The planimetric Grothoff's criteria by cardiac magnetic resonance can improve the specificity of left ventricular non-compaction diagnosis in thalassemia intermedia.

We differentiated the left ventricle non-compaction (LVNC) from hypertrabeculated myocardium due to a negative remodeling in thalassemia intermedia (TI) patients applying linear and planimetric criteria and comparing the cardiovascular magnetic resonance (CMR) findings. CMR images were analyzed in 181 TI patients enrolled in the Myocardial Iron Overload in Thalassemia Network and 27 patients with proved LVNC diagnosis. The CMR diagnostic criteria applied in TI patients were: a modified linear CMR Petersen's criterion based on a more restrictive ratio of diastolic NC/C > 2.5 at segmental level and the combination of planimetric Grothoff's criteria (percentage of trabeculated LV myocardial mass LV-MM ≥ 25% of global LV mass and total LV-MMI NC ≥ 15 g/m2). Seventeen TI patients showed at least one positive NC/C segment. Compared to LVNC patients, these patients showed a lower frequency of segments with non-compaction areas (2.41 ± 1.33 vs 5.48 ± 2.26; P < 0.0001), significantly lower LV-MM NC percentage (10.99 ± 4.09 vs 28.20 ± 4.27%; P < 0.0001), LV-MMI (7.58 ± 4.86 vs 19.88 ± 5.02 g/m2; P < 0.0001) and extension of macroscopic fibrosis (0.44 ± 0.18 vs 4.65 ± 2.89; P = 0.004), and significantly higher LV ejection fraction (61.29 ± 5.17 vs 48.50 ± 17.55%; P = 0.016) and cardiac index (4.80 ± 1.49 vs 3.46 ± 1.11 l/min/m2; P = 0.002). No TI patient fulfilled the Grothoff's criteria. All TI patients with an NC/C ratio > 2.5 showed morphological and functional CMR parameters significantly different from the patients with a proved diagnosis of LVNC. Differentiation of LVNC from hypertrabeculated LV in β-TI patients due to a negative heart remodeling depends on the selected CMR criterion. We suggest using planimetric Grothoff's criteria to improve the specificity of LVNC diagnosis.