1. Home
  2. thrombosis

thrombosis

Adverse Events Associated With the Addition of Aspirin to Direct Oral Anticoagulant Therapy Without a Clear Indication

Author/s: 
Schaefer, J. K., Errickson, J., Li, Y., Kong, X., Alexandris-Souphis, T., Ali, M. A., Decamillo, D., Haymart, B., Kaatz, S., Kline-Rogers, E., Kozlowski, J. H., Krol, G. D., Shankar, S, R., Sood, S. L., Froehlich, J. B., Barnes, G. D.

Importance: It is unclear how many patients treated with a direct oral anticoagulant (DOAC) are using concomitant acetylsalicylic acid (ASA, or aspirin) and how this affects clinical outcomes.

Objective: To evaluate the frequency and outcomes of prescription of concomitant ASA and DOAC therapy for patients with atrial fibrillation (AF) or venous thromboembolic disease (VTE).

Design, setting, and participants: This registry-based cohort study took place at 4 anticoagulation clinics in Michigan from January 2015 to December 2019. Eligible participants were adults undergoing treatment with a DOAC for AF or VTE, without a recent myocardial infarction (MI) or history of heart valve replacement, with at least 3 months of follow-up.

Exposures: Use of ASA concomitant with DOAC therapy.

Main outcomes and measures: Rates of bleeding (any, nonmajor, major), rates of thrombosis (stroke, VTE, MI), emergency department visits, hospitalizations, and death.

Results: Of the study cohort of 3280 patients (1673 [51.0%] men; mean [SD] age 68.2 [13.3] years), 1107 (33.8%) patients without a clear indication for ASA were being treated with DOACs and ASA. Two propensity score-matched cohorts, each with 1047 patients, were analyzed (DOAC plus ASA and DOAC only). Patients were followed up for a mean (SD) of 20.9 (19.0) months. Patients taking DOAC and ASA experienced more bleeding events compared with DOAC monotherapy (26.0 bleeds vs 31.6 bleeds per 100 patient years, P = .01). Specifically, patients undergoing combination therapy had significantly higher rates of nonmajor bleeding (26.1 bleeds vs 21.7 bleeds per 100 patient years, P = .02) compared with DOAC monotherapy. Major bleeding rates were similar between the 2 cohorts. Thrombotic event rates were also similar between the cohorts (2.5 events vs 2.3 events per 100 patient years for patients treated with DOAC and ASA compared with DOAC monotherapy, P = .80). Patients were more often hospitalized while undergoing combination therapy (9.1 vs 6.5 admissions per 100 patient years, P = .02).

Conclusion and relevance: Nearly one-third of patients with AF and/or VTE who were treated with a DOAC received ASA without a clear indication. Compared with DOAC monotherapy, concurrent DOAC and ASA use was associated with increased bleeding and hospitalizations but similar observed thrombosis rate. Future research should identify and deprescribe ASA for patients when the risk exceeds the anticipated benefit.

Keywords 
aspirin anticoagulant therapy treatment heart-valve replacement thrombosis

Rivaroxaban Versus Vitamin K Antagonist in Antiphospholipid Syndrome: A Randomized Noninferiority Trial

Author/s: 
Ordi-Ros, J, Sáez-Comet, L., Pérez-Conesa, M., Vidal, X., Riera-Mestre, A., Castro-Salomó, A., Cuquet-Pedragosa, J., Ortiz-Santamaria, V., Mauri-Plana, M., Solé, C., Cortés-Hernández, J.

BACKGROUND:

The potential role of new oral anticoagulants in antiphospholipid antibody syndrome (APS) remains uncertain.

OBJECTIVE:

To determine whether rivaroxaban is noninferior to dose-adjusted vitamin K antagonists (VKAs) for thrombotic APS.

DESIGN:

3-year, open-label, randomized noninferiority trial. (EU Clinical Trials Register: EUDRA [European Union Drug Regulatory Authorities] code 2010-019764-36).

SETTING:

6 university hospitals in Spain.

PARTICIPANTS:

190 adults (aged 18 to 75 years) with thrombotic APS.

INTERVENTION:

Rivaroxaban (20 mg/d or 15 mg/d, according to renal function) versus dose-adjusted VKAs (target international normalized ratio, 2.0 to 3.0, or 3.1 to 4.0 in patients with a history of recurrent thrombosis).

MEASUREMENTS:

The primary efficacy outcome was the proportion of patients with new thrombotic events; the primary safety outcome was major bleeding. The prespecified noninferiority margin for risk ratio (RR) was 1.40. Secondary outcomes included time to thrombosis, type of thrombosis, changes in biomarker levels, cardiovascular death, and nonmajor bleeding.

RESULTS:

After 3 years of follow-up, recurrent thrombosis occurred in 11 patients (11.6%) in the rivaroxaban group and 6 (6.3%) in the VKA group (RR in the rivaroxaban group, 1.83 [95% CI, 0.71 to 4.76]). Stroke occurred more commonly in patients receiving rivaroxaban (9 events) than in those receiving VKAs (0 events) (corrected RR, 19.00 [CI, 1.12 to 321.9]). Major bleeding occurred in 6 patients (6.3%) in the rivaroxaban group and 7 (7.4%) in the VKA group (RR, 0.86 [CI, 0.30 to 2.46]). Post hoc analysis suggested an increased risk for recurrent thrombosis in rivaroxaban-treated patients with previous arterial thrombosis, livedo racemosa, or APS-related cardiac valvular disease.

LIMITATION:

Anticoagulation intensity was not measured in the rivaroxaban group.

CONCLUSION:

Rivaroxaban did not show noninferiority to dose-adjusted VKAs for thrombotic APS and, in fact, showed a non-statistically significant near doubling of the risk for recurrent thrombosis.

PRIMARY FUNDING SOURCE:

Bayer Hispania.

Keywords 
rivaroxaban thrombosis wafarin

Treatment of Superficial Vein Thrombosis: A Systematic Review and Meta-Analysis

Author/s: 
Duffett, Lisa, Kearon, Clive, Rodger, Marc, Carrier, Marc

BACKGROUND:

The optimal first line treatment for patients with isolated superficial venous thrombosis (SVT) of the lower extremity is unknown.

OBJECTIVE:

This article reports estimates of the rate of venous thromboembolic complications among patients with SVT according to treatment.

MATERIALS AND METHODS:

A systematic review and meta-analysis was performed using unrestricted searches of electronic databases. Reported events were transformed to event per 100 patient-years of follow-up and a random effects model was used to calculate pooled rates according to pre-specified treatment categories. The primary outcome was the occurrence of deep vein thrombosis (DVT) or pulmonary embolism (PE) during the study follow-up period.

RESULTS:

 Seventeen articles, including 6,862 patients, were included in the meta-analysis. Fondaparinux had the lowest event rate with 1.4 events per 100 patient-years of follow-up (95% confidence interval [CI], 0.5-2.8, I 2 = 18%). Pooled event rates for DVT or PE ranged from 9.3 to 16.6 events per 100 patient-years across other treatment categories, and the pooled event rate for no treatment/placebo was 10.5 events per 100 patient-years (95% CI, 3.0-22.0). Major bleeding was low and similar across all treatment categories. Heterogeneity was moderate to high for most pooled estimates.

CONCLUSION:

While pooled event rates suggest that fondaparinux achieves the lowest rate of DVT or PE, low-quality evidence for other treatments prevents firm conclusions about the optimal treatment for SVT.

Keywords 
thrombosis deep vein thrombosis pulmonary embolism fondaparinux arixstra
Subscribe to thrombosis