Increased risk of arterial thromboembolic events in transfusion-naïve thalassemia: a nationwide population-based study

Transfusion-naive thalassemia minor/trait is often associated with decreased risk of coronary artery diseases. The present study aimed to evaluate the effect of transfusion-naive thalassemia on the incidence of arterial thromboembolic events using the National Health Insurance Research Database, Taiwan (2001–2010). Data from patients with transfusion-naive thalassemia (n=2356) frequency matched with non-thalassemia subjects (n=9424) according to sex, age, and index year at a ratio of 1:4 were included. The risk of arterial thromboembolic events, cerebrovascular ischemic events, arterial embolism/thrombosis, peripheral embolism, myocardial infarction, myocardial ischemia, and angina pectoris in transfusion-naive thalassemia were analyzed using Cox proportional hazard regression models. The transfusion-naive thalassemia group had significantly higher risk of arterial thromboembolic events (aHR=1.28, 95% CI 1.07 to 1.52) and myocardial ischemia (aHR=1.41, 95% CI 1.13 to 1.76) as compared with the non-thalassemia group. In addition, they also had a significantly higher cumulative incidence of arterial thromboembolic event and myocardial ischemia. Interestingly, a higher risk of arterial thromboembolic events (aHR=1.58, 95% CI 1.22 to 2.04) and myocardial ischemia (aHR=1.73, 95% CI 1.25 to 2.41) was observed in men with thalassemia as compared with those without. Furthermore, patients with comorbidities had an increased risk of arterial thromboembolic events than did those without comorbidities. The effect of thalassemia on arterial thromboembolic events may be mainly attributed to the influence of thalassemia on myocardial ischemia, as no significant differences were observed in other outcomes evaluated in the present study. In conclusion, the present study confirms the increased risk of arterial thromboembolic events, mainly attributed to the dramatic increase in myocardial ischemia, inminor patients with transfusion-naive thalassemia.