Michel Labeeuw

A clinical score to predict 6-month prognosis in elderly patients starting dialysis for end-stage renal disease.

AIM The aim of this study was to develop and validate a prognostic score for 6-month mortality in elderly patients starting dialysis for end-stage renal disease. METHODS Using data from the French Rein registry, we developed a prognostic score in a training sample of 2500 patients aged 75 years or older who started dialysis between 2002 and 2006, which we validated in a similar sample of 1642 patients. Multivariate logistic regression with 500 bootstrap samples allowed us to select risk factors from 19 demographic and baseline clinical variables. RESULTS The overall 6-month mortality was 19%. Age was not associated with early mortality. Nine risk factors were selected and points assigned for the score were as follows: body mass index <18.5 kg/m2 (2 points), diabetes (1), congestive heart failure stages III to IV (2), peripheral vascular disease stages III to IV (2), dysrhythmia (1), active malignancy (1), severe behavioural disorder (2), total dependency for transfers (3) and unplanned dialysis (2). The median score was 2. Mortality rates ranged from 8% in the lowest risk group (0 point) to 70% in the highest risk group (> or =9 points) and 17% in the median group (2 points). Seventeen percent of all deaths occurred after withdrawal from dialysis, ranging from 0% for a score of 0-1 to 15% for a score of 7 or higher. CONCLUSIONS This simple clinical score effectively predicts short-term prognosis among elderly patients starting dialysis. It should help to illuminate clinical decision making, but cannot be used to withhold dialysis. It ought to only be used by nephrologists to facilitate the discussion with the patients and their families.

Age and comorbidity may explain the paradoxical association of an early dialysis start with poor survival

Starting patients on dialysis early has been increasing in incidence in several countries. However, some studies have questioned its utility, finding a counter-intuitive effect of increased mortality when dialysis was started at a higher estimated glomerular filtration rate (eGFR). To examine this issue in more detail we measured mortality hazard ratios associated with Modification of Diet in Renal Disease eGFR at dialysis initiation for 11,685 patients from the French REIN Registry, with sequential adjustment for a number of covariates. The eGFR was analyzed both quantitatively by 5-ml/min per 1.73 m(2) increments and by demi-decile (i.e., 5 percentiles of the distribution); the 15th demi-decile, including values around 10 ml/min per 1.73 m(2), was our reference point. The patients more likely to begin dialysis at a higher eGFR were older male patients; had diabetes, cardiovascular diseases, or low body mass index and level of albuminemia; or were started with peritoneal dialysis. During a median follow-up of 21.9 months, 3945 patients died. The 2-year crude survival decreased from 79 to 46%, with increasing eGFR from less than 5 to over 20 ml/min per 1.73 m(2). Each 5-ml/min/1.73 m(2) increase in eGFR was associated with a 40% increase in crude mortality risk, which weakened to 9%, but remained statistically significant after adjusting for the above covariates. Analysis by demi-decile showed only the highest to be at significantly higher risk. Hence we found that age and patient condition strongly determine the decision to start dialysis and may explain most of the inverse association between eGFR and survival.

Effect of Age, Gender, and Diabetes on Excess Death in End-Stage Renal Failure

Life expectancy is short in elderly individuals with end-stage renal failure (ESRF). This study aimed to compare mortality in patients with ESRF versus the general population (GP) to assess the evolution of excess mortality by age, gender, nephropathy, and dialysis modality after first dialysis. All incident adult dialysis patients from January 1,1999, to December 31, 2003, who lived in Rhône-Alpes Region (France) were included and followed up to death or December 31, 2005. Standardized mortality ratios (SMR) in comparison with GP were computed in the first to the fifth years after first dialysis. In the whole cohort (3025 incident patients), SMR decreased during these 5 yr from 7.4 to 5.2 (P = 0.002). In the 18- to 44-, 45- to 64-, 65- to 74-, 75- to 84-, and > or =85-yr-old groups, SMR decreased from 26.7 to 6.2 (P = 0.01), from 12.8 to 8.1 (P = 0.03), from 8.6 to 5.6 (P = 0.051), from 7.1 to 4.5 (P = 0.02), and from 3.5 to 1.2 (P = 0.14), respectively. Among age categories, differences were significant in the first 3 yr (P < 0.05). SMR were higher 1.5-fold in women than in men in the first 4 yr (P < 0.05). In patients with diabetic nephropathy (DN), SMR increased during the first 3 yr (P = 0.045) and were higher than in patients without DN in the second, third, and fourth years (P < 0.05). SMR were higher in the peritoneal dialysis than in the hemodialysis group in the fourth year (P < 0.01). Patients with ESRF have a high excess mortality compared with the GP. Older patients with ESRF experienced less excess mortality. ESRF cancels out womens survival advantage noted in the GP. SMR evolution in patients with DN was different from that in patients without DN.

Survival advantage of hemodialysis relative to peritoneal dialysis in patients with end-stage renal disease and congestive heart failure

Peritoneal dialysis (PD) has been proposed as a therapeutic option for patients with end-stage renal disease and associated congestive heart failure (CHF). Here, we compare mortality risks in these patients by dialysis modality by including all patients who started planned chronic dialysis with associated congestive heart failure and were prospectively enrolled in the French REIN Registry. Survival was compared between 933 PD and 3468 hemodialysis (HD) patients using a Kaplan-Meier model, Cox regression, and propensity score analysis. The patients were followed from their first dialysis session and stratified by modality at day 90 or last modality if death occurred prior. There was a significant difference in the median survival time of 20.4 months in the PD group and 36.7 months in the HD group (hazard ratio, 1.55). After correction for confounders, the adjusted hazard ratio for death in PD compared to the HD patients remained significant at 1.48. Subgroup analyses showed that the results were not changed with regard to the New York Heart Association stage, age strata, or estimated glomerular filtration rate strata at first renal replacement therapy. The use of propensity score did not change results (adjusted hazard ratio, 1.55). Thus, mortality risk was higher with PD than with HD among incident patients with end-stage renal disease and congestive heart failure. These results may help guide clinical decisions and also highlight the need for randomized clinical trials.

Transplant Renal Artery Stenosis: Evaluation of Diagnosis with Magnetic Resonance Angiography Compared with Color Duplex Sonography and Arteriography

The goal of this study was to assess the value of a three-dimensional phase contrast magnetic resonance angiography (3D PC MRA) for diagnosing transplant renal artery stenosis (TRAS). Twelve consecutive patients clinically suspected of having TRAS were prospectively enrolled during a period of 18 months. Delays from transplantation varied from 3 months to 4 years (mean: 18.3 months). Patients first had color Doppler sonography, then MRA-and, on the following day, intraarterial digital subtraction angiography (IADSA). The site of the maximum peak systolic velocity was noted when doing the report of each color Doppler sonogram. On MRA images, any signal cutoff or any vascular narrowing of more than 50% of the diameter of the vessel was considered to be a significant stenosis. Eight patients were considered to have TRAS on MRA, but only two stenoses were noted on IADSA. The six false-positive results of MRA (due to major intravoxel phase dispersion) were observed when elevated peak systolic velocities were noted on doppler sonograms (mean: 214 cm/sec). These elevated peak systolic velocities were noted in the proximal part of the renal artery when there was a tortuous vessel or a sharp angle between the renal artery and the parent vessel. It is our opinion that 3D PC MRA is of limited value for the diagnosis of renal transplant artery stenosis because of a high number of false-positive results.

Spécificités méthodologiques de l’analyse de survie des patients dialysés

Epidemiological and observational studies are needed in nephrology for evidence-based medical decision and global knowledge of renal patients. Using strong methodology, such studies are useful to formulate hypotheses for further explanatory studies or clinical trials. Survival analysis of dialysis patients are based on the usual and robust Kaplan-Meier and Cox regression methods. Nevertheless, their use should take into account the specificities of the dialysis population, especially when non-constant risks for death with time and sub-groups analyses are considered. In addition, survival curves from birth or standardised mortality ratio are able to provide a new view of survival by changing of analytical perspective. Our aim is to summarize the specificities of survival study methodology in dialysis patients using concrete examples in French cohorts.

Confounding factors for early death in incident end-stage renal disease patients: Role of emergency dialysis start.

Hemodialysis (HD) has been associated with higher 1‐year mortality than peritoneal dialysis (PD) after dialysis start. Confounding effects of late referral, emergency dialysis start, or start with central venous catheter on this association have never been studied concomitantly. Survival was studied among the 495 incident dialysed patients in our department from 1995 to 2006 and followed at least 1 year until December 31, 2007. Nested Cox models adjusted on patient characteristics explored factors associated with 1‐year and ≥1‐year mortality. Hemodialysis patients were 332 (67.1%), 104 (21.0%) were late referred (<6 months), 167 (33.7%) started dialysis in emergency, and 144 (29.1%) started with central venous catheter. When adjusted only on age, sex, and comorbidities, HD was associated with poor 1‐year outcome: adjusted hazard ratio (aHR) for death in HD vs. PD was 1.77, P=0.02. In fully adjusted model, among first dialysis feature variables, only emergency dialysis start was significantly associated with 1‐year mortality: aHR 1.53, P=0.02. Dialysis modality was not associated with 1‐year mortality rates in this fully adjusted model: aHR in HD vs. PD became 1.03, P=0.91. In ≥1‐year period, HD was associated with lower mortality than PD (aHR 0.61, P=0.004), whereas other first dialysis features were not associated with death. Other factors associated with death were age, type 2 diabetes, peripheral vascular disease, heart failure, and hepatic failure. Negative association between HD and 1‐year survival on dialysis was explained by confounders. Emergency dialysis start was strongly associated with early mortality on dialysis. Its prevention may improve patient survival.

Relative mortality risk in chronic kidney disease and end-stage renal disease: the effect of age, sex and diabetes

6 months of initiating PD and another has one peritonitis episode 2 years after starting PD, a relative risk analysis would consider these patients to be equivalent with respect to the outcome because the occurrence of peritonitis is registered only as a ‘yes/no event’ (despite the fact that most clinicians would agree that these patients are quite different from one another). Based on these concerns, we would argue that relative risk is not a meaningful way to assess the association of any variable with peritonitis. With regard to the authors’ conclusion that APD is associated with a lower peritonitis rate than CAPD, we note that this conclusion is based on only two randomized controlled trials. Of these trials, the study by Bro et al. [2] reported only three total episodes of peritonitis (one on APD, two on CAPD), likely related to the relatively short (6 month) follow-up time in this study. Since so few peritonitis episodes occurred in this trial, the results of the ‘review’ of the effect CAPD versus APD on peritonitis are almost entirely driven by the findings of the other trial by De Fijter et al. from 1994, showing a lower peritonitis rate with APD. The conclusions of the review with respect to peritonitis should therefore be interpreted with caution. While we commend the authors for trying to synthesize the existing literature on CAPD versus APD into a systematic review, the paucity of data available from randomized trials with respect to peritonitis limits the value of this exercise.

Vascular access conversion and patient outcome after hemodialysis initiation with a nonfunctional arteriovenous access: a prospective registry-based study

BackgroundLittle is known about vascular access conversion and outcomes for patients starting hemodialysis with nonfunctional arteriovenous (AV) access. We assessed mortality risk associated with nonfunctional AV access at hemodialysis initiation, taking subsequent changes in vascular access into account.MethodsWe studied the 53,092 incident adult hemodialysis patients included in the French REIN registry from 2005 through 2012. AV access placed predialysis was considered nonfunctional when dialysis began with a central venous catheter. Information about vascular access changes was obtained from treatment modality updates.ResultsAt hemodialysis initiation, AV access was functional for 47% of patients and nonfunctional for 9%; 44% had a catheter alone. After a 3-year follow-up, 63% of patients beginning hemodialysis with a nonfunctional AV access had changed to a functional one, 4% had had a transplant, 19% had died before any vascular access change, and 13% still used a catheter. Cox proportional hazard models with vascular access treated as a time-dependent variable showed an adjusted mortality hazard ratio (95% confidence interval) for patients with nonfunctional AV access who subsequently converted to functional access of 0.95 (95% CI 0.89–1.03) compared with the reference group with functional AV access since first hemodialysis, versus 1.43 (95% CI 1.31–1.55) for those who did not convert.ConclusionsAmong patients starting hemodialysis with a nonfunctional AV access, a substantial percentage may never experience successful vascular access conversion. Poor survival seems to be limited to these patients, while those who subsequently convert to functional AV access have similar mortality risk compared to patients with such access since hemodialysis initiation. Every effort should be made to obtain functional AV access in all suitable patients.

Predictors of nonfunctional arteriovenous access at hemodialysis initiation and timing of access creation: A registry-based study

Determinants of nonfunctional arteriovenous (AV) access, including timing of AV access creation, have not been sufficiently described. We studied 29 945 patients who had predialysis AV access placement and were included in the French REIN registry from 2005 through 2013. AV access was considered nonfunctional when dialysis began with a catheter. We estimated crude and adjusted odds ratio (OR) with 95% confidence intervals (CI) of nonfunctional versus functional AV access associated with case-mix, facility characteristics, and timing of AV access creation. Analyses were stratified by dialysis start condition (planned or as an emergency) and comorbidity profile. Overall, 18% patients had nonfunctional AV access at hemodialysis initiation. In the group with planned dialysis start, female gender (OR 1.43, 95% CI 1.32–1.56), diabetes (OR 1.28, 95% CI 1.15–1.44), and a higher number of cardiovascular comorbidities (OR 1.27, 95% CI 1.09–1.49, and 1.31, 1.05–1.64, for 3 and >3 cardiovascular comorbidities versus none, respectively) were independent predictors of nonfunctional AV access. A higher percentage of AV access creation at the region level was associated with a lower rate of nonfunctional AV access (OR 0.98, 95% CI 0.98–0.99 per 1% increase). The odds of nonfunctional AV access decreased as time from creation to hemodialysis initiation increased up to 3 months in nondiabetic patients with fewer than 2 cardiovascular comorbidities and 6 months in patients with diabetes or 2 or more such comorbidities. In conclusion, both patient characteristics and clinical practices may play a role in successful AV access use at hemodialysis initiation. Adjusting the timing of AV access creation to patients’ comorbidity profiles may improve functional AV access rates.