Coenzyme Q10 Deficiency and Elevated LEAK Mitochondrial Respiration as Potential Heart Failure Markers in Ebstein Anomaly

Congenital heart diseases (CHDs) are characterized by profound metabolic remodeling of mitochondrial pathways. However, data regarding mitochondrial respiration, oxidative phosphorylation (OXPHOS), and fatty acid oxidation (FAO) in patients with Ebstein anomaly (EA) are currently unavailable. This study evaluated 14 EA patients and 18 healthy volunteers. In accordance with the 2020 ESC guidelines, patients were stratified into two cohorts: EA-0 (patients currently without an indication for intervention) and EA-1 (patients meeting Class Ia or IIb indications for surgical intervention). Platelet OXPHOS and FAO parameters were determined simultaneously via high-resolution respirometry. CI-linked LEAK respiration (substrates: pyruvate and malate) and FAO-linked LEAK respiration (substrates: octanoylcarnitine and malate) were significantly elevated in EA patients. Furthemore, the EA-1 group showed significantly lower coenzyme Q10 (CoQ10) and γ-tocopherol levels than EA-0. Differences in the measured parameters between groups suggest a state of myocardial adaptation and transient metabolic reprogramming in EA-0 patients, whereas in EA-1 patients, a significant change in mitochondrial metabolism and bioenergetics was found. We hypothesize that increased platelet LEAK mitochondrial respiration and CoQ10 deficiency could be key signals of mitochondrial reprogramming and serve as potential biomarkers for right ventricular dysfunction. The analysis of platelet mitochondrial bioenergetics represents a novel area of translational mitochondrial cardiology, contributing to personalized diagnostics, risk stratification and optimal surgical timing in EA patients.