Hemodynamic Phenotype of the Failing Fontan in an Adult Population

Abstract

Fontan failure can occur even with normal systolic ventricular function and often in the context of significant liver disease. We hypothesized that Fontan failure is hemodynamically distinct from traditional heart failure and characterized by low systemic vascular resistance (SVR) index and preserved cardiac index. Twenty-seven symptomatic adult Fontan (SAF) patients who underwent catheterization from 2001 to 2011 constituted our study group. Fifty-four predominantly asymptomatic pediatric Fontan (PF) patients who underwent catheterization during the same period were randomly selected to perform a control:case cohort analysis. Clinical comparisons were made between the 2 groups. The adults were more symptomatic than the PF cohort (New York Heart Association classes I and II or III and IV: 48% or 52% [SAF] vs 94% or 6% [PF], respectively, p <0.01). SAF versus PF mean catheterization findings were central venous pressure 18 ± 6 versus 14 ± 3 mm Hg (p <0.01), SVR index 1,680 ± 368 versus 1,960 ± 550 dyn s/cm5/m2 (p = 0.02), and cardiac index 2.7 ± 0.8 versus 2.8 ± 0.7 L/min/m2 (p = 0.25). By imaging, the SAF cohort demonstrated a greater incidence of abnormal liver texture changes (96% vs 75%, p = 0.04) and nodularity (77% vs 42%, p = 0.02). In conclusion, adult patients with failing Fontan circulation had a lower SVR index and similar cardiac index compared with the pediatric cohort. Liver disease in the adults was more advanced. Our data suggest that Fontan failure is a distinct circulatory derangement with hemodynamic features similar to portal hypertension, albeit with limited ability to augment cardiac output.

Hemodynamics of Fontan Failure

“…19 In the current study, we did not observe any significant difference in the systemic vascular resistance between Groups 1 and 2. A possible explanation for the observed difference between our data and that of the Hebson et al study again may relate to a higher prevalence of liver disease in their cohort as well, which decreases systemic vascular resistance independent of cardiac status for the reasons outlined above.…”

“…In a different study, Hebson et al 19 reported that symptomatic Fontan patients had lower systemic vascular resistance in comparison to asymptomatic patients. 19 In the current study, we did not observe any significant difference in the systemic vascular resistance between Groups 1 and 2.…”

“…The invasive hemodynamic indices observed in our cohort were comparable to other previously published hemodynamic studies. 18, 19 …”

Ventricular function and cardiac reserve in contemporary Fontan patients

“…There is considerable concern over long-term deterioration of clinical state and ventricular performance in older Fontan patients [2,4,5]. Other remaining questions with regard to ventricular function in this population include the role of ventricular anatomy (left vs. right type ventricular dominance), the impact of more recent strategies towards staging and timing of the TCPC and the differences resulting from different surgical techniques available for this operation [6,7].…”

Adult Fontan failure — Distinct disease entity

“…Therefore, failure has been defined in pediatric literatures as the development of protein-losing enteropathy, hospitalization, ventricular failure, and exercise intolerance to name a few. While risk factors associated with pediatric Fontan failure may help to identify the poorly functioning Fontan circulation in children and adolescents, caution must be exercised when applying this model to the adult population with distinct hemodynamics and prevalent end-organ manifestations [4].…”