The optimal timing of catheter ablation in individuals with atrial fibrillation (AF) and left ventricular systolic dysfunction (LVSD) remains uncertain. We examined whether AF diagnosis to ablation time (DAT) influences outcomes following catheter ablation(CA) in patients with persistent AF (PsAF) and LVSD from the CAMERA MRI and CAPLA randomized studies. We evaluated clinical outcomes according to DAT <1 year ("shorter DAT") and >1 year ("longer DAT"), comparing AF recurrence, AF burden, left ventricular ejection fraction (LVEF) and LV recovery (LVEF>50%) at 12 months. DAT was also compared according to the median (24 months). 210 individuals with AF and LVSD were identified, with a median DAT of 24 months. Shorter DAT was associated with lower LA global and posterior wall scar (<0.05mV; both p<0.05). At 12 months, 69.4% with shorter DAT (<1year) were free from recurrent atrial arrhythmias vs 53.6% in longer DAT (HR 1.63, 95% CI 1.01-2.65 p=0.040). Median AF burden was 0% in both groups (shorter DAT:IQR 0.0-2.0% vs longer DAT:IQR 0.0-7.3%,p=0.017). At 12 months, shorter DAT was associated with higher LVEF (55.3% vs 51.0%, p=0.009), greater LVEF improvement (+20.8±13.0% vs +13.9±13.2% longer DAT, p<0.001) and LV recovery (75.0% vs longer DAT: 57.2%, p=0.011). Shorter DAT was associated with fewer hospitalisations and electrical cardioversions at 12 months. In individuals with AF and LVSD, shorter DAT was associated with greater LVEF improvement and arrhythmia-free survival with lower AF burden and rehospitalization at 12 months, highlighting the prognostic benefit of early CA in AF and LVSD.