Risk of arterial and venous thromboembolism in patients with atrial fibrillation or flutter: A nationwide population-based cohort study

Studies on Atrial Fibrillation and Venous Thromboembolism in the Past 20 Years: A Bibliometric Analysis Via CiteSpace and VOSviewer

The conjunction of atrial fibrillation (AF) and venous thromboembolism (VTE) is common in clinical practice. Over the last 2 decades, a significant number of articles (2500) have been published about AF and VTE. To effectively analyze and present these vast amounts of information, this study uses bibliometric research methods to categorize and consolidate these publications. The number of publications has increased yearly, especially since 2012. The United States was the most prolific country, with 1054 studies published. The most productive institution was McMaster University. Gregory Y.H. Lip was the most prolific author. The keyword analysis identified that the research focuses from 2003 to 2014 were factor Xa inhibitor, dabigatran etexilate, direct thrombin inhibitor, double-blind, deep vein thrombosis, molecular weight heparin, stroke prevention, etc. From 2015 to 2016, research mainly focused on venous thromboembolism, antithrombotic therapy, anticoagulant, warfarin, atrial fibrillation, stroke, and pulmonary embolism. Studies during 2017 to 2022 focused on apixaban, direct oral anticoagulant, rivaroxaban, dabigatran, hemorrhage, edoxaban, medicine efficacy and safety, risk factors, clinical management, and vitamin K antagonists. Since 2018, novel oral anticoagulants have been the most commonly used keywords. On the whole, most studies of AF and VTE focus on pathogenesis and therapeutic drugs. The causal relationship between AF and VTE, the effectiveness and safety of novel oral anticoagulants in the treatments, the anticoagulant regimen of AF and VTE co-disease, and the treatment regimen for vulnerable populations such as the elderly or obese people were the focus of current research and will continue to be the central point of future research.

Venous Thromboembolism in Patients With Atrial Fibrillation: A Systematic Review and Meta-Analysis of 4,170,027 Patients

Background

Data on the association between atrial fibrillation (AF) and venous thromboembolism (VTE) are controversial.

Objectives

The purpose of this study was to investigate the risk of VTE in patients with AF according to the time from AF diagnosis.

Methods

Systematic review of MEDLINE (PubMed), Embase, Cumulative Index to Nursing and Allied Health Literature (EBSCO host), Cochrane Central Register of Controlled Trials (2020) in the Cochrane Library, and World Health Organization Global Index Medicus databases and meta-analysis of observational studies. The risk of VTE, deep vein thrombosis (DVT) and pulmonary embolism (PE) was analyzed according to the time of AF onset: 1) short (≤3 months); 2) medium (≤6 months); and 3) long (>6 months) time groups.

Results

Eight studies were included with 4,170,027 patients, of whom 650,828 with AF. In the short-term group, AF was associated with the highest risk of either PE (HR: 9.62; 95% CI: 7.07-13.09; I2 = 0%) or DVT (HR: 6.18; 95% CI: 4.51-8.49, I2 = 0%). Even if to a lesser extent, AF was associated with a higher risk of VTE (HR: 3.69; 95% CI: 1.65-8.27; I2 = 79%), DVT (HR: 1.75; 95% CI: 1.43-2.14; I2 = 0%), and PE (HR: 4.3; 95% CI: 1.61-11.47; I2 = 68%) in the up to 6 months and long-term risk group >6 months groups (HR: 1.39; 95% CI: 1.00-1.92; I2 = 72%) and PE (HR: 1.08; 95% CI: 1.00-1.16; I2 = 0%).

Conclusions

The risk of VTE is highest in the first 3 to 6 months after AF diagnosis and decreases over time. The early initiation of anticoagulation in patients with AF may reduce the risk of VTE.

The bidirectional association between atrial fibrillation and myocardial infarction

Atrial fibrillation (AF) is associated with an increased risk of myocardial infarction (MI) and vice versa. This bidirectional association relies on shared risk factors as well as on several direct and indirect mechanisms, including inflammation, atrial ischaemia, left ventricular remodelling, myocardial oxygen supply-demand mismatch and coronary artery embolism, through which one condition can predispose to the other. Patients with both AF and MI are at greater risk of stroke, heart failure and death than patients with only one of the conditions. In this Review, we describe the bidirectional association between AF and MI. We discuss the pathogenic basis of this bidirectional relationship, describe the risk of adverse outcomes when the two conditions coexist, and review current data and guidelines on the prevention and management of both conditions. We also identify important gaps in the literature and propose directions for future research on the bidirectional association between AF and MI. The Review also features a summary of methodological approaches for the study of bidirectional associations in population-based studies.

Risk of Venous Thromboembolic Complications in Patients with Atrial Fibrillation: a Systematic Review and Meta-analysis

Aim: The aim of this meta-analysis and systematic review was to evaluate the possible connection between AF and VTE.

Material and methods. Atrial fibrillation (AF) and atrial flutter (AFL) contribute to intra-atrial blood stasis which leads to thrombus formation with its embolization. There is some evidence that AF can be a risk factor for deep vein thrombosis (DVT) and pulmonary embolism (PE). The following databases were searched: PubMed (MEDLINE), EMBASE, Google Scholar, the Cochrane Central Register of Controlled Trials. The time frame for conducting a systematic literature search ranged from January 1, 1990 to November 1, 2021. The diagnosis of atrial fibrillation had to be confirmed by using ECG. The diagnosis of VTE could be made with Doppler imaging, ventilation/perfusion scan, CT angiography, venography, angiography or autopsy. Only the three studies with 102192 patients meeting the requirement were included in the meta-analysis.

Results. The prevalence of DVT and PE were assessed using incidence rate ratios (IRR) method of the inverse variance random effects model and its 95% confidence interval (CI). The significant association between atrial fibrillation and pulmonary embolism was found (IRR, 4.18 95% Cl 1.958.98). Also there is obvious association between DVT and AF (IRR, 2.97 95% Cl 2.18-4.03).

Conclusion. It can be concluded that the increased risk of developing VTE is associatedwith concomitant AF.

Atrial fibrillation, liver cirrhosis, thrombosis, and bleeding: A Danish population‐based cohort study

Objectives

We examined the impact of liver cirrhosis on the risk of thromboembolic events and bleeding complications in patients with atrial fibrillation or flutter (AFF).

Methods

This population‐based cohort study used data from Danish health registries. We identified all patients with a first‐time diagnosis of AFF during 1995 to 2015, and followed them from their AFF diagnosis until the end of 2016. Patients were categorized according to the presence or absence of liver cirrhosis. We computed incidence rates per 1000 person‐years and hazard ratios (HRs) with 95% confidence intervals (CIs) based on Cox regression analyses, adjusting for age, CHA₂DS₂VASc score, and Charlson Comorbidity Index score.

Results

We identified 273 225 patients with AFF. Of these, 1463 (0.54%) had liver cirrhosis. During 0 to 5 years of follow‐up, compared to patients without liver cirrhosis, patients with liver cirrhosis had higher incidence rates and hazards of ischemic stroke (29.7 vs 21.6; HR, 1.3; 95% CI, 1.1‐1.6), venous thromboembolism (9.2 vs 5.5; HR, 1.5; 95% CI, 1.2‐2.3), but not myocardial infarction (10.2 vs 11.2; HR, 0.9; 95% CI, 0.7–1.2). Patients with liver cirrhosis also had higher rates of hemorrhagic stroke (5.8 vs 3.3; HR, 1.7; 95% CI, 1.1‐2.6), subdural hemorrhage (5.3 vs 1.6; HR, 3.2; 95% CI, 2.1‐4.9), hemorrhage of the lung or urinary tract (24.6 vs 15.2; HR, 1.6; 95% CI, 1.3–2.0), and gastrointestinal hemorrhage (34.5 vs 10.4; HR, 3.3; 95% CI, 2.7–3.9).

Conclusion

In patients with AFF, liver cirrhosis was associated with an elevated risk of ischemic stroke, venous thromboembolism, and all evaluated bleeding complications.

The association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes

Microalbuminuria is associated with both with chronic kidney disease and various cardiovascular abnormalities. Given the common use of electrocardiograms (EKGs) in diagnosing cardiovascular dysfunction, this study is analyzing the relationship between EKG abnormalities and diabetic nephropathy in type 2 diabetes mellitus (DM) patients. The enrollments of this study were from the 10-year follow-up data (2003-2012) of the Diabetes Management through an Integrated Delivery System project. All study subjects underwent at least 1 EKG measurement. The urinary microalbuminuria was recorded annually. The logistic regression model was used to evaluate the association between EKG abnormalities and the occurrence of diabetic nephropathy in type 2 DM patients. The total of 1189 patients with type 2 DM are included in this study and a total of 552 patients had microalbuminuria during a 10-year follow-up. A significantly higher odds ratio of microalbuminuria occurrence (4.85) was found in the patients with premature supraventricular contraction or tachycardia compared to those without EKG abnormalities. The odds ratios of microalbuminuria occurrence were 1.00, 2.43, 2.64, and 2.98, respectively, for patients with insulin resistance in the Q (quartile) 1(as the reference), Q2, Q3, and Q4, respectively. Our findings can serve as a reference for the association between EKG abnormalities and the development of microalbuminuria in type 2 diabetes.

Venous Thromboembolism and Critical Limb Events in Patients with Atrial Fibrillation: A Nationwide Population-Based Cohort Study

Little is known about whether venous thromboembolism (VTE) causes worse critical limb events in populations with atrial fibrillation (AF). A retrospective cohort study using claims data from Taiwan's National Health Insurance program between 2001 and 2013 compared AF patients with or without VTE. Outcomes were percutaneous transluminal angioplasty (PTA), amputation, systemic thromboembolism, all-cause mortality, cardiovascular death, ischemic stroke, and acute myocardial infarction. Patients (n = 316,817) with newly diagnosed AF were analyzed; of those, 2514 (0.79%) had VTE history. After inverse probability of treatment weighting, a history of VTE was significantly associated with higher risks of PTA (3.3 vs 2.2%; subdistribution hazard ratio [SHR] 1.47; 95% confidence interval [CI] 1.17-1.84); above knee amputation (0.7 vs 0.3%; HR 2.15; 95% CI 1.10-4.21); systemic thromboembolism (5.8 vs 3.9%; SHR 1.48; 95% CI 1.21-1.80); all-cause mortality (53 vs 46.4%; HR 1.20, 95% CI 1.12-1.29); and cardiovascular death (34.8 vs 29.4%; HR 1.25, 95% CI 1.14-1.36). In conclusion, VTE might increase the risk of critical lower limb events (PTA and above-knee amputation), systemic thromboembolism, and mortality in the AF population. However, current data cannot confirm a causal relationship between VTE and clinical outcomes in this population.

Atrial fibrillation and risk of venous thromboembolism: a Swedish Nationwide Registry Study

AIMS

Atrial fibrillation (AF) is associated with arterial thromboembolism, mainly ischaemic stroke, while venous thromboembolism (VTE) in AF is less well studied. The aim of this study, therefore, was to examine the relationship between AF and VTE, including pulmonary embolism (PE) and deep venous thrombosis (DVT).

METHODS AND RESULTS

AF cases without previous VTE, ischaemic stroke or pulmonary arterial hypertension were identified from the Swedish Inpatient Registry between 1987 and 2013 and compared to two population controls per case without AF matched for age, sex, and county with respect to the incidence of VTE, PE, and DVT. In total, 463 244 AF cases were compared to 887 336 population controls. In both men and women, VTE rates were higher among AF patients the first 30 days after an AF diagnosis [40.2 vs. 5.7 in men and 55.7 vs. 6.6 in women per 1000 person-years at risk, respectively; hazard ratios 6.64 (95% confidence interval, 5.74-7.69) and 7.56 (6.47-8.83)]; and then decreasing, simultaneously with an increasing number of AF patients being treated with oral anticoagulation. VTE risk was similar to controls after 9 months in men but remained slightly elevated in women.

CONCLUSION

AF is strongly associated with an increased risk of VTE during the first months after diagnosis. Introduction of anticoagulant therapy soon after AF diagnosis might reduce the risk of VTE as well as of ischaemic stroke.

Should We Reintroduce Previous Venous Thromboembolism Into Decision-Making for Anticoagulation in Atrial Fibrillation?

BACKGROUND

We aimed to investigate whether history of venous thromboembolism should be considered a prognostic factor for future thromboembolic events in patients with atrial fibrillation.

METHODS

This was a nationwide cohort study of patients with incident atrial fibrillation from 2000-2017, defined and characterized using Danish health registries. Cox regression analyses were used to calculate hazard ratios and 95% confidence intervals for the outcomes ischemic stroke or systemic embolism, and ischemic stroke, systemic embolism, or venous thromboembolism, according to history of venous thromboembolism. Analyses were adjusted for components of the CHA₂DS₂-VASc score and time-varying use of oral anticoagulation.

RESULTS

The study included 246,313 patients with incident atrial fibrillation, of which 6,516 (2.6%) had previous venous thromboembolism. Patients with previous venous thromboembolism carried an overall similar adjusted risk of ischemic stroke or systemic embolism compared with patients without previous venous thromboembolism (reference; hazard ratio 0.99; 95% confidence interval, 0.90-1.09). When analyzing a composite thromboembolic outcome of ischemic stroke, systemic embolism, or venous thromboembolism, patients with previous venous thromboembolism were at high-risk (hazard ratio 1.76; 95% confidence interval, 1.64-1.90). Similar conclusions were drawn when stratifying by venous thromboembolism subtype, and when restricting to patients with low CHA₂DS₂-VASc scores or the non-anticoagulated subset of the study population.

CONCLUSION

Patients with atrial fibrillation and previous venous thromboembolism carried similar risk of ischemic stroke or systemic embolism compared with patients with atrial fibrillation without previous venous thromboembolism. Nonetheless, patients with previous venous thromboembolism remain a high-risk population due to an excess risk of future venous thromboembolism. Patients and physicians should keep this excess thromboembolic risk in mind when weighing the expected risks and benefits of oral anticoagulation in patients with atrial fibrillation.

Atrial fibrillation, venous thromboembolism, ischemic stroke, and all-cause mortality: The Tromsø study

Background

Atrial fibrillation (AF) is associated with increased risk of ischemic stroke and all-cause mortality. Patients with AF are also at increased risk of venous thromboembolism (VTE), but information on how AF impacts VTE-related mortality is scarce.

Objectives

To investigate the impact of AF on all-cause mortality in subjects with and without a thromboembolic event (VTE or ischemic stroke).

Methods

We followed 29 833 participants from the Tromsø study (1994-2008) through 2013 and recorded all deaths during follow-up. Incident AF, VTE, and ischemic stroke were registered as time-dependent exposures. We calculated mortality rates (MRs) by exposure during follow-up and obtained hazard ratios (HRs) for death with 95% confidence intervals (CIs).

Results

A total of 2087 AF cases, 756 VTEs, and 1279 ischemic strokes were registered during a median follow-up of 18.7 years, and 4797 people (16.1%) died. The age-adjusted MR for participants without any event was 1.19 per 100 person-years (PY; 95% CI, 1.15-1.23). Compared to these participants, subjects with the joint AF + VTE exposure had a 3.7-fold increased risk of death (HR, 3.67; 95% CI, 2.77-4.66) in age- and sex-adjusted analyses, similar to the risk observed for VTE alone (HR, 3.76; 95% CI, 3.28-4.30). Participants with stroke had a 2.9-fold increased risk of death (HR, 2.85; 95% CI, 2.56-3.18), and the risk was further increased in participants with both AF and stroke (HR, 4.38; 95% CI, 3.85-4.98).

Conclusions

AF was significantly associated with increased risk of death in participants with incident stroke. In contrast, concomitant AF was not associated with excess mortality risk in VTE patients.

The EGFR-rearranged adenocarcinoma is associated with a high rate of venous thromboembolism

BACKGROUND

The purpose of this study was to investigate the incidence of venous thromboembolism (VTE) in epidermal growth factor receptor (EGFR) mutations patients with lung adenocarcinoma, to provide clinical basis for the perioperative prevention and treatment of VTE in patients with lung cancer.

METHODS

This study included patients with invasive lung adenocarcinoma confirmed by pathology from July 2016 to March 2018 after surgical pulmonectomy in Thoracic Surgery Department of Beijing Chaoyang Hospital. All enrolled patients were tested for relevant gene mutations. All patients were classified as adenocarcinoma subtypes by the 2011 International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS) and European Respiratory Society (ERS). Patients were divided into the VTE group and the control group according to whether VTE occurred postoperatively. Baseline data, gene test results, operative data and tumor pathology data between the two groups were compared.

RESULTS

According to the inclusion criteria, a total of 323 patients underwent lung cancer surgery were analyzed in this study, including 148 males and 175 females, aged from 25 to 82 years old. Postoperative VTE occurred in 33 patients, with an incidence of 10.2%. Compared the baseline data, there were significant differences in age and BMI between the two groups, but no significant differences in other indicators. Comparing the results of postoperative genetic tests, the cases of exon 18, 19, 20, 21, 30, 31 mutation, exon 18 and 20 mixed mutation and exon 20 and 21 mixed mutation were 5, 42, 6, 57, 1, 3, 1 and 1. The total EGFR mutation rate in the enrolled patients was 36.2% (117/323). Among them, the proportion of EGFR mutation in the VTE group was significantly higher than that in the non-VTE group (60.6% vs. 33.4%, P=0.002). Exon mutations in specific regions and mixed region of EGFR were not statistically significant between them; there was no statistical difference in the concomitant KRAS and ALK gene mutations between them. Comparing the pathological conditions, the proportion of acinar dominant lung adenocarcinoma in the VTE group was higher than that in the non-VTE group (57.6% vs. 30.7%, P=0.002); other histologic subtypes showed no statistical difference. The D-dimer difference before and 1 day after surgery, preoperative FEV1, surgical method, duration of surgery and blood loss were statistically significant differences between the two groups. The results of univariate analysis showed that there were significant differences between the VTE group and the control group in proportion of EGFR mutant lung adenocarcinoma, age, BMI, D-dimer difference before and 1 day after surgery, preoperative FEV1, surgical method, duration of surgery, blood loss and proportion of acinar dominant lung adenocarcinoma (P<0.05). However, VTE was not significantly correlated with gender, ALK or KRAS gene mutation and other factors. Multi-factor logistics regression analysis shows that Patients with EGFR gene mutation infiltrating lung adenocarcinoma, acinar dominant lung adenocarcinoma, FEV1 and difference of D-dimer (d1-pre) are independent risk factors for postoperative lung cancer complicated with VTE.

CONCLUSIONS

The incidence of VTE was 10.2% in patients with invasive lung adenocarcinoma without prophylactic anticoagulant therapy. EGFR gene mutation is an independent risk factor for postoperative VTE in lung cancer, and the incidence of VTE in adenocarcinoma with alveolar predominance is the highest. Other independent risk factors included the difference of D-dimer (d1-pre) and preoperative FEV1.

Risk and Prognosis of Cancer After Lower Limb Arterial Thrombosis

BACKGROUND

Venous thromboembolism can be a presenting symptom of cancer, but the association between lower limb arterial thrombosis and cancer is unknown. We therefore examined cancer risk and prognosis of cancer in patients with lower limb arterial thrombosis.

METHODS

Using nationwide population-based Danish medical registries, we identified all patients diagnosed with first-time lower limb arterial thrombosis (1994-2013) and followed them until the occurrence of any subsequent cancer diagnosis, emigration, death, or November 30, 2013, whichever came first. We computed standardized incidence ratios with 95% confidence intervals as the observed number of cancers relative to the expected number based on national incidence rates by sex, age, and calendar year. To examine the prognostic impact of lower limb arterial thrombosis on all-cause mortality after cancer, we constructed a matched comparison cohort of patients who had cancer without lower limb arterial thrombosis.

RESULTS

Among 6600 patients with lower limb arterial thrombosis, we observed 772 subsequent cancers. The risk of any cancer was 2.5% after 6 months of follow-up, increasing to 17.9% after 20 years. During the first 6 months of follow-up, the standardized incidence ratio of any cancer was 3.28 (95% confidence interval, 2.79-3.82). The standardized incidence ratio remained elevated during 7 to 12 months (1.42; 95% confidence interval, 1.09-1.83) and beyond 12 months (1.14; 95% confidence interval, 1.05-1.24). The strongest associations were found for lung cancer and other smoking-related cancers. Lower limb arterial thrombosis also was associated with increased all-cause mortality after colon, lung, urinary bladder, and breast cancer, but not after prostate cancer.

CONCLUSIONS

Lower limb arterial thrombosis was a marker of occult cancer, especially lung cancer, and was an adverse prognostic factor for mortality in common cancers.

Identifying mutation-driven changes in gene functionality that lead to venous thromboembolism

Venous thromboembolism (VTE) is a common hematological disorder. VTE affects millions of people around the world each year and can be fatal. Earlier studies have revealed the possible VTE genetic risk factors in Europeans. The 2018 Critical Assessment of Genome Interpretation (CAGI) challenge had asked participants to distinguish between 66 VTE and 37 non-VTE African American (AA) individuals based on their exome sequencing data. We used variants from AA VTE association studies and VTE genes from DisGeNET database to evaluate VTE risk via four different approaches; two of these methods were most successful at the task. Our best performing method represented each exome as a vector of predicted functional effect scores of variants within the known genes. These exome vectors were then clustered with k-means. This approach achieved 70.8% precision and 69.7% recall in identifying VTE patients. Our second-best ranked method had collapsed the variant effect scores into gene-level function changes, using the same vector clustering approach for patient/control identification. These results show predictability of VTE risk in AA population and highlight the importance of variant-driven gene functional changes in judging disease status. Of course, more in-depth understanding of AA VTE pathogenicity is still needed for more precise predictions.

Identifying risk factor for development of perioperative venous thromboembolism in patients with gastrointestinal malignancy

BACKGROUND

Current data suggests that decreasing VTE incidence may require focus on other factors. This study aimed to identify perioperative risk factors for VTE in patients undergoing surgery for gastrointestinal (GI) malignancy.

METHODS

Patients undergoing surgery for GI malignancy from 2013 to 2016 were grouped according to whether or not they developed a postoperative VTE, and groups were compared along demographic, perioperative, and outcome variables.

RESULTS

Patients who developed VTE were more likely to be older (67 ± 11 VTE vs. 61 ± 10 no VTE, p = 0.04), male (92% vs. 59%, p = 0.02), and have a history of atrial fibrillation (39% vs. 11%, p = 0.01). They also experienced higher intraoperative blood loss (328 ± 724 mL no VTE vs. 918 ± 1885 mL VTE, p = 0.01). On multivariable analysis, history of atrial fibrillation was independently associated with development of postoperative VTE (odds ratio = 3.83, 95% confidence interval = 1.13-13.05, p = 0.03).

CONCLUSION

A prior history of atrial fibrillation independently predicts increased risk of developing VTE after surgery for GI malignancy. Improving understanding of the underlying VTE pathophysiology in these patients can help guide effective prevention strategies.