The CALF (Congenital Heart Disease in Adults Lower Extremity Systemic Venous Health in Fontan Patients) study

Objectives: The objective of this study was to document the prevalence of chronic venous insufficiency (CVI) and its associated factors in adults with Fontan physiology.

Background: As the population of adults with complex congenital heart disease and Fontan physiology increases, so does the occurrence of highly morbid and mortal outcomes, including heart failure and thromboembolism. The presence of abnormal peripheral hemodynamic conditions in this population and their potential contribution to adverse outcomes is not well known. The primary objective of this study was to document the prevalence of CVI in adults with Fontan physiology.

Methods: A total of 159 adults with Fontan physiology from 7 adult congenital heart centers were prospectively assessed for lower extremity CVI, with the assignment of clinical, etiological, anatomical, and pathophysiological classification grades, and compared with age-matched and sex-matched controls. Leg photographs were independently reassessed to confirm interobserver reliability.

Results: The prevalence of CVI was significantly greater in the Fontan population (60%; 95% confidence interval [CI]: 52% to 68%) compared with healthy controls (32%; 95% CI: 15% to 54%) (p = 0.008). Strikingly, the prevalence of severe CVI (clinical, etiological, anatomical, and pathophysiological grade > or = 4) was significantly higher in the Fontan group (22%; 95% CI: 16% to 29%) versus the healthy controls (0%; 95% CI: 0% to 14%) (p = 0.005). In a multivariate analysis, several factors were independently associated with severe CVI, including increased numbers of catheterizations with groin venous access, lower extremity itching, and deep venous thrombosis.

Conclusions: CVI is common in adult patients with congenital heart disease with Fontan physiology. The contribution of abnormal peripheral hemodynamic conditions to comorbidities, including thromboembolism and heart failure, and interventions to improve peripheral hemodynamic conditions require further exploration.