Stan Benjamens

A high abdominal aortic calcification score by dual X-ray absorptiometry is associated with cardiovascular events after kidney transplantation

BackgroundnAortic calcification is associated with an increased risk for cardiovascular events in renal transplant recipients. This study focused on the association of abdominal aortic calcification (AAC) and cardiovascular events assessed using a dual-energy X-ray absorptiometry (DXA) scoring methodology for AAC.nnnMethodsnFrom 2008 to 2014, renal transplant recipients referred for a DXA procedure within 6u2009months after transplantation were included in a retrospective, single-centre study. The primary endpoint was the occurrence of cardiovascular events, defined as myocardial infarction, cerebrovascular accident or transient ischaemic attack, after transplantation. AAC was quantified using an 8-point scoring system and patients were divided into three groups; a control group (AACu2009=u20090), a low AAC group (AACu2009=u20091-3) and a high AAC group (AACu2009=u20094-8).nnnResultsnWe evaluated 701 patients, 267 (38.1%) had detectable calcifications (low AAC 190 patients, high AAC 77 patients) and 434 (61.9%) had no calcifications. Cardiovascular events were seen in 37 (8.5%) patients in the control group, in 18 (9.5%) in the low AAC group and in 20 (26.0%) in the high AAC group. Univariate Cox proportional hazards analysis of the high AAC score showed a hazard ratio (HR) of 4.23 [95% confidence interval (CI) 2.44-7.33; Pu2009<u20090.01] for cardiovascular events, while results were not significant for the low AAC score. Multivariate analysis showed an independent significant association between a high AAC score and cardiovascular events [HR 2.78 (95% CI 1.05-7.64); Pu2009=u20090.04]. Assessment of the continuous net reclassification index (NRI), comparing the combined clinical variables with a model of both AAC scoring and clinical variables, showed an NRI of 0.76 (95% CI 0.65-0.86; Pu2009<u20090.01).nnnConclusionsnAn independent association between a high AAC score, assessed by DXA, and cardiovascular events was identified and provides an opportunity for early cardiovascular risk stratification in renal transplant recipients.

Renal scintigraphy for post-transplant monitoring after kidney transplantation

BACKGROUNDnClinicians use several diagnostic modalities to recognize post-transplant complications, such as acute tubular necrosis, acute rejection, urologic and vascular complications. Currently, there is no consensus about the best procedural approach to evaluate post-transplant renal dysfunction. Renal needle-biopsy is often required, however, this is invasive and may lead to sample errors and complications, and most clinicians prefer using one of the noninvasive diagnostic modalities.nnnMETHODSnA systematic literature search was performed using PubMed, EMBASE, the Cochrane Library, MEDLINE (OvidSP), Web of Science, and Google Scholar to identify relevant articles. This review provides a literature overview of the technical aspects, new developments and clinical value of renal scintigraphy (RS), after kidney transplantation. Additionally, the advantages and limitations of RS in comparison to other diagnostic modalities are addressed. The study protocol is registered with PROSPERO, protocol number CRD42017078391.nnnRESULTSnA total of 32 studies were included. Studies were categorized in the following groups: tracer pharmacokinetics; acute rejection and acute tubular necrosis; vascular complications; urological complications; postoperative fluid collections; early transplant outcomes; one-year transplant outcomes.nnnCONCLUSIONSnSeveral studies have described the use of RS for the diagnosis of acute rejection, however, differentiating between rejection and acute tubular necrosis remains difficult. For the diagnosis of vascular complications, RS has been described as an alternative for invasive procedures. For urologic complications, studies support the use of RS in combination with routine ultrasonography (US) surveillance. For the diagnosis of postoperative fluid collections, RS provides information to differentiate lymphoceles and urinomas. Altogether, RS should be considered in case of non-acute complications, and if US provides insufficient results.

A High Abdominal Aortic Calcification Score by Dual X-Ray Absorptiometry (DXA) is Associated with Cardiovascular Events after Kidney Transplantation

Introduction It is unknown whether aortic calcification is associated with increased risk for cardiovascular events in renal transplant recipients. Therefore, this study focused on the association of abdominal aortic calcification (AAC) and cardiovascular events, using a dual X-ray absorptiometry (DXA) scoring methodology for AAC. Methods Renal transplant recipients, referred for a DXA procedure within 6 months after transplantation, were included in a single-centre study, between 2008 to 2014, with an end of follow-up at December 2017. Primary endpoint was the occurrence of cardiovascular events, defined as myocardial infarction, cerebrovascular accident or transient ischemic attack, within 36 months after transplantation. AAC was quantified using an 8-score scale system and patients were divided into 3 groups; a control group (AAC = 0), a low-AAC group (AAC = 1 – 3), and a high-AAC group (AAC = 4 – 8). Results We evaluated 701 patients, 267 (38.1%) had detectable calcifications (low-AAC 190 patients; high-AAC 77 patients) and 434 (61.9%) had no calcifications. Univariate Cox proportional hazard analysis of the high-AAC score showed a hazard ratio (HR) of 3.3 (95% CI 1.7 – 6.3, p < 0.01) for cardiovascular events, while results were not significant for the low-AAC score, HR 1.0 (95% CI 0.5 – 2.1, p = 0.91). Multivariate analysis showed an independent significant association between a high-AAC score and cardiovascular events, HR 2.4 (95% CI 1.2 – 5.0), p = 0.02). Conclusions An independent association between a high-AAC score and cardiovascular events was identified and provides an opportunity for physicians for early cardiovascular risk stratification in renal transplant recipients. Figure. No caption available. Figure. No caption available.

Decline in Pancreas Transplantation Numbers is Accompanied with Lower Publication Rates

Introduction After several years of growth in many pancreas transplant programs, the United Network for Organ Sharing (UNOS) database reports a decline in transplant numbers in the USA. This trend urges for an evaluation of the transplant numbers and scientific productivity in the Eurotransplant (ET) region and the UK. Materials and Methods We used the UNOS database, ET registry, and the UK transplant registry to describe the development of pancreas transplantation rates between 1997 and 2016. Next, we used the Web of Science database for a bibliometric analysis of scientific publications in the field of pancreas transplantation. Transplantation rates were adjusted for changes in population size in the different regions. We calculated graph specific slopes and annual average changes to assess trends in pancreas transplantation and scientific publications rates. Results and Discussion For the USA and the ET region, from 2004 the trend in transplant numbers changes from growth to decline, with highest annual transplant numbers of 5.1 per million inhabitants in the USA and of 2.4 per million in the ET region. Between 2004 and 2016 the average annual decline rate per million inhabitants was 3.3% for the USA and 2.5% for the ET region. In the UK, yearly transplant numbers show a growth until 2009, with 3.6 transplants per million inhabitants, after which the numbers showed an average annual decline of 1.0%. Following this trend, publications in Q1 journals showed an annual average change of +0.1%, -2.1% and +20.1%, before 2004, and a change of -4.1%, -3.8% and -5.45%, between 2004 and 2016, for respectively worldwide, the USA and the ET publications (Figure 2). From the 10 publications with the highest impact in this field, 9 publications were from USA-based authors and 5 out of 10 used data from the UNOS database, none were based on European studies. Figure. No caption available. Figure. No caption available. Conclusions Adjusting pancreas transplantation rates for changes in population size showed a clear decline in transplant numbers in both the USA and ET region, with first signs of a decline in the UK. Following this trend, the number of scientific publications declines worldwide and specifically in the USA and ET region. With the UNOS database in mind, we advocate for a renewed European pancreas collaboration to evaluate the decline in transplant numbers and to establish a comprehensive database for multivariate analyses of pancreas transplant outcomes. A European registry is the key to a reliable transplant trend evaluation and will support transplant programs in their progress to better outcomes.

The fear for contrast-induced nephropathy in kidney transplant recipients: time for a paradigm shift?

A recently published article in the Lancet (AMACING trial) challenges a long-standing clinical consensus: intravenous (i.v.) volume expansion with isotonic saline as a prophylactic measure for iodinated contrast-induced nephropathy (CIN) [1]. The randomized trial showed that - in patients with an estimated glomerular filtration rate (eGFR) of 30-59 mL/min/1.73m², undergoing an elective procedure - as compared to i.v. hydration, no prophylaxis is non-inferior in preventing CIN. This article is protected by copyright. All rights reserved.

Can transplant renal scintigraphy predict the duration of delayed graft function?: A dual center retrospective study

Introduction This study focused on the value of quantitatively analyzed and qualitatively graded renal scintigraphy in relation to the expected duration of delayed graft function after kidney transplantation. A more reliable prediction of delayed graft function duration may result in a more tailored and patient-specific treatment regimen post-transplantation. Methods From 2000 to 2014, patients with early transplant dysfunction and a Tc-99m MAG3 renal scintigraphy, within 3 days post-transplantation, were included in a dual center retrospective study. Time-activity curves of renal scintigraphy procedures were qualitatively graded and various quantitative indices (R20/3, TFS, cTER, MUC10) were combined with a new index (Average upslope). The delayed graft function duration was defined as the number of days of dialysis-based/functional delayed graft function. Results A total of 377 patients were included, with a mean age (± SD) of 52 ± 14 years, and 58% were male. A total of 274 (73%) patients experienced delayed graft function≥ 7 days. Qualitative grading for the prediction of delayed graft function≥ 7 days had a sensitivity and specificity of respectively 87% and 65%. The quantitative indices with the most optimal results were cTER (76% sensitivity, 72% specificity), and Average upslope (75% sensitivity, 73% specificity). Conclusions Qualitative renal scintigraphy grading and the quantitative indices cTER and Average upslope predict delayed graft function ≥ 7 days with a high sensitivity. This finding may help to support both clinicians and patients in managing early post-operative expectations. However, the specificity is limited and thus renal scintigraphy does not reliably help to identify patients in whom the course of delayed graft function is longer than anticipated.

Have we forgotten imaging prior to and after kidney transplantation

Key Points• The number of publications on imaging and kidney transplantation is low.• These publications are poorly cited, as compared with other fields of imaging.• Conversely, there is a clinical need for evidence-based recommendations.• Innovative advances for the use of imaging and kidney transplantation are essential.• An increased focus and adequate research funding are highly anticipated by clinicians.