Reduced risk of stroke in patients with cardiac arrhythmia receiving traditional Chinese medicine: A nationwide matched retrospective cohort study.

Objective: Patients with cardiac arrhythmia were more likely to develop stroke than general population. The therapeutic effect of traditional Chinese medicine (TCM) on the risk of stroke in patients with cardiac arrhythmia was unknown. The aim of this study is to investigate the risk of stroke in patients with cardiac arrhythmia receiving TCM.

Methods: From the one million cohort of the Taiwan's National Health Insurance Research Database, we identified cohort of cardiac arrhythmia included 2029 patients who received TCM treatment in 2000-2004. The matching methods with propensity score was used to select 2029 appropriate control cohort for comparison. Incident events of stroke were identified during the follow-up period at the end of 2010. Cox proportional hazard model was used to calculate adjusted hazard ratios and 95% confidence intervals of stroke associated with TCM treatment.

Results: During the follow-up period, patients with cardiac arrhythmia who underwent TCM treatment (11.4 per 1000 person-years) had a lower incidence of new-onset stroke than those without TCM treatment (17.7 per 1000 person-years), with an HR of 0.62 (95% CI=0.50-0.78). The association between TCM treatment and decreased new-onset stroke was both significant in women and men. The young patients aged 45-54 years who received TCM had the lowest risk of stroke (HR=0.48, 95% CI=0.27-0.87).

Conclusions: Receiving TCM treatment was associated with a lower risk of stroke in patients with cardiac arrhythmia. However, this study was limited by lack of information regarding lifestyles, biochemical profiles, the dose of herbal medicine, and acupuncture points used in treatments.