Adverse Events in Patients With Left Ventricular Noncompaction: Risk Stratification and Treatment Options

Abstract

Aim. To study the clinical manifestations, incidence of life-threatening complications, and their possible mechanisms and outcomes of left ventricular non-compaction (LVNC) in adults.Material and methods. This study included 125 adult patients with LVNC, 74 men (59.2%) and 51 women (40.8%) aged 46.4±15.1 years. Echocardiography (EchoCG) (n=125), Holter monitoring (n=125), cardiac magnetic resonance imaging (MRI) (n=60), and contrast-enhanced multislice computed tomography (MSCT) of the heart (n=90), and, if indicated, coronary angiography (CAG) (n=33) and myocardial scintigraphy (n=27) were performed. The diagnosis of LVNC was confirmed in 74 cases using two methods, and in 21 cases, using three imaging methods. DNA diagnostics was performed in most patients. For most patients, the level of anticardiac antibodies and the genome of cardiotropic viruses were determined in the blood. Mean left ventricular (LV) ejection fraction (EF) was 38.6±14.0%; LV end-diastolic volume (EDV) was 158.1±67.8 ml; LV end-diastolic dimension (EDD) was 6.1±0.9 cm; and left atrial (LA) volume was 97.1±38.1 ml. The mean follow-up period was 14 months [4.0; 41.0]; from 1 month to 10 years.Results. Death rate was 14.4%; heart transplantation was performed in 5.6% of cases. Nonsustained ventricular tachycardia (VT) was detected in 45.6% of cases and sustained VT in 13.6%. The presence of VT was associated with poor R-wave progression in the precordial ECG leads, low QRS voltage, QRS duration >105 ms, NYHA chronic heart failure functional class (CHF FC) ≥2-3, LV EF <40%; LV EDD >6.1 cm, the presence of myocarditis, and higher death rate. Cardioverter defibrillators, including cardiac resynchronization therapy defibrillators (CRTD), were implanted in 38 patients. Appropriate defibrillator shocks were associated with frequent premature ventricular contractions (PVCs). The incidence of thrombosis and embolism was 22.4%. Their predictors included CHF FC ≥2-3, RV anteroposterior dimension >3.1 cm, LA volume >98 ml, E/A >1.65, LV EDD >6.3 cm, LV EDV >153 ml, LV EF <35%, and myocardial necrosis of unknown origin (in patients without coronary atherosclerosis). The incidence of myocardial necrosis in LVNC was 16.0%. The mechanisms identified, in addition to coronary atherosclerosis, were embolism in unchanged coronary arteries, secondary myocarditis, and the presence of genetically determined thrombophilia.Conclusion. LVNC is associated with a high risk of life-threatening conditions, such as ventricular arrhythmias, thrombosis and embolism, and myocardial necrosis, that are typical complications of LVNC in adults. Reassessing the predictors for the risk of thromboembolic and arrhythmic events, specifying the indications for implantable cardioverter defibrillator and anticoagulants, and actively identifying and treating concomitant myocarditis are essential.