Budts, Werner

Background: Fontan circulation is characterized by the absence of a subpulmonary ventricle with resultant systemic venous hypertension. Despite exercise intolerance being nearly universal in this population, the determinants of exercise capacity in this population are still poorly understood. Research Question: We investigated the prevalence of peripheral impairment and assessed the contribution of peripheral O 2 extraction versus central hemodynamics to peak O 2 consumption (pVO 2 ) post-Fontan palliation. Methods: This single-center retrospective cross-sectional study compared 52 consecutive adults post-Fontan procedure who underwent exercise catheterization to patients with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnea (NCD) at 1:1 ratio. Several previously reported measures for peripheral O 2 extraction were evaluated in the absence of a golden standard. Correlates of pVO 2 were identified by multivariate linear regression analyses using the backward selection method. Results: Patients with Fontan circulation were younger [age 32 (24;36) years] and tended to have a lower body mass index [26 (23; 29) kg/m 2 ] compared to patients with HFpEF [70 (57; 75) years, p<0.001 and 33 (27; 39) kg/m 2 , p<0.001] and NCD [48 (38; 61) years, p<0.001 and 27 (24; 35) kg/m 2 , p=0.08]. Peak heart rate [108 (85;126) vs 108 (95;125) bpm] and indexed stroke volume [46 (39;54) vs 45 (40;53) ml/m 2 ] were similar in the Fontan and HFpEF groups but lower compared to NCD [126 (108;141) bpm, p<0.001 and 51 (45;59) ml/m 2 , p<0.001]. Peak mean pulmonary artery pressures were highest in HFpEF [45 (41;50) mmHg, p<0.001], followed by Fontan and NCD [26 (22;31) vs 23 (19;25) mmHg, p=0.03]. Median peak O 2 extraction post-Fontan was comparable to HFpEF [12 (10;14) vs 11 (10;13) ml/dl, p=0.17] but higher than in NCD [10 (9;12) ml/dl, p<0.001]. It was <14 ml/dl in 73% compared to 94% and 98% of patients with HFpEF and NCD [p<0.001]. O 2 extraction ratio was <70% in 62% compared to 60% in HFpEF and 96% in NCD [p<0.001]. Correlates of pVO 2 post-Fontan were peak O 2 extraction [β 0.5±0.1 per ml/dl; p<0.001], mean pulmonary artery pressures [β -0.2±0.05 per mmHg; p=0.002], heart rate [β 0.03±0.01 per bpm; p=0.01], and systolic arterial blood pressure [β 0.03±0.01 per mmHg; p=0.02]. Conclusion: Impaired O 2 extraction is prevalent amongst adults post-Fontan. Whether exercise can modulate this important determinant of exercise capacity post-Fontan merits further investigation.

Background In Fontan patients with atrial arrhythmias (AA), non-vitamin K antagonist oral anticoagulants(NOACs) have a class III recommendation according to the Pediatric & Congenital Electrophysiology Society (PACES)/Heart Rhythm Society (HRS) guideline in 2014, due to lack of data on outcomes as opposed to evidence of harm. To address this gap in data, we investigated the safety and efficacy of NOACs in adults with a Fontan circulation in a worldwide study. Methods This is an international multicentre prospective cohort study, using data from the NOTE ( n on-vitamin K antagonist o ral anticoagulants for t hrombo e mbolic prevention in patients with congenital heart disease) registry. The study population comprised consecutive adults with a Fontan circulation using NOACs. Follow-up took place at 6 months and yearly thereafter. The primary endpoints were thromboembolism and major bleeding. Secondary endpoint was minor bleeding. Results From April 2014 onward, 74 patients (mean age 32±10 years (range 18–68), 54% male) with a Fontan circulation using NOACs were included. During a median follow-up of 1.2 (IQR 0.8–2.0) years, three thromboembolic events (2.9 per 100 patient-years (95% CI 0.7 to 7.6)) and three major bleedings (2.9 per 100 patient-years (95% CI 0.7 to 7.6)) occurred in five atriopulmonary Fontan and one total cavopulmonary connection Fontan patients with AA. Fifteen patients experienced minor bleeding episodes (15.8 per 100 patient-years (95% CI 9.1 to 25.2)). In patients (n=37) using vitamin K antagonists (VKAs) prior to the initiation of NOAC, annual incidence of historical thromboembolic events and major bleeding were 2.4% (95% CI 0.4% to 7.4%) (n = 2) and 1.2% (95% CI 0.7% to 5.1%) (n = 1), respectively. Conclusions In this review of the largest Fontan cohort using NOACs with prospective follow-up, NOACs appear to be well tolerated and their efficacy and safety during short-term follow-up seem comparable to VKAs. Longer term data are required to confirm these promising short-term results.

Abstract A unique and highly versatile technique, stress echocardiography (SE) is increasingly recognized for its utility in the evaluation of non-ischaemic heart disease. SE allows for simultaneous assessment of myocardial function and haemodynamics under physiological or pharmacological conditions. Due to its diagnostic and prognostic value, SE has become widely implemented to assess various conditions other than ischaemic heart disease. It has thus become essential to establish guidance for its applications and performance in the area of non-ischaemic heart disease. This paper summarizes these recommendations.