Statins associated with lower risk of stroke in patients with atrial fibrillation

Statin therapy appears to reduce the risk of stroke or transient ischemic attack in patients with atrial fibrillation, and longer use gives more protection.

The findings were presented on April 16, 2023 at EHRA 2023, the annual congress of the European Heart Rhythm Association (EHRA), a branch of the European Society of Cardiology (ESC).

“Our study indicates that taking statins for many years was even more protective against stroke than short-term use,” said study author Ms. Jiayi Huang, a PhD student at the University of Hong Kong, China.

As background, the investigator’s noted that atrial fibrillation is the most common type of heart rhythm disorder, and patients with atrial fibrillation have five-fold increased risk of stroke compared with the general population.

Anticoagulant medication is commonly prescribed for stroke prevention in patients. The benefit of statin therapy for stroke prevention in patients with atrial fibrillation has not yet been determined.

To evaluate the association between statin therapy and the incidence of stroke and transient ischaemic attack in patients with atrial fibrillation, the investigators used the Hong Kong Clinical Data Analysis and Reporting System to identify all patients with a new diagnosis of atrial fibrillation between 2010 and 2018.

They divided the subjects into statin users and non-users. Users had received statin therapy for a minimum of 90 consecutive days in the year after being diagnosed with atrial fibrillation.

The primary outcomes were ischaemic stroke, systemic embolism, haemorrhagic stroke and transient ischaemic attack.

The researchers enrolled 51,472 subjects, all with a new diagnosis of atrial fibrillation. They tracked the subjects until the occurrence of a primary outcome, death or the end of the study on October 31, 2022.

Of the 51,472 subjects, 11,866 were statin users and 39,606 were non-users.

The median follow up was five years.

Statin users achieved a significantly lower risk of all primary outcomes compared to non-users.

Statin use was associated with a 17% reduced risk of ischaemic stroke or systemic embolism, a 7% reduced risk of haemorrhagic stroke and a 15% reduced risk of transient ischaemic attack.Notably, subjects taking statins for six years or longer had a 43% lower risk of ischaemic stroke or systemic embolism, 44% reduced likelihood of haemorrhagic stroke and 42% reduced risk of transient ischaemic attack.

“These associations were consistent regardless of whether or not patients used anticoagulant medication and the type of anticoagulant,” the investigators noted.

Huang added, “These data support the use of statins to prevent stroke and transient ischaemic attack in patients with new-onset atrial fibrillation. The findings have important clinical implications particularly given that in atrial fibrillation patients, ischaemic strokes are often fatal or disabling, and have a high risk of recurrence.”