Hypertrophic cardiomyopathy (HCM) is the most common cardiomyopathy, characterized by left ventricular (LV) hypertrophy and associated with an increased risk of sudden cardiac death (SCD). One of the key morphological predictors of SCD is myocardial fibrosis, which is visualized on cardiac magnetic resonance (CMR) imaging using late gadolinium enhancement (LGE). An LGE extent of ≥15 % of LV mass significantly increases the risk of ventricular arrhythmias and SCD. A potential parameter for predicting this is the maximum LV wall thickness, which may correlate with the extent of myocardial fibrosis. However, this association remains a subject of scientific investigation, and it is the main focus of this study.

Aim. To assess the relationship and degree of correlation between maximum LV wall thickness and the presence of extensive myocardial fibrosis (LGE ≥15 %) detected by multiparametric CMR in patients with HCM.

Materials and methods. Data from 207 patients with confirmed HCM who underwent multiparametric CMR at the National M. Amosov Institute of Cardiovascular Surgery affiliated to National Academy of Medical Sciences of Ukraine between January and December 2024 were analyzed. Radiologists performed LV myocardial segmentation and quantified fibrosis, reporting LGE as a percentage of total LV mass. Patients were divided into two groups according to the degree of fibrosis: Group I – patients without extensive fibrosis (LGE <15 %) and Group II – patients with extensive fibrosis (LGE ≥15 %).

Results. The study included 207 patients with a mean age of 48.4 ± 12.9 years and a mean maximum LV wall thickness of 24.3 ± 5.5 mm. Extensive LV myocardial fibrosis (LGE >15 %) was detected in 35 patients (16.9 %), whereas 172 patients (83.1 %) had absent, mild, or moderate fibrosis. Patients with extensive fibrosis (Group II) had significantly greater maximum wall thickness (29.8 ± 5.5 mm) compared to Group I (23.2 ± 4.8 mm, p < 0.001). ROC curve analysis identified an optimal cutoff value of maximum LV wall thickness of 26 mm to detect extensive fibrosis, with a sensitivity of 83 %, specificity of 69 %, and an AUC of 0.823.

Conclusions. This study demonstrates a statistically significant correlation between maximum LV wall thickness and the presence of extensive myocardial fibrosis (LGE ≥15 %) in patients with HCM. This finding could be useful for assessing SCD risk when CMR is unavailable.