Stroke while on anticoagulant therapy predicts recurrence, bleeding risks

Patients who have had a stroke despite being on nonvitamin K antagonist oral anticoagulant therapy are likely to experience a recurrent ischaemic stroke episode and bleeding, according to data from the RENO-EXTEND Study.

Researchers estimated the rates of ischaemic and bleeding events and their risk factors in the follow-up of 1,240 consecutive patients with atrial fibrillation who suffered an acute cerebrovascular ischaemic event while on nonvitamin K antagonist oral anticoagulant treatment. The estimated rates were then compared between the patients in whom anticoagulant therapy was changed and those who continued the original treatment.

Over a mean follow-up of 15.0 months, 192 patients (15.5 percent) experienced 207 ischaemic or bleeding events, corresponding to an annual rate of 13.4 percent. Of the events, 111 were ischaemic strokes, 15 were systemic embolisms, 24 were intracranial bleedings, and 57 were major extracranial bleedings.

Predictors of recurrent ischaemic events (strokes and systemic embolisms) included CHA2DS2-VASc score after the index event (for each point increase: odds ratio [OR], 1.2, 95 percent confidence interval [CI], 1.0–1.3; p=0.05) and hypertension (OR, 2.3, 95 percent CI, 1.0–5.1; p=0.04).

Factors predictive of bleeding events (intracranial and major extracranial bleedings), on the other hand, were age (for each year increase: OR, 1.1, 95 percent CI, 1.0–1.2; p=0.002), history of major bleeding (OR, 6.9, 95 percent CI, 3.4–14.2; p=0.0001), and the concomitant administration of an antiplatelet agent (OR, 2.8, 95 percent CI, 1.4–5.5; p=0.003).

The odds of ischaemic and bleeding events were similar in patients who switched from and those who persisted with the original nonvitamin K antagonist oral anticoagulant treatment (OR, 1.2, 95 percent CI, 0.8–1.7).

More studies are needed to investigate the mechanisms of recurrent ischemic stroke and bleeding with the goal of improving secondary prevention.