RT Journal Article
SR Electronic
T1 Predictors of risk for sudden death in childhood hypertrophic cardiomyopathy: the importance of the ECG risk score
JF Open Heart
JO Open Heart
FD British Cardiovascular Society
SP e000658
DO 10.1136/openhrt-2017-000658
VO 4
IS 2
A1 Ingegerd Östman-Smith
A1 Gunnar Sjöberg
A1 Annika Rydberg
A1 Per Larsson
A1 Eva Fernlund
YR 2017
UL http://openheart.bmj.com/content/4/2/e000658.abstract
AB Objective To establish which risk factors are predictive for sudden death in hypertrophic cardiomyopathy (HCM) diagnosed in childhood.Methods A Swedish national cohort of patients with HCM diagnosed <19 years of age was collected between 1972 and 2014, consisting of 155 patients with available ECGs, with average follow-up of 10.9±(SD 9.0) years, out of whom 32 had suffered sudden death or cardiac arrest (SD/CA group). Previously proposed risk factors and clinical features, ECG and ultrasound measures were compared between SD/CA group and patients surviving >2 years (n=100), and features significantly more common in SD/CA group were further analysed with univariate and multivariate Cox hazard regression in the total cohort.Results Ranked according to relative risk (RR) the ECG risk score >5 points had an RR of 46.5 (95% CI 6.6 to 331), sensitivity of 97% (83% to 100%) and specificity of 80% (71% to 88%) (p<0.0001), and was the best ECG predictor, predicting a 5-year risk of SD/CA of 30.6%. The following are other features with importantly raised RR: Detroit wall thickness Z-score >4.5: 9.9 (3.1 to 31.2); septal thickness ≥190% of upper limit of normal for age (septum in % of 95th centile for age (SEPPER) ≥190%): 7.9 (3.2 to 19.4); ventricular tachycardia: 9.1 (3.6 to 22.8); ventricular ectopics on exercise testing: 7.4 (2.7 to 20.2); and left ventricular outflow gradient (left ventricular outflow tract obstruction (LVOTO)) >50 mm Hg: 6.6 (4.0 to 11.0). Family history was non-significant. Multivariate Cox hazard analysis gives the following as early predictors: limb-lead QRS amplitude sum (p=0.020), SEPPER ≥190% (p<0.001) and LVOTO at rest (p=0.054); and for late predictors: last ECG risk score (p=0.002) and last Detroit Z-score (p=0.001). Both early (p=0.028) and late (p=0.037) beta-blocker doses reduced risk in the models.Conclusions ECG phenotype as assessed by ECG risk score is important for risk of sudden death and should be considered for inclusion in risk stratification of paediatric patients with HCM.