Atrial fibrillation in patients on haemodialysis in Andalusia. Prevalence, clinical profile and therapeutic management. / Fibrilación auricular en los pacientes en hemodiálisis en Andalucía. Prevalencia, perfil clínico y manejo terapéutico.

Atrial fibrillation (AF) represents an important social and healthcare problem. There is wide variability in the prevalence of this arrhythmia in studies analysing patients on haemodialysis (HD). OBJECTIVE: To investigate the prevalence, clinical profile and therapeutic management of patients with AF on HD in Andalusia. METHODS: We asked the public healthcare system of Andalusia to provide us with the number of patients who were being treated with HD. We asked attending nephrologists from all hospital and outpatient centres in 5 of the 8 Andalusian provinces to perform an electrocardiogram and to fill out a questionnaire on patients selected by simple random sampling. RESULTS: A total of 2,348 patients were being treated with HD in the 5provinces included in the study. The estimated sample size was 285 patients. We obtained an electrocardiogram and information from 252 patients (88.4%); mean age 65.3±16 years; 40.9% women. Sixty-three patients (25%) had AF. Of these, 36 (14.3%) had AF in the recorded ECG and in the rest it had been documented previously. In the multivariate analysis, older age (OR: 1.071; 95% CI: 1.036-1.107; P=0.000) and greater time on HD (OR: 1.009; 95% CI: 1.004-1.014; P=0.000) were independently associated with the presence of AF. Of the patients with AF, 41.3% were on anticoagulant treatment at the time of the study; and 41.2% were on antiplatelet agents. CONCLUSIONS: AF in dialysis units is an important finding. Establishing the risk-benefit ratio of anticoagulant treatment constitutes a real challenge. Well-designed clinical trials are pivotal in order to define the rational use of antithrombotic drugs.

Bleeding Risk of Antithrombotic Treatment in Patients on Hemodialysis.

BACKGROUND: The risk-benefit of antithrombotic treatment (ATT) has not been established in patients on dialysis. Our objective was to determine the influence of ATT on the risk of hemorrhage in patients on hemodialysis. METHODS: We included patients who began dialysis between 2003 and 2007. We determined the rates of fatal bleeding or bleeding leading to hospitalization or transfusion. RESULTS: Two hundred twenty-one patients were included. Over the follow-up period (45.5 ± 34 months), there were 76 hemorrhages in 52 patients. There were 10 fatal bleedings. The annual incidence of patients presenting with hemorrhagia was 6.2%. Bleeding occurred in 5.2% of those being treated with aspirin, 7% with acenocumarol, 12.3% with clopidogrel, 15.2% with aspirin + clopidogrel, 45.9% with anticoagulants + antiplatelets, 49.6% with low-molecular-weight heparin, and 3.9% without ATT. On multivariate analysis, masculine gender [hazard ratio (HR): 2.421; 95% confidence interval (CI), 1.261-4.650; P = 0.003], treatment with dicumarins (HR: 2.406; 95% CI, 1.013-5.718; P = 0.047), treatment with clopidogrel (HR: 2.697; 95% CI, 1.440-5.051; P = 0.002), and treatment with low-molecular-weight heparin (HR: 21.463; 95% CI, 9.067-50.806; P = 0.001) were independent predictors of bleeding. CONCLUSIONS: ATT increases the risk of bleeding in patients on hemodialysis. The incidence of hemorrhage varies with the type of antithrombotics used.

Valvular calcifications at the start of dialysis predict the onset of cardiovascular events in the course of follow-up.

OBJECTIVE: To analyse the presence of VC at the start of dialysis and its relationship with events and/or death from cardiovascular causes in the course of follow-up. METHODS: In the study, we included patients who started dialysis between November 2003 and September 2007. In the first month of treatment, we assessed the presence of VC by Doppler echocardiography, along with demographic factors and risk factors for cardiovascular disease, coronary artery disease, stroke, atrial fibrillation (AF), and cardiac dimensional and functional electrocardiographic and echocardiographic parameters. The biochemistry values assessed were: haemoglobin, calcium/phosphorous/iPTH metabolism, cholesterol and fractions, triglycerides, troponin I, albumin, CRP and glycosylated haemoglobin. We analysed the association between VC and the presence of myocardial infarction (MI), stroke and/or death from cardiovascular causes up to transplantation, death or the end of the study (December 2012). RESULTS: Of 256 enrolled patients (83% haemodialysis, 17% peritoneal dialysis), 128 (50%) had VC (mitral: 39, aortic: 20, both: 69). In the multivariate analysis, VC was associated with older age (OR: 1.110; 95% CI: 1.073-1.148; p = 0.000) and lower albumin levels (OR: 0.29; 95% CI: 0.14-0.61; p = 0.001). In a follow-up lasting 42.1 ± 30.2 months (898.1 patient-years), 68 patients suffered MI, stroke and/or died from cardiovascular causes. In the Cox regression analysis, older age (HR: 1.028; 95% CI: 1.002-1.055; p = 0.037), coronary artery disease and/or stroke (HR: 1.979; 95% CI: 1.111-3.527; p = 0.021), AF (HR: 2.474; 95% CI: 1.331-4.602; p = 0.004), and the presence of VC at the start of dialysis (HR: 1.996; 95% CI: 1.077-3.700; p = 0.028) were the predictor variables for the occurrence of the analysed events. CONCLUSIONS: The prevalence of VC at the start of dialysis is high and its presence predicts the occurrence of events and/or cardiovascular death in the course of follow-up.

Sudden death in incident dialysis patients.

BACKGROUND: Sudden death (SD) constitutes one of the principal causes of death and is an important problem in healthcare provision. Cardiovascular diseases have a high prevalence in dialysis patients and constitute the principal cause of death. We sought to analyze retrospectively the incidence of SD in patients commencing dialysis and the factors related to its presence. METHODS: We evaluated all the patients who began dialysis in our center between 1/11/2003 and 15/9/2007, and who were followed up until death, transplant, or study completion on 31/12/2012. We determined the presence of SD according to the following criteria: SD at 24 h (SD 24H): unexpected death occurring in the 24 h following the start of symptoms, or when the patient was found dead and had been seen alive 24 h earlier; SD at 1 h (SD 1H): death witnessed as occurring in the first hour following the start of symptoms. RESULTS: We evaluated 285 patients, mean age 65.67 ± 15.7 years. In a follow-up of 39.9 ± 34.2 months (947.6 patient-years of follow-up) 168 died (59%), 28 (10%) patients presented SD 24H (2.9/100 patient-years), and 16 (6%) patients presented SD 1H (1.7/100 patient-years). In the multivariate analysis, having had a myocardial infarction or having had electrocardiographic abnormalities (Q wave, negative T wave, subendocardial lesion or QRS >120 ms) were the principal independent predictors of SD 24H (OR 7.83; 95% CI 2.20-27.86; p = 0.001) and of SD 1H (OR 13.43; 95% CI 1.56-115.42; p = 0.018). CONCLUSIONS: SD on dialysis is very frequent. Two groups can be identified easily, with risk profiles clearly differentiated.

Incidence of acute myocardial infarction in the evolution of dialysis patients.

BACKGROUND: Although the estimated frequency of coronary artery disease (CAD) in patients on dialysis is very high, there is considerable variation in the studies published to date regarding the rate of acute myocardial infarction (AMI) in these patients. OBJECTIVE: To establish the incidence of AMI and to analyse the characteristics and consequences of this entity on the clinical progression of incident dialysis patients. METHODS: We recorded AMI in the patients treated in our dialysis unit between 01/01/1999 and 31/12/07. The variables assessed were: prior diagnosis of diabetes, hypertension, CAD (AMI or lesions observed in coronary angiography), ischaemic cerebrovascular accident, advanced peripheral artery disease (PAD), atrial fibrillation and tobacco use. Biochemical analyses included: urea, creatinine, haematocrit, calcium, phosphorous, iPTH, lipids and albumin. Follow-up lasted until transplant, death, loss to follow-up or study end in Dec. 2010. RESULTS: Of the 576 patients recruited (aged 64.6 ± 16 years), 24.7% had diabetes, 82.3% were on haemodialysis (17.7% on peritoneal dialysis), and 34 (5.9%) had a previous diagnosis of CAD. In a follow-up lasting a mean of 40.2 ± 32 months (1931.5 patient-years), 40 patients (6.9%) suffered an AMI. The incidence was 2.13/100 patient-years. The patients without CAD had an incidence of 1.84/100 patient-years and those with a previous diagnosis of CAD had an incidence of 7.53/100 patient-years. In 22.5% of patients, AMI happened in the first 3 months of dialysis, and 37.5% in the 1st year. Of the 40 AMI, 15 were with ST-segment elevation (incidence: 0.79/100 patient-years) and 25 were non ST-segment elevation (incidence: 1.33/100 patient-years). The factors that predicted the occurrence of AMI in dialysis were older age (OR: 1.037; 95% CI: 1.009-1.067; P=.011), previous CAD (OR: 3.35; 95% CI: 1.48-7.16; P=.004), and diabetes as a cause of nephropathy (OR: 2.96; 95% CI: 1.49-5.86; P=.002). In-hospital mortality was 30%, with 72.5% of deaths occurring in the 1st year and 82.5% in the 2nd; 80% of the patients who underwent a coronary angiography had multi-vessel disease. CONCLUSIONS: The incidence of AMI in incident dialysis patients is high. In previous coronary disease patients, the incidence is 3-fold higher. Post-infarction mortality is very high and multi-vessel disease is very frequent.

Ischaemic stroke in incident dialysis patients.

BACKGROUND: Despite the high frequency of cardiovascular disease among the population on dialysis, there are few studies on ischaemic stroke and associated factors. The objective of the present study is to assess the prevalence of ischaemic stroke at the start of dialysis, its incidence in the course of follow-up and possible factors associated in its presentation. METHODS: All patients in our dialysis programme between 1 January 1999 and 31 December 2005 were included in the study and followed up until death, transplant, transfer out of our catchment area, or conclusion of the study on 31 December 2008. Factors analysed were age, gender, smoking habit, diabetes, hypertension, previous ischaemic stroke, ischaemic coronary disease, peripheral vascular disease and atrial fibrillation. Other factors measured in the first month of dialysis were haematocrit, urea, creatinine, lipids, calcium, phosphorus, parathyroid hormone and albumin. RESULTS: Of 449 patients included in the study (age 64.4 ± 16 years), 30 commenced dialysis having had previous stroke (prevalence 6.7%). In a follow-up of 38.77 ± 29 months, 34 patients presented with one or more strokes; an incidence of 2.41/100 patient-years. Greater age [odds ratio (OR): 1.05; 95% confidence interval (CI): 1.01-1.09; P = 0.007], diabetes (OR: 2.29; 95% CI: 1.15-4.55; P = 0.018) and presence of atrial fibrillation (OR: 3.11; 95% CI: 1.53-6.32; P = 0.002) were independent predictors of stroke occurrence. Conclusions. The prevalence of ischaemic stroke is high at the commencement of dialysis, and its incidence is elevated in the course of follow-up. As with the general population, atrial fibrillation is an important factor predictive of ischaemic stroke, and as such, the clinical implication is that prophylactic anti-coagulation therapy needs to be considered for these individuals.

Atrial fibrillation in incident dialysis patients.

Despite the importance of cardiovascular disease in dialysis patients, the frequency of atrial fibrillation in incident dialysis patients has not been determined. We analyzed the prevalence of atrial fibrillation in patients starting dialysis over a 4-year period, its occurrence over the course of dialysis, and its influence on ischemic stroke and mortality. Factors predisposing to atrial fibrillation were noted, as was the influence of arrhythmia on mortality and presentation of ischemic stroke. Of the 256 patients studied, 31 had atrial fibrillation at the start of dialysis. Increased age, larger left atrium, and female gender were independently related to the presence of atrial fibrillation at dialysis inception. Of the 225 patients who were in sinus rhythm at the start of dialysis, 28 developed atrial fibrillation during a mean follow-up time of 2 years. The presence of valvular calcifications, bundle branch block, previous ischemic stroke, lower ejection fraction, higher pulse pressure, and lower hemoglobin concentration were predictors of the clinical evolution of atrial fibrillation. Overall, atrial fibrillation increased mortality risk 1.72-fold and ischemic stroke risk 9.8-fold. Therefore, it appears that atrial fibrillation is quite prevalent and its presence is associated with significant risk.

[Prevalence of and predisposing factors for bundle branch block in patients starting dialysis]. / Análisis de la prevalencia y los factores predisponentes de los bloqueos de rama en los pacientes que inician diálisis.

INTRODUCTION AND OBJECTIVES: Although bundle branch block (BBB) is regarded as a frequent finding, data on its prevalence are scarce in the general population and nonexistent in patients on dialysis. The aims of this study were to determine the prevalence of complete BBB in patients starting dialysis, to identify factors associated with its presence and, secondarily, to explore its association with mortality and the occurrence of cardiovascular events. METHODS: The study involved patients who started dialysis at our institution between November 1, 2003 and December 31, 2006. All underwent cardiological evaluation at the start of treatment. The presence of BBB was determined and its relationship with clinical factors and biochemical and echocardiographic parameters was examined. Patients were followed up until November 30, 2007. RESULTS: The study included 211 patients (age 65.05+/-15.7 years; 56.4% male). Of these, 24 (11.4%) presented with BBB: 6 (2.8%) with left BBB and 18 (8.5%) with right BBB. Age (odds ratio [OR]=1.05; 95% confidence interval [CI], 1.008-1.113; P=.02) and body mass index (OR=1.12; 95% CI, 1.019-1.234; P=.02) were independently associated with BBB. During a mean follow-up period of 23.7+/-12.9 months, patients who presented with left BBB showed a clear trend towards a poorer outcome than those without a conduction defect. CONCLUSIONS: The prevalence of BBB was high in patients starting dialysis and greater than that observed in the general population. Its presence was independently associated with older age and obesity. During the mean follow-up period of 2 years, patients with left BBB demonstrated a trend towards a poor prognosis.

[Incidence of atrial fibrillation in hemodialysis patients. A prospective long-term follow-up study]. / Incidencia de la fibrilación auricular en los pacientes en hemodiálisis. Estudio prospectivo a largo plazo.

INTRODUCTION AND OBJECTIVES: Although atrial fibrillation (AF) is the most commonly occurring arrhythmia in the general population and is a serious health problem, its incidence in patients on hemodialysis is unknown. Our objectives were to determine the incidence of AF in our hemodialysis patients, to investigate factors that predispose to its occurrence, and to assess the clinical implications of AF. METHODS: In total, 164 patients in sinus rhythm (SR) were followed for seven years. The occurrence of AF and its influence on mortality and on the occurrence of thromboembolic events were recorded. RESULTS: In a mean follow-up period of 47 (29.5) months (i.e., 643.2 patient-years), 20 patients developed AF (3.1 per 100 patient-years). It was not possible to identify factors that predisposed to the arrhythmia. In patients aged > or =65 years, 1-year and 2-year mortality rates following the occurrence of AF were 38% and 53%, respectively, whereas the rates in those who remained in SR were 14% and 31%, respectively (P=NS). The development of AF was not found to be an independent predictor of mortality. Five patients in the AF group experienced six thromboembolic episodes in a follow-up period of 23.6 (21.4) months (i.e., 15 episodes per 100 patient-years), compared with three episodes per 100 patient-years in the SR group (relative risk=5.2; 95% CI, 2.1-12.4). CONCLUSIONS: Each year, three in every 100 patients in our dialysis unit developed AF. The occurrence of AF increased the risk of a thromboembolic complication five-fold. The use of anticoagulant treatment in these patients should be carefully evaluated.

Comparison of prognostic value of atrial fibrillation versus sinus rhythm in patients on long-term hemodialysis.

The influence of atrial fibrillation (AF) on the clinical pattern of patients with chronic renal insufficiency on hemodialysis remains unknown despite the cardiovascular pathology in these patients being well documented and being the primary cause of death in this patient population. The objective of this study was to compare the long-term outcome in those patients on our dialysis unit in sinus rhythm with those in AF.

Ought dialysis patients with atrial fibrillation be treated with oral anticoagulants?

BACKGROUND: Dialysis patients with atrial fibrillation have an increased thrombolic risk. Dicoumarin anticoagulant therapy is often considered contra-indicated in chronic renal insufficiency in which the risk of haemorrhage, though not defined, is perceived to be high. We assessed haemorrhage complications in dialysis patients receiving dicoumarin anticoagulant therapy to establish whether the haemorrhage risk justifies the contra-indication of anticoagulant therapy in patients with atrial fibrillation. PATIENTS AND METHODS: Over a period of a decade in our dialysis centre, 29 patients receiving anticoagulant therapy over a protracted period presented haemorrhage complications. These were classified with respect to severity and location and compared with 211 patients not receiving anticoagulant therapy. The relative risk of haemorrhage was calculated and was compared to risk of thrombo-embolism in dialysis patients with atrial fibrillation. RESULTS: Of the 29 patients, nine had 13 episodes of haemorrhage complications (26 episodes/100 patient-years). None was fatal, nor intra-cranial nor with serious clinical sequelae. In the group without anticoagulants, 29 patients had 39 haemorrhage complications (11 episodes/100 patient-years); four (10.2%) intra-cranial and all fatal. The relative risk of bleeding with anticoagulant therapy was 2.36 (95% confidence interval=1.19-4.27). CONCLUSIONS: (1) Dialysis patients with anticoagulant therapy presented with a higher risk of haemorrhage; (2) the relative risk of bleeding was double that of the dialysis population without anticoagulant therapy; (3) despite the high risk of haemorrhage that we observed, the high risk of thrombo-embolism and the attendant serious sequelae to which dialysis patients with atrial fibrillation are predisposed indicates that oral anticoagulation therapy ought not to be considered automatically contra-indicated in this patient group but that an exhaustive evaluation of the risk-benefit needs to be conducted on an individual patient basis.