Influence of atrial fibrillation on the morbido-mortality of patients on hemodialysis

Frequency of atrial fibrillation and factors related to its development in dialysis patients

BACKGROUND

The frequency of atrial fibrillation is increased in patients with end-stage renal disease. In this study, we sought to determine the incidence of persistent and paroxysmal atrial fibrillation in patients with end-stage renal disease and to identify the risk factors associated with this arrhythmia.

METHODS

Two hundred seventy-five patients with end-stage renal disease who were in a hemodialysis program for at least 4 months were included in the study. Patients with permanent, persistent, or paroxysmal atrial fibrillation were identified and recorded. All patients were evaluated for cardiac risk factors and arrhythmias.

RESULTS

Thirty (10.9%) of the 275 patients were found to have atrial fibrillation. Ten (33.3%) of these patients had permanent or persistent atrial fibrillation, and 20 (66.6%) of these patients had paroxysmal atrial fibrillation. Patients with atrial fibrillation were older. Incidences of hypertension, coronary artery disease, left ventricular systolic dysfunction, right atrial diameters, and mitral and/or aortic calcification were significantly higher in patients with atrial fibrillation. Serum albumin and high-density lipoprotein levels were significantly lower in patients with atrial fibrillation.

CONCLUSIONS

Our data indicate that atrial fibrillation is a frequent arrhythmia in patients with end-stage renal disease, and the most frequently encountered form is paroxysmal atrial fibrillation. In this patient group, presence of coronary artery disease, age, and right atrial diameter are independent factors for determination of the risk of development of atrial fibrillation.

Thromboembolism and anticoagulant management in hemodialysis patients: A practical guide to clinical management

The need for anticoagulation in dialysis patients is common and the incidence of venous thromboembolism (VTE) and atrial fibrillation in this population is high. While direct data are lacking on the management of anticoagulation in dialysis patients, careful weighing of risks and benefits on the basis of evidence from other populations is crucial. VTE should be managed with adjusted dose warfarin for most patients. Placement of an inferior vena cava filter is a reasonable option for those patients with unacceptable bleeding risks. Studies are ongoing to assess the safety of some low-molecular-weight heparins (LMWH), which may potentially be useful for long-term anticoagulation in hemodialysis patients. In atrial fibrillation the available data on risk of bleeding, risk of stroke, and patient preferences should all be taken into account when considering long-term anticoagulation. We have constructed an evidence model to help quantitate the risks and benefits for an individual patient. The impact of dialysis on risk of bleeding is such that the risk of bleeding will outweigh the benefit in many patients, and anticoagulation will not be used: in some of these patients aspirin therapy may be an alternative. Finally, in the area of prevention of graft and access thrombosis, some randomized controlled trials are available, but none have to date shown benefit from anticoagulation for primary or secondary prevention of thrombosis, and the risk of bleeding in these studies was high.

Incidence, predictors, and associated outcomes of atrial fibrillation after kidney transplantation

The risk for and predictors of atrial fibrillation (AF) after kidney transplantation are not well described. Registry data that were collected by the United States Renal Data System were used to investigate retrospectively new-onset AF among adult first renal allograft recipients and transplant candidates who received a transplant or were wait-listed in 1995 to 2001 with Medicare as the primary payer. AF events were ascertained from billing records, and participants were followed until loss of Medicare coverage or December 31, 2001. Cox hazards analysis was used to identify independent correlates of posttransplantation AF (adjusted hazard ratio [AHR]; 95% confidence interval [CI]) and to examine AF as an outcomes predictor. Among 31,136 eligible transplant recipients, the cumulative incidence of new-onset AF was 3.6% (95% CI 3.4 to 3.8%) and 7.3% (95% CI 7.0 to 7.6%) at 12 and 36 mo and declined below the demographics-adjusted cumulative incidence on the waiting list by approximately 17 mo. Risk factors for posttransplantation AF included older recipient age, male gender, white race, renal failure from hypertension, and coronary artery disease. Extended pretransplantation dialysis duration, posttransplantation diabetes, and graft failure were identified as potentially modifiable correlates of AF. In separate analyses, AF independently predicted death (AHR 3.2; 95% CI 2.9 to 3.6) and death-censored graft loss (AHR 1.9; 95% CI 1.6 to 2.3). As the population of renal transplant recipients grows older, the incidence and prevalence of AF among these patients will likely increase. Appropriate risk stratification may identify transplant recipients who are in need of close monitoring for and management of this adverse cardiovascular event.

Prevalence of atrial fibrillation and associated factors in a population of long-term hemodialysis patients

BACKGROUND

Hemodialysis (HD) is associated with cardiovascular structural modifications; moreover, during HD, rapid electrolytic changes occur. Both factors may favor the onset of atrial fibrillation.

METHODS

To define the prevalence of atrial fibrillation and identify associated factors, 488 patients on long-term HD therapy (age, 66.6 +/- 13.4 years; men, 58.0%; duration of HD, 76.5 +/- 84.3 months) were studied.

RESULTS

Atrial fibrillation was reported in 27.0% of patients; paroxysmal in 3.5%, persistent in 9.6%, and permanent in 13.9%. Clinical and echocardiographic variables were considered: patients with atrial fibrillation were older (71.8 +/- 9.3 versus 64.7 +/- 14.2 years; P < 0.01), and its prevalence increased with age. Patients with arrhythmia had a longer duration of dialysis therapy (93.2 +/- 100.5 versus 70.2 +/- 76.7 months; P = 0.02). Atrial fibrillation was associated significantly with ischemic heart disease (P < 0.01), dilated cardiomyopathy (P < 0.01), acute pulmonary edema (P < 0.05), valvular disease (P < 0.05), cerebrovascular accidents (P < 0.05), and predialytic hyperkalemia (P < 0.05). Patients with atrial fibrillation more frequently showed left atrial dilatation (59.8% versus 34.5%; P < 0.0001), and in these subjects, left ventricular ejection fraction was significantly lower (53.9% versus 57.4%; P = 0.029). No association was found between arrhythmia and hypertension or diabetes. Multivariate analysis confirmed that patient age (P < 0.001), duration of HD therapy (P = 0.001), and left atrial dilatation (P < 0.001) were associated with atrial fibrillation.

CONCLUSION

Atrial fibrillation is much more frequent in HD patients than in the general population; age, duration of HD history, presence of some heart diseases, and left atrial dilatation are associated with the arrhythmia.

The effect of oral anticoagulation on clotting during hemodialysis

BACKGROUND

Between 5% and 10% of hemodialysis patients are treated with oral anticoagulants. It is currently unknown whether additional anticoagulation with heparin or low-molecular-weight heparin (LMWH) is needed to prevent clotting during hemodialysis.

METHODS

In this prospective, randomized, cross-over study 10 patients treated with oral anticoagulants (phenprocoumon) received either no additional anticoagulation or low dose dalteparin (bolus of 40 IU/kg body weight) before dialysis. Efficacy of hemodialysis was measured by normalized weekly Kt/V and urea reduction rate (URR). Thrombus formation was evaluated by measurement of D-dimer and inspection of air traps and dialyser.

RESULTS

The median international normalized ratio (INR) did not differ between both observation periods (phenprocoumon 2.2(2 to 3) vs. dalteparin 2.1(2 to 2.9). The anti-Xa level in dalteparin patients was 0.33 (0.27 to 0.38) IU/mL after 2 hours and 0.16 (0.03 to 0.23) IU/mL after 4 hours of hemodialysis. The median increase of D-dimer was significantly higher in patients without additional dalteparin therapy during hemodialysis (DeltaD-dimer 0.23 microg/mL vs. 0.03 mug/mL) (P= 0.0004). Complete thrombosis of the dialyser membrane occurred in one patient in the phenprocoumon group but in none with combined treatment. The extent of thrombosis in the arterial and venous air trap and dialyser was significantly less in patients with additional dalteparin therapy (P= 0.0014, P= 0.0002, and P= 0.0005, respectively). Weekly Kt/V and URR was similar in both groups.

CONCLUSION

Standard oral anticoagulation with an INR between 2 and 3 is insufficient to prevent clotting during hemodialysis. Additional low dose anticoagulation with a LMWH or heparin is necessary to facilitate treatment.

Increased P wave dispersion and maximum P wave duration after hemodialysis

BACKGROUND

Atrial fibrillation is a frequent arrhythmia in patients undergoing hemodialysis. The consequences of hemodialysis on P wave durations and P wave dispersion have not been fully understood. The objective of this study was to study the effect of dialysis on P wave maximum (Pmax), P wave minimum (Pmin), and P wave dispersion (Pd).

METHODS

We studied Pmax, Pmin, and Pd in 32 patients (17 men and 15 women, mean age 54 +/- 18 years) with chronic renal failure undergoing hemodialysis. The difference between maximum and minimum P wave duration was calculated and defined as P wave dispersion (Pd= Pmax- Pmin).

RESULTS

There was a significant increase in Pmax at the end of dialysis compared to the beginning (98 +/- 13 ms vs. 125 +/- 12 ms, P < 0.001). Pmin did not show any significant change (71 +/- 11 ms vs. 73 +/- 10 ms, P = 0.42). Pd was significantly increased at the end of dialysis (27 +/- 9 ms vs. 52 +/- 11 ms, P < 0.001). There was a negative correlation between serum potassium, magnesium, phosphate, blood urea nitrogen, and creatinin at the end of dialysis and Pmax and Pd, respectively (P < 0.05). A weak positive correlation was found between serum calcium, bicarbonate at the end of dialysis and Pmax and Pd (P < 0.05).

CONCLUSION

Hemodialysis ends with significant increase in P wave maximum duration and P wave dispersion, which might be responsible for the increased occurrence of atrial fibrillation in these groups of patients.

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.

Atrial fibrillation in chronic dialysis patients in the United States: risk factors for hospitalization and mortality

BACKGROUND

The incidence and risk factors for hospitalized atrial fibrillation have not been previously assessed in a national population of dialysis patients.

METHODS

We analyzed the United States Renal Data System (USRDS) Dialysis Morbidity and Mortality Study (DMMS) Wave II in a historical cohort study of hospitalized atrial fibrillation. Data from 3374 patients who started dialysis in 1996 with valid follow-up times were available for analysis, censored at the time of renal transplantation and followed until November 2000. Cox Regression analysis was used to model factors associated with time to first hospitalization for atrial fibrillation (ICD9 code 427.31x) adjusted for comorbidities, demographic factors, baseline laboratory values, blood pressures, dialysis modality, and cardioprotective medications.

RESULTS

The incidence density of atrial fibrillation was 12.5/1000 person years. Factors associated with atrial fibrillation were older age (> or = 71 years vs. <48 years), extremes (both high and low) of pre-dialysis systolic blood pressure, dialysis modality (hemodialysis vs. peritoneal dialysis), and digoxin use. Baseline use of coumadin was associated with reduced mortality in patients later hospitalized for atrial fibrillation.

CONCLUSIONS

Dialysis patients had a high incidence of atrial fibrillation. This risk was largely segregated among those with established risk factors for atrial fibrillation, and hemodialysis patients. Use of coumadin was associated with improved survival among patients later hospitalized for atrial fibrillation.

Patrones clínicos de presentación de la fibrilación auricular en los pacientes hospitalizados

INTRODUCTION AND OBJECTIVES

The ACC/AHA/ESC 2001 guidelines for the management of atrial fibrillation (AF) establish 4 categories: first episode, paroxysmal, persistent and permanent. The aim of this study was to analyze the frequency of the different clinical patterns of presentation of AF in hospitalized patients.

PATIENTS AND METHOD

We analyzed the pattern of AF in 300 hospitalized patients, 200 of whom were admitted to the cardiology and 100 to the internal medicine department. We determined the clinical profile and evaluated the factors influencing therapeutic management.

RESULTS

The permanent form was present in 30% of the patients admitted to the cardiology department and in 51% if those admitted to the internal medicine department. The first episode pattern was the most frequent in cardiology department patients (41%). In patients hospitalized the in cardiology the percentage use of anticoagulants (57.9% vs. 41%; p < 0.01) and beta blockers was greater than in internal medicine patients, and digitalis use was lower. In the multivariate analysis, admission to the cardiology department was an independent predictor of treatment with beta blockers (OR = 3.8; 95% CI, 1.3-11.1; p < 0.05), and discharge from the hospital with AF was a predictor of anticoagulant prescription (OR = 4.8; 95% CI, 2.5-9.2; p < 0.001).

CONCLUSIONS

a) Atrial fibrillation is an arrhythmia with a heterogeneous clinical pattern that varies depending on the type of care provided; b) on admission to cardiology, only 30% of the patients present with permanent arrhythmia, and the most frequent clinical pattern is first episode; and c) discharge from the hospital with AF was the principal determinant of therapeutic management.