Ventricular arrhythmic severity using Lown and Wolf classification is correlated with a low metabolic activity on hybrid PET/MR in patients with mitral valve prolapse

Background 18Flourodeoxyglucose positron emission tomography/ Magnetic Resonance (18F-FDGPET/MR) is a sensible marker for metabolic activity, which is altered in patients with mitral valve prolapse (MVP), its relationship with ventricular arrhythmias (VAs) is unknown. Purpose to perform a comprehensive assessment of cardiac metabolic activity in patients with MVP using hybrid 18F-FDGPET/MR and to evaluate its relationship with various VA classifications. Methods using the largest, prospective, unicentric cohort of 76 consecutive patients with MVP and hybrid 18F-FDGPET/MR; VA was categorized according to the Lown and Wolf classification, European Heart Rhythm Association (EHRA) consensus diagnostic and severity criteria. Results after univariable logistic regression, complex VAs (Lown and Wolf grade ≥3), exhibited an OR of 0.83 [0.71-0.97(p=0.021)] indicating a negative association with higher SUVmax, whereas both EHRA diagnostic and severity classifications failed to demonstrate a significant association (Table). The Lown and Wolf classification captures a wider spectrum of VA complexity that is overlooked by the other classifications, accounting for pleomorphic PVCs, which might represent early stages of MVP-related arrhythmic events, in which the Purkinje system plays a significant role in the setting of VT and VF(1); this could identify individuals at high risk of VAs in the future, potentially guiding the implementation of preventive measures. The protective OR of the SUVmax might indicate that a higher uptake is present in early stages of the disease, whereas lower SUVmax might reflect a more advanced phase. Conclusion our findings support the use of the Lown and Wolf classification over the EHRA consensus diagnostic and severity criteria in the setting of metabolic activity assessment by hybrid 18F-FDGPET/MR in patients with MVP. .