The role of the electrocardiographic phenotype in risk stratification for sudden cardiac death in childhood hypertrophic cardiomyopathy

• Published in: European journal of preventive cardiology Vol. 29; no. 4; p. 645
• Main Authors: Norrish, Gabrielle, Topriceanu, Cristian, Qu, Chen, Field, Ella, Walsh, Helen, Ziółkowska, Lidia, Olivotto, Iacopo, Passantino, Silvia, Favilli, Silvia, Anastasakis, Aris, Vlagkouli, Vasiliki, Weintraub, Robert, King, Ingrid, Biagini, Elena, Ragni, Luca, Prendiville, Terrence, Duignan, Sophie, McLeod, Karen, Ilina, Maria, Fernández, Adrian, Bökenkamp, Regina, Baban, Anwar, Drago, Fabrizio, Kubuš, Peter, Daubeney, Piers E F, Chivers, Sian, Sarquella-Brugada, Georgia, Cesar, Sergi, Marrone, Chiara, Medrano, Constancio, Alvarez Garcia-Roves, Reyes, Uzun, Orhan, Gran, Ferran, Castro, Fernandez J, Gimeno, Juan R, Barriales-Villa, Roberto, Rueda, Fernando, Adwani, Satish, Searle, Jonathan, Bharucha, Tara, Siles, Ana, Usano, Ana, Rasmussen, Torsten B, Jones, Caroline B, Kubo, Toru, Mogensen, Jens, Reinhardt, Zdenka, Cervi, Elena, Elliott, Perry M, Omar, Rumana Z, Kaski, Juan P
• Format: Journal Article
• Language: English
• Published: England 30.03.2022
• Subjects: Cardiomyopathy, Hypertrophic - complications; Cardiomyopathy, Hypertrophic - diagnosis; Death, Sudden, Cardiac - epidemiology; Death, Sudden, Cardiac - etiology; Electrocardiography - methods; Humans; Phenotype; Retrospective Studies; Risk Assessment; Risk Factors; Children; Cardiomyopathy; Hypertrophic; Electrocardiogram; Sudden death
• DOI: 10.1093/eurjpc/zwab046

The 12-lead electrocardiogram (ECG) is routinely performed in children with hypertrophic cardiomyopathy (HCM). An ECG risk score has been suggested as a useful tool for risk stratification, but this has not been independently validated. This aim of this study was to describe the ECG phenotype of childhood HCM in a large, international, multi-centre cohort and investigate its role in risk prediction for arrhythmic events. Data from 356 childhood HCM patients with a mean age of 10.1 years (±4.5) were collected from a retrospective, multi-centre international cohort. Three hundred and forty-seven (97.5%) patients had ECG abnormalities at baseline, most commonly repolarization abnormalities (n = 277, 77.8%); left ventricular hypertrophy (n = 240, 67.7%); abnormal QRS axis (n = 126, 35.4%); or QT prolongation (n = 131, 36.8%). Over a median follow-up of 3.9 years (interquartile range 2.0-7.7), 25 (7%) had an arrhythmic event, with an overall annual event rate of 1.38 (95% CI 0.93-2.04). No ECG variables were associated with 5-year arrhythmic event on univariable or multivariable analysis. The ECG risk score threshold of >5 had modest discriminatory ability [C-index 0.60 (95% CI 0.484-0.715)], with corresponding negative and positive predictive values of 96.7% and 6.7. In a large, international, multi-centre cohort of childhood HCM, ECG abnormalities were common and varied. No ECG characteristic, either in isolation or combined in the previously described ECG risk score, was associated with 5-year sudden cardiac death risk. This suggests that the role of baseline ECG phenotype in improving risk stratification in childhood HCM is limited.