Impaired Pulmonary Function is an Additional Potential Mechanism for the Reduction of Functional Capacity in Clinically Stable Fontan Patients.

Central factors negatively affect the functional capacity of Fontan patients (FP), but "non-cardiac" factors, such as pulmonary function, may contribute to their exercise intolerance. We studied the pulmonary function in asymptomatic FP and its correlations with their functional capacity. Pulmonary function and cardiopulmonary exercise tests were performed in a prospective study of 27 FP and 27 healthy controls (HC). Cardiovascular magnetic resonance was used to evaluate the Fontan circulation. The mean age at tests, the mean age at surgery, and the median follow-up time of FP were 20(±6), 8(±3), and 11(8-17) years, respectively. Dominant ventricle ejection fraction was within normal range. The mean of peak VO2 expressed in absolute values (L/min), the relative values to body weight (mL/kg/min), and their predicted values were lower in FP compared with HC: 1.69 (±0.56) vs 2.81 (±0.77) L/min; 29.9 (±6.1) vs 41.5 (±9.3) mL/kg/min p < 0.001 and predicted VO2 Peak [71% (±14) vs 100% (±20) p < 0.001]. The absolute and predicted values of the forced vital capacity (FVC), forced expiratory volume in one second (FEV1), inspiratory capacity (IC), total lung capacity (TLC), diffusion capacity of carbon monoxide of the lung (DLCO), maximum inspiratory pressure (MIP), and sniff nasal inspiratory pressure (SNIP) were also significantly lower in the Fontan population compared to HC. An increased risk of restrictive ventilatory pattern was found in patients with postural deviations (OD:10.0, IC:1.02-97.5, p = 0.042). There was a strong correlation between pulmonary function and absolute peak VO2 [FVC (r = 0.86, p < 0.001); FEV1 (r = 0.83, p < 0.001); IC (r = 0.84, p < 0.001); TLC (r = 0.79, p < 0.001); and DLCO (r = 0.72, p < 0.001). The strength of the inspiratory muscles in absolute and predicted values was also reduced in FP [-79(±28) vs -109(±44) cmH2O (p = 0.004) and 67(±26) vs 89(±36) % (p = 0.016)]. Thus, we concluded that the pulmonary function was impaired in clinically stable Fontan patients and the static and dynamic lung volumes were significantly reduced compared with HC. We also demonstrated a strong correlation between absolute Peak VO2 with the FVC, FEV1, TLC, and DLCO measured by complete pulmonary test.

Lessons Learned From a Critical Analysis of the Fontan Operation Over Three Decades in a Single Institution.

BACKGROUND: The Fontan operation (FO) has evolved and many centers have demonstrated improved results relative to those from earlier eras. We report a single-institution experience over three decades, describing the outcomes and evaluating risk factors. METHODS: Successive patients undergoing primary FO were divided into era I (1984-1994), era II (1995-2004), and era III (2005-2014). Clinical and operative notes were reviewed for demographic, anatomic, and procedure details. End points included early and late mortality and a composite of death, heart transplantation (HTX), or Fontan takedown. RESULTS: A total of 420 patients underwent 18 atriopulmonary connections, 82 lateral tunnels (LT), and 320 extracardiac conduit (EC) Fontan procedures. Forty-six (11%) patients died; early and late mortality were 7.9% and 3.1%, respectively. Eight (1.9%) patients underwent HTX, 11 (2.6%) underwent Fontan conversion to EC, and 1 (0.2%) takedown of EC to bidirectional Glenn shunt. Prevalence of concomitant valve surgery ( P < .001) and pulmonary artery reconstruction ( P < .001) differed over the eras. Preoperative valve regurgitation was associated with likelihood of early mortality (odds ratio [OR] = 3.5, P = .002). Embolic events (OR = 1.9, P = .047), preoperative valve regurgitation (OR = 2.3, P = .029), diagnosis of unbalanced atrioventricular canal defect (OR = 1.14, P = .03), and concomitant valve replacement (OR = 6.9, P = .001) during the FO were associated with increased risk of the composite end point (death, HTX, or takedown). CONCLUSION: Technical modifications did not result in improved results across eras, due in part to more liberal indications for surgery in the recent years. Valve regurgitation, unbalanced atrioventricular canal, embolic events, or concomitant valve replacement were associated with FO failure.

Evidence of endothelial dysfunction in patients with functionally univentricular physiology before completion of the Fontan operation.

INTRODUCTION: Postoperative thrombosis after a cavopulmonary connection has been widely described. Abnormalities in coagulation seem to occur early in the course of patients with functionally univentricular physiology, and may precede surgery. Endothelial abnormalities due to chronic hypoxia, and hyperviscosity, may contribute to this scene. The purpose of our study was to investigate if patients with a superior cavopulmonary connection have altered levels of endothelial and coagulative markers in the plasma. METHODS: We compared findings in 10 patients, aged from 4 to 19 years, with 6 age-matched normal controls. We measured levels of von Willebrand factor antigen, thrombomodulin, tissue-type plasminogen activator, plasminogen activator inhibitor-1 and d-dimer in the plasma using enzyme-linked immunosorbent assay. RESULTS: We found increased levels of von Willebrand factor antigen (p = 0.01), tissue-type plasminogen activator (p = 0.01), and decreased levels of thrombomodulin (p = 0.008) in the patients when compared to controls, while levels of plasminogen activator inhibitor-1 were not different. Values of d-dimer were within the reference range. Levels of tissue-type plasminogen activator had a positive correlation with von Willebrand factor antigen (r = 0.66, p = 0.008). CONCLUSIONS: Altered levels of endothelial markers in the plasma, in the presence of normal levels of d-dimer, suggest that endothelial dysfunction may precede the occurrence of intravascular coagulation and thrombosis in patients with functionally univentricular physiology. These observations may have therapeutical implications.