P4682Left ventricular noncompaction in adults: complications, their predictors and outcomes
Authors: Varionchik N , Blagova O , Pavlenko E , Nedostup A , Sedov V , Gagarina N , Mershina E 
Published: October 2019

Abstract

Background
Left ventricular noncompaction (LVNC) is characterized by high frequency of heart failure, arrhythmias, thromboembolism and ischemia.

Purpose
To estimate frequency, predictors, outcomes of adverse events in patients with LVNC.

Methods
120 patients with LVNC were included (male, 58.3%); mean age, 45.9±15.0 years. To diagnose LVNC EchoCG (n=120), CT (n=85), MRI (n=55) were performed. The mean LV EF was 39.0±13.9%, LV EDV 155.5±65.0ml, LV EDD 6,03±0.8cm, LA volume 96.3±38.4ml. The median follow-up was 15 [4.0; 41.0] months. We also performed NGS sequencing, followed by Sanger sequencing.

Results
Pathological mutations in genes MYH7, MyBPC3, LAMP2, DES, DSP, TTN were found in 10% of patients. The main clinical manifestations were chronic heart failure NYHA II-III (66.7% of patients), ventricular arrhythmias (PVCs>500/day in 46.7%, sustained/unsustained VT in 49.2%), AF 30.8% (paroxysmal, n=18; persistent, n=11; permanent, n=9), ischemia (angina pectoris in 20%, myocardial necrosis in 13.3%), intracardiac thrombosis without anticoagulants (19.2%), embolism (6.7%), AV block degree II-III (11.7%), bundle branch blocks (37.5%), sinus node dysfunction (10%). VT frequency was associated with lower LV EF (34.6±13.4 v 42.8±13.1 p=0.001), higher NYHA functional class (class 2.5 [2.0; 3.0] v class 2 [0.75; 3.0], p<0,01), low voltage ECG (20.3% v 5.2% p<0,05), poor R-wave progression (42.4% v 20.7% p<0,01), QRS duration (110ms [100; 140] v 100ms [90; 110], p=0,001), myocarditis presence (66.1% v 37.9% p<0.01) and higher mortality (22% v 6.9% p<0.05). AF correlated with the size of LA (AUC 0.712), and RA (AUC 0.716), p<0.001. Pacemakers were implanted in 7 cases, ICD in n=25 (20.8%), CRTD in n=9 (7.5%). Appropriate ICD shocks were recorded in 26.5%. In two patients without ICD sudden cardiac death occurred. Radiofrequency ablation was performed in 5 cases, in 3 of them without effect. Patients with thromboembolic events (renal, pulmonary, myocardial infarction, stroke) had significantly lower LV EF (31.8%±11.4 v 41.0±13.9%, p<0.005), higher NYHA functional class (class 3 [1.75; 3.0] v class 2 [1.0; 3.0], p<0.05), greater LV EDD (6.34±0.83 v 5.9±0.81, p<0.05), E/A ratio (2.15±0.8 v 1.5±0.84 p<0.01), lower VTI (10.19±2.9 v 12.8±3.6 p<0.05). The main MI mechanisms were embolism, thrombosis, myocarditis, inadequate myocardium perfusion. Six patients (5%) underwent heart transplantation. The mortality rate was 14.2% (17 patients) due to myocardial infarction, arrhythmias, heart failure.

Conclusion
Thromboembolic events, arrhythmias and ischemia are typical adverse events of LVNC. Non-sustained/sustained ventricular tachycardia, myocardial infarction is significantly associated with increased mortality. LV dilation, systolic and diastolic dysfunction increases the frequency of thromboembolism in these patients. Low voltage ECG, poor R-wave progression, QRS duration and myocarditis should considered predictors for arrhythmias in LVNC patients.