218-06: Fragmented QRS is Associated with an Increased Risk of Ventricular Tachycardia Recurrence and Cardiac Death after Catheter Ablation in Ischemic Heart Disease

Abstract

Background: Fragmented QRS (fQRS) has been associated with cardiac death and ventricular arrhythmias in patients (pts) with myocardial infarction. However, the clinical impact of fQRS on recurrent ventricular tachycardia (VT) and cardiac death after radiofrequency catheter ablation (RFCA) in post-infarct pts is unknown. Method: We retrospectively included 160 pts (68 ± 9 years; 138 men; left ventricular ejection fraction 33 ± 12%) who underwent RFCA of post-infarct VT from 2009 to 2015. Pre-procedural 12 lead ECGs were evaluated for fQRS defined as RSR' patterns (>1 R' or notching of R or S wave) in pts with a narrow QRS complex and >2 notches of R or S wave in pts with wide QRS complex, present in ≥2 contiguous leads. The primary endpoint was freedom from any VT recurrence and cardiac death after RFCA. Result: Among 160 pts, fQRS was present in 37 (23%) pts; anterior leads in 20 pts, lateral in 9 pts, inferior in 19 pts. Pts were inducible for 3 (interquartile range [IQR] 2–5) VTs. Procedural success (non-inducibility of any VT) was achieved in 74 pts. During follow-up of 17 (IQR 9–24) months, 44 (34%) pts experienced the primary end point. The presence of fQRS was associated with an increased risk of VT recurrence and cardiac death (P = 0.006 by log-rank test). The significant difference was driven by VT recurrence (p = 0.002) but not by cardiac death (p = 0.361). Considering specific locations only fQRS in anterior leads was associated with the primary endpoint (p = 0.005); not in inferior and lateral leads (p = 0.145 and p = 0.84, respectively). A multivariable Cox regression analysis revealed that the presence of fQRS (hazard ratio [HR] 2.27; 95% CI 1.23–4.21; p = 0.009), left ventricular ejection fraction less than 30% (HR 2.36; 95% CI 1.24–4.48; p = 0.009), and number of induced VT during RFCA (HR 1.25; 95% CI 1.12–1.39; p < 0.001) were independent predictors for the endpoint. Conclusion: An fQRS predicts VT recurrence and cardiac death after RFCA of post-infarct VT.