Sixteen adult patients with IVNC as defined by previously validated MRI criteria [ratio between end-diastolic thickness of non-compacted and compacted myocardium (NC/C ratio) > 2.3 in ¡Ý 1 LV segment] were enrolled. Short-axis cine images were employed for analysis. Applying a 16-segment LV model, regional systolic performance was assessed qualitatively (wall motion score, WMS; 1 = normal, 2 = mild hypokinesia, 3 = moderate-to-severe hypokinesia, and 4 = a/dyskinesia) as well as quantitatively [fractional wall thickening, FWT ( % ) = 100 ¡Á (end-diastolic wall thickness ? end-systolic wall thickness) / end-diastolic wall thickness)].
Mean LV ejection fraction was 43.8 ¡À 15.4 % (range, 17-68 % ). Regional disease severity, as expressed by the NC/C ratio, revealed a significant correlation with WMS (r = 0.26; p = 0.018) and FWT (r = ? 0.30; p = 0.006). The total number of non-compacted segments/patient (NoNC) as an index of disease extent was a significant independent correlate of LV ejection fraction by multivariate regression analysis (¦Â = ?5.24; p = 0.038) and an excellent predictor of global LV dysfunction (ROC analysis, AUC = 0.98; p < 0.0001).
In patients with IVNC, disease severity correlates with the degree of LV dysfunction at a regional level. The extent of myocardial non-compaction is an independent predictor of global LV dysfunction.