Predictors of life-threatening events in adult patients with left ventricular noncompaction

Abstract

BACKGROUND

Left ventricular noncompaction (LVNC) is a genetic cardiomyopathy. It is characterized by intensely developed trabeculae in the ventricles with deep intertrabecular lacunae. LVNC manifests as arrhythmias and heart failure with a predisposition for thrombus formation.

AIM

To study predictors of arrhythmic, thromboembolic events and adverse outcomes (death/transplantation) in adult patients with LVNC.

METHODS

Adult patients with LVNC were included (n = 125; mean follow-up: 14 months). Electrocardiography, echocardiography, and 24-hour electrocardiography monitoring were performed. Other procedures were conducted for some patients including: Coronary angiography; cardiac magnetic resonance imaging; cardiac computed tomography; genetic testing; myocardial pathological examination; and anti-cardiac antibody level estimation. Primary endpoints were death, heart transplantation, combined endpoint (death + transplantation), and sudden cardiac death. Secondary endpoints were intracardiac thrombosis, embolic events, myocardial infarction, sustained ventricular tachycardia (VT), and implantable cardioverter-defibrillator intervention.

RESULTS

LVNC manifestations included non-sustained VT, thrombosis/embolism, sustained VT, and sudden cardiac death. Non-sustained VT was associated with the New York Heart Association (NYHA) chronic heart failure (CHF) class, poor R-wave progression, superimposed myocarditis, and higher mortality. Thrombosis/embolism was associated with NYHA CHF class ≥ 3, right ventricular end-diastolic diameter ≥ 3 cm, right atrium volume ≥ 67 mL, left ventricle end-diastolic diameter ≥ 6.3 cm, and velocity time integral ≤ 11.2 cm. Sustained VT was associated with premature ventricular contractions (PVCs), low QRS voltage, and atrioventricular block. PVCs > 500/day were predictive of defibrillator intervention. Fatal outcomes were associated with E wave/A wave ratio > 1.9, left ventricle ejection fraction < 35%, NYHA CHF class ≥ 3, VT, and myocarditis.

CONCLUSION

Frequent PVCs, non-sustained VT, low QRS voltage, and signs of systolic dysfunction on echocardiogram are predictors of life-threatening events in patients with LVNC.

Keywords: Left ventricular noncompaction; Predictors; Arrhythmic events; Thromboembolic events; Adverse outcomes; Myocarditis; Heart failure

Core Tip: Left ventricular noncompaction (LVNC) is associated with a high risk of thrombosis/embolism and arrhythmias. We investigated the predictors of these types of events in 125 patients with LVNC over an average follow-up of 14 months. Following electrocardiography, echocardiography, 24-hour electrocardiogram monitoring, cardiac magnetic resonance imaging, cardiac computed tomography, genetic testing, myocardial morphological examination, and laboratory examination, the acquired data were analyzed. Frequent premature ventricular contractions, non-sustained ventricular tachycardia, low QRS voltage, and signs of systolic dysfunction must be considered for risk assessment in patients with LVNC.