Coronary artery calcification, cardiovascular events, and death: a prospective cohort study of incident patients on hemodialysis.

BACKGROUND: Coronary calcification in patients with end-stage renal disease (ESRD) is associated with an increased risk of cardiovascular outcomes and death from all causes. Previous evidence has been limited by short follow-up periods and inclusion of a heterogeneous cluster of events in the primary analyses. OBJECTIVE: To describe coronary calcification in patients incident to ESRD, and to identify whether calcification predicts vascular events or death. DESIGN: Prospective substudy of an inception cohort. SETTING: Tertiary care haemodialysis centre in Ontario (St Joseph's Healthcare Hamilton). PARTICIPANTS: Patients starting haemodialysis who were new to ESRD. MEASUREMENTS: At baseline, clinical characterization and spiral computed tomography (CT) to score coronary calcification by the Agatston-Janowitz 130 scoring method. A primary outcome composite of adjudicated stroke, myocardial infarction, or death. METHODS: We followed patients prospectively to identify the relationship between cardiac calcification and subsequent stroke, myocardial infarction, or death, using Cox regression. RESULTS: We recruited 248 patients in 3 centres to our main study, which required only biochemical markers. Of these 164 were at St Joseph's healthcare, and eligible to participate in the substudy; of these, 51 completed CT scanning (31 %). Median follow up was 26 months (Q1, Q3: 14, 34). The primary outcome occurred in 16 patients; 11 in the group above the median and 5 in the group below (p = 0.086). There were 26 primary outcomes in 16 patients; 20 (77 %) events in the group above the coronary calcification median and 6 (23 %) in the group below (p = 0.006). There were 10 deaths; 8 in the group above the median compared with 2 in the group below (p = 0.04). The hazard ratios for coronary calcification above, compared with below the median, for the primary outcome composite were 2.5 (95 % CI 0.87, 7.3; p = 0.09) and 1.7 (95 % CI 0.55, 5.4; p = 0.4), unadjusted and adjusted for age, respectively. For death, the hazard ratios were 4.6 (95 % CI 0.98, 21.96; p = 0.054) and 2.4 (95 % CI 0.45, 12.97; p = 0.3) respectively. LIMITATIONS: We were limited by a small sample size and a small number of events. CONCLUSIONS: Respondent burden is high for additional testing around the initiation of dialysis. High coronary calcification in patients new to ESRD has a tendency to predict cardiovascular outcomes and death, though effects are attenuated when adjusted for age.

CONTEXTE: La calcification de l'artère coronaire chez les patients atteints d'insuffisance rénale terminale (IRT) est associée à un risque accru de troubles cardiovasculaires et de mortalité, toutes causes confondues. Les données précédemment recueillies se limitaient à un suivi de courte durée, de même qu'à l'inclusion de séries d'accidents non liés lors de l'analyse préliminaire. OBJECTIFS: Décrire la calcification de l'artère coronaire chez les patients atteints d'IRT et déterminer si la calcification de l'artère coronaire peut prédire des accidents vasculaires et la mort. TYPE D'ÉTUDE: Sous-étude prospective de cohorte selon le mode d'installation. CADRE: Une unité de soins tertiaires en dialyse, en Ontario (St Joseph's Healthcare Hamilton). PARTICIPANTS: Des patients qui sont nouvellement atteints d'IRT et qui entament une hémodialyse. MESURES: En début de traitement, une caractérisation clinique et une tomodensitométrie (TDM) hélicoïdale qui permettent de mesurer la calcification de l'artère coronaire sur 130, selon l'échelle d'Agatston-Janowitz. L'indicateur principal des résultats comprend l'AVC, l'infarctus du myocarde ou la mort. MÉTHODES: Nous avons suivi les patients de manière prospective, afin de cibler la relation entre la calcification de l'artère coronaire et l'AVC, l'infarctus du myocarde ou la mort subséquente, en utilisant la régression de Cox. RÉSULTATS: Nous avons recruté 248 patients dans trois unités, dans le cadre de l'étude principale, qui ne requérait que des biomarqueurs chimiques. De ces patients, 164 étaient de St Joseph's Healthcare, et étaient admissibles à la sous-étude; 51 avaient effectué une tomographie par ordinateur (31 %). Le suivi médian s'étendait sur 26 mois (Q1, Q3: 14, 34). L'indicateur principal a été observé chez 16 patients; 11 dans le groupe se trouvant au-dessus de la médiane, et 5 dans le groupe inférieur (p?=?0,086). On a observé 26 indicateurs principaux chez 16 patients; 20 (77 %) accidents dans le groupe se trouvant au-dessus de la médiane en ce qui a trait à la calcification et 6 (23 %) dans le groupe inférieur (p?=?0,006). Il y a eu 10 décès; 8 dans le groupe se trouvant au-dessus de la médiane et 2 dans le groupe inférieur (p?=?0,04). Les taux de risque de calcification de l'artère coronaire se trouvant au-dessus et sous la médiane, pour les indicateurs principaux, étaient respectivement de 2,5 (95 % IC 0,98; 21,96; p?=?0,054) et 2,4 (95 % IC 0,45, 12,97; p?=?0,3). LIMITES DE L'ÉTUDE: Nous avons été limités par la taille restreinte de l'échantillon, de même que par le petit nombre d'accidents. CONCLUSION: Le fardeau du répondant repose sur des examens supplémentaires au moment de commencer la dialyse. Un fort taux de calcification de l'artère coronaire chez les patients nouvellement atteints d'IRT tend à prédire des accidents cardiovasculaires et la mort, bien que les effets soient atténués après révision en fonction de l'âge.

Low-intensity adjusted-dose warfarin for the prevention of hemodialysis catheter failure: a randomized, controlled trial.

BACKGROUND AND OBJECTIVES: To determine whether warfarin prolongs the time to first mechanical-catheter failure. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a multicenter parallel-group randomized controlled trial with blinding of participants, trial staff, clinical staff, outcome assessors, and data analysts. Randomization was in a 1:1 ratio in blocks of four and was concealed by use of fax to a central pharmacy. Hemodialysis patients with newly-placed catheters received low-intensity monitored-dose warfarin, target international normalized ratio (INR) 1.5 to 1.9, or placebo, adjusted according to schedule of sham INR results. The primary outcome was time to first mechanical-catheter failure (inability to establish a circuit or blood flow less than 200 ml/min). RESULTS: We randomized 174 patients: 87 to warfarin and 87 to placebo. Warfarin was associated with a hazard ratio (HR) of 0.90 (P=0.60; 95% confidence interval [CI], 0.57, 1.38) for time to first mechanical-catheter failure. Secondary analyses were: time to first guidewire exchange or catheter removal for mechanical failure (HR 0.78; 95% CI, 0.37, 1.6); time to catheter removal for mechanical failure (HR 0.67; 95% CI, 0.19, 2.37); and time to catheter removal for any cause (HR 0.89; 95% CI, 0.42, 1.81). Major bleeding occurred in 10 participants assigned to warfarin and seven on placebo (relative risk, 1.43; 95% CI, 0.57, 3.58; P=0.61). CONCLUSIONS: We found no evidence for efficacy of low-intensity, monitored-dose warfarin in preventing mechanical-catheter failure.

Waist-to-Hip Ratio, Cardiovascular Outcomes, and Death in Peritoneal Dialysis Patients.

Objectives. The primary objective of this study was to determine the relationship between waist-to-hip ratio (WHR), cardiovascular (CV) events, and mortality in peritoneal dialysis (PD) patients. A secondary objective was to investigate the association between abdominal obesity and systemic inflammatory markers. Methods. This is a prospective study of 22 prevalent PD patients. WHR was measured at baseline. C-reactive protein (CRP), tumour necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured. Main outcomes were first CV event and death from all causes. Survival analysis was used to examine the relationship between anthropomorphic measures and clinical outcomes. Results. Mean follow-up period was 3.1 years. In Kaplan-Meier analysis, survival was lower in those with higher WHR (P = .002). In Cox regression, WHR independently predicted mortality and first CV event after adjustment for known ischemic heart disease (hazard ratio [HR] 1.17, confidence interval [CI] 1.05-1.30 for death; HR 1.13, CI 1.01-1.26 for CV event). WHR correlated with serum TNF-α (r = 0.45; P = .05). Conclusion. The results of this study suggest WHR may be a risk factor for increased CV events and mortality in PD patients. Abdominal obesity is also associated with inflammatory markers. Larger studies are warranted to confirm these findings.