Comprehensive analysis of echocardiographic and clinical features in patients with hypertrophic cardiomyopathy
Background. Hypertrophic cardiomyopathy (HCM) is an autosomal dominant disease resulting from sarcomere protein gene mutations, exhibits increased left ventricular (LV) wall thickness, leading to LV outflow tract (LVOT) obstruction (LVOTO), diastolic dysfunction, ischemia, and mitral regurgitation. Obstructive HCM (OHCM) is confirmed by the presence of LV outflow tract obstruction in about twothirds of cases. Exercise stress echocardiography is essential for detecting latent findings and revealing hidden symptoms during activity. Aim. This study aimed to evaluate echocardiographic disparities in HCM patients with and without LVOTO using exercise stress echocardiography. Methods. We retrospectively analysed 36 HCM patients at the Hospital of Lithuanian University of Health Sciences, Kaunas Clinics, from 1 January 2020 to 1 January 2022. Exercise echocardiography was performed for all patients. Patients were categorized into two groups based on LVOTO presence. Data analysis employed SPSS Statistics with p values < 0.05 considered statistically significant. Results. Of 36 patients, 25 were male (69.4%), 11 were female (30.6%) (median age: 61 ± 16.2 years). OHCM was diagnosed in 41.67% (n = 15). LVOTO group (13 males, 2 females) and non-LVOTO group (12 males, 9 females) differed in Vmax and gradient in LVOT, with LVOTO group showing higher resting Vmax (2.26 ± 0.87 vs. 1.62 ± 0.84 m/s), exercise Vmax (3.57 ± 1.13 vs. 2.21 ± 0.90 m/s), also LVOT peak gradient at rest (22.73 ± 18.54 vs. 8.63 ± 4.22 mmHg) and exercise (55.64 ± 35.28 vs. 21.93 ± 25.49 mmHg) (p < 0.05). In both groups, exercise-induced right ventricle (RV) pressure does not differ significantly (LVOTO group 17.04 ± 14.98 vs. non-LVOTO 18.17 ± 10.55 mmHg). During exercise, the LVOTO group’s tricuspid regurgitation (TR) changed from 0 to I grade, and the non-LVOTO group’s TR from I to II (p < 0.05). Laboratory tests, BNP levels showed no statistically significant difference. Although BNP levels had a tendency to be higher in the LVOTO group (237.63 vs. 175.40 pg/mL). All LVOTO patients were treated with beta-adrenergic blockers, while in the non-LVOTO group only 71.4%. One of the LVOTO patients underwent septal myectomy, with a pre-intervention LVOT max gradient of 150 mmHg. Conclusion. Our study found higher rest and exercise-induced LVOT peak gradients in HCM patients with LVOTO. Additionally, BNP levels were higher in LVOTO patients.