Myocardial fibrosis in isolated left ventricular non-compaction and its relation to disease severity

Aims The aim of the present study was to evaluate the prevalence and extent of myocardial fibrosis in patients with isolated left ventricular non-compaction (LVNC) and to determine its relation to clinical status and LV systolic function. Methods and results The cardiac magnetic resonance imaging (MRI) database of our institution was searched for all patients with a first diagnosis of isolated LVNC. The diagnosis of isolated LVNC was based on the presence of standard cardiac MRI and clinical criteria. For each patient, cine and contrast-enhanced cardiac MR images were analysed to evaluate LV systolic function and the prevalence and extent of late gadolinium enhancement (LGE), a surrogate of myocardial fibrosis. A total of 42 patients (mean age 46 +/- 20 years, 62% male) were identified. Late gadolinium enhancement was observed in 23 (55%) patients with isolated LVNC, occupying 4.8 +/- 6.7% of the LV mass. Both the presence and extent of LGE were significantly related to the number of abnormal clinical features (i.e. symptomatic status, resting electrocardiogram abnormalities, and 24 h Holter monitoring abnormalities; P < 0.001 and P = 0.001, respectively). Similarly, LGE was more prevalent and extensive in patients with LV ejection fraction (EF) <50% compared with patients with LVEF >= 50% (90 vs. 23%; P < 0.001 and 8.9 +/- 7.6 vs. 1.1 +/- 2.4%; P < 0.001, respectively). At multivariate analysis, both the presence and extent of LV LGE were independently related to LVEF (beta = -20.63; P < 0.001 and beta = -20.62; P < 0.001, respectively). Conclusion Myocardial fibrosis is related to clinical disease severity and LV systolic dysfunction in isolated LVNC.