Prognostic role of novel variables in sudden cardiac death risk associated to hypertrophic cardiomyopathy.

INTRODUCTION

Models for estimating the risk of sudden cardiac death (SCD) in pediatric hypertrophic cardiomyopathy (HCM) used in our setting do not consider some parameters of routine clinical practice. The objective was to identify non-classical risk factors and evaluate their prognostic value.

PATIENTS AND METHODS

Retrospective observational study, including patients with isolated HCM 0-18 years old, evaluating clinical, genetic, and imaging variables. The risk of SCD or major arrhythmic cardiac events (MACEs) was estimated according to the three most widely used European models (HCM Risk-SCD, European Society of Cardiology [ESC] algorithm, and HCM Risk-Kids), analyzing their predictive capacity by adding genotyping and advanced cardiac imaging parameters.

RESULTS

The sample included 77 patients followed up for 5.25 years. Ten (13%) experienced a MACE. We found that MACE was significantly associated with myocardial deformation and positive genotype status, and associated, although not significantly, to late gadolinium enhancement (LGE) in cardiac MRI (P = .062). Events were more frequent (hazard ratio = 18.5; P = .006) and occurred earlier (P = .022) in association with variants in genes other than MYBPC3. The inclusion of "genotype other than MYBPC3" and "presence of LGE" improved the predictive capacity of the models for the high-risk (C-statistic 0.94 vs 0.84 with HCM Risk-SCD; 0.88 vs 0.74 with ESC algorithm; 0.90 vs 0.80 with HCM Risk-Kids) and intermediate-risk categories (C-statistic 0.88 vs 0.51 with HCM Risk-SCD; 0.85 vs 0.64 with ESC algorithm; 0.84 vs 0.51 with HCM Risk-Kids).

CONCLUSIONS

The predictive capacity of European risk models improves by incorporating the variables "genotype other than MYBPC3" and "presence of LGE", although larger studies are required to validate their prognostic value.