LAUSR

The phenotypic expression of non-compaction cardiomyopathy (NCM) ranges from subclinical arrhythmias to sudden cardiac death. Search of identifying predictors of life-threatening ventricular tachyarrhythmias (ltVTA) and analysis arrhythmic risk stratification capacity of ECG (heart rate turbulence – HRT, microvolt T-wave alternans – mTWA, QT interval corrected - QTc, and fragmented QRS - frQRS), Echo and MRI features in pts with NCM was the goal of this study. The study enrolled and followed up 59,7±16,2 months 72 pts (family – 13; sporadic – 59; aged 39.2±14.1 years; 43/59.7% male; LVEF 44.7±13.2%) with morphological signs of non-compaction myocardium, confirmed by any three of the four standart criteria: Echo (Jenni, Stöllberger), MRI (Petersen, Jacquier). For analysis as primary end-points the following ltVTA events were accepted: SCD, successful resuscitation, stVT/VF/syncope, appropriated ICD discharges. As a result of the rank correlation Spearman analysis positive correlations (p<0.0001) of an MRI markers of myocardial fibrosis were revealed with ECG parameters; thus, leads (n) with frQRS (frQRSn: r=0.65) and QT interval corrected (QTc: r=0.66) correlated with T1 native relaxation time (ms) and the LGE myocardial segments (n). Significant correlations (p<0.0005) are found between LGE (%) and frQRS(n): r=0.61; QTc: r=0.56; VTA (r=0.48); systolic dysfunction (LVEF: r=−0.59; GLS: r=0.58; TAPSE: r=−0.55; RVEF: r=−0.54) and biventricular non-compaction (r=0.60). Positive correlations of the frQRS(n) with the pathological mTWA test (mTWA mean: r=0.55; p<0.001), VTA (r=0.61; p=0.0008) and negative correlations with systolic/contractile function (LVEF: r=−0.56, p=0.001; TAPSE: r=−0.51, p=0.003; LV GLS “–”%: r=−0.57, p<0.001) were determined. Surprisingly, significant correlations between NC/C ratio (one of the main diagnostic criteria of LVNC) and other phenotypic signs or clinical complications were not identified. As a result of step-by-step multiple regression analysis, a predictive model was constructed (R=0.53; F=8.50; p<0.ehz748.05257) and 3 independent predictors of ltVTA were revealed: HRT slope (TS: β=−0.36; p=0.002), QRS fragmentation (nQRSfr: β=0.32; p=0.001), and myocardial fibrosis (LGE%: β=0.27; p=0.02). As a result of ROC analysis following cut-off value were detected: fibrosis (LGE ≥22.5%; AUC 0.742; 95% CI: 0.594–0.889; sensitivity 77%; specificity 78%), pathological HRT (TS ≤2.5 ms/RR; AUC 0.771; 95% CI: 0.629–0.912; sensitivity 67%, specificity 87%), and fragmented QRS (frQRSn ≥5 leads; AUC 0.721; 95% CI: 0.559–0.883; sensitivity 80%, specificity 87%). These markers (frQRSn along with LGE) reflect pathophysiological substrate triggering fatal arrhythmias; association of higher number of leads with frQRS, expressed LGE and pathological TS-HRT may be used as independent predictors of ltVTA for NCM pts