Clinical features of isolated ventricular noncompaction in adults long-term clinical course, echocardiographic properties, and predictors of left ventricular failure

Background: Isolated ventricular non-compaction (IVNC) is a rare disorder characterized by prominent trabecular meshwork and deep recesses. We retrospectively assessed the clinical characteristics and natural course of IVNC in adults diagnosed at our hospital. Methods and Results: Sixty-seven adult patients (44 male, mean age 41 +/- 18 years) with the diagnosis of IVNC were evaluated in this retrospective cohort. Its prevalence was found to be .14%. Forty-seven patients (70%) had class I/II functional capacity. Fifty-seven patients (85%) had electrocardiographic abnormalities, and the most common one was left ventricular (LV) hypertrophy (25%). LV systolic function was depressed in 44 patients (66%), with a median ejection fraction (EF) of 35% (range: 20%-48%) at diagnosis. Multiple regression analysis revealed that age at initial presentation, the total number of affected segments, and the ratio of non-compaction/compaction (NC/C) were the independent predictors of LV systolic dysfunction. Familial occurrence of IVNC was 33%. During a mean follow-up of 30 months (range: 9-50 months), major complications including ventricular tachycardia, heart failure requiring hospitalization, and cerebrovascular events were observed in 36%, 34%, and 9% of the patients, respectively. Ten patients (15%) with IVNC died in this study. LVEF at initial presentation and functional capacity at last visit were found to be independent predictors of mortality. Conclusion: This study suggests that IVNC is a form of cardiomyopathy with higher prevalence and relatively better prognosis than previously reported. Age at initial presentation, ratio of NC/C, and number of affected segments seem to be major determinants of LV systolic dysfunction, while initial LVEF and last functional capacity predict mortality in this cohort.