THE ROLE OF CARDIAC MAGNETIC RESONANCE IN ASSESSING MYOCARDIAL SCARRING IN HYPERTROPHIC CARDIOMYOPATHY
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Abstract
Objectives: To describe the imaging characteristics of myocardial scarring in hypertrophic cardiomyopathy on cardiac magnetic resonance (CMR). Methods: This is a retrospective, cross-sectional descriptive study involving 50 patients with hypertrophic cardiomyopathy at the Medic Hòa Hảo Medical Center in Ho Chi Minh City, Vietnam, from February 2023 to March 2024. Results: The final study population consisted of 50 patients (36 males, mean age 54.4 ± 12.38 years), with a higher proportion of males (68% compared to 32% females). Maximum wall thickness was 28 mm, ranging from 16 to 26 mm. Late gadolinium enhancement (LGE) was observed in 45 patients (90%). Scarring was typically found in hypertrophied myocardial regions, with distribution as follows: midwall (71%), junctional with the right ventricle (20%), and a combination of both (9%). Scar patterns were: patchy (77,8%) or focal (22,2%). Most HCM patients exhibited mild fibrosis, with LGE involving less than 5% of left ventricular mass (62%), moderate fibrosis with LGE between 5-14.9% (20%), and severe fibrosis with LGE ≥ 15% (8%). The average LGE mass was 9.71 ± 14 (range 0–62). The average LGE extent as a percentage of left ventricular mass was 6.7% (range 0–34). The average Native T1 value was 1244.3 ± 85 ms (range 1110–1400). The average extracellular volume (ECV) was 38.7 ± 7.5% (range 31–67). The average ejection fraction (EF) was 65.3 ± 8.97%. Left ventricular end-diastolic volume (LVEDV) was 132.8 ± 27.8 mL, and left ventricular end-systolic volume (LVESV) was 46.4 ± 18.2 mL. The average left ventricular mass was 179.8 ± 42 g. The ROC curve indicated sensitivity values of Native T1 (97%), ECV (77%), and LGE (53%) and specificity values of Native T1 (75%), ECV (80%), and LGE (95%). A moderate positive correlation was found between LGE and the LV mass index (r = 0.723, p < 0.001), while a negative correlation was found between LGE and EF (r = -0.839, p < 0.001). Multivariate regression analysis identified that ECV had a strong positive impact on LGE, while EF had a negative impact on LGE. Conclusion: Cardiac magnetic resonance (CMR) is a valuable tool in assessing myocardial hypertrophy and fibrosis in patients with hypertrophic cardiomyopathy (HCM). Parameters such as Native T1, ECV, and LGE provide crucial information on the presence and extent of myocardial fibrosis, and they help predict risk factors associated with cardiac dysfunction. The findings of this study contribute to a better understanding of the pathogenesis of HCM and improve diagnostic and patient management strategies.
Article Details
Keywords
Late gadolinium enhancement, Hypertrophic cardiomyopathy, Cardiac magnetic resonance, Risk prediction, Extracellular volume, T1 mapping.
References
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