Prevalencia y asociación de la hipertrabeculación en el ventrículo izquierdomiocardiopatía no compactada: cuantificación y pronóstico

Abstract

Introduction: Since the inclusion of non-compaction cardiomyopathy as unclassifiable subtype by WHO in 1990, there is controversy about definition, threshold disease, technique and measurement criteria, prevalence and prognosis. Goals: Define the prevalence of hypertrabeculation and non-compaction cardiomyopathy in patients referred for performing MRI in our hospital. Assess the association with dilated or hypertrophic cardiomyopathy. Describe the evolution of LVEF in these patients prospectively. Validate a diagnostic tool for automatic quantification that expedites the measurement process. Define quantitative cutoffs to discriminate between healthy and affected. Methodology: Hypertrabeculation was defined as existence of trabeculae in ?2 segments and ?2 slices of the left ventricle. To define non-compaction cardiomyopathy were used Jenni and Petersen criteria, based on the linear relationship between the solid and trabecular wall. Hypertrabeculation and non-compaction cardiomyopathy patients, between 2003 and 2010, were counted. We classified patients according to the presence of dilated, hypertrophic cardiomyopathy (HC), both or neither. Reduction of LVEF between two echocardiographic studies was quantified and calculated the annual rate of change of LVEF (LVEF variation between two echocardiography studies and divided by years between studies). A tool for automatic quantification of trabeculae was developed. To validate the tool, healthy patients non-carriers (control group) and patients with LVNC and mutation carriers of various cardiomyopathies (HC, dilated, and arrhythmogenic dysplasia) in their families (affected group) were used. Quantification of trabeculae was expressed in trabecular and compacted mass and percentage of trabeculae respect to the total mass of the myocardium. A subjective test of qualification for the accuracy of the tool to discriminate trabecular and compacted wall was performed. Results: We found LV hypertrabeculation in 103 of a total of 764 patients (13.4%). The prevalence of non-compaction cardiomyopathy was 6% following Jenni criteria or 5% following Petersen criteria. We detected hypertrabeculation and non-compaction cardiomyopathy associated with hypertrophic cardiomyopathy (15% and 11%), dilated (21% and 27%) or both (12% and 10%). 51% of hearts with hypertrabeculation and 52% of non- compacted showed normal LV dimensions. LVEF in hypertrabeculation patients (50%) and uncompacted patients (46%) was somewhat lower than that of controls (53%) but difference was not significant. Hypertrabeculation was associated with an annual rate of decline in LVEF of 1% per year while non- compaction of 2% per year compared to patients without trabeculae. The automatic measurement of left ventricular wall was excellent agreement with the subjective observation. Using this tool, the percentage of the total mass trabeculation and trabecular indexed by body surface, with cutoffs of 27.4 % and 39.9 g / m2, obtained a sensitivity of 80 % and a specificity of 78% for the diagnosis of non compaction cardiomyopathy. Conclusions: Hypertrabeculation prevalence in our general population is 13.4 % and non -compaction cardiomyopathy 5-6%. The trabeculae are an independent predictor of the decline in LVEF at follow-up. The tool developed can identify patients with non-compaction cardiomyopathy, by the percentage of trabeculation and trabecular index layer.