We appreciate the interest of Dr Eleftherios Giozitzoglou in our work.1 In the first retrospective registry,2 in which more than 300,000 individuals had an ECG over a period of 11 years (29 % of total population), a separate analysis of asymptomatic subjects and sudden cardiac death was not addressed in the group of 310 subjects with ventricular pre-excitation. However, and interestingly, ventricular pre-excitation was associated with an increased morbidity related to increased risk of AF (HR 3.12, 95 % CI [2.07–4.70]) and heart failure (HF) (HR 2.11, 95 % CI [1.27–3.50]). The risk of AF persisted even after performing catheter ablation. The higher risk of HF was associated in particular with the anteroseptal localisation, with tachycardiomyopathy or dyssynchrony as the potential mechanism. Although there was no significant difference between subjects with and without pre-excitation in the entire population, total mortality was significantly higher in those ≥65 years of age (HR 1.85, 95 % CI [1.07–3.18]). The poorly tolerated supraventricular tachycardias among individuals with pre-excitation ≥60 years and the increased burden of AF could explain this finding. The anteroseptal localisation was associated with a borderline statistically significant higher risk of total mortality (HR 2.4, 95 % CI [0.96–4.77]) and the higher risk of HF with this localisation could be the reason for that.
The second multicentre retrospective observational study in a paediatric population (≤21 years of age),3 published subsequent to our review, showed a high incidence of life-threatening events (49 % of rapidly conducted pre-excited AF, 45 % of aborted sudden death and 6 % of sudden death) and in 40 % of these cases as a first manifestation of the disease. But, more importantly, 36 % of evaluated cases had a shortest pre-excited RR interval (SPERRI) >250, 37 % did not have concerning pathway characteristics and 25 % had neither concerning pathway characteristics nor inducible atrioventricular reciprocant tachycardia.
Consequently, and according to these data, catheter ablation could be considered as a better strategy than follow-up in all asymptomatic subjects to reduce the known risk of sudden cardiac death regardless of the anterograde conduction properties. Despite ventricular pre-excitation being a risk factor for HF, total mortality needs to be confirmed in future studies. Available data so far reinforce the role of catheter ablation in decreasing morbidity and mortality in this group of patients.