Left Ventricular Noncompaction: Anatomical Phenotype or Distinct Cardiomyopathy?

Area of Science:

• Cardiology
• Medical Imaging
• Pathology

Background:

• Left ventricular noncompaction (LVNC) shows significant overlap with other cardiomyopathies.
• Its high prevalence in the general population (up to 40%) challenges its classification as a distinct pathological entity.
• Questions arise whether LVNC is a pathological entity, a remodeling epiphenomenon, or an anatomical phenotype.

Purpose of the Study:

• To determine the prevalence and predictors of LVNC in a healthy population.
• To evaluate the diagnostic performance of four cardiac magnetic resonance imaging (CMR) criteria for LVNC.
• To investigate the specificity of current LVNC diagnostic criteria in an asymptomatic cohort.

Main Methods:

• 1,651 volunteers over 40 without cardiovascular disease (CVD) underwent CMR.
• Four diagnostic criteria for LVNC were applied, including noncompaction ratios and myocardial mass ratios.
• Participants meeting all four criteria were classified as having LVNC.

Main Results:

• Of 1,480 analyzed participants, 1.3% met all four diagnostic criteria for LVNC.
• 14.8% met at least one criterion, indicating low specificity of current diagnostic methods.
• The noncompacted to compacted myocardial mass ratio was the most specific criterion (4.4%).

Conclusions:

• A substantial proportion of asymptomatic individuals without CVD meet current CMR diagnostic criteria for LVNC.
• This suggests that current criteria have poor specificity for diagnosing LVNC.
• LVNC may represent an anatomical phenotype rather than a distinct cardiomyopathy.