Hypertrophic cardiomyopathy (HCM) is a frequent hereditary cardiac disease and a major cause of sudden cardiac death (SCD). Although very useful, ESC risk score's predictive value has been interrogated since it was retrospective and did not include MRI parameters and new echocardiographic markers.

To assess the additional value of new echocardiographic and MRI parameters in predicting SCD and outcome in patients with HCM.

Between 2007 and 2017, 307 patients with HCM were prospectively included and followed for 1.63 years. In addition to conventional prognostic factors, all patients underwent cardiac MRI evaluation of late gadolinium enhancement (LGE), and echocardiographic measurements of LV and LA volumes and strains, including left atrial peak longitudinal strain (PALS) and left atrial peak contraction strain (PACS). Primary end-point was SCD or appropriate defibrillator therapy. Secondary end-point was a composite end-point including death, hospitalization for heart failure, new-onset of atrial fibrillation, need for septal ablation, myomectomy, or heart transplantation.

Among the 307 patients, 6 patients (2%) died and the secondary end-point occurred in 65 (21%). Factors associated with SCD by univariate analysis were low LVEF [HR 0.91 (0.93–0.99)] impaired PALS [HR 0.86 (0.72–0.97)], and moderate mitral regurgitation (MR). Factors associated with the secondary end-point were impaired LV GLS [HR 1.23 (1.13; 1.35)], impaired LA 4-chamber PALS [HR 0.94 (0.91; 0.97)] and PACS [HR 0.91 (0.86; 95)], LA 2 chamber PALS [HR 0.93 (0.89; 0.96)] and PACS [HR 0.86 (0.83;0. 94)], as well as TTE and MRI MR, and presence of MRI LGE. Impaired LA 4-chamber PALS remained as an independent predictor for the composite end-point [HR 0.92 (0.87; 0.97)] after adjustment.

This study suggests an additive prognostic value of an impaired LV and LA TTE strain, the presence of MR, and MRI LGE, to the classical ESC 7 recommended risk factors.