Race, gender and clinical presentation in apical hypertrophic cardiomyopathy

Funding Acknowledgements Type of funding sources: None. Background The apical variant of hypertrophic cardiomyopathy (ApHCM) has male predominance and is a relatively rare phenotype in Western population. Characteristics of female and black patients diagnosed with ApHCM are very limited in the existing literature. Purpose We aimed to investigate whether gender and race are associated with a different clinical presentation and CMR findings in apical HCM. Methods We retrospectively analysed 150 patients (113 males and 37 females) with a diagnosis of apical HCM who have been followed in our inherited cardiac conditions (ICC) clinic between 2010 and 2020. Only patients with a CMR study and apical hypertrophy defined as ≥ 13mm at the time of diagnosis were included. Demographics and clinical characteristics were obtained from electronic records. Volumetric CMR data were taken from confirmed reports while other parameters were measured by standard protocol. "Pure" ApHCM was defined as isolated apical hypertrophy and "mixed" with both apical and septal hypertrophy but with the apex thickest (1). Apical displacement of papillary muscles (PM) was defined when the base of PM originated from the apical one-third of the left ventricle (LV) in the apical 4- or 2-chamber views. Giant T-wave inversion was defined as T-wave inversion that is equal or greater than 10 mm (1 mV) in any electrocardiogram lead. Results Our study population included patients of White (55, 37%), Black (37, 25%), Asian (36, 24%) and Mixed/Others (22, 15%) ethnicity. Black patients were more likely to have a diagnosis of hypertension at presentation when compared to White (70% vs 40%, p = 0.01) and to Asian and Mixed/Other patients (70% vs 48%, p = 0.03). Similarly, they were more likely to have "mixed" ApHCM than White (49% vs 20%, p = 0.003) and Asian and Mixed/Other (49% vs 26%, p = 0.02) patients. Females were diagnosed at an older age (63 ± 12 vs 52 ± 14, p < 0.001) and were less likely to have deep T-wave inversion on their ECG at presentation (14% vs 32%, p = 0.03) compared to their male counterparts. Females in this cohort also had higher representation of black ethnicity and were more likely to have hypertension (68% vs 47%, p = 0.03). Apart from the expected gender related differences in volumes and LV mass, there were no differences in cardiomyopathy-specific parameters we investigated. Conclusions In our cohort, females with ApHCM presented at an older age and were less likely to have giant T-wave inversion on ECG. Black patients with ApHCM were more likely to have hypertension and the "mixed" type of the disease.