Non-O-blood types associated with higher risk of high-grade atrioventricular block

INTRODUCTION: The non-O phenotype of the ABO genotype has been linked with an increased risk of cardiovascular disease. Atrioventricular (AV) block (AVB) is defined as retardation or cessation in the route of an electrical impulse passing from the atria to the ventricles because of an anatomical or functional disruption in the conduction system. We aimed to interpret the association between blood group status and high-grade atrioventricular block (HAVB). MATERIAL AND METHODS: This study was implemented as a retrospective review of the recorded data of patients diagnosed with high-grade AV block and a control group. The study population consisted of 640 patients with HAVB and 570 control subjects. RESULTS: Presence of non-O blood group (p < 0.001) was significantly more prevalent in HAVB patients than in the control subjects. Blood group type was the sole independent predictor of HAVB in multiple regression analysis (p < 0.001, OR = 1.35, 95% CI: 1.08–1.57). Also, third-degree AVB had a higher incidence in the non-O blood subgroup and also non-O blood group was a predictor of third-degree AVB (p < 0.001, OR = 1.39, 95% CI: 1.13–1.69). The incidence of HAVB did not distinguish between the two Rh (D) groups. Rh (D) status did not have an impact on HAVB. CONCLUSIONS: This is the first study that has evaluated the potential relationship between HAVB and ABO blood groups. The main finding of this report is that patients with non-O blood group types have a higher risk for development of HAVB compared with O blood group patients.