Decreased risk of acute myocardial infarction in stroke patients receiving acupuncture treatment: A nationwide matched retrospective cohort study

Background: Whether acupuncture protects stroke patients from acute myocardial infarction (AMI) has not been studied previously. The purpose of this study was to investigate the risk of AMI among stroke patients receiving acupuncture treatment. Methods: Taiwan's National Health Insurance Research Database was used to conduct a retrospective cohort study of 23475 stroke patients aged 40-79 years receiving acupuncture treatment and 46950 propensity score-matched stroke patients not receiving acupuncture treatment who served as controls from 2000 to 2004. Both stroke cohorts were followed until the end of 2009 and were adjusted for immortal time to measure the incidence and adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) for new-onset AMI in multivariate Cox proportional hazard models. Results: Stroke patients who received acupuncture treatment (9.2 per 1000 person-years) exhibited a lower incidence of AMI compared with those who did not receive acupuncture treatment (10.8 per 1000 person-years), with an HR of 0.86 (95% CI, 0.80-0.93) after adjusting for age, sex, low income, coexisting medical conditions and medications. The relationship between acupuncture treatment and AMI risk was investigated in female stroke patients (HR, 0.85; 95% CI, 0.76-0.95), male stroke patients (HR, 0.87; 95% CI, 0.80-0.95), patients from 50 to 59 years of age (HR, 0.75; 95% CI, 0.63-0.90), patients from 60 to 69 years of age (HR, 0.85; 95% CI, 0.75-0.95), patients suffering from ischemic stroke (HR, 0.87; 95% CI, 0.79-0.95), and patients suffering from hemorrhagic stroke (HR, 0.62; 95% CI, 0.44-0.88). Conclusions: We raised the possibility that acupuncture may be effective in lowering the risk of AMI in stroke patients aged 50-69 in this study, which was limited by a lack of information regarding stroke severity and acupuncture points. Our results suggest that prospective randomized trials are needed to establish the efficacy of acupuncture in preventing AMI.