A perfect storm: Root cause analysis of supra-therapeutic anticoagulation with vitamin K antagonists during the COVID-19 pandemic

Study of INR results show significant increase in high INRs during COVID-19 pandemic, with majority occurring after introduction of lockdown, with 30/3214 (0.9%) INR samples >8.0 (n=30) vs. 6/4079 (0.1%; n=6) during same period in previous year (OR 6.3, 95% CI, 2.6–15.2; p<0.001)

SPS commentary:

The time in therapeutic range during this period was 69.6% compared with 73.7% in 2019; the reasons for this were likely multifactorial, however more than half of cases had COVID-19 (possible or confirmed) and/or antibiotic use.

The authors highlight the importance of careful individual risk assessment, given the high incidence of elevated INRs, frequent prescribing of co-medications and unforeseen consequences of a lockdown.

The MHRA has published guidance following these concerns and reminds healthcare professionals and patients that continued close INR monitoring is crucial during the COVID-19 pandemic.

Thrombosis Reasearch

Resource links:

MHRA Advice