significant CAD was found in 449 (51.8%) of 866 patients who underwent coronary angiography. An abnormal finding on myocardial perfusion scan and the presence of CAD were significantly associated with a 74% and 22% increased risk of cardiovascular events, respectively. In patients undergoing percutaneous coronary intervention or coronary artery bypass grafting (n=99), there was an 18% reduction in the risk of all-cause death relative to patients receiving medical treatment (P=.03).

CONCLUSION

In this cohort of middle-aged, asymptomatic patients on dialysis, assessment of CAD identified individuals at higher risk of events, and coronary intervention was associated with reducing the risk of death in selected patients.

The Minimisation of Cardiovascular Disease Screening for Kidney Transplant Candidates

Background: There is increasing evidence that cardiac screening prior to kidney transplantation does not improve its outcomes. However, risk aversion to perioperative events means that, in practice, testing remains common, limiting the availability of 'real-world' data to support any change. Our objective was to assess perioperative and 1-year post-transplant cardiovascular events in a kidney transplant candidate cohort who received minimal cardiovascular screening. Methods: The retrospective cohort study included all adult kidney-only transplant recipients in a single UK region between January 2015 and December 2021. Kidney transplant recipients asymptomatic of cardiac disease, even those with established risk factors, did not receive cardiac stress testing. The perioperative and 1-year post-transplant cardiovascular event incidences were examined. Logistic regression was used to identify variables of statistical significance that predicted cardiovascular or cerebrovascular events. Results: A total of 895 recipients fulfilled the inclusion criteria. Prior to transplantation, 209 (23%) recipients had an established cardiac diagnosis, and 193 (22%) individuals had a diagnosis of diabetes. A total of 18 (2%) patients had a perioperative event, and there was a 5.7% incidence of cardiovascular events 1 year post-transplantation. The cardiovascular mortality rate was 0.0% perioperatively, 0.2% at 3 months post-transplant, and 0.2% at 1 year post-transplant. Conclusions: This study demonstrates comparable rates of cardiovascular events despite reduced screening in asymptomatic recipients. It included higher risk individuals who may, on the basis of screening results, have been excluded from transplantation in other programmes. It provides further evidence that extensive cardiac screening prior to kidney transplantation is unlikely to be offset by reduced rates of cardiovascular events.

Screening and Management of Coronary Artery Disease in Kidney Transplant Candidates

Cardiovascular disease (CVD) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD), especially in end-stage renal disease (ESRD) patients and during the first year after transplantation. For these reasons, and due to the shortage of organs available for transplant, it is of utmost importance to identify patients with a good life expectancy after transplant and minimize the transplant peri-operative risk. Various conditions, such as severe pulmonary diseases, recent myocardial infarction or stroke, and severe aorto-iliac atherosclerosis, need to be ruled out before adding a patient to the transplant waiting list. The effectiveness of systematic coronary artery disease (CAD) treatment before kidney transplant is still debated, and there is no universal screening protocol, not to mention that a nontailored screening could lead to unnecessary invasive procedures and delay or exclude some patients from transplantation. Despite the different clinical guidelines on CAD screening in kidney transplant candidates that exist, up to today, there is no worldwide universal protocol. This review summarizes the key points of cardiovascular risk assessment in renal transplant candidates and faces the role of noninvasive cardiovascular imaging tools and the impact of coronary revascularization versus best medical therapy before kidney transplant on a patient's cardiovascular outcome.

The Cardio-Kidney Patient: Epidemiology, Clinical Characteristics and Therapy

Patients with chronic kidney disease (CKD) are at high risk to develop cardiovascular disease with its manifestations coronary artery disease, heart failure, arrhythmias, and sudden cardiac death. In addition, the presence of CKD has a major impact on the prognosis of patients with cardiovascular disease, leading to an increased morbidity and mortality if both comorbidities are present. Therapeutic options including medical therapy and interventional treatment are often limited in patients with advanced CKD, and in most cardiovascular outcome trials, patients with advanced CKD have been excluded. Thus, in many patients, treatment strategies for cardiovascular disease need to be extrapolated from trials conducted in patients without CKD. The current article summarizes the epidemiology, clinical presentation, and treatment options for the most prevalent manifestations of cardiovascular disease in CKD and discusses the currently available treatment options to reduce morbidity and mortality in this high-risk population.

Association of Pretransplant Coronary Heart Disease Testing With Early Kidney Transplant Outcomes

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 79 334 adult, first-time kidney transplant recipients (30 147 women [38%]; 25 387 [21%] Black and 48 394 [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.

Emerging Evidence on Coronary Heart Disease Screening in Kidney and Liver Transplantation Candidates: A Scientific Statement From the American Heart Association: Endorsed by the American Society of Transplantation

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.

Is Exclusion of Coronary Artery Disease in the Kidney Allocation System Preventing Optimal Longevity Matching?

BACKGROUND

Coronary artery disease (CAD) in a kidney transplant candidate is an important predictor of posttransplant mortality. It is not known how the exclusion of CAD in the kidney allocation system has impacted its goal of longevity matching.

METHODS

This is an observational study on adult deceased donor kidney transplant alone recipients between December 4, 2014, and December 31, 2018, with Medicare fee for service (FFS) insurance. Patients were categorized on the basis of Kidney Donor Profile Index (KDPI), Estimated Posttransplant Survival (EPTS), and CAD. Outcomes studied were mortality, death with a functioning graft, overall graft loss, and death-censored graft loss.

RESULTS

Among 21 151 patients with Medicare FFS coverage for >1 y before transplant, there were 2869 and 18 282 patients with and without CAD, respectively. On Kaplan-Meier analysis, there was higher risk of mortality, death with a functioning graft, overall graft loss, and death-censored graft loss with CAD ( P < 0.05 for all). Mortality was higher for CAD group within each category of KDPI and among patients with Estimated Posttransplant Survival 0% to 20% receiving kidneys with KDPI <20% ( P < 0.001 for all). On Cox multivariate analysis, the hazard ratios (HRs) of mortality and graft loss were higher with CAD diagnosis without intervention (HR 1.38 [1.25-1.52] and 1.29 [1.18-1.4]), CAD with stents (HR 2.76 [1.68-4.53] and 2.36 [1.46-3.81]), and CAD with bypass surgery (HR 1.56 [1.29-1.89] and 1.39 [1.17-1.65]). Posttransplant CAD events were higher in patients with preexisting CAD ( P < 0.001).

CONCLUSIONS

The exclusion of a candidate's history of CAD in the kidney allocation system adversely impacts its goal of optimal longevity matching.

Cardiac Imaging and Management of Cardiac Disease in Asymptomatic Renal Transplant Candidates: A Current Update

Given the high cardiovascular risk accompanying end-stage kidney disease, it would be of paramount importance for the clinical nephrologist to know which screening method(s) identify high-risk patients and whether screening asymptomatic transplant candidates effectively reduces cardiovascular risk in the perioperative setting as well as in the longer term. Within this review, key studies concerning the above questions are reported and critically analyzed. The lack of unified screening criteria and of a prognostically sufficient screening cardiovascular effect for renal transplant candidates sets the foundation for a personalized patient approach in the near future and highlights the need for well-designed studies to produce robust evidence which will address the above questions.

Cardiovascular Disease Assessment Prior to Kidney Transplantation

Cardiovascular disease is highly prevalent and the leading cause of mortality in patients with chronic kidney disease, end-stage kidney disease, and kidney transplantation. However, kidney transplantation offers improved survival and quality of life, with an overall reduction in cardiovascular disease events; therefore, it remains the optimal treatment choice for those with advanced kidney disease. Pretransplantation cardiovascular assessment is performed prior to wait-listing and at routine intervals with the principal goal of screening for asymptomatic cardiac disease, intervening when necessary to improve long-term patient and allograft survival. Current clinical practice guidelines are based on expert opinion, with a lack of high-quality evidence to guide standardized screening practices. Recent studies support de-escalation in screening with avoidance of preemptive revascularization in asymptomatic patients, but they fail to provide clear guidance on how best to assess the cardiovascular fitness of this high-risk group. Herein we summarize current practice guidelines, discuss key study findings, highlight the role of optimal medical therapy, and evaluate future directions for cardiovascular disease assessment in this population.

Prognostic Value of Exercise Capacity in Kidney Transplant Candidates

Background Exercise stress testing for cardiovascular assessment in kidney transplant candidates has been shown to be a feasible alternative to pharmacologic methods. Exercise stress testing allows the additional assessment of exercise capacity, which may have prognostic value for long-term cardiovascular outcomes in pre-transplant recipients. This study aimed to evaluate the prognostic value of exercise capacity on long-term cardiovascular outcomes in kidney transplant candidates. Methods and Results We retrospectively evaluated exercise capacity in 898 consecutive kidney transplant candidates between 2013 and 2020 who underwent symptom-limited exercise stress echocardiography for pre-transplant cardiovascular assessment. Exercise capacity was measured by age- and sex-predicted metabolic equivalents (METs). The primary outcome was incident major adverse cardiovascular events, defined as cardiac death, non-fatal myocardial infarction, and stroke. Cox proportional hazard multivariable modeling was performed to define major adverse cardiovascular events predictors with transplantation treated as a time-varying covariate. A total of 429 patients (48%) achieved predicted METs. During follow-up, 93 (10%) developed major adverse cardiovascular events and 525 (58%) underwent transplantation. Achievement of predicted METs was independently associated with reduced major adverse cardiovascular events (hazard ratio [HR] 0.49; [95% CI 0.29-0.82], P=0.007), as was transplantation (HR, 0.52; [95% CI 0.30-0.91], P=0.02). Patients achieving predicted METs on pre-transplant exercise stress echocardiography had favorable outcomes that were independent (HR, 0.78; [95% CI 0.32-1.92], P=0.59) and of similar magnitude to subsequent transplantation (HR, 0.97; [95% CI 0.42-2.25], P=0.95). Conclusions Achievement of predicted METs on pre-transplant exercise stress echocardiography confers excellent prognosis independent of and of similar magnitude to subsequent kidney transplantation. Future studies should assess the benefit on exercise training in this population.

A population cohort analysis of English transplant centers indicates major adverse cardiovascular events after kidney transplantation

Major adverse cardiovascular event (MACE) rates immediately after kidney transplantation remain uncertain due to heterogeneous reporting in the literature. To clarify this, we retrospectively studied every eligible kidney transplant procedure performed in England between April 1, 2002 and March 31. 2018 with follow-up through August 31, 2019. The primary outcome of interest was MACE broadly defined as any hospital admission with myocardial infarction, stroke, unstable angina, heart failure, any coronary revascularisation procedure and/or any cardiovascular death. Among 30,325 kidney transplant recipients, MACE occurred in 781 within the first year after transplantation (2.6% of all kidney transplant procedures). Of these 781 events, 201 occurred during the index admission for kidney transplantation surgery representing 25.7% of all first-year MACE and 0.7% of all kidney transplant procedures. Kidney transplant recipients who suffered a non-fatal MACE within the first year had significantly decreased 1-, 3-, 5- and 10-year patient survival of 80.5%, 70.2%, 59.5% and 38.6% respectively, compared to 97.4%, 94.4%, 90.7% and 78.4% for kidney transplant recipients not developing MACE.. In an adjusted Cox proportional hazard model, non-fatal MACE within the first-year post-transplant was associated with significant long-term mortality risk (hazard ratio 2.59; 95% confidence interval 2.34-2.88). Kidney transplant recipients experiencing MACE during the index admission compared to subsequent admissions were differentiated by age, sex and previous cardiac history but had similar patient survival. These rates are significantly lower than those reported in North America. Thus, our data confirms MACE is not a benign post-transplant event and has a strong association with long-term mortality risk.

Kidney transplant candidacy evaluation and waitlisting practices in the United States and their association with access to transplantation

There are limited data on the degree of variability in practices surrounding prioritization of referrals for transplant evaluation and criteria for transplant candidacy and their association with transplantation rates. We surveyed transplant programs across the United States between January 2020 and May 2020 to determine current pre-transplantation practices. We examined the relation between these reported practices and the outcomes of waitlisted patients at responding programs between January 2015 and March 2021 using Scientific Registry of Transplant Recipients data. We used adjusted Cox models with random effects to accommodate clustering by program. Primary outcomes included living or deceased donor transplantation. Of 172 surveyed programs, 90 participated. Substantial variations were noted in when the candidacy evaluation began (13% reported when eGFR was <30 mL/min/1.73 m2 and 17% reported no set policy) and the approach to pre-transplantation cardiac workup (multi-modality [58%], stress echocardiogram [20%]). Using adjusted models, a program policy of using other measures of body habitus to determine transplant candidacy rather than requiring patients to meet a body mass index (BMI) threshold of ≤35 kg/m2 (reference group) for candidacy was associated with a higher hazard of living donor transplantation (HR 1.83 [95% CI 1.10-3.03]). Pre-transplant practices vary substantially across the United States, and select practices were associated with transplantation rates.

Coronary Artery Disease in Chronic Kidney Disease: Need for a Heart-Kidney Team-Based Approach

Chronic kidney disease and coronary artery disease are co-prevalent conditions with unique epidemiological and pathophysiological features, that culminate in high rates of major adverse cardiovascular outcomes, including all-cause mortality. This review outlines a summary of the literature, and nuances pertaining to non-invasive risk assessment of this population, medical management options for coronary heart disease and coronary revascularisation. A collaborative heart-kidney team-based approach is imperative for critical management decisions for this patient population, especially coronary revascularisation; this review outlines specific periprocedural considerations pertaining to coronary revascularisation, and provides a proposed algorithm for approaching revascularisation choices in patients with end-stage kidney disease based on available literature.

Trends in Coronary Artery Disease Screening before Kidney Transplantation

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.

Screening for occult coronary artery disease in potential kidney transplant recipients: time for reappraisal?

Screening for occult coronary artery disease in potential kidney transplant recipients has become entrenched in current medical practice as the standard of care and is supported by national and international clinical guidelines. However, there is increasing and robust evidence that such an approach is out-dated, scientifically and conceptually flawed, ineffective, potentially directly harmful, discriminates against ethnic minorities and patients from more deprived socioeconomic backgrounds, and unfairly denies many patients access to potentially lifesaving and life-enhancing transplantation. Herein we review the available evidence in the light of recently published randomized controlled trials and major observational studies. We propose ways of moving the field forward to the overall benefit of patients with advanced kidney disease.

Time to press the reset button-can we use the COVID-19 pandemic to rethink the process of transplant assessment?

Coronavirus disease 2019 has taken a severe toll on the transplant community, with significant morbidity and mortality not just among transplant patients and those on the waiting list, but also among colleagues. It is therefore not surprising that clinicians in this field have viewed the events of the last 18 months as predominantly negative. As the pandemic is gradually ebbing away, we argue that this is also a unique opportunity to rethink transplant assessment. First, we have witnessed a step-change in the use of technology and virtual assessments. Another effect of the pandemic is that we have had to make do with what was available-which has often worked surprisingly well. Finally, we have learned to think the unthinkable: maybe things do not have to continue the way they have always been. As we emerge on the other side of the pandemic, we should rethink which parts of the transplant assessment process are necessary and evidence-based. We emphasize the need to involve patients in the redesign of pathways and we argue that the assessment process could be made more transparent to patients. We describe a possible roadmap towards transplant assessment pathways that are truly fit for the 21st century.

Atherosclerotic Vascular Disease Associated with Chronic Kidney Disease

Cardiovascular risk increases as glomerular filtration rate (GFR) declines in progressive renal disease and is maximal in patients with end-stage renal disease requiring maintenance dialysis. Atherosclerotic vascular disease, for which hyperlipidemia is the main risk factor and lipid-lowering therapy is the key intervention, is common. However, the pattern of dyslipidemia changes with low GFR and the association with vascular events becomes less clear. While the pathophysiology and management of patients with early chronic kidney disease (CKD) is similar to the general population, advanced and end-stage CKD is characterized by a disproportionate increase in fatal events, ineffectiveness of statin therapy, and greatly increased risk associated with coronary interventions. The most effective strategies to reduce atherosclerotic cardiovascular disease in CKD are to slow the decline in renal function or to restore renal function by transplantation.

Kidney Transplant List Status and Outcomes in the ISCHEMIA-CKD Trial

BACKGROUND

Patients with chronic kidney disease (CKD) and coronary artery disease frequently undergo preemptive revascularization before kidney transplant listing.

OBJECTIVES

In this post hoc analysis from ISCHEMIA-CKD (International Study of Comparative Health Effectiveness of Medical and Invasive Approaches-Chronic Kidney Disease), we compared outcomes of patients not listed versus those listed according to management strategy.

METHODS

In the ISCHEMIA-CKD trial (n = 777), 194 patients (25%) with chronic coronary syndromes and at least moderate ischemia were listed for transplant. The primary (all-cause mortality or nonfatal myocardial infarction) and secondary (death, nonfatal myocardial infarction, hospitalization for unstable angina, heart failure, resuscitated cardiac arrest, or stroke) outcomes were analyzed using Cox multivariable modeling. Heterogeneity of randomized treatment effect between listed versus not listed groups was assessed.

RESULTS

Compared with those not listed, listed patients were younger (60 years vs 65 years), were less likely to be of Asian race (15% vs 29%), were more likely to be on dialysis (83% vs 44%), had fewer anginal symptoms, and were more likely to have coronary angiography and coronary revascularization irrespective of treatment assignment. Among patients assigned to an invasive strategy versus conservative strategy, the adjusted hazard ratios for the primary outcome were 0.91 (95% confidence interval [CI]: 0.54-1.54) and 1.03 (95% CI: 0.78-1.37) for those listed and not listed, respectively (pinteraction= 0.68). Adjusted hazard ratios for secondary outcomes were 0.89 (95% CI: 0.55-1.46) in listed and 1.17 (95% CI: 0.89-1.53) in those not listed (pinteraction = 0.35).

CONCLUSIONS

In ISCHEMIA-CKD, an invasive strategy in kidney transplant candidates did not improve outcomes compared with conservative management. These data do not support routine coronary angiography or revascularization in patients with advanced CKD and chronic coronary syndromes listed for transplant. (ISCHEMIA-Chronic Kidney Disease Trial [ISCHEMIA-CKD]; NCT01985360).

Managing cardiovascular disease risk in South Asian kidney transplant recipients

South Asians (SA) are at higher cardiovascular risk than other ethnic groups, and SA kidney transplant recipients (SA KTR) are no exception. SA KTR experience increased major adverse cardiovascular events both early and late post-transplantation. Cardiovascular risk management should therefore begin well before transplantation. SA candidates may require aggressive screening for pre-transplant cardiovascular disease (CVD) due to their ethnicity and comorbidities. Recording SA ethnicity during the pre-transplant evaluation may enable programs to better assess cardiovascular risk, thus allowing for earlier targeted peri- and post-transplant intervention to improve cardiovascular outcomes. Diabetes remains the most prominent post-transplant cardiovascular risk factor in SA KTR. Diabetes also clusters with other metabolic syndrome components including lower high-density lipoprotein cholesterol, higher triglycerides, hypertension, and central obesity in this population. Dyslipidemia, metabolic syndrome, and obesity are all significant CVD risk factors in SA KTR, and contribute to increased insulin resistance. Novel biomarkers such as adiponectin, apolipoprotein B, and lipoprotein (a) may be especially important to study in SA KTR. Focused interventions to improve health behaviors involving diet and exercise may especially benefit SA KTR. However, there are few interventional clinical trials specific to the SA population, and none are specific to SA KTR. In all cases, understanding the nuances of managing SA KTR as a distinct post-transplant group, while still screening for and managing each CVD risk factor individually in all patients may help improve the long-term success of all kidney transplant programs catering to multi-ethnic populations.

Individualized protocol for radiation and contrast medium dose reduction in one-stop assessment for kidney transplantation patients

OBJECTIVE

To compare image quality, radiation, and contrast medium (CM) doses between individualized and conventional scan protocols in combined coronary CT angiography (CCTA) and iliac artery CTA for kidney transplantation patients.

METHODS

148 patients needing assessment for coronary and iliac arteries before kidney transplantation were prospectively enrolled and randomly divided into the conventional and individualized groups. All patients underwent one-stop combined scans on a 256-row CT scanner with automatic tube current modulation, 50 % pre-ASIR-V to control radiation dose. CCTA was performed first using one heartbeat axial scan mode with bolus tracking technique and iliac CTA was performed 3 s after CCTA using a spiral scan. The conventional group (n = 72) used the standard protocol: 100 kVp, 60 mL of 350 mgI/mL CM at 4.5 mL/s flow rate. The individualized group (n = 76) used a body-mass-index (BMI)-dependent protocol: kVp: 80 (BMI < 24) and 100 (BMI ≥ 24) and CM: 19 mgI/kg (BMI < 18); 21 mgI/kg (18 ≤ BMI < 24); and 22 mgI/kg (BMI ≥ 24). Image quality radiation and CM doses of the two groups were compared.

RESULTS

There was no significant difference in patient demographic data. Compared with the conventional group, the individualized group reduced contrast flow rate (in mL/s) by 14.4 % (3.85 ± 0.72 vs. 4.5), contrast dose (in mL) by 35.8 % (38.53 ± 7.18 vs. 60) and radiation dose (in mSv) by 34.3 % (4.30 ± 1.73 vs. 6.54 ± 1.45). The individualized group had significantly higher subjective image quality score (P ＜ 0.05), lower noise (17.30 ± 4.97 HU vs. 19.13 ± 4.73 HU, P = 0.02) and higher signal-to-noise ratio (22.09 ± 7.41 vs. 19.55 ± 6.18, P = 0.03) for the three main vessels in CCTA compared with the conventional group. There were no differences in both subjective scores and objective measurements in iliac artery CTA between the two groups.

CONCLUSION

The individualized scanning protocol in the one-stop assessment of coronary and iliac arteries before kidney transplantation significantly reduces both radiation and CM doses while maintaining image quality in iliac artery CTA and providing better coronary artery images in CCTA.

Cardiovascular evaluation in advanced chronic kidney disease

Patients with chronic kidney disease (CKD) display an increased cardiovascular comorbidity, which is often underdiagnosed. Thus, effective cardiovascular diagnostic testing is of particular importance for this group of patients. Data from prospective randomized trials with cardiovascular diagnostic testing in CKD patients and improved outcome are limited. Diagnostic stress testing for CKD patients requires special consideration. Guidelines recommend cardiovascular diagnostic testing for patients undergoing an evaluation before transplantation.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Cardiac screening prior to renal transplantation-good intentions, rather than good evidence, dictate practice

Cardiovascular disease is the leading cause of death in kidney transplant recipients in many transplant registries. An analysis of transplant recipients from the United Kingdom using propensity score matching (PSM) suggests there are limited or no benefits to cardiovascular screening before transplant listing. We suggest that short of a randomized controlled trial (RCT) in this area, these data are sufficient to suggest that transplant centers should reflect on their current protocols for cardiovascular workup required before transplantation.

Examining barriers to timely waitlisting for kidney transplantation for Indigenous Australians in Central Australia

BACKGROUND

Indigenous Australians are disproportionately affected by end stage kidney disease. Despite this, they face significant delays being assessed and waitlisted for kidney transplant.

AIMS

To examine the kidney transplant waitlisting process in our region, to compare the workup process between Indigenous Australians and non-Indigenous patients, and identify major sources of delay.

METHODS

We analysed the records of all patients being treated by our service who were on the kidney transplant waitlist between January 2017 and June 2018. Between-group differences were used to compare the time between commencement of dialysis and completion of each component of assessment. Patients who had more than 1 year between commencement of dialysis and waitlisting were further analysed for major sources of delay.

RESULTS

Twenty-five patients were included (20 Indigenous Australians and 5 non-Indigenous). The median time to waitlisting for transplant after commencing dialysis was significantly longer in the Indigenous group (1215 vs 264 days, P = 0.032). Indigenous Australian patients waited longer before commencing the transplant assessment process and before completing dental assessment, tissue typing and review by the transplant nephrologist and surgeon. Five patients (two Indigenous Australians, three non-Indigenous) were waitlisted within 1 year of commencing dialysis. Among the remaining 20 patients, cardiac and systems issues were the two most common major sources of delay.

CONCLUSION

Indigenous Australian patients face significant delays accessing the kidney transplant waitlist. Cardiac assessment and systems issues are prominent sources of delay and efforts to address these areas may help to improve equity of access to kidney transplantation.

A propensity score-matched analysis indicates screening for asymptomatic coronary artery disease does not predict cardiac events in kidney transplant recipients

Screening for asymptomatic coronary artery disease prior to kidney transplantation aims to reduce peri- and post-operative cardiac events. It is uncertain if this is achieved. Here, we investigated whether pre-transplant screening with a stress test or coronary angiogram associated with any difference in major adverse cardiac events (MACE) up to five years post-transplantation. We examined a national prospective cohort recruited to the Access to Transplant and Transplant Outcome Measures study who received a kidney transplant between 2011-2017, and linked patient demographics and details of cardiac screening investigations to outcome data extracted from the Hospital Episode Statistics dataset and United Kingdom Renal Registry. Propensity score matched groups were analyzed using Kaplan-Meier and Cox survival analyses. Overall, 2572 individuals were transplanted in 18 centers; 51% underwent screening and the proportion undergoing screening by center ranged from 5-100%. The incidence of MACE at 90 days, one and five years was 0.9%, 2.1% and 9.4% respectively. After propensity score matching based on the presence or absence of screening, 1760 individuals were examined (880 each in screened and unscreened groups). There was no statistically significant association between screening and MACE at 90 days (hazard ratio 0.80, 95% Confidence Interval 0.31-2.05), one year (1.12, 0.51-2.47) or five years (1.31, 0.86-1.99). Age, male sex and history of ischemic heart disease were associated with MACE. Thus, there is no association between screening for asymptomatic coronary artery disease and MACE up to five years post-transplant. Practices involving unselected screening of transplant recipients should be reviewed.

Non-invasive cardiac stress studies may not offer significant benefit in pre-kidney transplant evaluation: A retrospective cohort study

Background

Screening with cardiac non-invasive stress studies (NISS) prior to listing for kidney transplantation can help in identifying treatable coronary disease and is considered an integral part of pre-kidney transplant evaluation. However, few studies assessed their effectiveness in all patients evaluated for transplantation in clinical practice. To evaluate the role of NISS in pre-kidney transplant evaluation we analyzed their impact prior to waitlisting in 1053 adult CKD-5 patients consecutively evaluated in Greater Manchester, UK during a 6-year period.

Methods

918 waitlisted patients were grouped based on presence or absence of Diabetes or Cardio-Vascular Disease (CVD): Group-1 (255 DM-/CVD-/NISS-), Group-2 (368 DM-/CVD-/NISS+) and Group-3 (295 with DM or CVD).

Results

Group-2 patients had longer ‘time-to-listing’ (5.5months in Group-1 vs 6.9months in ‘Normal-NISS’ vs 9.9months in ‘Abnormal-NISS’, p<0.01) but none with ‘Abnormal-NISS’ needed coronary revascularization before listing. NISS was followed by revascularization in 8 Group-3 patients (3%). In multi-variate analyses, there was no association of NISS on death or MACE in listed patients. During follow up, Transplantation was the most significant factor associated with improved outcomes in all subgroups (HR:0.97, p<0.001). 135 patients were considered unsuitable for waitlisting, with NISS influencing management in 11 of these patients (8%).

Conclusions

Pre-kidney transplant evaluation with NISS influenced clinical management in 19 of 1053 (2%) patients. Screening with NISS added limited benefit but contributes to significant delays in listing and adding resource implications. Further studies are needed to assess clinical and cost effectiveness of NISS in pretransplant evaluation to optimize outcomes and resources.

Cardiac Imaging for Coronary Heart Disease Risk Stratification in Chronic Kidney Disease

Chronic kidney disease (CKD), defined as dysfunction of the glomerular filtration apparatus, is an independent risk factor for the development of coronary artery disease (CAD). Patients with CKD are at a substantially higher risk of cardiovascular mortality compared with the age- and sex-adjusted general population with normal kidney function. The risk of CAD and mortality in patients with CKD is correlated with the degree of renal dysfunction including presence of microalbuminuria. A greater cardiovascular risk, albeit lower than for patients receiving dialysis, persists even after kidney transplantation. Congestive heart failure, commonly caused by CAD, also accounts for a significant portion of the cardiovascular-related events observed in CKD. The optimal strategy for the evaluation of CAD in patients with CKD, particularly before renal transplantation, remains a topic of contention spanning over several decades. Although the evaluation of coexisting cardiac disease in patients with CKD is desirable, severe renal dysfunction limits the use of radiographic and magnetic resonance contrast agents due to concerns regarding contrast-induced nephropathy and nephrogenic systemic sclerosis, respectively. In addition, many patients with CKD have extensive and premature (often medial) calcification disproportionate to the severity of obstructive CAD, thereby limiting the diagnostic value of computed tomography angiography. As such, echocardiography, non-contrast-enhanced magnetic resonance, nuclear myocardial perfusion, and metabolic imaging offer a variety of approaches to assess obstructive CAD and cardiomyopathy of advanced CKD without the need for nephrotoxic contrast agents.

Outcomes of Surgical Coronary Revascularization Performed Before Solid Abdominal Organ Transplants

BACKGROUND

Cardiac risk stratification and coronary angiography are routinely performed as part of kidney and liver transplant candidacy evaluation. There are limited data on the outcomes of surgical coronary revascularization in this patient population. This study investigated outcomes in patients with end- stage renal or hepatic disease who were undergoing coronary artery bypass grafting (CABG) to attain kidney or liver transplant candidacy.

METHODS

This study was a retrospective analysis of all patients who underwent isolated CABG at our institution, Indiana University School of Medicine (Indianapolis, IN), between 2010 and 2016. Patients were divided into 2 cohorts: pretransplant (those undergoing surgery to attain renal or hepatic transplant candidacy) and nontransplant (all others). Baseline characteristics and postoperative outcomes were compared between the groups.

RESULTS

A total of 1801 patients were included: 28 in the pretransplant group (n = 22, kidney; n = 7, liver) and 1773 in the nontransplant group. Major adverse postoperative outcomes were significantly greater in the pretransplant group compared with the nontransplant group: 30-day mortality (14.3% vs 2.8%; P = .009), neurologic events (17.9% vs 4.8%; P = .011), reintubation (21.4% vs 5.8%; P = .005), and total postoperative ventilation (5.2 hours vs 5.0 hours; P = .0124). The 1- and 5-year mortality in the pretransplant group was 17.9% and 53.6%, respectively. Of the pretransplant cohort, 3 patients (10.7%) underwent organ transplantation (all kidney) at a mean 436 days after CABG. No patients underwent liver transplantation.

CONCLUSIONS

Outcomes after CABG in pre-kidney transplant and pre-liver transplant patients are poor. Despite surgical revascularization, most patients do not ultimately undergo organ transplantation. Revascularization strategies and optimal management in this high-risk population warrant further study.

The transition clinic in chronic kidney disease care

People with advanced chronic kidney disease and evidence of progression have a high risk of renal replacement therapy. Specialized transition clinics could offer a better option for preparing these patients for dialysis, transplantation or conservative care. This review focuses on the different aspects of such transition clinics. We discuss which patients should be referred to these units and when referral should take place. Patient involvement in the decision-making process is important and requires unbiased patient education. There are many themes, both patient-centred and within the healthcare structure, that will influence the process of shared decision-making and the modality choice. Aspects of placing an access for haemodialysis and peritoneal dialysis are reviewed. Finally, we discuss the importance of pre-emptive transplantation and a planned dialysis start, all with a focus on multidisciplinary collaboration at the transition clinic.

[Cardiovascular diagnostic testing in advanced chronic kidney disease: which tests are useful?]

Against the background of drastically increased cardiovascular comorbidity in patients with chronic kidney disease (CKD), an effective cardiovascular diagnostic approach appears essential. However, patients with CKD are often underdiagnosed. Prospective randomized studies showing an improved outcome for cardiovascular diagnostic in patients with CKD are limited. Special attention is paid to stress diagnostics in CKD patients. Guidelines recommend cardiovascular diagnostic evaluation prior to inclusion on the transplantation waiting list.