Survival Trends in Children With Tetralogy of Fallot in Sweden From 1970 to 2017

IMPORTANCE: Mortality in patients with tetralogy of Fallot (TOF) has decreased substantially since the start of surgical correction of this abnormality in the 1950s. However, nationwide data in Sweden comparing survival trends among pediatric patients with TOF with the general population are still limited. OBJECTIVE: To study survival trends in pediatric patients with TOF and compare them with matched controls. DESIGN, SETTING, AND PARTICIPANTS: A Swedish registry-based, nationwide, matched cohort study was conducted; data were collected from national health registers from January 1, 1970, to December 31, 2017. Patients with a registered diagnosis of TOF as well as controls without TOF matched by birth year and sex were included in the study. Follow-up data were collected from birth to age 18 years, death, or the end of follow-up (December 31, 2017), whichever occurred first. Data analysis was performed from September 10 to December 20, 2022. Survival trends among patients with TOF were compared with matched controls using Cox proportional hazards regression and Kaplan-Meier survival analyses. MAIN OUTCOMES AND MEASURES: All-cause mortality during childhood in patients with TOF and matched controls. RESULTS: The population included 1848 patients (1064 [57.6%] males; mean [SD] age, 12.4 [6.7] years) with TOF and 16 354 matched controls. The number of patients who underwent congenital cardiac surgery (henceforth, surgery group) was 1527 (897 [58.7%] males). In the whole TOF population from birth until age 18 years, 286 patients (15.5%) died during a mean (SD) follow-up time of 12.4 (6.7) years. In the surgery group, 154 of 1527 patients (10.1%) died during a follow-up time of 13.6 (5.7) years with a mortality risk of 21.9 (95% CI, 16.2-29.7) compared with matched controls. When stratified by birth period, a substantial decrease in the mortality risk was noted in the surgery group, from 40.6 (95% CI, 21.9-75.4) in those born in the 1970s to 11.1 (95% CI, 3.4-36.4) in those born in the 2010s. Survival increased from 68.5% to 96.0%. The risk of mortality for surgery decreased from 0.52 in the 1979s to 0.19 in the 2010s. CONCLUSIONS AND RELEVANCE: The findings of this study suggest there has been substantial improvement in survival in children with TOF who underwent surgery from 1970 to 2017. However, the mortality rate is still significantly higher in this group compared with matched controls. Predictors of good and poor outcomes in this group need to be further explored, with the modifiable ones evaluated for further outcome improvements.