Risk factors in noncompaction cardiomyopathy - data from the German NCCM registry (ALKK)

Objective: Isolated noncompaction cardiomyopathy (NCCM) is considered a primary genetic cardiomyopathy. Smaller studies suggest that the prognosis of pts with NCCM is determined by heart failure (HF) symptoms, different arrhythmias, and thrombembolic events, ranging from asymptomatic to life threatening events. To investigate possible risk factors in this disease we analysed the data of the German NCCM registry (ALKK), which is a registry in a real life clinical setting. Methods: By January 31th, 2013 the German NCCM registry had enrolled a total of 269 pts with NCCM (180 male, age 18 to 88 years, mean age 53.8 yrs) with a mean follow up period of 28 mths. ECGs, echocardiographic and cardiac MR images were reviewed. The pts were followed in 6 mths intervals for clinical events and symptoms. The incidence of severe HF symptoms (NYHA III/IV), malignant arrhythmias (VT/VF), embolic events and deaths were analysed in respect to the factors: age, gender, LV systolic function, atrial fibrillation (AF), left bundle branch block (LBBB) and the presence of late enhancement (LE) in the MR images. Results: Age and gender showed no significant influence on the clinical events of the pts, although there were more men included. The presence of a LBBB was significantly associated with symptoms of heart failure (Odds ratio (OR) 2.54, 95%-confidence interval (CI) (1.42, 4.54)), malignant arrhythmias (OR 2.49, CI (1.23, 5.05)) and cardiac (OR 8.49, CI (2.52, 28.65)) and all cause (OR 4.17, CI (1.61, 10.79)) death. The presence of AF was correlated with a higher risk of death for all-cause mortality (OR 4.66, CI (1.78, 12.19)) and for cardiac deaths (OR 5.86, CI (1.88, 18.32)). Severely depressed LV ejection fraction (EF) was a significant risk factor for deaths (OR 6.78, CI (2.18, 21.04)), for cardiac deaths (OR 9.63, CI (2.09, 44.37)), for heart failure (OR 8.9, CI (5.05, 15.67)) and for VT/VF (OR 2.32, CI (1.18-4.55)). LE in MRI was rarely found in the pts of the registry. There was no statistic significant correlation between the presence of LE and events. The analysed risk factors showed no correlations to embolic events. Summary: In the real life clinical setting of the German NCCM registry prognosis was better than previously reported. Pts with NCCM and AF, LBBB, depressed LVEF (<35%) were at high risk for a significant clinical event.