The impact of new-onset cancer among veterans who are receiving warfarin for atrial fibrillation and venous thromboembolism

Causal relationship between atrial fibrillation/warfarin and cutaneous melanoma: a two-sample Mendelian randomization study

Purpose

In recent years, the relationship between malignant tumors and atrial fibrillation has attracted more and more attention. Atrial fibrillation can also cause a series of adverse events, such as the risk of thromboembolism. Also, Warfarin is often used here. But, the relationship between cutaneous melanoma and atrial fibrillation, and between cutaneous melanoma and warfarin is still unclear. Therefore, we used a two-sample Mendelian randomization to assess the causal relationship between atrial fibrillation/warfarin and cutaneous melanoma (cM).

Methods

Firstly, atrial fibrillation (ukb-b-11550; nCase = 3,518, nControl = 459,415) and warfarin (ukb-b-13248; nCase = 4,623, nControl = 458,310) as exposures, with genome-wide association studies (GWAS) data from the United Kingdom Biobank. And cM (ieu-b-4969; nCase = 3,751, nControl = 372,016) as outcome, with GWAS data from the IEU Open GWAS project. Subsequently, single-nucleotide polymorphisms (SNPs) were filtered from GWAS studies using quality control measures. In addition, two-sample Mendelian randomization (MR) analysis was performed to explore the causal relationship between atrial fibrillation or warfarin and cM and used inverse variance weighting (IVW) as the primary analytical method. Finally, relevant heterogeneity and sensitivity analysis were performed to ensure the accuracy of the results.

Results

A causal relationship between atrial fibrillation and cutaneous melanoma was observed, and between warfarin and cutaneous melanoma.

Conclusion

The atrial fibrillation may play a causal role in the development of cutaneous melanoma, but the mechanism and the causal relationship between warfarin and cutaneous melanoma needs to be further elucidated.

Impact of malignancy on outcomes in European patients with atrial fibrillation: A report from the ESC-EHRA EURObservational research programme in atrial fibrillation general long-term registry

BACKGROUND

The management of patients with atrial fibrillation (AF) and malignancy is challenging given the paucity of evidence supporting their appropriate clinical management.

PURPOSE

To evaluate the outcomes of patients with active or prior malignancy in a contemporary cohort of European AF patients.

METHODS

Patients enrolled in the EURObservational Research Programme in AF General Long-Term Registry were categorized into 3 categories: No Malignancy (NoMal), Prior Malignancy (PriorMal) and Active Malignancy (ActiveMal). The primary outcomes were all-cause death and the composite outcome MACE.

RESULTS

A total of 10 383 patients were analysed. Of these, 9597 (92.4%) were NoMal patients, 577 (5.6%) PriorMal and 209 (2%) ActiveMal. Lack of any antithrombotic treatment was more prevalent in ActiveMal patients (12.4%) as compared to other groups (5.0% vs 6.3% for PriorMal and NoMal, p < .001). After a median follow-up of 730 days, there were 982 (9.5%) deaths and 950 (9.7%) MACE events. ActiveMal was independently associated with a higher risk for all-cause death (HR 2.90, 95% CI 2.23-3.76) and MACE (HR 1.54, 95% CI 1.03-2.31), as well as any haemorrhagic events and major bleeding (OR 2.42, 95% CI 1.49-3.91 and OR 4.18, 95% CI 2.49-7.01, respectively). Use of oral anticoagulants was not significantly associated with a higher risk for all-cause death or bleeding in ActiveMal patients.

CONCLUSIONS

In a large contemporary cohort of AF patients, active malignancy was independently associated with all-cause death, MACE and haemorrhagic events. Use of anticoagulants was not associated with a higher risk of all-cause death in patients with active malignancies.

Anticoagulation for atrial fibrillation in active cancer (Review)

Atrial fibrillation (AF) may often pre-exist in patients with newly diagnosed cancer or occur with increased frequency shortly after cancer diagnosis. Patients with active cancer and AF have a particularly high risk of thromboembolic complications, as both conditions carry a risk of thrombosis. Thromboembolic risk is determined by several factors, including advanced age, sex (females), cancer histology (adenocarcinomas), location (e.g., pancreas, stomach), advanced stage, anticancer regimens (e.g., platinum compounds, anti-angiogenic therapies, immune modulators), comorbidities (e.g., obesity, kidney disease) and concurrent therapies (e.g., surgery, central catheters). Physicians are often reluctant to prescribe anticoagulants to patients with active cancer and AF, mainly due to fear of bleeding complications, which is partly related to the paucity of evidence in the field. Decision making regarding anticoagulation for the prevention of ischemic stroke and systemic embolism in patients with active cancer and AF may be challenging and should not simply rely on the risk prediction scores used in the general AF population. By contrast, the administration and choice of anticoagulants should be based on the comprehensive, individualized and periodic evaluation of thromboembolic and bleeding risk, drug-drug interactions, patient preferences and access to therapies.

Association of anticoagulant-related bleeding events with cancer detection in atrial fibrillation: A systematic review and meta-analysis

BACKGROUND

A bleeding episode may herald cancer in the general population. Oral anticoagulants (OACs), the mainstay treatment for atrial fibrillation (AF), are known to increase the risk of bleeding, and may thus promote an earlier diagnosis of cancer. Data regarding the association of bleeding episodes with cancer in patients with AF on OACs are scarce.

METHODS

In this systematic review and meta-analysis, we searched electronic databases (Medline, Scopus, and Central) and gray literature sources for studies of patients with nonvalvular AF under any OAC, from inception until 14 October 2020. The primary outcome was the association of bleeding occurrences with the detection of cancer. A subgroup analysis was performed according to OAC type [NOAC (non-vitamin K oral anticoagulant) versus VKA (vitamin K antagonist)].

RESULTS

Overall, 4 studies were included, accounting for a total of 144,362 patients with AF receiving OAC. During follow-up, 816 (0.57%) cases of cancer were confirmed. The presence of a bleeding event, either major or minor, was associated with a higher risk for cancer detection (odds ratio [OR] 8.79, 95% confidence interval [CI] 4.98-15.51, and I² 85%). Heterogeneity was explained after studies were stratified by the type of OAC (NOACs: OR 6.12, 95% CI 4.47-8.37, I² 0%, VKAs: OR 15.16, 95% CI 12.61-18.23, and I² 0%).

CONCLUSION

The detection of a bleeding event could be an alerting sign of cancer in patients with AF on OACs, particularly in patients receiving VKAs. REGISTRATION NUMBER (DOI): available in https://doi.org/10.17605/OSF.IO/3948R, DOI: 10.17605/OSF.IO/3948R.

Atrial Fibrillation and Stroke Risk in Patients With Cancer: A Primer for Oncologists

Cancer and atrial fibrillation (AF) are common conditions, but for patients affected with both, there is a lack of data about management of anticoagulation and cerebrovascular outcomes. In the first section of this review, we summarize the most relevant studies on stroke risk and management of AF in patients with active cancer, attempting to answer questions of whether to anticoagulate, whom to anticoagulate, and what agents to use. In the second section of the review, we suggest a decision algorithm on the basis of the available evidence and provide practical recommendations for each of the anticoagulant options. In the third section, we discuss the limitations of the available evidence. On the basis of low-quality evidence, we find that patients with cancer and AF have a risk of stroke similar to that of the general population but a substantially higher risk of bleeding regardless of the anticoagulant agent used; this makes anticoagulation-related decisions complex and evidence from the general population not immediately applicable. In general, we suggest stopping anticoagulation in patients with high risk of bleeding and in those with a moderate bleeding risk without a high thromboembolic risk and recommend anticoagulation as in the general population for patients at a low risk for bleeding. However, regardless of initial therapy, we recommend reassessing whether anticoagulation should be given at each point in the clinical course of the disease. High-quality evidence to guide anticoagulation for AF in patients with cancer is needed.

Anticoagulants for cancer-associated ischemic stroke

Patients with cancer-associated ischemic stroke pose similar clinical manifestations and image characteristics, mainly embolic infarction, as patients with atrial fibrillation do. D-dimer, a degraded product of fibrin polymer, is a useful indicator of hypercoagulability, which frequently increases in cancer-associated stroke, but not in stroke resulted from atrial fibrillation. The level of serum D-dimer is associated with mortality, prognosis, and recurrence of systemic thromboembolism in these patients. Theoretically, drugs block coagulation cascade, such as heparin and low-molecular-weight-heparin (LMWH), oral direct anticoagulants, could attenuate the status of hypercoagulation and decrease the amount of D-dimer. These drugs may be helpful to prevent thromboembolic events in patients with cancer-associated hypercoagulability. Vitamin K antagonist, warfarin, decreases the production of coagulation factors, but not interrupts coagulation cascade may not be helpful to decrease hypercoagulability, but increase the risk of bleeding. However, the treatment of cancer-associated embolic stroke is still controversial. This article reviews relevant clinical studies and proposes the applicability of direct oral anticoagulants from the pathophysiological mechanism.

Atrial fibrillation and cancer - An unexplored field in cardiovascular oncology

An increasing body of evidence suggests an association between cancer and atrial fibrillation (AF). The exact magnitude and underlying mechanism of this association are however unclear. Cancer-related inflammation, anti-cancer treatment and other cancer-related comorbidities are proposed to affect atrial remodelling, increasing the susceptibility of cancer patients for developing AF. Moreover, cancer is assumed to modify the risk of thromboembolisms and bleeding. A thorough and adequate understanding of these risks is however lacking, as current literature is scarce and show ambiguous results in AF patients. The standardized risk-models that normally aid the clinician in the decision of initiating anticoagulant therapy do not take the presence of malignancy into account. Other factors that complicate risk assessment in AF patients with cancer include drug-drug interactions and other cancer-related comorbidities such as renal impairment. In this review, we highlight the available literature regarding epidemiological association, risk assessment and anticoagulation therapy in AF patients with cancer.

Atrial fibrillation in patients with active malignancy and use of anticoagulants: Under-prescription but no adverse impact on all-cause mortality

Prescription of anticoagulants (ACs) in patients with cancer and atrial fibrillation (AF) is challenging and the impact on survival is not defined. In this study data prospectively collected in Oncology Units were retrospectively evaluated. Among 4664 patients admitted for malignancy, 394 patients (8.4%) had documented AF (mean age of 74 ± 9) and AC was prescribed to 155 patients (40%). Neither the type of cancer, the stage of the disease (metastatic or not) nor the ongoing treatments were significantly associated with prescription of AC, which was independently associated with BMI (OR 1.10; CI 95% 1.03-1.17; p = .003), valvular heart disease (OR 3.76; CI95% 1.59-8.87; p = .002), and previous venous thromboembolism (OR 6.67; 95%CI 2.67-16.70; p < .001). During a median follow-up of 212 days, survival from all-cause death was 37%, 28% and 18% at 6 months, 1 and 2 years, respectively. Only variables related to neoplastic disease or to patient clinical complexity were independently associated with mortality. A CHA₂DS₂VASc ≥ 4 was significantly associated with mortality (HR 1.33; 95%CI 1.06-1.67; p = .013). Treatment with ACs was not significantly related to mortality, neither in the whole cohort of patients, nor in patients with metastatic malignancies. In conclusion the prescription of ACs in patients with AF and active cancer was suboptimal, with one fourth of the patients not treated with ACs and one third using LMWH at prophylactic, non-therapeutic doses. Only few variables (BMI, valvular heart disease and previous venous thromboembolism) predicted prescription of ACs. Prescription of ACs was not associated with all-cause mortality, even in the subgroup with metastasis.

Thromboembolism and bleeding in patients with cancer and mechanical heart valves

Mechanical heart valves (MHV) require life-long anticoagulation with vitamin K antagonists (VKA), but anticoagulation management is complex in patients with cancer due to a high risk of thrombosis and bleeding. This is a retrospective, single-center study to assess anticoagulation management and thrombotic (stroke/valve thrombosis) and bleeding events in patients with active cancer and MHV. The incidence of thrombotic complications was compared to a control group (matched 1:1) of patients with MHV but without cancer. We included 48 patients, 60% of whom had aortic prostheses, 23% mitral prostheses and 17% both types. All patients received VKA as anticoagulant. With a median follow-up of 5.12 years, we observed two arterial thrombotic events (two strokes and no heart valve thrombosis). The 5-year incidence (95% confidence interval [CI]) of stroke/valve thrombosis was 5.7% (0.9-17.9%). The control group had a similar incidence of stroke/valve thrombosis (5-year incidence 7.9% [95%CI 2-19.8], p = 0.16). There were also 15 major bleeding episodes in the cancer group, 11 of which were related to a surgical procedure. The 5-year incidence (95% CI) of major bleeding was 32.9% (18.5-48%), and that of major bleeding unrelated to any procedure was 10.3% (3-23%). We found a low incidence of thrombotic events in this series of patients with active cancer and MHV who were anticoagulated with VKA. However, the incidence of bleeding was high, particularly in relation to invasive procedures.

Incidence, predictive factors, management, and survival impact of atrial fibrillation in non-Hodgkin lymphoma

Atrial fibrillation (AF) and cancer are common disorders in the general population but there are few studies in patients with both diseases. More specifically, there are scarce data on AF in patients with non-Hodgkin lymphoma (NHL). We assessed the incidence, predictive factors, management, and survival impact of AF in a cohort of patients with NHL from a single institution between 2002 and 2016 (n = 747). Twenty-three patients were diagnosed with AF before and 40 after the diagnosis of NHL (of the later, 16 were secondary to an extracardiac comorbidity and 24 unrelated to any triggering event [primary AF]). The 5-year cumulative incidence of new-onset AF was 4% (95% confidence interval [CI] 3-6%). Age and hypertension were the only predictive factors for the development of AF. Management of AF was heterogeneous, primarily with anti-vitamin K agents but also antiplatelet therapy in a significant proportion of patients. Among the 63 patients, there were six episodes of ischemic stroke/transient ischemic attack and four venous thromboembolic events, with four major bleeding episodes. Overall survival (OS) was inferior in patients with AF (HR 0.1, 95% CI 0.01-0.7, p = 0.02), largely due to secondary AF. We conclude that the incidence of new-onset AF in NHL patients seemed somewhat higher than in the general population, although with similar predictive factors. The management was heterogeneous, and the risk of ischemic and hemorrhagic events did not seem higher than in cancer-free patients. Survival was particularly poor for patients with secondary AF.

Cancer, atrial fibrillation, and stroke

Cancer patients appear to be at increased risk for atrial fibrillation. Although surgery and chemotherapy exacerbate this risk, this association is observed even in the absence of any cancer-specific treatment. The underlying mechanism of this is likely multifactorial, but systemic inflammation and autonomic dysregulation are hypothesized to play critical roles. Cancer and atrial fibrillation are both independent risk factors for ischemic stroke; however, it is not clear whether this translates to an increased risk of stroke in patients with both comorbidities. As such, commonly used risk stratification tools including the CHADS2 score currently do not take cancer into account as a variable and it is possible that stroke risk is underestimated in this population. There is a paucity of data regarding anticoagulant choice in cancer patients with atrial fibrillation. Vitamin K antagonists are often preferred over direct oral anticoagulants; however, this may be changing in the near future as new trials specific to this patient population emerge.