Hemodynamic Determinants of Mortality after Fontan Operation

Background Elevated central venous pressure (CVP), low cardiac output and mild hypoxia are common early and late after Fontan operation. However, the association of these characteristics with late mortality is unclear. We aimed to elucidate the hemodynamic determinants of mortality after Fontan operation. Method We evaluated early (group Early; 0.5 to 5 years postoperatively, n = 387) and late (group Late; ≥15 years postoperatively, n = 161) Fontan hemodynamics that included CVP (mmHg), cardiac index (CI; L/min/m2 ), systemic ventricular end-diastolic volume index (EDVI; ml/m2 ), ejection fraction (EF; %), and arterial blood oxygen saturation (SaO2 ; %). We examined the effect of these variables on 5-year all-cause mortality. Results Mortality was higher in group Late than in group Early (17 vs. 11, P < .0001). In both Groups, higher CVP (hazard ratio [HR]:1.46 and 1.38, respectively, P < .001–0.0001) and lower SaO2 (HR: 1.12, P < .001 for both) were associated with increased mortality. Greater EDVI (HR per 20: 1.73) and lower EF (HR per 10%: 3.38) were associated with increased mortality only in group Early ( P < .0001 for both). In contrast, only in group Late was higher CI associated with increased mortality (HR: 2.50, 95% confidence interval: [1.30–4.55], P < .01). Seven patients in group Late with both high CVP (≥14) and CI (≥3.0) had the highest mortality (HR: 18.1, [5.55–52.4], P < .0001). Conclusions Elevated CVP and low SaO2 correlate with mortality in both early and late Fontan survivors. EDVI and EF are associated with mortality only in the earlier cohort, whereas interestingly, elevated cardiac output is associated with increased mortality in the later cohort.