Usefulness of Fragmented QRS Complex to Predict Arrhythmic Events and Cardiovascular Mortality in Patients With Noncompaction Cardiomyopathy

Abstract

We aimed to evaluate the prevalence and prognostic role of fragmented QRS complex (fQRS) in predicting arrhythmic events and cardiovascular mortality in patients with noncompaction cardiomyopathy (NCC). A total of 88 patients (64.8% men, mean age 38.6 ± 17.7 years) with the diagnosis of NCC were enrolled. Median follow-up time was 42.4 months. The fQRS was defined as the presence of ≥1 additional R wave (R') or notch on the R/S waves in ≥2 contiguous leads representing anterior (V1 to V5), inferior (II, III, and aVF), or lateral (I, aVL, and V6) myocardial segments. Compared to patients without fQRS group, patients with fQRS (fQRS (+) group) showed higher rates for total arrhythmic events, ventricular tachycardia, bradyarrhythmia requiring pacemaker, sudden cardiac death, cardiovascular mortality, and all-cause mortality. The cut-off point of ≥3 leads for the fQRS was the optimal point discriminating an arrhythmic event and cardiovascular mortality. In Kaplan-Meier survival analysis, total arrhythmic events and cardiovascular mortality occurred more frequently in the fQRS (+) group. In multivariate Cox proportional hazard regression analysis, after adjusting for other confounding factors, the presence of fQRS were found to be as an independent predictor of arrhythmic events (hazard ratio 3.850, 95% CI 1.062 to 9.947, p = 0.002) and cardiovascular mortality (hazard ratio 2.719, 95% CI 1.494 to 9.262, p = 0.005). In conclusion, the presence of fQRS complex, as a simple and feasible electrocardiographic marker, seems to be a novel predictor of arrhythmic events and cardiovascular mortality in patients with NCC. This simple parameter may be used in identifying patients at high risk for arrhythmic events and so individualization of specific therapies can be applied.