Abstract
Background There is little evidence on how the occurrence of a bleed in individuals on vitamin
K antagonists (VKAs) impacts the risk of subsequent bleeds, and thromboembolic and
ischemic events. Such information would help to inform treatment decisions following
bleeds.
Objective To estimate the impact of bleeding events on the risk of subsequent bleeds, venous
thromboembolism (VTE), stroke, and myocardial infarction (MI) among patients initiating
VKA treatment for new-onset nonvalvular atrial fibrillation (NVAF).
Methods We conducted an observational cohort study using a linked Clinical Practice Research
Datalink—Hospital Episode Statistics dataset. Among a cohort of individuals with NVAF,
the risk of clinically relevant bleeding, VTE, stroke, and MI was compared between
the period prior to the first bleed and the periods following each subsequent bleed.
The rate and cost of general practitioner (GP) consultations, prescriptions, and hospitalizations
were also compared across these periods.
Results The risk of clinically relevant bleeding events was observed to be elevated at least
twofold in all periods following the first bleeding event. The risk of VTE, stroke,
and MI was not found to differ according to the number of clinically relevant bleeding
events. The rate and cost of GP consultations, GP prescriptions, and hospitalizations
were increased in all periods relative to the period prior to the first bleed.
Conclusions The doubling in the risk of bleeding following the first bleed, taken alongside the
stable risk of MI, VTE, and stroke, suggests that the risk–benefit balance for VKA
treatment should be reconsidered following the first clinically relevant bleed.
Keywords
VKA - bleeding - atrial fibrillation - risk
