Clinical Course and Predictors of Heart Failure in Asymptomatic Obstructive Hypertrophic Cardiomyopathy

Figures

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  Figure 1. Incidence and rate of heart failure progression in asymptomatic oHCM. Proportion of asymptomatic (NYHA class I) patients with oHCM who experienced heart failure progression. The bar on the right highlights patients who underwent myectomy or alcohol septal ablation to mitigate their symptoms. NYHA indicates New York Heart Association; and oHCM, obstructive hypertrophic cardiomyopathy.

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  Figure 2. Forest plots of multivariable regression analyses. HRs with corresponding 95% CIs are displayed. For continuous variables, HRs represent the relative risk per 1‐SD increase. The plot demonstrates that female sex, the history of atrial fibrillation, and lower RV SVI are associated with a higher risk of progression to symptomatic heart failure in initially asymptomatic patients (NYHA class I) with obstructive HCM. HCM indicates hypertrophic cardiomyopathy; HR, hazard ratio; LV, left ventricular; NYHA, New York Heart Association; RV, right ventricular; and SVI, stroke volume index. *P<0.05, **P<0.01.

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  Figure 3. Relationship between RV SVI and HF progression in patients with asymptomatic oHCM. A, Cubic spline models show an inverse, near‐linear relationship between RV SVI and log‐relative hazard for HF progression, with lower RV SVI corresponding to increased risk. Shaded areas indicate 95% CIs. B, Adjusted hazard ratio by quartiles of RV SVI. Asymptomatic patients with oHCM with RV SVI in the lowest 2 quartiles exhibit an up to 2.5 times higher risk of HF progression compared with the reference quartile with the highest RV SVI >49 mL/m2. Numbers above the bars indicate P values; P<0.05 was considered statistically significant. C, Estimated 5‐year risk of HF progression, stratified by quartiles of RV SVI ranging from 18% in the highest quartile to 39% in the lowest quartile. HF indicates heart failure; oHCM, obstructive hypertrophic cardiomyopathy; RV, right ventricular; and SVI, stroke volume index.

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  Figure 4. Optimal cutoff for risk stratification using RV SVI in patients with asymptomatic obstructive hypertrophic cardiomyopathy. Kaplan–Meier curves demonstrate that at an optimal cutoff of 38 mL/m2, as derived via Youden Index, a lower RV SVI (<38 mL/m2) is associated with a significantly higher risk of HF progression compared with a higher RV SVI (≥38 mL/m2). HF indicates heart failure; RV, right ventricular; and SVI, stroke volume index.

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  Figure 5. Potential mechanisms of adverse interventricular coupling in obstructive hypertrophic cardiomyopathy. In patients with LVOT obstruction, elevated LV pressures from increased afterload acutely raise left heart filling and pulmonary venous pressures, producing limiting symptoms. Over time, this drives pulmonary vascular remodeling and reduces transpulmonary gradients. These chronic changes increase RV stroke work while diminishing RV stroke volume, thereby impairing LV preload. The consequent reduction in preload further exacerbates LVOT obstruction, reinforcing a vicious cycle of adverse interventricular interaction. Created in BioRender. Schulz, A. (2026) https://BioRender.com/kw8lr7d. HCM indicates hypertrophic cardiomyopathy; LA, left atrial; LV, left ventricular; LVOT, LV outflow tract; and RV, right ventricular.