INTERNATIONAL JOURNAL OF CARDIOVASCULAR IMAGING, cilt.40, sa.11, ss.2417-2428, 2024 (SCI-Expanded, Scopus)
This study aimed to identify the phenotypic features contributing to the development of left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM) and to evaluate the genotype-phenotype relationship. This cross-sectional study included 96 patients diagnosed with HCM (mean age: 56.9 +/- 13.5 years, 32.3% female). The patients were divided into hypertrophic nonobstructive cardiomyopathy (HNCM; n = 60) and hypertrophic obstructive cardiomyopathy (HOCM; n = 36) groups. All patients underwent CMR. Patients (n = 77) who had previously provided formal approval underwent a genetic examination that included 18 genes. The anterior mitral leaflet (AML) length/LVOT diameter ratio, posterior mitral leaflet (PML) length/LVOT diameter ratio, and anterolateral papillary muscle (AL-PM) mobility were associated with LVOTO, independent of the basal IVS thickness, abnormal chordal attachment, and bifid PM. An AML length/LVOT diameter ratio of >= 2.30, a PML length/LVOT diameter ratio of >= 1.83, and an AL-PM mobility of >= 57.7% were predictors of LVOTO, with good sensitivity and specificity. Positive variants (VUS, LP, and P) were detected in 37.7% (29 of 77) of the patients who underwent genetic testing. The LP/P variant was detected in 20.8% (16 of 77) of patients. Three groups (variant-negative, VUS, and LP/P groups) had significant differences in the LVOT diameter (median 14, 12, and 10 mm, respectively; p = 0.021), AML length (mean 25.3, 26.5, and 27.5 mm, respectively; p = 0.029), AML length/LVOT diameter ratio (median 1.74, 2.33, and 2.85, respectively; p = 0.006), PML length/LVOT diameter ratio (median 1.29, 1.82, and 2.10, respectively; p = 0.045), and abnormal chordal attachment (6.3%, not observed, and 31.3%, respectively; p = 0.009). The AML length/LVOT diameter ratio, PML length/LVOT diameter ratio, and AL-PM mobility were associated with LVOTO. In addition, genetic testing results may provide information regarding the phenotypic expression of patients with HCM.