Long-term statin use linked to cut stroke risk in atrial fibrillation patients

At the annual European Heart Rhythm Association Congress, new real-world data was presented by researchers from Hong Kong, demonstrating that the risk of strokes was lower in atrial fibrillation (AF) patients who had been using statins within a year of their diagnosis. While statin therapy is widely prescribed to lower blood cholesterol and reduce the likelihood of heart attack and stroke, the benefit of statins for stroke prevention in patients with AF has remained largely unclear. GlobalData believes these new findings supporting the use of statins for stroke prevention in AF patients could have important clinical implications, especially given that ischemic strokes are often fatal or disabling and have a high risk of recurrence in AF patients.

AF is the most common cardiac sustained arrhythmia, affecting approximately 2% of the population worldwide – a percentage that is projected to increase significantly. AF is characterised by the rapid and disorganised electrical activity of the atria resulting in accelerated and irregular ventricular activity, loss of atrial mechanical function, and increased risk of atrial clot formation. As a result, patients with the condition have a five times greater risk of stroke, coronary events, and mortality than their peers. While anticoagulant medication is recommended to prevent strokes in those with AF, it does not completely eliminate the risk, leaving room for the entry of more effective treatments for stroke prevention in these patients.

Until now, the benefit of statins for stroke prevention in patients with AF had been unclear. As such, researchers from the University of Hong Kong sought to investigate this further by evaluating the association between statin use and the incidence of stroke and transient ischemic attack in patients with AF. 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 and divided participants into two groups: statin users and non-users. Users had received statins for at least 90 consecutive days during the year after being diagnosed with AF.

The primary outcomes were the combined endpoint of ischemic stroke or systemic embolism; hemorrhagic stroke; and transient ischemic attack.

The results from the study demonstrated that statin users had a significantly lower risk of all primary outcomes compared to non-users during a median follow-up of five years. Statin use was associated with a 17% reduced risk of ischemic stroke or systemic embolism, a 7% reduced risk of haemorrhagic stroke, and a 15% reduced risk of transient ischemic attack. The researchers also found that long-term statin use was associated with greater protection than short-term use. Compared to those taking the medication for between three months and two years, patients using statins for six years or longer had a 43% lower risk of ischemic stroke or systemic embolism, 44% reduced likelihood of haemorrhagic stroke, and 42% reduced risk of transient ischemic attack. These associations were consistent regardless of whether or not patients used anticoagulant medication and the type of anticoagulant.

GlobalData predicts that the findings from this study could have important clinical implications especially given that in AF patients, ischemic strokes are often fatal or disabling, and have a high risk of recurrence.