Statin Therapy May be Protective Against Stroke in People with Atrial Fibrillation: New Study

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Risk of ischemic stroke or systemic embolism among people with atrial fibrillation (AF) was reduced by 17% among those who initiated treatment with a statin within 1 year of diagnosis, according to a recent study. Long-term use of statins was associated with a more than 40% reduction in risk, investigators reported.

The findings, based on a region-wide investigation of >50 000 patients with AF, were presented at EHRA, a scientific congress 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 Jiayi Huang, a PhD student at the University of Hong Kong, China, in an ESC news release.

People with AF are at a 5 times greater risk of stroke than those without the arrhythmia and while oral anticoagulation is recommended for people with AF, it does not completely eliminate the risk. The benefits of the lipid-lowering effects of the HMG-CoA reductase inhibitor class of medications, ie, reduced risk of myocardial infarction, are well known. However, whether statins might be effective for stroke prevention in AF patients has been unclear.

The researchers used the Hong Kong Clinical Data Analysis and Reporting System to identify all patients with a new diagnosis of AF between 2010 and 2018. Participants were divided into statin users and non-users. Users had received statins for at least 90 consecutive days during the year after an AF diagnosis.

People with AF are at a 5 times greater risk of stroke than those without the arrhythmia and while oral anticoagulation is recommended for people with AF, it does not completely eliminate the risk.

Investigators specified the primary outcomes as a combined endpoint of ischemic stroke or systemic embolism; hemorrhagic stroke; and transient ischemic attack. Study participants were followed until occurrence of the primary outcomes, death, or the end of the study on 31 October 2022.

The final cohort numbered 51 472 participants of which 11 866 were classified as statin users and 39 606 as non-users. The median age was 74.9 years and 47.7% were women.

During a median follow up of 5.1 years, statin use was associated with a significantly lower risk of all primary outcomes compared to no use. Specifically, statin users had a 17% reduced risk of ischemic stroke or systemic embolism (hazard ratio [HR] 0.83; 95% CI 0.78–0.89), a 7% reduced risk of hemorrhagic stroke (HR 0.93; 95% CI 0.89–0.98) and a 15% reduced risk of transient ischemic attack (HR 0.85; 95% CI 0.80–0.90).

Long-term statin use, investigators found, was associated with greater protection than short-term use. When researchers compared those taking the medication for >3 months but <2 years with participants taking statins for ≥6 years, the latter had a:

• 43% lower risk of ischemic stroke or systemic embolism (HR 0.57; 95% CI 0.54–0.61)
• 44% reduced likelihood of hemorrhagic stroke (HR 0.56; 95% CI 0.53–0.60)
• 42% reduced risk of transient ischemic attack (HR 0.58; 95% CI 0.52–0.64)

These associations were consistent regardless of anticoagulation treatment and across types of anticoagulants, according to the study.

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

Reference: Huang J, Wu MZ, Ren QW, et al. Statin use improves the outcomes in patients with atrial fibrillation: a population-based study. Abstract presented at EHRA Congress 2023; April 16-18, 2023; Barcelona, Spain. Moderated ePoster Session 1.