Statin use reduces risk of stroke in patients with atrial fibrillation

A region-wide study of more than 50,000 patients with atrial fibrillation found a reduced risk of stroke and transient ischemic attack in those who started statins within a year of diagnosis by compared to those who did not. The results are presented at EHRA 2023, the scientific congress of the European Society of Cardiology (ESC).

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“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, who holds a Ph.D. student at the University of Hong Kong, China.

Atrial fibrillation is the most common heart rhythm disorder, affecting more than 40 million people worldwide. Patients with the disease have a five times higher risk of stroke than their peers. Blood-thinning medications are recommended to prevent strokes in people with atrial fibrillation, but do not entirely eliminate the risk. Additionally, statin therapy is widely prescribed to lower blood cholesterol and reduce the risk of heart attack and stroke. However, the benefit of statins for the prevention of stroke in patients with atrial fibrillation is unclear.

This study assessed the association between statin use and the incidence of stroke and transient ischemic attacks in patients with atrial fibrillation. Researchers 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. Participants were divided into two groups: statin users and non-users. The users had received statins for at least 90 consecutive days during the year after being diagnosed with atrial fibrillation.

The primary endpoints were the combined endpoint of ischemic stroke or systemic embolism, hemorrhagic stroke, and transient ischemic attack. Patients were followed until the occurrence of the primary endpoints, death or the end of the study on October 31, 2022.

A total of 51,472 patients with a new diagnosis of atrial fibrillation were included, of whom 11,866 were classified as statin users and 39,606 were nonusers. The median age of participants was 75 years and 48% were female. Over a median follow-up of five years, statin users had a significantly lower risk of all primary outcomes compared to nonusers. For example, the use of statins was associated with a 17% reduction in the risk of ischemic stroke or systemic embolism (relative risk [HR] 0.83; 95% confidence interval [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).

The researchers also found that long-term use of statins was associated with greater protection than short-term use. Compared with those taking the drug between three months and two years, patients using statins for six years or more had a 43% lower risk of ischemic stroke or systemic embolism (HR 0.57; 95% CI 0.54-0.61), a 44% reduced chance of hemorrhagic stroke (HR 0.56; 95% CI 0.53-0.60), and a 42% reduced risk of transient ischemic attack ( HR 0.58, 95% CI 0.52-0.64). These associations were consistent whether or not patients used anticoagulants and type of anticoagulant.

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

Related articles of interest

• Pastori, Daniele, et al. “Statin use and mortality in atrial fibrillation: a systematic review and meta-analysis of 100,287 patients.” Pharmacological Research, vol. 165, March 2021, p. 105418, https://doi.org/10.1016/j.phrs.2021.105418. Accessed June 6, 2022, https://www.sciencedirect.com/science/article/pii/S1043661821000013
• Eun, Mi, et al. “Effects of statins in atrial fibrillation-related stroke: a systematic review and meta-analysis.” Frontiers in Neurology, vol. 11, 2020, https://doi.org/10.3389/fneur.2020.589684., https://www.frontiersin.org/articles/10.3389/fneur.2020.589684/full
• Gupta, Aakriti, et al. “Association between prior statin use and decreased mortality in hospitalized patients with COVID-19.” Nature Communication, flight. 12, no. 1, 26 February 2021, p. 1325, https://doi.org/10.1038/s41467-021-21553-1, https://www.nature.com/articles/s41467-021-21553-1