Clinical Outcomes of Patients With AF and Contraindications to Oral Anticoagulation

Older patients with atrial fibrillation who have contraindications to oral anticoagulation (OAC) because of high bleeding risk have increased mortality compared with untreated patients who have no contraindications, according to a recent study published in JACC: Clinical Electrophysiology.

Study researchers conducted an observational, longitudinal analysis comparing patients with and without contraindications to OAC based on ischemic and bleeding outcomes during a 3-year period. Using patients diagnosed in 2007 with prevalent atrial fibrillation and a CHA2DS2-VASc score ≥2 who were 65 years or older and living in the United States, study researchers analyzed nationally representative files of a 5% sample of Medicare beneficiaries. Because the study period (2007-2010) occurred before the use of non–vitamin K antagonist oral anticoagulants, study researchers defined OAC as the use of warfarin. Contraindications to warfarin included 1 or more instances of intracranial hemorrhage or mass, gastrointestinal bleeding, end-stage liver disease, and blood dyscrasia. Exclusions included certain patients enrolled in Medicare managed care and those who had a change in anticoagulation status, resulting in a primary study population of 26,684 patients not receiving oral anticoagulation. 

The primary analysis (contraindications and outcomes without OAC) illustrated that when a contraindication to warfarin was present, it was significantly associated with death (hazard ratio [HR], 1.17; 95% CI, 1.12-1.22; P <.001), gastrointestinal bleed (adjusted HR, 2.31; 95% CI, 1.64-3.24; P <.001), and hospitalization (adjusted HR, 1.20; 95% CI, 1.16-1.24; P <.001). 

The secondary analysis (OAC use and contraindications) showed a significant association with a lower risk for death (adjusted HR, 0.79; 95% CI, 0.76-0.83; P <.001), stroke (adjusted HR, 0.90; 95% CI, 0.83-0.99; P =.03), and hospitalization (adjusted HR, 0.93; 95% CI, 0.90-0.96; P <.001) among patients using OACs.

However, this group had a significantly higher risk for intracranial hemorrhage (adjusted HR, 1.42; 95% CI, 1.17-1.72; P <.001). 

Although the study did not include patients who had been treated with non–vitamin K antagonist OACs, study researchers thought that evidence from sensitivity analyses was “consistent with topline results.” Additional limitations included observational data, a heterogeneous sample, and difficulty defining objective criteria for oral anticoagulation contraindications.

Despite these limitations, study researchers concluded by noting “the use of OAC is associated with lower rates of all-cause stroke, hospitalization, and death, but higher risk of [intracranial hemorrhage].” Further, they noted that “future research should identify subgroups in which the net clinical benefit favors [oral anticoagulation] in these high bleeding-risk patients versus other potential treatment modalities such as left atrial appendage occlusion.”

Disclosures: This study was supported by Boston Scientific. Please see the original reference for a full list of authors’ disclosures. 

Reference

Steinberg BA, Ballew NG, Greiner MA, et al. Ischemic and bleeding outcomes in patients with atrial fibrillation and contraindications to oral anticoagulation [published online October 2, 2019]. JACC Clin Electrophysiol. doi:10.1016/j.jacep.2019.07.011