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Final Program


Program-At-A-Glance

Rapid Fire Session

Session: Rapid Fire Session 2: Multiparametric Mapping, Cardiomyopathy (Monitor 3)

Genotype phenotype correlation of non-ischemic dilated cardiomyopathy: Initial data from India

Thursday, February 5, 2026
4:20 PM - 4:27 PM  
Location: Galapagos / Aruba / Ilhabela (2nd Lower Level)
Background: Non-ischemic dilated cardiomyopathy (NIDCM) is genetically heterogeneous and associated with variable imaging phenotypes. Late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) is a marker of fibrosis and poor outcomes. Prior reports have shown genotype-specific LGE patterns, but Indian data are limited. We aimed to evaluate genotype - phenotype associations in an Indian NIDCM cohort using standardized LGE categorization.

Methods: We prospectively analyzed 40 consecutive NIDCM patients (mean age 37.6 ± 16 years, 70% male) undergoing CMR and genetic testing. LVEF and LGE characteristics were recorded. LGE was categorized as absent, midwall, subepicardial, or “others” (transmural, subendocardial, or RV insertion). Genetic results were grouped into genotype-positive and genotype-negative. Major ventricular arrhythmia (MVA: VT/VF, appropriate shocks, aborted arrest) events were noted.

Results: Of 40 patients, 32 (80%) were genotype-positive and 8 (20%) genotype-negative. TTN was the most frequent gene (22.5%) detected, followed by TNNI3 and LMNA (5% each). Median LVEF was 23.6%. LGE was present in 9/40 (22.5%): 5 classified as midmyocardial (all in septum) and 3 as subepicardial (out of which 2 were ring like-1 DSP and FLNC each). LGE was more frequent in genotype-positive patients (25% in TTN carriers vs 12.5% in genotype-negative). The dominant LGE pattern among TTN-positive was septal midmyocardial pattern. LGE was absent in PKP2, VIM and NPPA carriers. 16 (40%) had positive family history (in first degree relatives), with MYH7 and LMNA being common genetic variants in this group. MVA events were uncommon (5%) at median follow up of 1.2 years, but occurred only in LGE-positive patients.

Conclusion: This initial Indian NIDCM experience shows a high rate of genotype positivity, with TTN being most frequent. LGE prevalence was modest but clustered among genotype-positive patients and tracked with arrhythmic outcomes. These findings, although preliminary, underscore the prognostic role of genotype–phenotype integration to enable risk stratification models tailored to Indian patients.

Panel A (4 chamber cine image) shows features of dilated cardiomyopathy in a 21 year old male. LV was dilated. LGE image (Panel B) shows ring like LGE. Genetic testing revealed Filamin C mutation.