Impact of hospitalisation burden on mortality in adult congenital heart disease: A nationwide population study

BACKGROUND: As the hospitalisation rate for adults with congenital heart disease (ACHD) increases, information regarding the outcome of these hospitalisations is needed.

METHOD: This retrospective cohort study utilized the Danish National Patient Registry to identify ACHD patients who reached 18 years old ≥1st Jan 1995 and followed them to either death or 31st Dec 2018. Each patient was matched 1:10 to controls. Mortality was estimated as the mortality rate per 100 patient-years (/100PY) and the association of hospitalisation burden and mortality was examined.

RESULTS: 7830 ACHD patients were included (50.5 % female, 64.7 % mild ACHD, 28.1 % moderate ACHD and 7.2 % severe ACHD) and followed for a median of 8.6 years. When not having any hospitalisation in the past one year, the mortality rate for all ACHD patients was 0.04/100PY[95 % confidence interval: 0.02;0.05]. Having any hospitalisation in the past year increased the mortality rate by 5.2-fold to 0.55/100PY[0.42;0.72]. In mild ACHD, the mortality rate increased by 10.7-fold. In moderate ACHD, it increased by 4.8-fold, while in severe ACHD, no significant increase in mortality was observed. Compared to the matched controls, mild ACHD patients also had an increase in excess mortality from 0.8-fold when having no hospitalisation to 1.6-fold when having any hospitalisation in the past year. This increase in excess mortality was however not observed in moderate and severe ACHD.

CONCLUSION: Hospitalisation in the past year has a greater impact on mortality in mild ACHD patients than in other ACHD severities. This indicates a greater gap in the follow-up care needed by patients with mild ACHD.