Blood type B antigen is associated with worse New York Heart Association classification in male patients with hypertrophic cardiomyopathy

Objective: ABO blood type is associated with cardiovascular diseases. Several studies have suggested sex-related differences in both hypertrophic cardiomyopathy (HCM) clinical features and ABO blood type. However, few data are available regarding the relationship between ABO blood type and HCM clinical features. We aimed to analyze the relationship between ABO blood type and HCM clinical features, and the potential effects of sex on these relationship. Methods: A total of 549 patients with HCM were enrolled consecutively. Left ventricular outflow tract gradients at rest (LOVTG-R) were measured by echocardiography. Left ventricular end-diastolic dimension, interventricular septum, left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and left ventricular mass (LVM) were assessed using cardiovascular magnetic resonance imaging. Results: Compared with the non-B antigen group, patients with B antigen had significantly higher LOVTG-R and LVEF values, worse New York Heart Association (NYHA) classification, lower left ventricular volume index values, as well as no difference in LVM index values. After adjustments for sex, male patients with B antigen still had higher LOVTG-R values and frequency of NYHA classification III/IV as well as lower LVEDV and LVESV index values. These differences were not present in female patients. Additionally, patients with NYHA classification III/IV had lower LVEDV index values. Conclusion: In males, not females, patients with HCM with blood type B antigens exhibited worse cardiac functional capacity, higher LOVTG-R values, and lower left ventricular volume index values. These relationships are a potential indicator for clinical prevention. We speculate that rehydration is more efficient in relieving symptoms in male patients with HCM with B antigens. Keywords: