Clinical significance of intermediate left ventricular trabeculations in cardiac magnetic resonance

Although the clinical importance of left ventricular noncompaction cardiomyopathy (LVNC) is known, few data exist that describe the prognosis associated with intermediate levels of LV trabeculations that do not meet criteria for LVNC.

Trabeculation/possible LVNC by CMR was retrospectively observed among 122 consecutive cases. We assessed the end-systolic noncompacted-to-compacted ratios (ESNCCR) along with deaths, embolic events, congestive heart failure (CHF) readmissions, ventricular arrhythmias, myocardial thickening (MT), and ejection fraction (EF). ESNCCRs were categorized as follows: <1, 1<1.5, 1.5<2, ≥2. General linear models were used to compare combined events (death, CHF readmission, embolism, ventricular arrhythmia) between categories of ESNCCR. There were 3 models used: model 1: unadjusted; model 2: adjusted for age, race, gender, body surface area, LV ejection fraction, and trabeculated segments; model 3: model 2+adjustment for myocardial thickening.

In model 1, those with an ESNCCR<1 had a lower association with composite clinical events than those with a ratio between 1.5<2 and those≥2 (P<0.002 and P<0.001, respectively). In model 2, the lower association continued, (P=0.009 and P<0.001, respectively), but in model 3, those with a ratio from 1.5-2 only had a trend towards a higher association with composite clinical events than those with a ratio<1 (P=-0.09). Those with a ratio≥2 continued to have a higher association (P=-0.001).

Patients with intermediate trabeculations not meeting criteria for LVNC had a higher association with composite clinical events, but it was mediated by decreased myocardial thickening in the associated compacted layer.