Follow-up after pulmonary valve replacement in adults with tetralogy of Fallot: association between QRS duration and outcome.

Objectives: The aim of this study was to analyze whether QRS duration, before and after pulmonary valve replacement (PVR), is related to long-term outcome in patients with tetralogy of Fallot (TOF).

Background: Key factors that determine outcome after PVR in adult TOF patients are largely unknown. Recognition of such factors assists the identification of patients at increased risk of adverse events.

Methods: Adults who previously underwent total correction for TOF (n=90; age 31.4±10.3 years) and required PVR for pulmonary regurgitation were included. The QRS duration was measured pre-operatively and 6 months after PVR. The post-operative changes in QRS duration were calculated. Adverse events (death, re-PVR, ventricular tachycardia, and symptomatic heart failure) were noted during follow-up.

Results: During 5.5±3.5 years of follow-up, 13 adverse events occurred. The 5-year event-free survival rate was 76% for patients with a pre-operative QRS duration>180 ms and 90% in patients with a QRS duration≤180 ms (p=0.037). For patients with a post-operative QRS duration>180 ms, 5-year event-free survival was 71%, whereas it was 91% for patients with a post-operative QRS duration≤180 ms (p=0.004). After multivariate correction, a post-operative QRS duration>180 ms (hazard ratio: 3.685, 95% confidence interval: 1.104 to 12.304, p<0.05) and the absence of a reduction in QRS duration post-PVR (hazard ratio: 6.767, 95% confidence interval: 1.704 to 26.878, p<0.01), was significantly associated with adverse outcome.

Conclusions: Severe QRS prolongation, before or after PVR, and the absence of a reduction in QRS duration after PVR, are major determinants of adverse outcome during long-term follow-up of patients with TOF.