TOPLINE

Left ventricular (LV) hypertrabeculation occurred in approximately 30% of patients with dilated cardiomyopathy (DCM) but was not linked to increased risk for embolic events, advanced heart failure (HF), or arrhythmic events. Among patients in sinus rhythm with LV ejection fraction (LVEF) ≤ 40%, hypertrabeculation was not linked to embolic risk.

METHODOLOGY

• Researchers conducted a retrospective observational study of 1160 patients with nonischemic DCM from 22 European centers in Netherlands and Spain between 2003 and 2023.
• Participants underwent cardiac MRI (CMR) and genetic testing (86% of cohort), with hypertrabeculation assessed using fractal dimension (FD) analysis (apical maximum FD ≥ 1.30) and Petersen criteria (noncompacted/compacted ratio > 2.3).
• A total of 978 patients were unrelated index cases and 181 were relatives; median age at CMR was 55.5 years, 65.3% were men, and median LVEF was 36%.
• The primary outcome was embolic events (ischemic stroke, transient ischemic attack, or systemic embolism); median follow-up was 5.1 years.
• Secondary outcomes included the prevalence of hypertrabeculation across genetic subgroups and its association with advanced HF (ventricular assist device implantation, heart transplant, or advanced HF-related mortality) and major ventricular arrhythmias (sustained ventricular tachycardia, sudden cardiac death, or appropriate implantable cardioverter defibrillator interventions).

TAKEAWAY

• LV hypertrabeculation was identified in 30.5% of patients. Hypertrabeculation was not associated with an increased risk for embolism, whereas atrial fibrillation or atrial flutter (hazard ratio [HR], 3.26; P = .004) and lower LVEF (HR, 1.04 per 1% decrease; P = .005) were associated with embolic events in multivariable analysis.
• Among 496 patients in sinus rhythm without anticoagulation and with LVEF ≤ 40%, embolic events occurred in 2.8%, with hypertrabeculation showing no significant association with embolic events.
• Hypertrabeculation prevalence varied by genotype: 56.6% in patients with variants in motor sarcomeric genes, 37.7% in those with TTN variants, 32.8% in genotype-negative patients, 7.3% in those with variants in cytoskeletal/Z-disk genes, and 5% in those with variants in nuclear envelope genes.
• In multivariable analysis (adjusted for genotype, late gadolinium enhancement, New York Heart Association functional class, and LVEF), hypertrabeculation was not associated with arrhythmic events or advanced HF.

IN PRACTICE

"[The] findings suggests that the presence of hypertrabeculation should not prompt changes in therapeutic management in these patients beyond standard care for DCM. Accordingly, the low rates of embolic events observed do not support the use of anticoagulation in patients with LV hypertrabeculation with LVEF ≤40% who are in sinus rhythm in the absence of other indications," the authors of the study wrote.

SOURCE

The study was led by Nerea Mora-Ayestarán, MD, and Noemi Ramos-Lopez, MD, Hospital Universitario Puerta de Hierro, Instituto de Investigación Sanitaria Puerta de Hierro Majadahonda (IDIPHIM) in Madrid, Spain. It was published online on August 3 in Circulation.

LIMITATIONS

Low event rates constrained statistical power to detect modest differences. CMR referral was clinically driven across multiple sites over a prolonged period, potentially introducing referral bias. Participating centers specialized in inherited cardiac diseases may have enrolled patients with more advanced phenotypes, thereby limiting generalizability. The predominantly White cohort may not reflect outcomes in other racial and ethnic populations.

DISCLOSURES

The study was supported by grants from the Instituto de Salud Carlos III, the European Regional Development Fund, the European Social Fund, and the HORIZON European Innovation Council. The Centro Nacional de Investigaciones Cardiovasculares is a Severo Ochoa Center of Excellence and received support from various sources. One author reported support from the EU4H-Programme of the European Union. The authors reported no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.