Louis-Olivier Roy, BSc: No financial relationships to disclose
Background: Variable rates of loss to follow-up (LTFU) in patients with congenital heart disease have been reported. However, our ability to assess their outcomes is often impaired as patients are no longer attending cardiac care. We leveraged the data from the TRIVIA study, a cohort of tetralogy of Fallot (TOF) study that linked clinical and administrative data over >30 years. This linkage enables assessment of outcomes of patients, even when they are LTFU.
METHODS AND RESULTS: This is a population-based cohort of all 904 tetralogy of Fallot (TOF) patients born in Québec between 1982 and 2015. Risk factors and outcomes were assessed by Cox proportional hazards models and marginal means/rates models. Patients LTFU were propensity score matched with patients not LTFU to account for variation in native anatomy and comorbidities. The multiple episodes of loss and return to cardiology follow-up were considered in the analysis.
The cumulative risk from being LTFU, defined as >3 years without any consultation in cardiology, increased steadily with age to reach 50.3% at 30 years. However, 349 of the 440 patients LTFU eventually returned to follow-up (79.3%). The proportions of patients actively followed were 86.5% at 10 years, 78.3% at 20 years, and 68.4% at 30 years. Factors that protected against LTFU include pulmonary atresia (HR 0.60; 95% CI 0.42-0.86), 22q11 deletion (HR 0.41; 95% CI 0.19-0.87), and primary repair with a surgical conduit (HR 0.27; 95% CI 0.15-0.48) or a transannular patch (HR 0.61; 95% CI 0.47-0.79). Compared to matched patients without LTFU, patients LTFU had lower rates of mortality (HR 0.43; 95% CI 0.23-0.81), cardiac interventions (HR 0.39; 95% CI 0.31-0.50), unplanned hospitalizations (HR 0.76; 95% CI 0.60-0.97) and hospitalizations for an arrhythmia (HR 0.42; 95% CI 0.28-0.62).
Conclusion: When considering return to follow-up, the proportion of TOF patients actively followed was higher than previously published. Protective factors for LTFU were associated with more complex conditions. This is likely due to the impression that follow-up is not needed for patients with milder course and fewer symptoms. Despite being LTFU, these patients had good overall outcomes. While a milder course of disease decreased the likelihood of having continued follow up, being LTFU has not translated into poorer outcomes. Risk stratified patient-centered follow-up guidelines may help target the populations most likely to benefit from close surveillance while decreasing the need for health services utilization in those who can be expected to have better outcomes.
