COMMENTARY

CHA2DS2-VASc Score and Risk for Major Bleeding

Sumit Patel, MD

Disclosures

December 29, 2016

CHA2DS2-VASc Scores and Major Bleeding in Patients With Nonvalvular Atrial Fibrillation Who Are Receiving Rivaroxaban

Peacock WF, Tamayo S, Patel M, Sicignano N, Hopf KP, Yuan Z
Ann Emerg Med. 2016 Nov 29. [Epub ahead of print]

Study Summary

Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its diagnosis and management are crucial tasks for emergency physicians. An important aspect of treating patients with AF is reducing their risk for stroke.

The CHA2DS2-VASc score is a validated risk stratification tool used to help determine when the benefit outweighs the risks of anticoagulation for a patient with AF. However, clinicians often find themselves in a difficult predicament when using CHA2DS2VASc scores in deciding to initiate anticoagulation for patients, because of the potential increased risk in major bleeding. Relating to this dilemma, the CHA2DS2-VASc score and its direct relationship to major bleeding risk has not been previously studied.

In this observational, retrospective cohort investigation, researchers sought to elucidate any relationship which may exist between a patient's CHA2DS2-VASc score and the incidence of nontraumatic major bleeding in patients with nonvalvular AF being treated with rivaroxaban. Ten million patient records from the Department of Defense Military Health System were analyzed as part of this study.

Inclusion criteria were a diagnosis of nonvalvular AF and treatment with rivaroxaban from January 1, 2013, to June 30, 2015. A total of 44,793 patients were identified in the analysis.

The primary outcome was major bleeding defined by the Cunningham algorithm, which is a validated database algorithm used to identify major bleeding during hospitalization from administrative data. Researchers analyzed the composition of the patient population studied, including age, gender, and details regarding bleeding events; dosage of rivaroxaban used; and hospitalization details.

A total of 1352 major bleeding events were identified for 1293 patients. The overall major bleeding incidence rate, based on a person's first major bleeding event, was 2.84 (95% confidence interval, 2.69 to 3.00) per 100 person-years. Forty-one patients had a major bleeding-related fatal outcome. Subgroup analysis was further performed to identify risk for bleeding on the basis of total CHA2DS2-VASc score as well as by category of the score itself.

Overall, researchers found that higher CHA2DS2-VASC scores correlated with increased risk for major bleeding, and patients with vascular disease were at the highest risk.

Viewpoint

There are several key limitations of this study. As a retrospective study based on data regarding dispensing of medications and data primarily stored for financial reasons, the study can suggest only a temporal association rather than a causal relationship. In addition, the use of coding data does not allow researchers to comment on the clinical importance of the bleeding events, and perhaps clinically insignificant bleeding may have been included with the bleeding outcome data.

Readers may wonder why researchers did not study the HAS-BLED (hypertension, abnormal renal/liver function, stroke, bleeding history or predisposition, labile international normalized ratio [INR], elderly, drugs/alcohol concomitantly) score, but the data set did not include INRs. There are important opportunities for further study on this topic.

Although limited, the study certainly provides relevant data and information for emergency physicians. As the use of rivaroxaban and other types of anticoagulation increases with the incidence of diagnosis of AF, patients with higher risk for bleeding will present to the emergency department. It is prudent for us all to be aware of this increased risk, and although it is probably discussed already amongst clinicians, this study does provide data to back up the concerns we all have when starting anticoagulation for patients with AF.

In my own emergency department practice, I have previously started patients with elevated CHA2DS2-VASC scores on anticoagulation to reduce their risk for thromboembolic events. I will be cautious in starting anticoagulation for patients with significantly elevated scores without first discussing the risks for major bleeding and other complications with patients and their primary care teams, and this study provides data to support us all cautiously weighing the risks and benefits of any anticoagulation therapy in patients with AF.

Abstract

Follow Medscape Emergency on Twitter for more Emergency Medicine news: @MedscapeEM

Comments

3090D553-9492-4563-8681-AD288FA52ACE
Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as:

processing....

Recommendations