engleski

Relation of ABO blood groups to coronary lesion complexity in patients with stable coronary artery disease

To the Editor, In the past decades, several studies have suggested the possibility of ABO blood groups antigens to participate in pathogenesis of coronary artery disease (CAD), especially acute myocardial infarction and sudden cardiac death (1-3). Association between ABO blood groups and stable CAD has been significantly less investigated. That is why we read the paper of Kaya et al. (4) published in The Anatolian Journal of Cardiology 2014 ; 14 : 55-60 with particular interest, as it is in an important segment associated with our research published several months ago (5).Contrary to the study by Kaya et al. (4) no association between ABO blood groups and the extent of coronary atherosclerosis in our study was observed. In our opinion, although very similar in the initial idea, our studies have different results, possibly the consequence of the different methodologies used in the atherosclerotic lesions assessment. Contrary to our study, in which the main indicator of CAD severity was the extent of coronary atherosclerosis assessed by modified Gensini scoring system (GS), in the study by Kaya et al. (4) the indicator of CAD severity was complexity of coronary lesions assessed by SYNTAX score (SS).The SS has been developed as a useful predictor for the outcome of patients undergoing multi-vessel percutaneous coronary intervention, and provides a possibility for choosing optimal revascularization strategies for patients with complex coronary artery disease. This scoring system includes only diameter stenosis ≥50% in vessels ≥1.5 mm long. This is the main difference between the SS and the GS. The GS includes all grades of the narrowing in all cardinal epicardial vessels, including diagonal and obtuse marginal branches, taking into consideration the lesion's position in the coronary arterial tree. For example, an SS patient with five 49% lesions on the proximal segments of all the main epicardial coronary arteries, middle segments of the left anterior descending and right coronary artery, has no complex coronary artery disease so he/she could be excluded from the mentioned study (4). At the same time, according to the GS, this patient would be recognized as the patient with significant atherosclerotic changes (GS=20) and would be included in the analysis.In that context, the 342 patients excluded from the study by Kaya et al. (4) despite SS=0, might have numerous significant atherosclerotic changes in their coronary arteries. In that case SS=0 only suggests these patients are not yet candidates for coronary interventions. Therefore, it would be very interesting to know if the distribution of the ABO blood groups in the group of SS=0 patients is equal to the distribution in SS=1-3 groups and how inclusion of that group in an analysis would influence the results of the presented study. If the O blood group really dominates in the non-CAD patients and patients with less complex CAD, we could expect significantly more patients with O blood group in this, relatively large group of excluded patients. However, despite the mentioned differences, our two studies can be observed together as a significant contribution in investigation of pathophysiological link between ABO blood groups antigens and stable CAD. Different results obtained and conclusion drawn by different methodologies used in assessment of coronary atherosclerotic changes should be tested in the future prospective studies.

Coronary artery disease ; Blood groups ; Atherogenesis

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