Table 1.

Characteristics of patients registered between June 2012 and July 2015 (n = 8421)^a

Characteristics	Percentage/Median (range)
Age (median and range in years)	9.8 (0.15–20.9)
Age group (%)
0–1 year	2.8
1–4 years	18.3
4–12 years	39.3
12–16 years	22.9
>16 years	16.7
Gender (%)
Female	44.7
Male	55.3
Status (%)
Alive and in follow-up	91
Alive at discharge or transferb	5.1
Died at or after birth	0.2
Unknown status or loss to follow-up	3.7

^aValues are percentages in case of categorical variables, or means (with standard deviation) in case of continuous variables

^bAlive at discharge from follow-up or at transfer to adult cardiologist or general paediatrician