Left ventricular global longitudinal strain and diagnostic yield of genetic testing in hypertrophic cardiomyopathy in a multicenter registry analysis.

In this multicenter study we investigated whether echocardiography-derived left ventricular global longitudinal strain (LV GLS), an indicator of myocardial fibrosis, independently predicts a positive genotype in hypertrophic cardiomyopathy (HCM). We performed a cross-sectional analysis including HCM patients with genetic testing results and echocardiographic data from two Austrian HCM registries. Echocardiographic parameters were measured in post-processing analysis by a blinded investigator. Among 125 patients with HCM, a positive genotype was present in 39%. Worse LV GLS was associated with a positive genotype in univariate analysis (Odds Ratio [OR] 95% CI 1.141, 1.018-1.279, p = 0.023). In multivariate regression analysis adjusted for genotype predictors (age at diagnosis < 45 years, arterial hypertension, positive family history of HCM, maximal to posterior wall thickness [MWTH: PWTH], reverse curve septal phenotype), the reverse curve septal phenotype remained as a single independent predictor of genotype-positive HCM (OR 6.948, 2.342-20.614, p < 0.001). Adding LV GLS to established Toronto and Mayo genotype prediction scores did not improve their performance. To conclude, worse LV GLS was not independently associated with genotype-positive HCM and did not improve the diagnostic yield of genetic testing in HCM in a multivariate model. Our study highlights the reverse curve septal phenotype as the strongest genotype predictor in HCM.