Register of adult patients with noncompact left ventricular myocardium: classification of clinical forms and a prospective assessment of progression

Abstract

Aim. To study clinical forms of noncompact myocardium (NCM) in adults, the features of their manifestation, course and progression.Material and methods. The study included 116 adult patients with NCM of the left ventricle (LV) (67 men, mean age 46,3±15,1 years) and 42 patients with increased LV trabecularity (24 men, mean age 43,5±15,2 years). The mean LV end-diastolic diameter was 6,0±0,8 and 5,9±1,1 cm, LV ejection fraction was 38,6±14,0% and 44,6±18,3%, respectively. NCM was diagnosed using echocardiography, multispiral computed tomography (n=77) and magnetic resonance imaging (n=51), increased LV trabecularity was diagnosed according to echocardiography, multispiral computed tomography (n=11), multispiral computed tomography (n=24). DNA diagnostics was carried out according to the NGS method, followed by Sanger sequencing. The examination included the determination of anticardial antibodies, the genome of cardiotropic viruses by PCR, coronary angiography (n=29/2), scintigraphy (n=27/4). A morphological study of the myocardium was performed on 22/6 patients with NCM/increased LV trabecularity (14/6 endomyocardial biopsy, 1 intraoperative biopsy, 3 explanted heart studies, 6 autopsies).Results. Pathogenic mutations were found in 12 (10,3%) patients (MYH7, MyBPC3, LAMP2, DES, DSP, TTNgenes), variants of uncertain clinical significance (VUCS) — in other 5 (4,3%) patients; we detected VUCS in 1 patient with increased LV trabecularity. Familial cardiomyopathy may be diagnosed in 24 patients (22%). The combination of NCM with congenital heart defects was diagnosed in 11 (9,5%) patients. We identified six clinical variants of NCM: asymptomatic (2%), arrhythmic (15%), ischemic (7%), NCM in patients with dilated cardiomyopathy (42%), NCM in patients with acute/subacute myocarditis (12%) and in combination with other primary cardiomyopathies (22%) — hypertrophic cardiomyopathy, arrhythmogenic right ventricular dysplasia, restrictive cardiomyopathy, primary myodystrophy, cardiac sarcoidosis, Danon disease. Myocarditis was diagnosed in 51,7% of patients with various forms of NCM and in 59,5% of patients with increased LV trabecularity. The frequency of the main clinical manifestations of NCM (chronic heart failure, various cardiac arrhythmias, thromboembolic complications) and outcomes varied in groups of patients with different variants of the NCM course. In patients with increased LV trabecularity, similar clinical variants were noted with a less severe myocardial dysfunction, rare arrhythmias and embolism. A significant improvement in dynamics of EF and LV end-diastolic diameter was noted only in the group of patients with acute/subacute, most of which received basic myocarditis therapy. In other groups, there was an unreliable improvement.Conclusion. NCM can be detected in a patient of any age with a previously diagnosed heart disease (coronary heart disease, arterial hypertension, congenital heart defects, cardiomyopathy, myocarditis, etc.), and in the absence of any symptoms. Stable clinical forms are characterized by stability over time with a tendency to improvement against the background of complex medical therapy.

Keywords

• noncompact myocardium
• clinical forms
• idiopathic arrhythmias
• dcmp
• myocarditis
• endomyocardial biopsy
• hypertrophic cardiomyopathy
• restrictive cardiomyopathy