Clinico-imaging profile and correlations of global longitudinal strain abnormalities in Indian hypertrophic cardiomyopathy patients.

BACKGROUND

Hypertrophic cardiomyopathy (HCM) is a prevalent genetic cardiac disorder with variable clinical expression. While global data are available, phenotypic characterization of Indian HCM patients remains limited. Speckle-tracking echocardiography (STE)-derived global longitudinal strain (GLS) may serve as a surrogate marker of myocardial fibrosis in settings with limited access to cardiac magnetic resonance (CMR).

OBJECTIVES

To characterize the clinical and imaging features of Indian patients with HCM and evaluate the correlation of GLS with CMR-derived late gadolinium enhancement (LGE) and electrocardiographic abnormalities.

METHODS

This cross-sectional study enrolled 150 consecutive adult HCM patients at a tertiary care center in North India. All patients underwent detailed clinical evaluation, standard transthoracic echocardiography including STE-derived GLS, electrocardiography, and 24-h Holter monitoring. CMR was performed in 74 patients based on physician discretion. GLS was quantified using vendor-specific semi-automated software. LGE was quantified as a percentage of total left ventricular mass. Correlations were assessed using Spearman's coefficient (ρ).

RESULTS

The mean age of the cohort was 46.7 ± 13.5 years, with 80 % males. Asymmetric septal hypertrophy (76 %) and obstructive HCM (53 %) were the predominant phenotypes. GLS was reduced (<-20 %) in 89 % of patients (mean GLS: -12.1 % ± 4.1 %). CMR revealed LGE in 92 % of patients, with ≥15 % LGE in 40 %. Peak GLS showed a strong positive correlation with percent LGE (ρ = 0.739). GLS was significantly lower in patients with CMR-detected perfusion deficits (p = 0.04), but not significantly associated with non-sustained ventricular tachycardia (p = 0.18). Modest inverse correlations were noted between GLS and tissue doppler indices (medial e': -0.55; lateral e': -0.60).

CONCLUSION

Indian HCM patients exhibit a distinct clinical profile with high fibrosis burden. STE-derived GLS correlates strongly with myocardial fibrosis on CMR and may serve as a practical risk stratification tool in resource-limited settings. Further multicentric studies are needed to validate these findings.