Oral anticoagulant use increases bleeding risk in untreated respiratory tract infection cases; BMJ

Majority of oral anticoagulants are used to prevent or treat venous thromboembolism or stroke in persons who have atrial fibrillation. Warfarin and direct oral anticoagulants are the most commonly used oral anticoagulants.

In a new study conducted by Haroon Ahmed and team it has been found that Oral anticoagulant use increases bleeding risk in untreated respiratory tract infection cases.

The study revealed that with use of Oral anticoagulant during the first 14 days after an untreated respiratory tract infection, there is a twofold increase in the risk of bleeding. 

The findings of this study were published in the British Medical Journal.

The goal of this study was to determine the link between community-acquired respiratory tract infections (RTIs) and a variety of bleeding episodes without prompt antibiotic prescription.

As a self-controlled trial, general practices in England contributed data to the Clinical Practice Research Datalink GOLD. Between January 2010 and December 2019, 1208 adult warfarin or direct oral anticoagulant users with a general practice or hospital admission record of a bleeding event and a general practice record of a consultation for a community acquired respiratory tract infection for which immediate antibiotics were not prescribed were studied (that is, untreated). The main outcomes were the relative incidence of major bleeding and clinically relevant non-major bleeding in the 0-14 days following an untreated respiratory tract infection, as compared to time periods when participants were not exposed.

The key findings of this study were as follow:

1. A total of 58% (n=701) of the 1208 study participants were men, with a median age of 79 years at the time of the first bleed and a median follow-up period of 2.4 years.

2. 292 large bleeds occurred within unexposed time periods, and 41 occurred within the first 14 days after a respiratory tract infection consultation.

3. During unexposed time periods, 1003 clinically relevant non-major bleeding occurred, with 81 occurring during the first 14 days after a visit for a respiratory tract infection.

4. In the 0-14 days after an untreated respiratory tract infection, the relative incidence of major bleeding and clinically relevant non-major bleeding (2.32, 1.82 to 2.94) rose after adjusting for age, season, and calendar year.

5. The results were unaffected by sensitivity tests and did not differ by gender or type of oral anticoagulant.

In conclusion, this study could affect how patients and doctors manage oral anticoagulant use during an acute intercurrent illness, but more research is needed before any clinical recommendations can be made. However, greater research is needed to fully comprehend the possible hazards and how they might be addressed.

Reference:

Ahmed H, Whitaker H, Farewell D, Hippisley-Cox J, Noble S. Respiratory tract infection and risk of bleeding in oral anticoagulant users: self-controlled case series BMJ 2021; 375 :e068037 doi:10.1136/bmj-2021-068037