2.2 Rationale Presently used risk predictors in HCM for the clinical outcomes of SCD and HF are still insufficient and limit clinical trials and institution of novel therapies in this disease. This large scale, prospective clinical registry will systematically answer the important question whether, through addition of a combination of advanced CMR phenotyping, genetic and biomarker analysis, risk stratification in HCM could be substantially improved over presently used clinical risk predictors. Emerging novel blood, genetic, and CMR markers offer the paradigm-shifting promise of reliably identifying those at risk. In addition, this will be the largest genotyped population of HCM available to correlate with comprehensive CMR and biomarker evaluation. This will allow unique opportunities to evaluate genotype-phenotype correlations and compare specific genetic subsets in a manner that has not been possible in the past. This study will also establish a predictive model that can be used to assess risk given a patient's combination of risk factors. This will help to select patients for future clinical trials to prevent SCD and HF. In addition, it will identify surrogate endpoints to monitor treatment response in HCM. In this way, the evidence base will be established in HCM to enable clinical trial design to reduce morbidity and mortality in HCM in a cost-effective manner.