Bleeding with oral anticoagulant dabigatran is highly associated with occult cancers in atrial fibrillation patients

Fatal Adverse Events of Dabigatran Combined With Aspirin in Elderly Patients: An Analysis Using Data From VigiBase

Introduction: The elderly are vulnerable to cardiovascular diseases and the incidence of atrial fibrillation (AF) and venous thromboembolism (VTE) increases significantly with age. Dabigatran is a commonly used new oral anticoagulant approved by the FDA for stroke prevention in patients with non-valvular AF and VTE treatment and prevention. Aspirin is commonly used as a preventive drug for cardiovascular diseases. AF and coronary heart disease share many risk factors, so these two diseases often coexist and thus dabigatran and aspirin are often combined in those people. The aim of this study was to analyze the clinical characteristics of fatal adverse events of dabigatran combined with aspirin in elderly patients, and to provide references for clinical rational use of drugs.

Materials and Methods: Fatal adverse events related to the combined use of dabigatran and aspirin in elderly patients aged over 75 were extracted from the WHO global database of individual case safety reports (VigiBase). Well-documented reports, vigiGrade completeness score ≥0.80, or with an informative narrative, were analyzed with a focus on the clinical features of the cases.

Results: From 1968 up to January 19, 2020, there were 112 eligible reports in VigiBase from 13 countries, of which 33 were identified as well-documented. Of these 33, 19 were male (58%) and 14 were female (42%), the average age of the patients was 84 (75–95 years), with five cases of extreme weights (>100 kg in one case, <50 kg in four cases). There were 31 cases of death by internal bleeding (mainly 15 of gastrointestinal hemorrhage and 12 of intracranial hemorrhage) and two cases of the sudden death of unknown cause. Medication errors existed in 15 patients. The times to onset (TTO) was provided in 24 cases, ranging from 2 days to 4 years, and in 12 patients occurred within a month. Of the 31 patients with fatal bleeding events, 29 were associated with other factors that increase the risk of bleeding, such as diseases (hypertension, renal impairment, stroke, gastrointestinal related diseases, hypothyroidism, and cancer), drugs (antiplatelets, anticoagulants, thrombolytics, P glycoprotein substrates, non-steroidal anti-inflammatory drugs, hormones, selective serotonin reuptake inhibitors, and acetaminophen) and other factors (low body weights and alcohol consumption), and 21 of these contained two or more risk factors.

Conclusion: The fatal adverse events associated with the combined use of dabigatran and aspirin in elderly patients were mainly serious bleeding events, which often occurred within 1 month. Most of these cases had medication errors and most of the patients had multiple diseases, medications, or other conditions at the same time that increase the risk of bleeding. It is suggested that prescription of dabigatran and aspirin in elderly patients should go along with alertness for medication errors, care for correct dose or control of other bleeding risk factors, and the combined medication time should be as short as possible to minimise serious adverse events.

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.

Usefulness of Bleeding After Acute Coronary Syndromes for Unmasking Silent Cancer

There is a growing body of evidence on the incidence and negative prognostic impact of postdischarge hemorrhagic complications after an acute coronary syndrome (ACS). However, the risk of subsequent cancer after postdischarge bleeding in these patients is currently poorly known. The aim of this study was to assess the association of postdischarge bleeding with newly diagnosed cancers after an ACS. Data from a single-center registry of 3,644 ACS patients, who were discharged with dual antiplatelet therapy and treated with percutaneous coronary intervention, were used to investigate the association between postdischarge bleeding and diagnosis of cancer. During a median follow-up of 56.2 months, bleeding events were documented in 1,216 patients and newly diagnosed cancers in 227 patients. Postdischarge bleeding was associated with cancer diagnosis (adjusted hazard ratio [HR] 3.43, 95% confidence interval [CI] 2.62 to 4.50), but only spontaneous bleeding (adjusted HR 4.38, 95% CI 3.31 to 5.79). This association was stronger as the severity of the bleeding increased (HR 1.52, 4.88, 7.30, and 12.29, for BARC type 1, 2, 3a, and 3b bleeding, respectively). Positive predictive values for cancer diagnosis of postdischarge bleeding was 7.7%. Median time from bleeding to cancer was 4.6 months. In conclusion, spontaneous postdischarge bleeding in ACS patients is strongly associated with subsequent cancer diagnosis within the first 6 months. A prompt evaluation of bleeding could be useful for enabling an early detection of cancer in these patients.

The Impact of Cancer on Major Bleeding and Stroke/Systemic Emboli in Patients Using Direct Oral Anticoagulants:From the Database of a Single-Center Registry

Background

Few data are available on direct oral anticoagulant (DOAC) use in patients with cancer and atrial fibrillation (AF).

Methods

We retrospectively analyzed prospectively collected data from a single-center registryon 2,272 patients who tookDOACs for AF (apixaban:1,014; edoxaban:267; rivaroxaban:498; dabigatran:493). Patients were monitored for 2 years andclassified into non-cancer (n=2009) and cancer group (n=263) (cancer onset during DOAC treatment, active canceratDOAC administration, and cancer history).Major bleeding (MB) and thromboembolic events (TEEs) were evaluated.

Results

The mean age was 73±10 years. CHADS2 and HAS-BLED scores were 1.95±1.32 and 1.89±0.96,respectively.In the present study, the prevalence of gastrointestinal and genitourinary cancer was 61% and 8%, respectively.The MB and TEEs incidences were 2.4 and 2.2 per 100-patient years, respectively. The appropriate dosing rate, body weight, and Ccrvalue in cancer patients were significantly lower than those in non-cancer patients. Cancer patients were significantly older than non-cancer patients. In MB patients diagnosed with gastrointestinal or genitourinary cancer during follow-up, the clinically relevant bleeding such as melena or hematuria occurred.Additionally, there was a significantly higher MB incidence in cancer patients than in non-cancer patients (p<0.01).

Conclusions

AF patients with cancer was associated with a higher risk of MB compared with those without cancer despite higher rate of inappropriate low dose. Bleeding such as melena and hematuria after DOAC administration might suggest that the symptoms are associated with cancer of the site.