Abstract 12506: Assessment of the Left Ventricular Trabeculation Phenotype Contributes to Risk Stratification in Hypertrophic Cardiomyopathy Patients

Aims: To investigate clinical values associated with the “left ventricular (LV) trabeculation phenotype” that did not meet the diagnostic criteria of LV noncompaction (LVNC) in hypertrophic cardiomyopathy (HCM). Hypothesis: The presence of left ventricular trabeculation phenotype was associated with a poor prognosis in HCM patients. Genetic factors contributed to this particular phenotype. Methods: A total of 940 HCM patients were recruited. The primary endpoint was cardiovascular death; the secondary endpoints were sudden cardiac death (SCD) and all-cause death. The LV trabeculation phenotype was assessed by cardiac magnetic resonance. Baseline and survival analyses regarding the LV trabeculation phenotype were conducted in general HCM patients and obstructive subset. A combination model was constructed by adding the LV trabeculation phenotype to the HCM risk-SCD model. The whole exome sequencing was used for genetic analysis. Results: The LV trabeculation phenotype was recognized in 34.5% HCM patients and was mostly observed at the apex and free wall. Patients with the LV trabeculation phenotype were younger, had a higher prevalence of family history of SCD and more frequent presence of late gadolinium enhancement. Cox proportional hazards regression analysis showed that the LV trabeculation phenotype increased the risk of cardiovascular death (P=0.031), SCD (P=0.008), and all-cause death (P=0.047) in obstructive HCM patients. Furthermore, the LV trabeculation phenotype-combined model improved risk stratification for SCD. The genetic analysis showed that DTNA variants were more frequently identified in patients with the LV trabeculation phenotype. Conclusions: The LV trabeculation phenotype contributes to risk stratification in obstructive HCM, thus this parameter should be assessed in obstructive HCM patients even if the degree of trabeculation does not fulfil the LVNC criteria. DTNA mutation underlies the cause of this phenotype.