ABSTRACT
At rest, a good Fontan circulation can provide a normal cardiac output (CO). However, as a consequence of its unique hemodynamic nature, the limitations of the Fontan circuit are exposed during exercise. We aimed to provide a comprehensive assessment of the pathophysiology of exercise in adult Fontan patients (FPs) and identify factors limiting their functional capacity (FC). In a single-center study conducted in 37 FPs aged ≥16 years and 19 healthy-controls (HCs) who underwent CPET on a cycle ergometer in February and March 2022, the mean peakVO2 was 21 ± 5.4 mL/kg/min, which was 55% of the predicted value. Morphologically, the left single ventricle showed a higher peakVO2% predicted value (57.4 ± 14.4% vs. 43.4 ± 8.1%, p = 0.045). The factors associated with low peakVO2 values were an early flattened or descending O2 pulse at maximal exertion (52 ± 14% vs. 62 ± 12.5, p = 0.04 and 47.6 ± 9% vs. 60 ± 14, p = 0.018, respectively) and chronotropic insufficiency (53 ± 12% vs. 69.8 ± 20%, p = 0.008). The OUES was found to be a useful parameter to assess the FC in FPs in maximal and submaximal exercise testing. A strong positive correlation was observed between the %OUES and peakVO2%predicted (r = 0.726, p > 0.001). The lung function was impaired in the FPs, mostly with a mild restrictive pattern (56.8%). The FPs showed lower inspiratory muscle strength compared to the HCs but it was not statistically associated with either the peakVO2 or VE/VCO2 slope. Regular intense physical activity improves one's FC. Although FPs have inspiratory muscle weakness, its impact on their FC is unclear. The peakVO2% predicted grew progressively higher as the level of physical activity increased (low level 49.5 ± 14%, moderate level 55 ± 12%, intense level 69 ± 20%).
ABSTRACT
BACKGROUND: Mortality of pulmonary hypertension associated with congenital heart disease (PAH-CHD) in adults remains high. OBJECTIVES: To identify predictors of death and to assess the impact of treatment on outcome. METHODS: Retrospective, multicenter cohort study of 103 adults with PAH-CHD followed-up for 8.6 ± 4.6 years. Patients were grouped according to underlying shunt type into pre-tricuspid, post-tricuspid and complex. Survival rates were analyzed and predictors of death were investigated with Cox regression models. RESULTS: In the post-tricuspid and complex groups (38 and 37 patients, respectively), the most common clinical PAH-CHD subgroup was Eisenmenger syndrome (76.3% and 59.5%, respectively) whereas, in the pre-tricuspid group (28 patients), 46.5% of patients had small or corrected defects. Overall, 88 patients received vasodilators; 39% required combination-therapy. Overall survival at 10 years was 65%. Mortality was highest in the pre-tricuspid group, FC-III-IV and amongst patients receiving monotherapy (p < 0.050). On multivariate analysis, predictors of poor outcome were pericardial effusion (HR: 4,520 [1,470-13,890]; p = 0,008), oxygen saturation(HR: 0.940 [0,900 - 0,990]; p = 0,018) and genetic syndromes(HR: 3,280 [1,098-9,780]; p = 0,033). CONCLUSIONS: Patients in advanced stages at initiation of treatment were at high risk of death and strong consideration should be given for more aggressive therapy.
