Abstract 2634: Arrhythmia Events in Patient with Heart Failure who Receive an ICD for Primary Prevention
Background: We have previously shown that fragmented QRS (fQRS) on a 12-lead ECG without typical bundle branch block (BBB) is associated with myocardial scar. Presence of myocardial scar is a significant risk factor for ventricular arrhythmias (VA). We postulate that fQRS in patients who receive an ICD for SCD-HeFT indication (NYHA class II and III CHF and EF <36%) is associated with a significantly higher risk for ICD therapy (shock or antitachycardia pacing) for VA than pts without fQRS.
Methods: Appropriate ICD therap, ECGs and echo parameters of 187 pts (mean age: 63.2±11.6 years, male: 89 %, , mean EF: 24%±7, ischemic cardiomyopathy:71%) who received an ICD for primary prophylaxis, were studied. fQRS was defined as various RSR patterns (rSR‘, rSr‘, RSr‘,notched R or S wave) in any two contiguous leads corresponding to a major coronary artery territory (figure⇓). Non-fQRS group included pts without fQRS and patients with bundle branch block.
Results: 67 pts (52.2%) had fQRS. 30 pts (16.1%) had VA(24 pts [25%] in fQRS group and 6 pts [6.7%] with non-fQRS group, P < 0.001) during a mean follow up: of 14 ± 6 months. The Cox Regression analysis revealed that fQRS was the only independent predictor of ICD therapy (p =0.001,RR: 3.7[95% CI: 1.5–9.2]). Kaplan Meier survival analysis revealed a significantly decreased ventricular arrhythmia-free survival in fQRS group versus non-fQRS group (p < 0.001).
Conclusion: fQRS on a 12-lead ECG is a significant independent predictor for ICD therapy for VA in SCD-HefT pts. Presence of fQRS is also associated with a significantly decreased time to first VA. Therefore, fQRS can be used as simple ECG sign for risk stratification for VA in these patients.