Survival, cumulative hospital days and infectious complications in urgent-start PD compared with urgent-start HD.

BACKGROUND: Urgent-start peritoneal dialysis (PD) carries a similar efficacy and safety profile compared to urgent-start haemodialysis (HD) but is only sparsely applied due to resource issues and concerns of complication risks. Furthermore, few data exist on adverse outcomes associated with central venous catheter (CVC) insertions in urgent-start HD patients. Thus, we sought to compare patient and dialysis-related outcomes in patients undergoing urgent-start PD or HD. METHODS: All patients initiating urgent-start PD in a tertiary research hospital in 2005-2018 were included in this retrospective, single-centre, comparative study and matched with urgent-start HD patients of similar age and chronic kidney disease aetiology. All urgent-start PDs were initiated within 72 h after catheter insertion, and urgent-start HDs were performed via a CVC. All analyses were performed at 3 months and at 1 year of follow-up, respectively. RESULTS: Thirty-three patients who commenced urgent-start PD and 58 matched urgent-start HD control patients were included. Altogether, 26 patients (29%; PD: 36%, HD 24%) died within the 1-year follow-up, and patient survival was similar at 3 months (hazard ratio (HR): 1.15, 95% confidence interval (CI): 0.35-3.81, p = 0.82) and at 1 year of follow-up (HR: 0.64, 95% CI: 0.30-1.39, p = 0.26) between the study groups. There were no differences in the total kidney replacement therapy (KRT)-related infection rate (p = 0.66) or cumulative first-year hospital care days (p = 0.43) between the treatment groups. Altogether, 139 CVCs were inserted during the 1-year follow-up. The number of CVCs per patient was associated with the emergence of blood culture-positive bacteraemia and increased cumulative first-year hospital care days. CONCLUSIONS: Patient survival, cumulative first-year hospital care days and total KRT-related infection rate at 3 months and 1-year follow-up are similar between urgent-start PD and urgent-start HD patients. Furthermore, CVC insertion rate is associated with incident blood culture-positive bacteraemia and increased cumulative first-year hospital care days.

Renal Perfusion, Oxygenation and Metabolism: The Role of Imaging.

Thanks to technical advances in the field of medical imaging, it is now possible to study key features of renal anatomy and physiology, but so far poorly explored due to the inherent difficulties in studying both the metabolism and vasculature of the human kidney. In this narrative review, we provide an overview of recent research findings on renal perfusion, oxygenation, and substrate uptake. Most studies evaluating renal perfusion with positron emission tomography (PET) have been performed in healthy controls, and specific target populations like obese individuals or patients with renovascular disease and chronic kidney disease (CKD) have rarely been assessed. Functional magnetic resonance (fMRI) has also been used to study renal perfusion in CKD patients, and recent studies have addressed the kidney hemodynamic effects of therapeutic agents such as glucagon-like receptor agonists (GLP-1RA) and sodium-glucose co-transporter 2 inhibitors (SGLT2-i) in an attempt to characterise the mechanisms leading to their nephroprotective effects. The few available studies on renal substrate uptake are discussed. In the near future, these imaging modalities will hopefully become widely available with researchers more acquainted with them, gaining insights into the complex renal pathophysiology in acute and chronic diseases.

Acute kidney injury in group A streptococcal bacteraemia: incidence, outcome and predictive value of C-reactive protein.

BACKGROUND: A ubiquitous human pathogen, Streptococcus pyogenes (Group A Streptococcus, GAS) causes infections from mild pharyngitis to severe septic infections. Acute kidney injury (AKI) is a condition of prompt decline of renal function. The aim of the present study was to report the incidence and outcome of AKI in GAS bacteraemia and to evaluate the diagnostic value of serum C-reactive protein as an indicator of AKI. METHODS: All adult patients with GAS bacteraemia treated at Turku University Hospital from 2007 to 2018 were identified and their patient records were scrutinised. RESULTS: Of 195 included patients, 38 (19.5%) had AKI stage 1, 20 (10.3%) AKI stage 2 and 26 (13.3%) AKI stage 3 and 111 (56.9%) did not have AKI. The adjusted seven-day mortality was significantly higher in AKI stages 2 and 3 compared to the non-AKI group (15% and 19% vs. 3.6%; p = .046 and .006, respectively). Of the survivors, 95.8% met the criteria of renal recovery at discharge. The higher the AKI stage, the higher was the mean serum CRP level on admission. The optimal cut-off for CRP to identify patients with AKI stage 2 or 3 was ≥244 mg/l (sensitivity 82.6% and specificity 75.8%). CONCLUSIONS: AKI is common in patients with GAS bacteraemia and the severity of AKI correlates with the CRP level on admission. The mortality of patients with GAS bacteraemia and AKI is significantly higher than of patients without AKI. Most survivors, however, show renal recovery.Key MessageAKI is common in group A Streptococcal bacteraemia and increases mortality compared to bacteraemia alone. However, renal recovery is also common. A high CRP level on admission correlates significantly positively with the degree of severity of AKI.

Evolution of Quality of Life in Chronic Kidney Disease Stage 4-5 Patients Transitioning to Dialysis and Transplantation.

INTRODUCTION: Chronic kidney disease (CKD) has a profound effect on patients' health-related quality of life (QoL). Longitudinal studies on QoL in CKD are scarce and have explored selected patients on renal replacement therapy (RRT). We studied the evolution of QoL in patients with advanced CKD transitioning to dialysis and transplantation in a prospective follow-up study. METHODS: A total of 100 participants of the Chronic Arterial Disease, Quality of Life, and Mortality in Chronic Kidney Injury (CADKID) study were enrolled in the study. Kidney Disease Quality of Life Short Form, biochemistry, and echocardiography were obtained at baseline and after a median interval of 33 (range 12-85) months. RESULTS: At the time of the follow-up QoL assessment, 32 patients were not receiving RRT, 30 were on hemodialysis (HD), 19 on peritoneal dialysis (PD), and 19 had received a kidney transplant. Among kidney transplant recipients (KTRs), "Burden of Kidney Disease" and "General Health" domains improved compared to patients who initiated HD (p < 0.0001 and p = 0.007, respectively), PD (p = 0.0005 and p = 0.03, respectively), or remained in predialysis care (p = 0.009 and p = 0.003, respectively) while "Effects of Kidney Disease" improved compared to those who started HD (p = 0.004) or PD (p = 0.002). The change in Short Form-36 (SF-36) Physical Component Summary was not different between patients on different treatment modalities. Higher plasma albumin and cholesterol levels were associated with improved QoL in "Symptoms/Problems" (r = 0.28, p = 0.005, and r = 0.30, p = 0.004, respectively) and "Effects of Kidney Disease" (r = 0.27, p = 0.008, and r = 0.24, p = 0.03, respectively). CONCLUSION: QoL improved in KTRs in kidney disease-specific domains compared to patients initiating dialysis or those without RRT. Plasma albumin and lipids were associated with QoL over time.

Association between bone mineral metabolism and vascular calcification in end-stage renal disease.

BACKGROUND: Development of vascular calcification is accelerated in patients with end-stage renal disease. In addition to traditional risk factors of cardiovascular disease (CVD) abnormal bone and mineral metabolism together with many other factors contribute to the excess cardiovascular burden in patients on dialysis. Aortic calcification score and coronary calcification score are predictive of CVD and mortality. The aim of this study was to evaluate the possible relationship between arterial calcification and bone metabolism. METHODS: Thirty two patients on dialysis were included. All patients underwent a bone biopsy to assess bone histomorphometry and a 18F-NaF PET scan. Fluoride activity was measured in the lumbar spine (L1 - L4) and at the anterior iliac crest. Arterial calcification scores were assessed by computerized tomography for quantification of coronary artery calcification score and lateral lumbar radiography for aortic calcification score. RESULTS: This study group showed high prevalence of arterial calcification and 59% had verified CVD. Both CAC and AAC were significantly higher in patients with verified CVD. Only 22% had low turnover bone disease. There was a weak association between fluoride activity, which reflects bone turnover, measured in the lumbar spine, and CAC and between PTH and CAC. There was also a weak association between erosion surfaces and AAC. No significant association was found between calcification score and any other parameter measured. CONCLUSIONS: The results in this study highlight the complexity, when evaluating the link between bone remodeling and vascular calcification in patients with multiple comorbidities and extensive atherosclerosis. Several studies suggest an impact of bone turnover on development of arterial calcification and there is some evidence of reduced progression of vascular calcification with improvement in bone status. The present study indicates an association between vascular calcification and bone turnover, even though many parameters of bone turnover failed to show significance. In the presence of multiple other factors contributing to the development of calcification, the impact of bone remodeling might be diminished. TRIAL REGISTRATION: The study is registered in ClinicalTrials.gov protocol registration and result system, ID is NCT02967042 . Date of registration is 17/11/2016.

Letermovir treatment for CMV infection in kidney and pancreas transplantation: A valuable option for complicated cases.

Cytomegalovirus (CMV) infection remains a major challenge in solid organ transplantation. Ganciclovir has changed the prognosis, but with the expense of possible viral resistance. New antiviral drugs, such as letermovir, have not been studied sufficiently in kidney and pancreas transplant recipients. We reviewed abdominal organ transplants recipients with CMV infection from the national transplant registry and identified patients treated with letermovir from electronic medical records. We report on letermovir treatment in one kidney and three simultaneous pancreas and kidney (SPK) transplant patients with refractory or ganciclovir-resistant CMV infection (UL54/ UL97 mutation). In SPK patients, persistent leukopenia undermined immunosuppressive and antiviral treatment, favoring life-threatening bacterial infections or ganciclovir resistance. All patients achieved viral clearance after letermovir monotherapy of 1.5-6 months. Letermovir was well tolerated and leukopenia resolved. Adjustments of calcineurin inhibitor doses were challenging. One acute rejection occurred because of under immunosuppression. After the end of treatment, recurrent low-grade CMV-DNAemia was common requiring reinitiating antiviral therapy to achieve viral clearance. To conclude, letermovir was a well-tolerated valuable option for the treatment of refractory or resistant CMV infection in kidney and pancreas transplantation.

Progression of Aortic Calcification in Stage 4-5 Chronic Kidney Disease Patients Transitioning to Dialysis and Transplantation.

BACKGROUND AND AIMS: Abdominal aortic calcification (AAC) is common in chronic kidney disease (CKD) patients and associated with increased mortality. Comparative data on the AAC score progression in CKD patients transitioning from conservative treatment to different modalities of renal replacement therapy (RRT) are lacking and were examined. METHODS: 150 study patients underwent lateral lumbar radiograph to study AAC in the beginning of the study before commencing RRT (AAC1) and at 3 years of follow-up (AAC2). We examined the associations between repeated laboratory tests taken every 3 months, echocardiographic and clinical variables and AAC increment per year (ΔAAC), and the association between ΔAAC and outcomes during follow-up. RESULTS: At the time of AAC2 measurement, 39 patients were on hemodialysis, 39 on peritoneal dialysis, 39 had a transplant, and 33 were on conservative treatment. Median AAC1 was 4.8 (0.5-9.0) and median AAC2 8.0 (1.5-12.0) (p < 0.0001). ΔAAC was similar across the treatment groups (p = 0.19). ΔAAC was independently associated with mean left ventricular mass index (LVMI) (log LVMI: ß = 0.97, p = 0.02) and mean phosphorus through follow-up (log phosphorus: ß = 1.19, p = 0.02) in the multivariable model. Time to transplantation was associated with ΔAAC in transplant recipients (per month on the waiting list: ß = 0.04, p = 0.001). ΔAAC was associated with mortality (HR 1.427, 95% confidence interval 1.044-1.950, p = 0.03). CONCLUSION: AAC progresses rapidly in patients with CKD, and ΔAAC is similar across the CKD treatment groups including transplant recipients. The increment rate is associated with mortality and in transplant recipients with the time on the transplant waiting list.

Maximal Exercise Capacity in Chronic Kidney Disease Stage 4-5 Patients Transitioning to Renal Replacement Therapy or Continuing Conservative Care: A Longitudinal Follow-Up Study.

INTRODUCTION: Chronic kidney disease (CKD) is associated with impaired maximal exercise capacity (MEC). However, data are scarce on the development of MEC in CKD stage 4-5 patients transitioning to renal replacement therapy (RRT). METHODS: We explored the change in MEC measured in watts (Wlast4) with 2 consecutive maximal bicycle stress ergometry tests in 122 CKD stage 4-5 patients transitioning to dialysis and transplantation in an observational follow-up study. RESULTS: Mean age was 58.9 ± 13.9 years and 43 (35.2%) were female. Mean time between the baseline and follow-up ergometry tests was 1,012 ± 327 days and 29 (23.8%) patients had not initiated RRT, 50 (41.0%) were undergoing dialysis, and 43 (35.2%) had received a kidney transplant at the time of the follow-up ergometry test. The mean Wlast4 was 91 ± 37 W and 84 ± 37 W for the baseline and follow-up ergometry tests, respectively (p < 0.001). The mean Wlast4 declined between the baseline and follow-up ergometry tests in patients not requiring RRT (p = 0.001) and transplant recipients (p = 0.005), but not in dialysis patients (p = 0.478). There were no differences in the ratio of Wlast4 of the follow-up to the baseline ergometry tests (∆Wlast4) between patients on different treatment modalities at the time of the follow-up test (p = 0.097). Mean capillary blood bicarbonate was significantly associated with ∆Wlast4 after adjusting for age and treatment modality in the multivariate linear regression analysis (ß = 0.226, p = 0.012). CONCLUSION: MEC declined or remained poor in advanced CKD patients transitioning to RRT or continuing conservative care in this observational study. Mean capillary blood bicarbonate was independently associated with the development of MEC.

Dental health assessed using panoramic radiograph and adverse events in chronic kidney disease stage 4-5 patients transitioning to dialysis and transplantation-A prospective cohort study.

BACKGROUND AND AIMS: Oral health could potentially be a modifiable risk factor for adverse outcomes in chronic kidney disease (CKD) patients transitioning from predialysis treatment to maintenance dialysis and transplantation. We aimed to study the association between an index of radiographically assessed oral health, Panoramic Tomographic Index (PTI), and cardiovascular and all-cause mortality, major adverse cardiovascular events (MACEs) and episodes of bacteremia and laboratory measurements during a three-year prospective follow-up in CKD stage 4-5 patients not on maintenance dialysis at baseline. METHODS: Altogether 190 CKD stage 4-5 patients without maintenance dialysis attended panoramic dental radiographs in the beginning of the study. The patients were followed up for three years or until death. MACEs and episodes of bacteremia were recorded during follow-up. Laboratory sampling for C-reactive protein and leukocytes was repeated tri-monthly. RESULTS: PTI was not associated with baseline laboratory parameters or C-reactive protein or leukocytes examined as repeated measures through the 3-year follow-up. During follow-up, 22 patients had at least one episode of bacteremia, but only 2 of the bacteremias were considered to be of oral origin. PTI was not associated with incident bacteremia during follow-up. Thirty-six patients died during follow-up including 17 patients due to cardiovascular causes. During follow-up 42 patients were observed with a MACE. PTI was independently associated with all-cause (HR 1.074 95% CI 1.029-1.122, p = 0.001) and cardiovascular (HR 1.105, 95% CI 1.057-1.157, p<0.0001) mortality, as well as, incident MACEs (HR 1.071 95% CI 1.031-1.113, p = 0.0004) in the multivariable Cox models adjusted for age and kidney transplantation or CKD treatment modality during follow-up. CONCLUSIONS: Radiographically assessed dental health is independently associated with all-cause and cardiovascular mortality and MACEs but not with the incidence of bacteremia in CKD stage 4-5 patients transitioning to maintenance dialysis and renal transplantation during follow-up.

Bone Histomorphometry and 18F-Sodium Fluoride Positron Emission Tomography Imaging: Comparison Between only Bone Turnover-based and Unified TMV-based Classification of Renal Osteodystrophy.

Bone biopsy is the gold standard for characterization of renal osteodystrophy (ROD). However, the classification of the subtypes of ROD based on histomorphometric parameters is not unambiguous and the range of normal values for turnover differ in different publications. 18F-Sodium Fluoride positron emission tomography (18F-NaF PET) is a dynamic imaging technique that measures turnover. 18F-NaF PET has previously been shown to correlate with histomorphometric parameters. In this cross-sectional study, 26 patients on dialysis underwent a 18F-NaF PET and a bone biopsy. Bone turnover-based classification was assessed using Malluche's historical reference values for normal bone turnover. In unified turnover-mineralization-volume (TMV)-based classification, the whole histopathological picture was evaluated and the range for normal turnover was set accordingly. Fluoride activity was measured in the lumbar spine (L1-L4) and at the anterior iliac crest. On the basis of turnover-based classification of ROD, 12% had high turnover and 61% had low turnover bone disease. On the basis of unified TMV-based classification of ROD, 42% had high turnover/hyperparathyroid bone disease and 23% had low turnover/adynamic bone disease. When using unified TMV-based classification of ROD, 18F-NaF PET had an AUC of 0.86 to discriminate hyperparathyroid bone disease from other types of ROD and an AUC of 0.87, for discriminating adynamic bone disease. There was a disproportion between turnover-based classification and unified TMV-based classification. More research is needed to establish normal range of bone turnover in patients with CKD and to establish the role of PET imaging in ROD.

Association of maximal stress ergometry performance with troponin T and abdominal aortic calcification score in advanced chronic kidney disease.

BACKGROUND: Cardiac biomarkers Troponin T (TnT) and N-terminal pro-B-type natriuretic peptide (proBNP) and abdominal aortic calcification score (AAC) are associated with cardiovascular events and mortality in patients with chronic kidney disease (CKD). The effects of cardiac biomarkers and AAC on maximal exercise capacity in CKD are unknown and were studied. METHODS: One hundred seventy-four CKD 4-5 patients not on maintenance dialysis underwent maximal bicycle ergometry stress testing, lateral lumbar radiograph to study AAC, echocardiography and biochemical assessments. RESULTS: The subjects with proportional maximal ergometry workload (WMAX%) less than 50% of the expected values had higher TnT, proBNP, AAC, left ventricular end-diastolic diameter, left ventricular mass index, E/e' and pulse pressure, and lower global longitudinal strain compared to the better performing patients. TnT (ß = - 0.09, p = 0.02), AAC (ß = - 1.67, p < 0.0001) and diabetes (ß = - 11.7, p < 0.0001) remained significantly associated with WMAX% in the multivariable model. Maximal ergometry workload (in Watts) was similarly associated with TnT and AAC in addition to age, male gender, hemoglobin and diastolic blood pressure in a respective multivariate model. AAC and TnT showed fair predictive power for WMAX% less than 50% of the expected value with AUCs of 0.70 and 0.75, respectively. CONCLUSIONS: TnT and AAC are independently associated with maximal ergometry stress test workload in patients with advanced CKD. TRIAL REGISTRATION: http://www.ClinicalTrials.gov NCT04223726.

Elevated Troponin T and Enlarged Left Atrium Are Associated with the Incidence of Atrial Fibrillation in Patients with CKD Stage 4-5.

INTRODUCTION: Atrial fibrillation (AF) and CKD are commonly coexisting conditions. However, data on epidemiology of AF in patients with CKD stage 4-5 is scarce. METHODS: We prospectively enrolled 210 consecutive non-dialysis patients with CKD stage 4-5 between 2013 and 2017. Follow-up data on AF incidence along with medical history, laboratory tests, and echocardiography at baseline were gathered. RESULTS: At baseline, mean age was 62 years, estimated glomerular filtration rate 12.8 mL/min, and 73/210 (34.8%) participants were female. Altogether, 41/210 (19.5%) patients had a previous diagnosis of AF. After median follow-up of 46 [IQR 27] months, new-onset AF occurred in 33/169 (19.5%) patients (69.9 events/1,000 person-years). In the Cox proportional hazard model, age >60 years (HR 4.27, CI 95% 1.57-11.64, p < 0.01), elevated troponin T (TnT) >50 ng/L (HR 3.61, CI 95% 1.55-8.37, p < 0.01), and left atrial volume index (LAVI) >30 mL/m2 (HR 4.82, CI 95% 1.11-21.00, p = 0.04) were independently associated with the incidence of new-onset AF. CONCLUSION: The prevalence and incidence of AF was markedly high in this prospective study on patients with CKD stage 4-5. Elevated TnT and increased LAVI were independently associated with the occurrence of new-onset AF in patients with severe CKD.

Arterial endothelial function, carotid artery intima-media thickness and abdominal aortic calcification in diabetic and nondiabetic CKD stage 4-5 patients not on dialysis.

AIMS: We aimed to study the effect of diabetes (DM) on endothelial dysfunction assessed by flow-mediated vasodilatation (FMD), carotid intima-media thickness (cIMT) and abdominal aortic calcification score (AAC) in chronic kidney disease (CKD) stage 4-5 patients not on dialysis. METHODS: Altogether 199 non-dialysis CKD stage 4-5 patients enrolled in the Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury (CADKID) study with plain lumbar radiograph for the assessment of AAC were included. Data on cIMT and FMD were available for 172 and 161 patients, respectively. RESULTS: Median age was 65 (IQR 54-76) years, 88 (44.2%) patients had DM and median eGFR was 12 (IQR 10-14) ml/min/1.73 m2 in the study. FMD [controls: 3.3(2.0-6.7)% vs. DM-patients: 4.3(1.3-6.6)%, p = 0.73] and cIMT [controls: 0.65(0.58-0.87)mm vs. DM-patients: 0.67(0.59-0.81)mm, p = 0.65], were similar between the groups. AAC was higher in patients with DM [controls: 5(1-9) vs. DM-patients: 7(2-13), p = 0.01]. The significant multivariate determinants for AAC were older age (ß = 0.22, p < 0.0001), pulse pressure (ß = 0.05, p < 0.0001), DM (ß = 1.33, p = 0.04) and ProBNP (per µg/l ß = 0.18, p = 0.0008). AAC and cIMT were associated with incident cardiovascular death independent of DM. CONCLUSIONS: DM is associated with increased AAC but not increased cIMT or attenuated FMD in advanced CKD patients.

Quality of Life Is Associated with Cardiac Biomarkers, Echocardiographic Indices, and Mortality in CKD Stage 4-5 Patients Not on Dialysis.

INTRODUCTION: Patients with CKD have an impaired health-related quality of life (QoL). Most studies have been conducted on dialysis patients, and less is known about QoL and its determinants in predialysis patients. We studied the association between QoL and comorbidities, cardiac biomarkers, echocardiography, and mortality in patients with CKD stage 4-5 not on dialysis. METHODS: A total of 140 patients enrolled in the Chronic Arterial Disease, Quality of Life and Mortality in Chronic Kidney Injury (CADKID) study filled the Kidney Disease Quality of Life Short Form (KDQOL-SF) at the beginning of the study. Echocardiography and biochemical parameters were obtained at baseline. Patients were followed up for at least 2 years or until death. RESULTS: The median age was 66 years, and 51 (36%) patients were female. The median estimated glomerular filtration rate was 13 mL/min per 1.73 m2. Obesity, diabetes, atrial fibrillation, and congestive heart failure were associated with lower QoL scores in multiple KDQOL-SF domains. Cardiac biomarkers, troponin T (p = 0.02), N-terminal pro-B-type natriuretic peptide (p = 0.006), and the echocardiographic parameter of cardiac systolic function left ventricular global longitudinal strain (p = 0.02) were significant predictors of lower physical component summary (PCS) score in multivariable regression models after controlling for age, BMI, and diabetes. A low PCS score predicted mortality in a multivariable Cox proportional hazards model [HR 0.96 (95% CI 0.92-0.99), p = 0.03]. QoL was not associated with kidney disease progression. CONCLUSION: Impaired QoL in CKD stage 4-5 patients not on dialysis is associated with cardiac biomarker levels, echocardiographic indices, and mortality.

Interatrial block, P terminal force or fragmented QRS do not predict new-onset atrial fibrillation in patients with severe chronic kidney disease.

BACKGROUND: The prevalence of left atrial enlargement (LAE) and fragmented QRS (fQRS) diagnosed using ECG criteria in patients with severe chronic kidney disease (CKD) is unknown. Furthermore, there is limited data on predicting new-onset atrial fibrillation (AF) with LAE or fQRS in this patient group. METHODS: We enrolled 165 consecutive non-dialysis patients with CKD stage 4-5 without prior AF diagnosis between 2013 and 2017 in a prospective follow-up cohort study. LAE was defined as total P-wave duration ≥120 ms in lead II ± > 1 biphasic P-waves in leads II, III or aVF; or duration of terminal negative portion of P-wave > 40 ms or depth of terminal negative portion of P-wave > 1 mm in lead V1 from a baseline ECG, respectively. fQRS was defined as the presence of a notched R or S wave or the presence of ≥1 additional R waves (R') or; in the presence of a wide QRS complex (> 120 ms), > 2 notches in R or S waves in two contiguous leads corresponding to a myocardial region, respectively. RESULTS: Mean age of the patients was 59 (SD 14) years, 56/165 (33.9%) were female and the mean estimated glomerular filtration rate was 12.8 ml/min/1.73m2. Altogether 29/165 (17.6%) patients were observed with new-onset AF within median follow-up of 3 [IQR 3, range 2-6] years. At baseline, 137/165 (83.0%) and 144/165 (87.3%) patients were observed with LAE and fQRS, respectively. Furthermore, LAE and fQRS co-existed in 121/165 (73.3%) patients. Neither findings were associated with the risk of new-onset AF within follow-up. CONCLUSION: The prevalence of LAE and fQRS at baseline in this study on CKD stage 4-5 patients not on dialysis was very high. However, LAE or fQRS failed to predict occurrence of new-onset AF in these patients.

Cardiovascular Determinants of Mortality in Advanced Chronic Kidney Disease.

BACKGROUND: Patients with advanced chronic kidney disease (CKD stage 4-5) have an increased risk of death. To study the determinants of all-cause mortality, we recruited 210 consecutive CKD stage 4-5 patients not on dialysis to the prospective Chronic Arterial Disease, quality of life and mortality in chronic KIDney injury (CADKID) study. METHODS: One hundred seventy-four patients underwent maximal bicycle ergometry stress testing and lateral lumbar radiography to study abdominal aortic calcification score and echocardiography. Carotid and femoral artery intima-media thickness and elasticity and brachial artery flow-mediated dilatation were measured in 156 patients. RESULTS: The duration of follow-up was 42 ± 17 months (range 134-2,217 days). The mean age was 61 ± 14 years, and the estimated glomerular filtration rate was 12 (11-15) mL/min/1.73 m2. Thirty-six (21%) patients died during follow-up (time to death 835 ± 372 days). Seventy-five and 21 patients had diabetes and coronary artery disease, respectively, and all but one had hypertension. In the respective multivariate proportional hazards models adjusted for age, sex, and coronary artery disease, the significant determinants of mortality were troponin T, N-terminal pro-B-type natriuretic peptide, maximal ergometry performance, abdominal aortic calcification score, E/e' ratio, and albumin. CONCLUSION: Stress ergometry performance, abdominal aortic calcification score, E/e' of echocardiography, and plasma cardiac biomarkers and albumin predict mortality in advanced CKD.

Prognostic imaging biomarkers for diabetic kidney disease (iBEAt): study protocol.

BACKGROUND: Diabetic kidney disease (DKD) remains one of the leading causes of premature death in diabetes. DKD is classified on albuminuria and reduced kidney function (estimated glomerular filtration rate (eGFR)) but these have modest value for predicting future renal status. There is an unmet need for biomarkers that can be used in clinical settings which also improve prediction of renal decline on top of routinely available data, particularly in the early stages. The iBEAt study of the BEAt-DKD project aims to determine whether renal imaging biomarkers (magnetic resonance imaging (MRI) and ultrasound (US)) provide insight into the pathogenesis and heterogeneity of DKD (primary aim) and whether they have potential as prognostic biomarkers in DKD (secondary aim). METHODS: iBEAt is a prospective multi-centre observational cohort study recruiting 500 patients with type 2 diabetes (T2D) and eGFR ≥30 ml/min/1.73m2. At baseline, blood and urine will be collected, clinical examinations will be performed, and medical history will be obtained. These assessments will be repeated annually for 3 years. At baseline each participant will also undergo quantitative renal MRI and US with central processing of MRI images. Biological samples will be stored in a central laboratory for biomarker and validation studies, and data in a central data depository. Data analysis will explore the potential associations between imaging biomarkers and renal function, and whether the imaging biomarkers improve the prediction of DKD progression. Ancillary substudies will: (1) validate imaging biomarkers against renal histopathology; (2) validate MRI based renal blood flow measurements against H2O15 positron-emission tomography (PET); (3) validate methods for (semi-)automated processing of renal MRI; (4) examine longitudinal changes in imaging biomarkers; (5) examine whether glycocalyx and microvascular measures are associated with imaging biomarkers and eGFR decline; (6) explore whether the findings in T2D can be extrapolated to type 1 diabetes. DISCUSSION: iBEAt is the largest DKD imaging study to date and will provide valuable insights into the progression and heterogeneity of DKD. The results may contribute to a more personalised approach to DKD management in patients with T2D. TRIAL REGISTRATION: Clinicaltrials.gov ( NCT03716401 ).

Myocardial perfusion reserve of kidney transplant patients is well preserved.

BACKGROUND: Chronic kidney disease (CKD) is associated with endothelial dysfunction and increased cardiovascular mortality. Endothelial dysfunction can be studied measuring myocardial perfusion reserve (MPR). MPR is the ratio of stress and rest myocardial perfusion (MP) and reflects the capacity of vascular bed to increase perfusion and microvascular responsiveness. In this pilot study, our aim was to assess MPR of 19 patients with kidney transplant (CKD stages 2-3) and of ten healthy controls with quantitative [15O]H2O positron emission tomography (PET) method. RESULTS: Basal MP was statistically significantly higher at rest in the kidney transplant patients than in the healthy controls [1.3 (0.4) ml/min/g and 1.0 (0.2) ml/min/g, respectively, p = 0.0015]. After correction of basal MP by cardiac workload [MPcorr = basal MP/individual rate pressure product (RPP) × average RPP of the healthy controls], the difference between the groups disappeared [0.9 (0.2) ml/min/g and 1.0 (0.3) ml/min/g, respectively, p = 0.55)]. There was no difference in stress MP between the kidney transplant patients and the healthy subjects [3.8 (1.0) ml/min/g and 4.0 (0.9) ml/min/g, respectively, p = 0.53]. Although MPR was reduced, MPRcorr (stress MP/basal MPcorr) did not differ between the kidney transplant patients and the healthy controls [4.1 (1.1) and 4.3 (1.6), respectively, p = 0.8]. CONCLUSIONS: MP during stress is preserved in kidney transplant patients with CKD stage 2-3. The reduced MPR appears to be explained by increased resting MP. This is likely linked with increased cardiac workload due to sympathetic overactivation in kidney transplant patients.

Correlation between 18F-Sodium Fluoride positron emission tomography and bone histomorphometry in dialysis patients.

BACKGROUND: The diagnosis of renal osteodystrophy is challenging. Bone biopsy is the gold standard, but it is invasive and limited to one site of the skeleton. The ability of biomarkers to estimate the underlying bone pathology is limited. 18F-Sodium Fluoride positron emission tomography (18F-NaF PET) is a noninvasive quantitative imaging technique that allows assessment of regional bone turnover at clinically relevant sites. The hypothesis of this study was, that 18F-NaF PET correlates with bone histomorphometry in dialysis patients and could act as a noninvasive diagnostic tool in this patient group. METHODS: This was a cross-sectional diagnostic test study. 26 dialysis patients with biochemical abnormalities indicating mineral and bone disorder were included. All the participants underwent a 18F-NaF PET scan and a bone biopsy. Fluoride activity in the PET scan was measured in the lumbar spine and at the anterior iliac crest. Dynamic and static histomorphometric parameters of the bone biopsy were assessed. As histomorphometric markers for bone turnover we used bone formation rate per bone surface (BFR/BS) and activation frequency per year (Ac.f). RESULTS: There was a statistically significant correlation between fluoride activity in the 18F-NaF PET scan and histomorphometric parameters such as bone formation rate, activation frequency and osteoclast and osteoblast surfaces and mineralized surfaces. 18F-NaF PET's sensitivity to recognize low turnover in respect to non-low turnover was 76% and specificity 78%. Because of the small number of patients with high turnover, we were unable to demonstrate significant predictive value in this group. CONCLUSIONS: A clear correlation between histomorphometric parameters and fluoride activity in the 18F-NaF PET scan was established. 18F-NaF PET may possibly be a noninvasive diagnostic tool in dialysis patients with low turnover bone disease, but further research is needed.

Renal vascular resistance is increased in patients with kidney transplant.

BACKGROUND: Despite improvement in short-term outcome of kidney transplants, the long-term survival of kidney transplants has not changed over past decades. Kidney biopsy is the gold standard of transplant pathology but it's invasive. Quantification of transplant blood flow could provide a novel non-invasive method to evaluate transplant pathology. The aim of this retrospective cross-sectional pilot study was to evaluate positron emission tomography (PET) as a method to measure kidney transplant perfusion and find out if there is correlation between transplant perfusion and histopathology. METHODS: Renal cortical perfusion of 19 kidney transplantation patients [average time from transplantation 33 (17-54) months; eGFR 55 (47-69) ml/min] and 10 healthy controls were studied by [15 O]H2O PET. Perfusion and Doppler resistance index (RI) of transplants were compared with histology of one-year protocol transplant biopsy. RESULTS: Renal cortical perfusion of healthy control subjects and transplant patients were 2.7 (2.4-4.0) ml min- 1 g- 1 and 2.2 (2.0-3.0) ml min- 1 g- 1, respectively (p = 0.1). Renal vascular resistance (RVR) of the patients was 47.0 (36.7-51.4) mmHg mL- 1min- 1g- 1 and that of the healthy 32.4 (24.6-39.6) mmHg mL- 1min-1g-1 (p = 0.01). There was a statistically significant correlation between Doppler RI and perfusion of transplants (r = - 0.51, p = 0.026). Transplant Doppler RI of the group of mild fibrotic changes [0.73 (0.70-0.76)] and the group of no fibrotic changes [0.66 (0.61-0.72)] differed statistically significantly (p = 0.03). No statistically significant correlation was found between cortical perfusion and fibrosis of transplants (p = 0.56). CONCLUSIONS: [15 O]H2O PET showed its capability as a method in measuring perfusion of kidney transplants. RVR of transplant patients with stage 2-3 chronic kidney disease was higher than that of the healthy, although kidney perfusion values didn't differ between the groups. Doppler based RI correlated with perfusion and fibrosis of transplants.