We read the article by Tizón-Marcos et al about the characteristics of trabeculated myocardium burden in young and apparently healthy adults. They investigated 100 healthy subjects without cardiovascular diseases and without electrocardiographic abnormalities by cardiac magnetic resonance imaging (CMRI) and found a considerable amount of trabeculations within the left ventricle. We have the following questions and concerns:
In the introduction, no studies are mentioned in which the sensitivity and specificity of CMRI in the detection of left ventricular hypertrabeculation/noncompaction (LVHT) has been assessed in comparison with pathoanatomic investigations of the heart as the gold standard. Thus, it seems unjustified to state that CMRI is the “gold standard imaging method.”
Unfortunately, up to now, no uniform echocardiographic or CMRI criteria for diagnosing LVHT have been adopted. Different echocardiographic criteria exist, as listed by the authors. For analysis of CMRI images, they applied the criteria of Jenni et al, Petersen et al, and Fazio et al. What was the reason not to apply the criteria of Chin et al or Stöllberger et al, and how many of the 100 adults met these other echocardiographic criteria?
How to explain that women more frequently than men had hypertrabeculation? A male preponderance is a frequent and unexplained finding in cohort studies of adult patients with LVHT. Pregnant women or those within 1 year of childbirth were excluded from the present study. Because it has been recently reported that LVHT may develop during pregnancy and remain after delivery, it would be interesting to know if the amount of trabeculations differed between previously pregnant and nonpregnant women.
Because LVHT is frequently associated with genetic and neuromuscular disorders, it should be mentioned how many of the 100 adults had elevated CK-levels, how many were investigated by a neurologist, and in how many was the family history positive for LVHT, a neuromuscular disorder, or a chromosomal defect.
There are indications from echocardiographic and CMRI studies that the prevalence of LVHT is higher in black Africans than in Caucasians and in physically active than in physically nonactive adults. Thus, mentioning the ethnicity and degree of physical activity of the included adults and if there were differences in the amount of trabeculations depending on these conditions are warranted.
LVHT is familial in at least one quarter of the cases. In how many of the 100 cases were other family members investigated and also presented with LVHT? LVHT is not a congenital abnormality in each case. How many of the included subjects had echocardiographies or CMRIs before the present study, and in how many of these cases was LVHT absent on previous investigations?
In conclusion, the clinical impact of this interesting study would be much stronger if more clinical details were provided and if the CMRI findings were compared with echocardiography because CMRI is expensive and not generally available, whereas echocardiography is nowadays commonly used. Application of echocardiography could be a contribution in distinguishing normal from abnormal cardiac findings and contribute to uniformly accepted criteria for LVHT.