Common Cancer Types and Risk of Stroke and Bleeding in Patients With Nonvalvular Atrial Fibrillation: A Population-Based Study in England

Bidirectional two-sample Mendelian randomization study of atrial fibrillation and breast cancer

Background

Observational studies have shown an association between Breast Cancer (BC) and Atrial Fibrillation (AF). However, due to confounding factors and reverse causality, the causal role between BC and AF remains unclear. In this study, bidirectional two-sample Mendelian randomization (MR) combined with meta-analysis was used to evaluate the causal association between BC and AF.

Methods

Based on the Genome-Wide Association Studies (GWAS) summary data sets, the Inverse variance weighted (IVW) method was used as the main method, the weighted median method and MR-Egger method were used for Bidirectional Two-Sample Mendelian Randomization, and the Egger intercept test was used to detect horizontal pleiotropy. Heterogeneity was tested by Cochran's Q test, and sensitivity analysis was performed by "leave-one-out". GWAS data for AF and BC were obtained from three separate databases (FinnGen, UKBiobank, GWAScatalog) for European individuals. Finally, meta-analysis was performed on the MR Analysis results from different databases.

Results

The pooled IVW results showed no evidence of an effect of BC on the risk of AF (IVW: OR = 0.9994; 95% CI = 0.9967-1.0022). There was also no evidence of an effect of AF on BC risk (IVW: OR = 0.9970; 95% CI = 0.9154-1.0859).

Conclusion

The results of the Bidirectional Two-Sample Mendelian Randomization study show that there is no causal relationship between BC and AF.

Bleeding Risk in Patients with Cancer

The hemostatic system and cancer display a tight interconnection, and hemostatic imbalance frequently occurs in patients with cancer. While extensive knowledge about thrombotic risk has been generated, less is known about bleeding risk and associated risk factors. However, bleeding risk is of high significance as patients with cancer frequently receive therapeutic anticoagulation for various indications and/or are candidates for primary thromboprophylaxis. The risk of bleeding in patients with cancer is variable and difficult to assess in clinical practice. Certain clinical settings such as hospitalization, specific underlying risk factors (e.g., tumor type), and medications (e.g., anticoagulation) can contribute to the individual bleeding risk of a patient with cancer. In addition, some dynamic factors such as platelet count or kidney function have an impact. Particularly, data on baseline risk of bleeding are lacking to allow for risk assessment in cancer patients without anticoagulation. In contrast, risk assessment models for the prediction of bleeding events in cancer patients receiving anticoagulation have been developed; however, these have yet to be validated. The recognition of the importance of bleeding risk in cancer patients is growing, leading to an increasing number of studies investigating and reporting bleeding complications. As study designs and reporting of bleeding events vary, it is challenging to offer a clear synthesis of evidence. In this narrative review, we provide an overview of currently available data about incidence, risk factors, and clinical impact of bleeding events in patients with cancer, and critically review risk assessment models for bleeding in cancer patients during anticoagulant therapy.

Apixaban vs Aspirin in Patients With Cancer and Cryptogenic Stroke: A Post Hoc Analysis of the ARCADIA Randomized Clinical Trial

Importance

Approximately 10% to 15% of ischemic strokes are associated with cancer; cancer-associated stroke, particularly when cryptogenic, is associated with high rates of recurrent stroke and major bleeding. Limited data exist on the safety and efficacy of different antithrombotic strategies in patients with cancer and cryptogenic stroke.

Objective

To compare apixaban vs aspirin for the prevention of adverse clinical outcomes in patients with history of cancer and cryptogenic stroke.

Design, Setting, and Participants

Post hoc analysis of data from 1015 patients with a recent cryptogenic stroke and biomarker evidence of atrial cardiopathy in the Atrial Cardiopathy and Antithrombotic Drugs in Prevention After Cryptogenic Stroke (ARCADIA) trial, a multicenter, randomized, double-blind clinical trial conducted from 2018 to 2023 at 185 stroke centers in North America. Data analysis was performed from October 15, 2023, to May 23, 2024.

Exposures

Oral apixaban, 5 mg (or 2.5 mg if criteria met), twice daily vs oral aspirin, 81 mg, once daily. Subgroups of patients with and without cancer at baseline were examined.

Main Outcomes and Measures

The primary outcome for this post hoc analysis was a composite of major ischemic or major hemorrhagic events. Major ischemic events were recurrent ischemic stroke, myocardial infarction, systemic embolism, and symptomatic deep vein thrombosis or pulmonary embolism. Major hemorrhagic events included symptomatic intracranial hemorrhage and any major extracranial hemorrhage.

Results

Among 1015 participants (median [IQR] age, 68 [60-76] years; 551 [54.3%] female), 137 (13.5%) had a history of cancer. The median (IQR) follow-up was 1.5 (0.6-2.5) years for patients with history of cancer and 1.5 (0.6-3.0) years for those without history of cancer. Participants with history of cancer, compared with those without history of cancer, had a higher risk of major ischemic or major hemorrhagic events (hazard ratio [HR], 1.73; 95% CI, 1.10-2.71). Among those with history of cancer, 8 of 61 participants (13.1%) randomized to apixaban and 16 of 76 participants (21.1%) randomized to aspirin had a major ischemic or major hemorrhagic event; however, the risk was not significantly different between groups (HR, 0.61; 95% CI, 0.26-1.43). Comparing participants randomized to apixaban vs aspirin among those with cancer, events included recurrent stroke (5 [8.2%] vs 9 [11.8%]), major ischemic events (7 [11.5%] vs 14 [18.4%]), and major hemorrhagic events (1 [1.6%] vs 2 [2.6%]).

Conclusions and Relevance

Among participants in the ARCADIA trial with history of cancer, the risk of major ischemic and hemorrhagic events did not differ significantly with apixaban compared with aspirin.

Trial Registration

ClinicalTrials.gov Identifier: NCT03192215.

Performance of CHA2DS2-VASc and HAS-BLED in predicting stroke and bleeding in atrial fibrillation and cancer

Aims

To compare the predictive performance of CHA2DS2-VASc and HAS-BLED scores in atrial fibrillation (AF) patients with and without cancer.

Methods and results

Using data from the Clinical Practice Research Datalink in England, we performed a retrospective cohort study of patients with new diagnoses of AF from 2009 to 2019. Cancer was defined as history of breast, prostate, colorectal, lung, or haematological cancer. We calculated the CHA2DS2-VASc and HAS-BLED scores for the 1-year risk of stroke and major bleeding events. Scores performance was estimated by discrimination [area under the receiver operating characteristic curve (AUC)] and calibration plots. Of 141 796 patients with AF, 10.3% had cancer. The CHA2DS2-VASc score had good to modest discrimination in prostate cancer AUC = 0.74 (95% confidence interval: 0.71, 0.77), haematological cancer AUC = 0.71 (0.66, 0.76), colorectal cancer AUC = 0.70 (0.66, 0.75), breast cancer AUC = 0.70 (0.66, 0.74), and lung cancer AUC = 0.69 (0.60, 0.79), compared with no-cancer AUC = 0.73 (0.72, 0.74). HAS-BLED discrimination was poor in prostate cancer AUC = 0.58 (0.55, 0.61), haematological cancer AUC = 0.59 (0.55, 0.64), colorectal cancer AUC = 0.57 (0.53, 0.61), breast cancer AUC = 0.56 (0.52, 0.61), and lung cancer AUC = 0.59 (0.51, 0.67), compared with no-cancer AUC = 0.61 (0.60, 0.62). Both the CHA2DS2-VASc score and HAS-BLED score were well calibrated across all study cohorts.

Conclusion

Amongst certain cancer cohorts in the AF population, CHA2DS2-VASc performs similarly in predicting stroke to AF patients without cancer. Our findings highlight the importance of cancer diagnosis during the development of risk scores and opportunities to optimize the HAS-BLED risk score to better serve cancer patients with AF.

Harnessing the potential of de-sulfated heparin for targeted drug delivery: A three-component approach exemplified by conjugation with galactose and paclitaxel

Heparin, an anticoagulant with a century-long history of use, has been investigated over the past decade as a potential drug delivery vehicle. Despite its safety and efficacy, its interactions with many proteins through specific sulfate patterns can complicate drug delivery by mediating diverse biological functions. Here, we present the synthesis of a three-component drug delivery system comprising de-sulfated heparin as the carrier, galactose as the targeting moiety, and paclitaxel as the therapeutic drug. Removal of sulfates eliminated most of its anticoagulant effects in all intermediates. Through coupling with galactose and paclitaxel, the system improved the solubility of the drug and achieved selective targeting and efficient drug delivery to HepG2 cells, a liver carcinoma cell line with high galactose receptor expression. While the three-component system exhibited a slightly higher IC50 value than native paclitaxel, demonstrating its efficacy as a drug carrier, the IC50 value for the normal human liver cell line QSG7701 was significantly higher, indicating its selectivity and safety. Our study introduces a novel approach utilizing desulfated heparin as a carrier, warranting further investigation to unlock its potential in targeted drug delivery strategies.

Oral anticoagulant prescribing among patients with cancer and atrial fibrillation in England, 2009-2019

BACKGROUND

Anticoagulation of patients with atrial fibrillation (AF) and cancer is challenging because of their high risk for stroke and bleeding. Little is known of the variations of oral anticoagulant (OAC) prescribing in patients with AF with and without cancer.

METHODS

Patients with first-time AF during 2009-2019 from the Clinical Practice Research Datalink were included. Cancer diagnosis was defined as a history of breast, prostate, colorectal, lung, or hematological cancer. Competing-risk analysis was used to assess the risk of OAC prescribing in patients with AF and cancer adjusted for clinical and sociodemographic factors.

RESULTS

Of 177,065 patients with AF, 11.7% had cancer. Compared to patients without cancer, patients with cancer were less likely to receive OAC: prostate cancer (subhazard ratio [SHR], 0.95; 95% CI, 0.91-0.99), breast cancer (SHR, 0.93; 95% CI, 0.89-0.98), colorectal cancer (SHR, 0.93; 95% CI, 0.88-0.99), hematological cancer (SHR, 0.70; 95% CI, 0.65-0.75), and lung cancer (SHR, 0.44; 95% CI, 0.38-0.50). The cumulative incidence function (CIF) of OAC prescribing was lowest for patients with lung cancer and hematological cancer compared with patients without cancer. The difference between the CIF of OAC prescribing in patients with and without cancer becomes narrower in the most deprived areas. Elderly patients (aged ≥85 years) overall had the lowest CIF of OAC prescribing regardless of cancer status.

CONCLUSIONS

In patients with AF, underprescribing of OAC is independently associated with certain cancer types. Patients with hematological and lung cancer are the least likely to receive anticoagulation therapy compared with patients without cancer. Underprescribing of OAC in cancer is linked to old age. Further studies of patients with AF and cancer are warranted to assess the net clinical benefit of anticoagulation in certain cancer types.