Abstract 12359: Clinical Impact of Left Ventricular Trabeculae in Hypertrophic Cardiomyopathy: Insights From Cardiac Magnetic Resonance Analysis

Abstract

Introduction: Hypertrabeculation has been associated with adverse events in patients with left ventricular (LV) non-compaction. However, the clinical significance remains unclear in patients with other cardiomyopathies. Hypothesis: LV trabeculae analyzed by cardiac magnetic resonance (CMR) may have a pathophysiological significance and clinical impact in patients with HCM. Methods: 102 HCM patients receiving regular outpatient treatment underwent CMR. LV volume and mass were analyzed from short-axis cine images using a steady-state free precession sequence and LV fibrosis mass were obtained from late gadolinium enhancement imaging. Individual trabeculae and papillary muscles (TPM) and papillary muscles (PM) were manually planimetered separately on each end-diastolic frame in every slice. Trabeculae (T) was calculated by subtraction of PM from TPM. The data were compared with those of 22 normal control subjects (Cont). Results: In total HCM patients, LV mass index (compacted muscle excluding TPM) was 83.5 ± 23.6 g/m2. TPM mass index were greater in patients with HCM compared with Cont (21.7 ± 7.3 vs 12.4 ± 2.5 g/m2, p < 0.001), and T mass index were also greater (16.8 ± 6.6 vs 9.2 ± 2.2 g/m2, p <0.001). Greater TPM and T masses were associated with more substantial LV mass (r = 0.662 and 0.572, both p <0.001). By multivariate analysis, increased T mass index was independently associated with LV outflow-tract obstruction, increased LV end-diastolic volume index, and LV fibrosis mass index. Kaplan-Meier analysis showed that baseline TPM or T mass index was not associated with cardiovascular outcomes during 14.7 months follow-up. However, baseline T mass / LV mass ratio was significantly associated with the clinical outcomes (p = 0.0124). Conclusions: Alterations of LV trabeculae in HCM may be associated with LV hemodynamic stress and LV remodeling. Furthermore, trabeculae mass to LV compacted mass ratio may be a useful marker for the prognosis in patients with HCM.