Interobserver Agreement of the Echocardiographic Diagnosis of LV Hypertrabeculation/Noncompaction

The aim of the study was to assess interobserver agreement (IOA) between 3 observers from 2 laboratories.

IOA of left ventricular hypertrabeculation/noncompaction (LVHT) in adults has only been studied within single echocardiographic laboratories.

Echocardiographic recordings with and without LVHT were selected and anonymized. The "not-LVHT" cases were matched for age and systolic function. Each observer reviewed the recordings, blinded to the initial diagnosis and the other observers' results. Pre-defined criteria for LVHT were: 1) >3 prominent trabeculae at end-diastole, distinct from papillary muscles, false tendons, or aberrant bands; 2) a noncompacted part of a 2-layered myocardial structure formed by these trabeculations; 3) a ratio of >2:1 of noncompacted to compacted layer at end-systole; and 4) perfusion of the intertrabecular spaces from the ventricular cavity. IOA was estimated using the kappa measure of concordance.

Cine-loops of 100 patients (42 women, ages 16 to 92 years), 50 from each center, and 51 with LVHT as the initial diagnosis, were reviewed. The left ventricular end-diastolic diameter was 32 to 78 mm, and ejection fraction, 4% to 88%. The observers agreed about presence (n = 29) or absence (n = 36) of LVHT and disagreed in 35 cases. Agreement was higher among the 2 observers from the same laboratory (kappa 0.793 [95% confidence interval (CI): 0.672 to 0.915]) than from different laboratories (kappa 0.628 [95% CI: 0.472 to 0.784], kappa 0.669 [95% CI: 0.521 to 0.818]). The observers agreed with the initial report of LVHT-presence in 53% and of absence in 67%. By reviewing the discordant cases, consensus was achieved about LVHT presence (n = 8) or absence (n = 16); in 11 cases, the diagnosis remained questionable. Discordance was due to poor image quality, lack of views in different apical planes, aberrant bands and chordae tendineae, abnormally sized or inserting papillary muscles, and localized calcifications of the endocardium.

IOA was substantial for diagnosing LVHT. However, even the application of pre-defined criteria yielded disagreement in 35% of cases; and after mutual review, there were still 11% questionable cases.