Prediction of Mortality in Incident Hemodialysis Patients: A Validation and Comparison of CHADS2, CHA2DS2, and CCI Scores

The CHA2DS2-VASC Score Predicts Mortality in Patients Undergoing Coronary Angiography

BACKGROUND

The CHA2DS2-VASC score is used to predict the risk of thromboembolic complications in patients with atrial fibrillation (AF). We hypothesized that the CHA2DS2-VASC score can be used to predict mortality in patients undergoing coronary angiography.

METHODS AND RESULTS

This was a prospective study of 990 patients undergoing coronary angiography. The median follow-up was 2294 days. The patients were categorized into two groups according to their CHA2DS2-VASC score: group I had scores <4 and group II had scores ≥4 (527 (53.2%) and 463 (46.8%), respectively). A Kaplan-Meier analysis demonstrated a significant association between the CHA2DS2-VASC score and mortality (69/527 (13.1%) vs. 179/463 (38.7%) for group I vs. group II, respectively, p < 0.0001). The association remained significant in patients with and without AF, reduced and preserved LVEF, normal and reduced kidney function, and with and without ACS (p < 0.009 to p < 0.0001 for all). In the Cox regression model, which combined the CHA2DS2-VASC score, the presence of AF, LVEF, anemia, and renal insufficiency, an elevated CHA2DS2-VASC score of ≥4 was independently associated with higher mortality (HR 2.12, CI 1.29-3.25, p = 0.001).

CONCLUSIONS

The CHA2DS2VASC score is a simple and reliable mortality predictor in patients undergoing coronary angiography and should be used for the initial screening for such patients.

Risk Factors for Lower Extremity Amputation in Patients with End-Stage Kidney Disease: A Nationwide Cohort Study

Individuals with end-stage kidney disease (ESKD) on dialysis are at a high risk of developing foot ulcerations and undergoing subsequent lower extremity amputation (LEA), which can exert significant impacts on their quality of life and contribute to rising healthcare costs. We aimed to identify risk factors associated with LEA in patients with ESKD to predict LEA progression and eventually prevent it. We used 18 years (2002-2019) of data from the Korean National Health Insurance Service (KNHIS). Data were collected from patients with ESKD who underwent renal replacement therapy (RRT) and had no history of amputation caused by trauma or toxins. The risk factors were compared between patients with or without LEA. We collected data from 220,838 patients newly diagnosed with ESKD, including 6348 in the LEA group and 214,490 in the non-LEA group. The total incidence of LEA was 2.9%. Older age, male gender, lower income, non-metropolitan residence, diabetes mellitus, dialysis treatment (compared to kidney transplantation), microvascular disease, peripheral vascular disease, endovascular procedure, and endovascular operation were associated with an increased risk of LEA. Thus, individuals with ESKD who are at a higher risk for LEA should be closely monitored, and kidney transplantation should be considered as a preventative measure.

A prospective follow-up of thyroid volume and thyroiditis features on ultrasonography among survivors of predominantly mild to moderate COVID-19

Background

We previously showed that higher SARS-CoV-2 viral load correlated with smaller thyroid volumes among COVID-19 survivors at 2 months after acute COVID-19. Our current follow-up study evaluated the evolution of thyroid volumes and thyroiditis features within the same group of patients 6 months later.

Methods

Adult COVID-19 survivors who underwent thyroid ultrasonography 2 months after infection (USG1) were recruited for follow-up USG 6 months later (USG2). The primary outcome was the change in thyroid volume. We also reassessed thyroiditis features on USG, thyroid function and anti-thyroid antibodies.

Results

Fifty-four patients were recruited (mean age 48.1 years; 63% men). The mean thyroid volume increased from USG1 to USG2 (11.9 ± 4.8 to 14.5 ± 6.2 mL, p < 0.001). Thirty-two patients (59.3%) had significant increase in thyroid volume by ≥15%, and they had a median increase of +33.3% (IQR: +20.0% to +45.0%). Multivariable logistic regression analysis showed that only higher baseline SARS-CoV-2 viral load independently correlated with significant thyroid volume increase on USG2 (p = 0.022). Among the seven patients with thyroiditis features on USG1, six (85.7%) had the features resolved on USG2. None had new thyroiditis features on USG2. All abnormal thyroid function during acute COVID-19 resolved upon USG1 and USG2.

Conclusion

Most COVID-19 survivors had an increase in thyroid volume from early convalescent phase to later convalescent phase. This increase correlated with high initial SARS-CoV-2 viral load. Together with the resolution of thyroiditis features, these may suggest a transient direct atrophic effect of SARS-CoV-2 on the thyroid gland with subsequent recovery of thyroid volume and thyroiditis features.

Outcome Analysis of Transition From Peritoneal Dialysis to Hemodialysis: A Population-Based Study

If a technical failure occurs during peritoneal dialysis (PD), the patients undergoing PD may be transitioned to hemodialysis (HD). However, the clinical outcomes of patients who have undergone such a transition are under studied. This study assessed whether patients undergoing HD who have transitioned from PD have the same clinical outcomes as HD-only patients. This research was a retrospective cohort study by searching a National Health Insurance research database for data on patients in Taiwan who had undergone HD between January 2006 and December 2013. The patients were divided into two groups, namely a case group in which the patients were transitioned from PD to HD and a HD-only control group, through propensity score matching at a ratio of 1:4 (n = 1,100 vs. 4,400, respectively). We used the Cox regression model to estimate the hazard ratios (HRs) for all-cause death, all-cause hospitalization, infection-related admission, and major adverse cardiac events (MACE). Those selected patients will be followed until death or the end of the study period (December, 2017), whichever occurs first. Over a mean follow-up of 3.2 years, 1,695 patients (30.8%) died, 3,825 (69.5%) required hospitalization, and 1,142 (20.8%) experienced MACE. Patients transitioning from PD had a higher risk of all-cause death (HR: 1.36; 95% CI: 1.21–1.53) than HD-only patients. However, no significant difference was noted in terms of MACE (HR: 0.91; 95% CI: 0.73–1.12), all-cause hospitalization (HR: 1.07; 95% CI: 0.96–1.18), or infection-related admission (HR: 0.97, 95% CI: 0.80–1.18) between groups. Because of the violation of the proportional hazard assumption, the piecewise-HRs showed that the risk of mortality in the case group was significant within 5 months of the transition (HR: 2.61; 95% CI: 2.04–3.35) not in other partitions of the time axis. In conclusion, patients undergoing HD who transitioned from PD had a higher risk of death than the HD-only patients, especially in the first 5 months after transition (a 161% higher risk). Therefore, more caution and monitoring may be required for patients undergoing HD who transitioned from PD.

Choice of antithrombotic therapy for patients with atrial fibrillation undergoing carotid angioplasty and stenting: a nationwide population-based study

Nonvalvular atrial fibrillation (NVAF) and carotid stenosis are important risk factors for stroke. Carotid angioplasty and stent placement (CAS) is recommended for patients with symptomatic high-grade carotid stenosis. The optimal medical management for patients with NVAF after CAS remains unclear. We aimed to clarify this issue using real-world data from the Taiwanese National Health Insurance Research Database (NHIRD). In total, 2116 consecutive NVAF patients who received CAS between January 1, 2010, and December 31, 2016, from NHIRD were divided into groups based on post-procedure medication as follows: only antiplatelet agent (OAP, n = 587); only anticoagulation agent (OAC, n = 477); dual antiplatelet agents (DAP, n = 49); and a combination of antiplatelet and anticoagulation agents (CAPAC, n = 304). Mortality, vascular events, and major bleeding episodes were compared after matching with the Charlson comorbidity index and CHA2DS2-VASc score. The CAPAC and the OAC groups had lower mortality rates than the OAP group (P = 0.0219), with no statistical differences in major bleeding, ischemic stroke, or vascular events. Conclusively, OAC therapy after CAS appears suitable for NVAF patients. CAPAC therapy might be considered as initial therapy or when there is concern about vascular events.

Hazardous Effect of Low-Dose Aspirin in Patients with Predialysis Advanced Chronic Kidney Disease Assessed by Machine Learning Method Feature Selection

Background: Low-dose aspirin (100 mg) is widely used in preventing cardiovascular disease in chronic kidney disease (CKD) because its benefits outweighs the harm, however, its effect on clinical outcomes in patients with predialysis advanced CKD is still unclear. This study aimed to assess the effect of aspirin use on clinical outcomes in such group. Methods: Patients were selected from a nationwide diabetes database from January 2009 to June 2017, and divided into two groups, a case group with aspirin use (n = 3021) and a control group without aspirin use (n = 9063), by propensity score matching with a 1:3 ratio. The Cox regression model was used to estimate the hazard ratio (HR). Moreover, machine learning method feature selection was used to assess the importance of parameters in the clinical outcomes. Results: In a mean follow-up of 1.54 years, aspirin use was associated with higher risk for entering dialysis (HR, 1.15 [95%CI, 1.10-1.21]) and death before entering dialysis (1.46 [1.25-1.71]), which were also supported by feature selection. The renal effect of aspirin use was consistent across patient subgroups. Nonusers and aspirin users did not show a significant difference, except for gastrointestinal bleeding (1.05 [0.96-1.15]), intracranial hemorrhage events (1.23 [0.98-1.55]), or ischemic stroke (1.15 [0.98-1.55]). Conclusions: Patients with predialysis advanced CKD and anemia who received aspirin exhibited higher risk of entering dialysis and death before entering dialysis by 15% and 46%, respectively.

A retrospective study of antithrombotic therapy use in an outpatient haemodialysis unit

WHAT IS KNOWN AND OBJECTIVE

Patients on haemodialysis (HD) are at increased risk of both bleeding and thrombotic events, due to comorbidities and nature of dialysis treatment. However, there is a lack of research on evidence-based treatment strategies and prescribing patterns for antithrombotic therapies (ATT) in this population. To characterize ATT use and its main indications in an outpatient HD unit.

METHODS

A single-centre retrospective chart review was conducted in a Toronto outpatient HD unit (n = 329). Medical histories, number of ATTs and corresponding indications were collected from adult patients prescribed at least one ATT from 1 October 2019 to 31 December 2019, inclusive.

RESULTS AND DISCUSSION

Of 329 patients in the unit, a total of 135 (41%) patients were on at least one ATT. Of these 135 patients, 80% were on monotherapy (55% antiplatelet, 25.1% anticoagulant), 12.6% were on dual antiplatelet therapy (DAPT), and 7.4% were on a antiplatelet and anticoagulant combination. Primary indications for ATT in our cohort were coronary artery disease (CAD; 55%), atrial fibrillation (18.5%) and venous thromboembolism (VTE; 17%). Described ATT use was in-line with current clinical guidelines. Monotherapy was primarily used in our HD cohort, whereas few patients were on dual therapy. Low-dose aspirin was the most common antiplatelet prescribed for secondary prevention of cardiovascular events. Warfarin monotherapy was primarily indicated for VTE, and DAPT aspirin/clopidogrel was the most commonly prescribed for CAD.

WHAT IS NEW AND CONCLUSION

Our characterization of ATT use in this HD cohort demonstrates that ATT is often prescribed for a number of different CVD reasons. Overlapping and confounding indications for prescribing ATTs, lack of randomized controlled trials and unclear clinical guidelines mean that individualized risk-benefit assessments for ATT use are still needed to provide care for these high-risk patients. More research to address the safety and efficacy of ATTs is warranted to develop more robust evidence-based treatment guidelines for the HD population.

Racial/Ethnic Disparities in Atrial Fibrillation Treatment and Outcomes among Dialysis Patients in the United States

BACKGROUND

Because stroke prevention is a major goal in the management of ESKD hemodialysis patients with atrial fibrillation, investigating racial/ethnic disparities in stroke among such patients is important to those who could benefit from strategies to maximize preventive measures.

METHODS

We used the United States Renal Data System to identify ESKD patients who initiated hemodialysis from 2006 to 2013 and then identified those with a subsequent atrial fibrillation diagnosis and Medicare Part A/B/D. Patients were followed for 1 year for all-cause stroke, mortality, prescription medications, and cardiovascular disease procedures. The survival mediational g-formula quantified the percentage of excess strokes attributable to lower use of atrial fibrillation treatments by race/ethnicity.

RESULTS

The study included 56,587 ESKD hemodialysis patients with atrial fibrillation. Black, white, Hispanic, and Asian patients accounted for 19%, 69%, 8%, and 3% of the population, respectively. Compared with white patients, black, Hispanic, or Asian patients were more likely to experience stroke (13%, 15%, and 16%, respectively) but less likely to fill a warfarin prescription (10%, 17%, and 28%, respectively). Warfarin prescription was associated with decreased stroke rates. Analyses suggested that equalizing the warfarin distribution to that in the white population would prevent 7%, 10%, and 12% of excess strokes among black, Hispanic, and Asian patients, respectively. We found no racial/ethnic disparities in all-cause mortality or use of cardiovascular disease procedures.

CONCLUSIONS

Racial/ethnic disparities in all-cause stroke among hemodialysis patients with atrial fibrillation are partially mediated by lower use of anticoagulants among black, Hispanic, and Asian patients. The reasons for these disparities are unknown, but strategies to maximize stroke prevention in minority hemodialysis populations should be further investigated.

Predicting the Risk of Ischemic Stroke among Patients with Rheumatoid Arthritis Using a Simplified RA-CHADSV Score Based on the CHA2DS2-VASc Score

Background and Objectives: The aim of this retrospective cohort study was to develop a new score (RA-CHADSV) (rheumatoid arthritis - congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack/thromboembolism, and vascular disease), modified from the CHA₂DS₂-VASc score (congestive heart failure, hypertension, age ≥75 years (doubled), diabetes mellitus, stroke/transient ischemic attack (doubled), vascular disease, age 65–74 years, and female), in predicting the risk of ischemic stroke in rheumatoid arthritis (RA) patients without atrial fibrillation (AF). Materials and Methods: Using the Taiwan’s National Health Insurance Research Database, 592 patients with RA diagnosed between 2000 and 2002 were identified and followed until first occurrence of ischemic stroke or the last available date in the database. Incidence rate ratios (IRR) of ischemic stroke for the CHA₂DS₂-VASc score were calculated using Poisson regression models. A new prediction score RA-CHADSV was developed using multiple logistic regression analysis with bootstrap validation. Results: The area under the receiver operating characteristic curve of the newly developed RA-CHADSV score and the CHA₂DS₂-VASc score were 0.73 (95% confidence interval (CI) 0.64–0.82) and 0.70 (95% CI 0.61–0.79), respectively. The RA-CHADSV score was significantly associated with a higher ischemic stroke incidence in the patients who scored ≥1 (adjusted IRR 7.39, p < 0.001). Conclusions: A simplified RA-CHADSV score, with comparable efficiency as the CHA₂DS₂-VASc score, but easier to use clinically was developed for predicting the risk of ischemic stroke among non-AF RA patients.

Increased risk of developing peripheral artery disease in hemodialysis patients receiving statin treatments: a population-based cohort study in Taiwan

Background

Few investigations have evaluated the influences on peripheral arterial disease (PAD) risk of statin treatment in hemodialysis (HD) subjects with hyperlipidemia (HL).

Methods

From the National Health Insurance Research Dataset, we identified 3658 HD patients with statin therapy for HL as the statin cohort, and then selected, by 1:1 propensity score matching, 3658 HD patients with HL but without statin use as the nonstatin cohort in 2000–07. The cohorts were followed through until the end of 2011. We used Cox proportional hazards regression analysis to assess the hazard ratio (HR) of PAD development.

Results

The average follow-up period was 4.18 years; the incident PAD risk was 1.35-fold greater in statin users than in nonusers (16.87 versus 12.46/1000 person-years), with an adjusted HR (aHR) of 1.34 for PAD [95% confidence interval (CI) 1.12–1.62]. The PAD risk increases were significant for patients receiving fluvastatin (aHR 1.88; 95% CI 1.12–3.14) and atorvastatin (aHR 1.60; 95% CI 1.24–2.08). The risk increased with higher annual average statin dosage (P for trend &lt;0.0001); the risk was higher for those receiving moderate-intensity statin treatment. The sensitivity test revealed similar findings.

Conclusions

HD patients with HL on statin medication were at increased PAD risk, which increased with cumulative statin dosage. Thorough considerations are needed before prescribing statins to HD patients.

eDRAM: Effective early disease risk assessment with matrix factorization on a large-scale medical database: A case study on rheumatoid arthritis

Recently, a number of analytical approaches for probing medical databases have been developed to assist in disease risk assessment and to determine the association of a clinical condition with others, so that better and intelligent healthcare can be provided. The early assessment of disease risk is an emerging topic in medical informatics. If diseases are detected at an early stage, prognosis can be improved and medical resources can be used more efficiently. For example, if rheumatoid arthritis (RA) is detected at an early stage, appropriate medications can be used to prevent bone deterioration. In early disease risk assessment, finding important risk factors from large-scale medical databases and performing individual disease risk assessment have been challenging tasks. A number of recent studies have considered risk factor analysis approaches, such as association rule mining, sequential rule mining, regression, and expert advice. In this study, to improve disease risk assessment, machine learning and matrix factorization techniques were integrated to discover important and implicit risk factors. A novel framework is proposed that can effectively assess early disease risks, and RA is used as a case study. This framework comprises three main stages: data preprocessing, risk factor optimization, and early disease risk assessment. This is the first study integrating matrix factorization and machine learning for disease risk assessment that is applied to a nation-wide and longitudinal medical diagnostic database. In the experimental evaluations, a cohort established from a large-scale medical database was used that included 1007 RA-diagnosed patients and 921,192 control patients examined over a nine-year follow-up period (2000-2008). The evaluation results demonstrate that the proposed approach is more efficient and stable for disease risk assessment than state-of-the-art methods.

Risk of psychiatric disorders in irritable bowel syndrome-A nationwide, population-based, cohort study

AIMS

This cohort study aimed to investigate the association between irritable bowel syndrome (IBS) and the risk of developing psychiatric disorders.

METHODS

Utilizing the National Health Insurance Research Database (NHIRD) of Taiwan, IBS patients were identified and compared with age, sex, and index year-matched controls (1:3).

RESULTS

Of the IBS subjects, 3934 in 22 356 (17.60%, or 1533.68 per 100 000 person-years) developed psychiatric disorders when compared with 6127 in 67 068 (9.14%, or 802 per 100 000 person-years) in the non-IBS control group. Fine and Gray's survival analysis revealed that the study subjects were more likely to develop psychiatric disorders. The crude hazard ratio (HR) is 3.767 (95% CI: 3.614-3.925, P < .001), and the adjusted HR is 3.598 (95% CI: 3.452-3.752, P < .001) in the risk of developing psychiatric disorders after being adjusted for age, sex, comorbidities, geographical area of residence, urbanisation level of residence, and monthly insurance premiums. The cohort study revealed that IBS subjects were associated with an increased risk of anxiety, depression, bipolar, and sleep disorders.

CONCLUSIONS

This cohort study, using NHIRD, shows evidence support that patients with IBS have a 3.6-fold risk of developing psychiatric disorders. Other large or national datasets should be done to explore to underlying mechanisms.

Risk of dementia after charcoal-burning suicide attempts: a nationwide cohort study in Taiwan

This study aimed to investigate the association between charcoal-burning suicide attempts and the risk of developing dementia. A nationwide, matched cohort, population-based study enrolled a total of 4103 patients with newly diagnosed charcoal-burning suicide attempts, between 2000 and 2010, which were selected from the National Health Insurance Research Database of Taiwan, along with 12,309 controls matched for sex and age. After adjusting for confounding factors, Fine and Gray's competing risk analysis was used to compare the risk of developing dementia during the 10-year follow-up period. Of the enrolled patients (n=16,412), dementia developed in 303 (1.85%), including 2.56% in the study group (105 in 4103) and 1.61% (198 in 12,309) in the control group. The Fine and Gray's survival analysis revealed that the patients with charcoal-burning suicide attempts were likely to develop dementia, with a crude HR of 5.170 (95% CI 4.022 to 6.644, p<0.001). After adjusting for age, sex, comorbidity, geographic area and urbanization level of residence, and monthly insured premium, the adjusted HR was 4.220 (95% CI 3.188 to 5.586, p<0.001). Suicide attempts were associated with an increased risk of degenerative dementia in this study. Patients with charcoal-burning suicide attempts had a fourfold risk of dementia than the control group.

Mortality in Elderly Waiting-List Patients Versus Age-Matched Kidney Transplant Recipients: Where is the Risk?

The number of elderly patients on the waiting list (WL) for kidney transplantation (KT) has risen significantly in recent years. Because KT offers a better survival than dialysis therapy, even in the elderly, candidates for KT should be selected carefully, particularly in older waitlisted patients. Identification of risk factors for death in WL patients and prediction of both perioperative risk and long-term post-transplant mortality are crucial for the proper allocation of organs and the clinical management of these patients in order to decrease mortality, both while on the WL and after KT. In this review, we examine the clinical results in studies concerning: a) risk factors for mortality in WL patients and KT recipients; 2) the benefits and risks of performing KT in the elderly, comparing survival between patients on the WL and KT recipients; and 3) clinical tools that should be used to assess the perioperative risk of mortality and predict long-term post-transplant survival. The acknowledgment of these concerns could contribute to better management of high-risk patients and prophylactic interventions to prolong survival in this particular population, provided a higher mortality is assumed.

Increased Risk of Psychiatric Disorders in Allergic Diseases: A Nationwide, Population-Based, Cohort Study

BACKGROUND/OBJECTIVE

Allergic diseases, such as bronchial asthma, allergic rhinitis, atopic dermatitis, and psychiatric disorders, are major health issues. There have been reports that allergic diseases were associated with depression or anxiety disorders. This study aimed to investigate the association between these allergic diseases and the risk of developing overall psychiatric disorders in patients from Taiwan.

METHODS

This cohort study used the database of the Taiwan National Health Insurance Program. A total of 186,588 enrolled patients, with 46,647 study subjects who had suffered from allergic diseases, and 139,941 controls matched for sex and age, from the Longitudinal Health Insurance Dataset of 2000-2015, were selected from a sub-dataset of the National Health Insurance Research Database. Fine and Gray's competing risk model analysis was used to explore the hazard ratio (HR), and 95% confidence interval, for the risk of allergic diseases being associated with the risk of developing psychiatric disorders during the 15 years of follow-up.

RESULTS

Of the study subjects, 5,038 (10.8%) developed psychiatric disorders when compared to 9,376 (6.7%) in the control group, with significant difference (p < 0.001). Fine and Gray's competing risk model analysis revealed that the adjusted HR was 1.659 (95% CI = 1.602-1.717, p < 0.001). In this study, we found that the groups of atopic dermatitis alone and the allergic rhinitis + atopic dermatitis were associated with a lower risk of psychiatric disorders, but all the other four groups, such as bronchial asthma alone, allergic rhinitis alone, bronchial asthma + allergic rhinitis, bronchial asthma + atopic dermatitis, and the combination of all these three allergic diseases, were associated with a higher risk of psychiatric disorders.

CONCLUSION

Allergic diseases are therefore associated with a 1.66-fold increased hazard of psychiatric disorders in Taiwan.

Cognitive enhancers associated with decreased risk of injury in patients with dementia: a nationwide cohort study in Taiwan

This study aimed to investigate the associations among dementia, psychotropic medications and the risk of overall injuries. In this nationwide matched cohort study, a total of 144 008 enrolled patients ≥age of 50, with 36 002 study subjects who suffered from dementia and 108 006 controls matched for sex and age, from the Inpatient Dataset, for the period 2000-2010 in Taiwan were selected from the National Health Insurance Research Database, according to International Classification of Diseases, 9th Revision, Clinical Modification. When adjusting for the confounding factors, a Cox proportional hazards analysis was used to compare the risk of developing psychiatric disorders during the 10 years of follow-up. Of the study subjects, 6701 (18.61%) suffered injury when compared with 20 919 (19.37%) in the control group. The Cox regression analysis revealed that the study subjects were more likely to develop an injury (HR: 2.294, 95% CI=2.229 to 2.361, P<0.001) after adjusting for sex, age, monthly income, urbanization level, geographic region, and comorbidities. Psychotropic medications in the subjects with dementia were associated with the risk of injury (adjusted HR=0.217, 95% CI: 0.206 to 0.228, P<0.001). Cognitive enhancers, including acetylcholinesterase inhibitors and memantine, were associated with the risk of injury in the study subjects after being adjusted for all comorbidities and medications (adjusted HR=0.712(95% CI=0.512 to 0.925, P<0.01)). In conclusion, patients who suffered dementia had a higher risk of developing injury, and the cognitive enhancers were associated with the decreased risk of injury.

Prevalence of Atrial Fibrillation and Antithrombotic Therapy in Hemodialysis Patients: Cross-Sectional Results of the Vienna InVestigation of AtriaL Fibrillation and Thromboembolism in Patients on HemoDIalysis (VIVALDI)

Background

Atrial fibrillation (AF) adds significant risk of stroke and thromboembolism in patients on hemodialysis (HD). The aim of this study was to investigate the prevalence of AF in a population-based cohort of HD patients and practice patterns of antithrombotic therapy for stroke prevention in AF.

Methods

The Vienna InVestigation of AtriaL fibrillation and thromboembolism in patients on hemodialysis (VIVALDI), an ongoing prospective observational cohort study, investigates the prevalence of AF and the risk of thromboembolic events in HD patients in Vienna, Austria. We analyzed cross-sectional data of 626 patients (63.4% men, median age 66 years, approx. 73% of HD patients in Vienna), who provided informed consent. A structured interview with each patient was performed, recent and archived ECGs were viewed and medical histories were verified with electronic records.

Results

The overall prevalence of AF was 26.5% (166 patients, 71.1% men, median age 72 years) of which 57.8% had paroxysmal AF, 3.0% persistent AF, 32.5% permanent AF, and 6.6% of patients had newly diagnosed AF. The median CHA₂DS₂-VASc Score was 4 [25^th-75^th percentile 3–5]. In multivariable analysis, AF was independently associated with age (odds ratio: 1.05 per year increase, 95% confidence interval: 1.03–1.07), male sex (1.7, 1.1–2.6), history of venous thromboembolism (2.0, 1.1–3.6), congestive heart failure (1.7, 1.1–2.5), history of or active cancer (1.5, 1.0–2.4) and time on HD (1.08 per year on HD, 1.03–1.13). Antithrombotic treatment was applied in 84.4% of AF patients (anticoagulant agents in 29.5%, antiplatelet agents in 33.7%, and both in 21.1%). In AF patients, vitamin-K-antagonists were used more often than low-molecular-weight heparins (30.1% and 19.9%).

Conclusions

The prevalence of AF is high amongst HD patients and is associated with age, sex, and distinct comorbidities. Practice patterns of antithrombotic treatment indicate a lack of consensus for stroke prevention in HD patients with AF.