Should Afib Patients with Sepsis Receive Anticoagulation?

Sepsis leads to approximately 1 million hospitalizations in the United States yearly, and atrial fibrillation (AF) is the most common arrhythmia to complicate its course. In fact, as many as 1 in 4 patients 65 years or older hospitalized with sepsis have concomitant AF.

Complicating this scenario, ischemic stroke risk among AF patients during sepsis is higher in both the nonseptic and septic AF populations. Despite this, little evidence exists to support using anticoagulation to prevent stroke in AF patients during sepsis.

Management decisions on this topic are complicated. Septic patients are susceptible to alterations in the coagulation cascade and acute organ dysfunction, both of which may increase bleeding and thrombosis risks. Because stroke during sepsis is a relatively rare but clinically important outcome (eg, 2%—3% of patients with newly diagnosed AF during sepsis), additional study to clarify the role of anticoagulation for AF patients with concomitant sepsis is clearly needed.

To this end, a recent study analyzed a dataset of patients 18 years or older hospitalized from July 1, 2010, to June 30, 2013. Those with sepsis on admission were selected through ICD-9-CM codes for sepsis (038.x) combined with receipt of an antibiotic, while AF was identified via ICD-9-CM code 427.31.

Those with AF were subclassified as having preexisting AF (eg, diagnosed prevalent AF present on admission) or newly diagnosed AF (eg, incident AF not present on admission). The researchers excluded patients with other potential indications for anticoagulation, including prosthetic heart valves, acute myocardial infarction, or venous thromboembolism (VTE).

Among 113,511 AF patients with sepsis, 38,582 were in the primary analysis cohort (18,976 men [49.2%] and 19,606 women [50.8%]; mean age 74.9 years), of whom 13,611 (35.3%) received an initial intravenous (IV) or subcutaneous anticoagulant, and 24,971 (64.7%) didn’t.

Because this was a nonrandomized cohort, there were significant differences at baseline between the groups (anticoagulation versus no anticoagulation). As such, the authors used propensity score matching to adjust for potential confounding.

In the propensity score—matched analysis, ischemic stroke rates didn’t differ significantly between groups, occurring in 174 of 13,505 patients (1.3%) who received anticoagulation and 185 of 13,505 (1.4%) who didn’t. On the other hand, there were more bleeding events among patients who received therapeutic anticoagulation (1163 of 13,505 [8.6%]) than those who didn’t (979 of 13,505 [7.2%]).

After adjusting for differences in measured patient characteristics, there was a large variation among hospitals concerning parenteral anticoagulation use for AF during sepsis. Younger patients with fewer risk factors for bleeding were more likely to receive parenteral anticoagulation. In multiple analyses adjusting for measured and unmeasured confounding, the results suggested that using therapeutic parenteral anticoagulation during hospitalization with sepsis and AF wasn’t associated with reduction in ischemic stroke and showed a potentially higher bleeding risk.

These results are limited by the study’s retrospective nature, alongside the inherent flaws of claims data analysis. The researchers were also unable to make comparisons between IV or subcutaneous anticoagulation regimens, anticoagulation type, or patients with supratherapeutic or subtherapeutic levels of anticoagulation.

Nevertheless, the results suggest the risks of anticoagulation outweigh the benefits in AF patients with concomitant sepsis. As such, it would be prudent for pharmacists to recommend against the routine use of therapeutic anticoagulation in these patients. However, prophylactic doses for VTE should still be used in all patients unless contraindicated.

Future study is warranted to determine optimal timing for restarting treatment with oral anticoagulants in patients with preexisting AF and clarify long-term anticoagulation strategies after hospitalization for patients with newly diagnosed AF during sepsis.

Reference

Walkey AJ, et al. Practice patterns and outcomes associated with use of anticoagulation among patients with atrial fibrillation during sepsis. 2016 Aug. JAMA Cardiol.