Association of ABO blood types with the risk of in-stent restenosis

Objectives: To investigate the prevalence of in-stent restenosis (ISR) in patients with various ABO blood types. Methods: Clinical information from 150 patients with a confirmed diagnosis of ISR and 150 patients with a diagnosis of patent coronary stents in the secondary angiography was collected. Comprehensive demographic and laboratory data, including ABO and Rhesus blood groups, as well as comorbid conditions and vessel and stent characteristics, were recorded for each patient. The association of ABO blood groups with the risk of ISR before and after controlling for coronary risk factors was determined. Categorical data were analyzed with the Chi-square test and numerical values were analyzed with t-tests. Binary logistic regression models were constructed to compare type A and non-A for the frequency of risk factors. Results: A total of 392 stents were implanted in 300 patients. Two hundred and fourteen stents (54.6%) were patent and 178 stents (45.4%) were stenosed. Blood group A was significantly more common in the ISR group (43.3% vs. 28.7%, p=0.03). However, the frequencies of other blood types, as well as Rh antigen, were similar between the two groups. Triglyceride and low-density lipoproteins were the only significantly different variables (221 198 mg/dL vs. 138 +/- 76 mg/dL, p<0.001 and 108 +/- 36 mg/dL vs. 96 +/- 73 mg/dL, p=0.04, in type-A vs. non-A, respectively). After matching for coronary risk factors, there was no difference between A blood type patients and their controls. Conclusion: ISR is significantly more prevalent in individuals with the type A blood group. However, this higher association is most likely due to higher atherogenic conditions in patients within this population.