Prognostic Role of Late Gadolinium Enhancement in Patients With Hypertrophic Cardiomyopathy and Low-to-Intermediate Sudden Cardiac Death Risk Score.

Sudden cardiac death (SCD) is the most life-threating complication of hypertrophic cardiomyopathy. Guidelines of the European Society of Cardiology (ESC) suggest the implantation of an implantable cardioverter defibrillator in primary prevention according to a 5-year risk SCD score ≥6%. The aim of the study is to evaluate the prognostic role of late gadolinium enhancement (LGE) in patients with a 5-year risk SCD score <6%. In this multicenter study, we performed cardiac magnetic resonance in 354 consecutive hypertrophic cardiomyopathy patients (257 males, range of age 54 ± 17) with a risk SCD score <6% (302 with <4% and 52 with ≥4 and <6% risk). Hard cardiac events, including SCD, resuscitated cardiac arrest, appropriate implantable cardioverter defibrillator interventions, sustained ventricular tachycardia, occurred in 22 patients. LGE was detected in a high proportion (92%) of patients with hard cardiac events (p = 0.002). At receiver-operating characteristic curve analysis, LGE extent ≥10% was the best threshold to predict major arrhythmic events (area under the curve: 0.74). Kaplan-Meier curves showed that patients with LGE ≥10% had a worse prognosis than those with lower extent (p < 0.0001). LGE extent was the best independent predictor of hard cardiac events (hazard ratio 1.05; 95% confidence interval [CI] 1.03 to 107; p < 0.0001). The estimates 5-year risk of hard cardiac event was 2.5% (95% CI 0.8 to 4.2) in patients with LGE extent <10% and 23.4% (95% CI 10.2 to 36.5) for those with LGE extent ≥10%. In conclusion, this study demonstrates as the extent of LGE ≥10% is able to recognize additional patients at increased risk for malignant arrhythmic episodes in a population with low-to-intermediate ESC SCD risk score.