Left Ventricular Hypertrabeculation and Ventricular Arrhythmias

Background/Objectives: Excessive trabeculation of the left ventricle, previously known as left ventricular non-compaction (LVNC), is a rare phenotypic trait whose mechanisms and pathogenesis still remain conflictual. Its presentations may range from heart failure to embolism and, most importantly, ventricular arrhythmias (VAs). This study aims to find novel predictive factors for the occurrence of potentially fatal VAs in patients with left ventricular hypertrabeculation. Methods: All consecutive patients meeting the echocardiographic (Chin, Jenny or Stöllberger) and/or MRI criteria (Petersen) for hypertrabeculation were prospectively enrolled from October 2009 to December 2023. The primary outcome was a composite of sudden cardiac death, sustained ventricular tachycardias (sVTs), ventricular fibrillation (VF) or appropriate implantable cardioverter defibrillator (ICD) interventions. The secondary outcome was a composite of cardiovascular death and cardiovascular hospitalizations. Results: Overall, 64 patients (41 males, mean age 46 ± 19 years old) were enrolled and followed for a median time of 2.2 years. Six patients (9.4%) experienced a composite outcome at eight years, three with previous sVTs and three with previous non-sustained VTs (nsVTs). The strongest predictor of the primary endpoint was the anamnesis of nsVTs and sVTs before LVNC diagnosis. In addition, nsVTs and sVTs were significantly associated with the secondary outcome. Conclusions: Hypertrabeculation of the left ventricle is a complex and poorly understood condition whose status of cardiomyopathy is currently challenged. In our population, patients with a trabecular pattern experienced a high incidence of VAs, cardiovascular death and hospitalizations. VAs before LVNC diagnosis were predictive of the outcome independently from systolic function.