The relationship between ABO blood group and cardiovascular disease: results from the Cardiorisk program.

BACKGROUND: The ABO blood group exerts a profound influence on hemostasis, and it has hence been associated with the development of thrombotic cardiovascular adverse events. In this study, we evaluated the relationship between the ABO blood group and the risk of cardiovascular disease assessed with the Cardiorisk score. METHODS: All blood donors aged between 35 and 65 years were enrolled in the Cardiorisk program, which included the assessment of 8 variables (sex, age, total cholesterol, high-density lipoprotein (HDL) cholesterol, plasma glucose, arterial blood pressure, anti-hypertensive therapy and smoking) which were used to generate a score. Individuals with a resulting score ≥20, considered at high cardiovascular risk, underwent additional instrumental tests (chest X-ray, stress electrocardiogram and Doppler ultrasound of supra-aortic trunks) and were closely clinically monitored. RESULTS: Between January 2005 and December 2015, 289 blood donors with Cardiorisk ≥20 were identified, 249 of whom were included in the study with at least 2 years of follow-up. Among these, 36 (14.5%) had instrumental abnormality tests and developed adverse cardiovascular events (10 acute coronary syndrome, 2 cerebral ischemia, 3 cardiac arrhythmia, 8 stenosis of supra-aortic trunks or iliac arteries) during a median follow-up of 5.3 years. In this group of 249 high risk individuals, a statistically significant association (P=0.02) was found between the non-O blood type and the risk of developing subclinical or clinical cardiovascular events (odds ratio, 3.3; 95% CI, 1.1-10.1; P=0.033). CONCLUSIONS: The results of this study underline the both key role of ABO blood group for the risk of developing arterial thrombotic events and the need for including such unmodifiable variable on the scores assessing the thrombotic risk.