Abstract 5937: Clinical Spectrum and Course of Idiopathic Hypertrophic Cardiomyopathy in Children. A Multicentre Cohort Study of Italian Patients
Since limited information is available on long-term course of childhood idiopathic hypertrophic cardiomyopathy (IHCM), we investigated this question. We reviewed database records of childhood IHCM patients (n=181) observed in 4 major national referral centres. The table⇓ reports characteristics and survival by age at presentation. Diagnosis after symptoms was associated with poor long-term outcome (figure⇓). At Cox analysis, predictors of cardiac death/heart transplantation (CD/HT) were posterior wall z score [per U: HR 1.17; 95%CI 1.08–1.27], history of syncope [4.4; 1.3–14.2], symptomatic diagnosis [3.5; 1.4 – 8.3], NYHA III–IV [3.51; 1.1–10.9] and medical therapy [2.6; 1.1–6.3]. Predictors of sudden death (SD) were history of syncope [6.6; 1.6–26. 8], medical therapy [3.4; 1.1–10.7] and (negative association) LV end-diastolic z score [per U; 0.69; 0.54 – 0.87]. We confirm that event rates in childhood IHCM are much lower than was thought. Infants without severe heart failure can expect clinical stability during the early phases of childhood, when sudden death is not an appreciable risk. In childhood IHCM, risk factors for HCM-related death include symptomatic presentation, history of syncope, cavity reduction and severity of LV hypertrophy.