Introduction: In primary prevention implantable cardioverter defibrillator (ICD) patients, the incidence of appropriate ICD therapy is relatively low, prompting better risk stratification. Fragmented QRS (fQRS) on a 12-lead ECG has been associated with adverse outcomes. The aim of this study was to evaluate the prognostic value of fQRS in ICD recipients.
Methods: Consecutive ICD patients implanted at our institution for primary prevention of sudden cardiac death (SCD) were retrospectively evaluated. Patients were divided in two groups based on the presence or the absence of fQRS on the ECG obtained before ICD implantation. The endpoint of the study was all-cause mortality or the occurrence of any appropriate ICD-delivered therapy, whether shock or antitachycardia pacing.
Results: Among 394 ICD recipients (334 men, age 66.4 ± 11.0), fQRS was observed in 103 patients (26.1%). There were 189 patients (48.0%) with wide QRS at the time of implantation. Among these patients, fQRS was found in 29 individuals (28.2%). Patients in fQRS(+) group were more likely to have coronary artery disease and a lower QRS duration than those without fQRS. During a mean follow-up of 26.3 ± 17.5 months, mortality or ICD therapy were 19.4 and 22.4%, respectively, for fQRS(+) patients, and 15.2 and 22.8% for fQRS(-) patients (P = NS). By Kaplan-Meier analysis, event-free survival was similar in the two groups.
Conclusion: In ICD recipients for primary prevention of SCD, fQRS is not helpful in selecting a subgroup of patients who benefit from prophylactic ICD implantation.