Catheter Ablation Versus Medical Rate Control in Atrial Fibrillation With Left Ventricular Systolic Dysfunction and Myocardial Fibrosis - The CAMERA-MRI II Randomised trial

Abstract

Background/Aims: Catheter ablation (CA) is associated with improvements in left ventricular ejection fraction (LVEF) and clinical outcomes among diverse HF populations. No studies have prospectively examined the impact of CMR-detected LV myocardial fibrosis on LVEF improvement and clinical outcomes. We examined the impact of CMR-detected LV myocardial fibrosis on outcomes following catheter ablation compared to medical rate control in patients with AF and left ventricular systolic dysfunction (LVSD). Method(s): This international multicentre randomised trial compared CA to medical rate control (MRC) in patients with AF and LVSD with LV myocardial fibrosis (LGE burden >=5%). An LGE negative group (LGE<5%) formed a non-randomised comparator group who all underwent CA. The primary outcome was change in CMR LVEF at 12m in those with LV fibrosis undergoing CA vs MRC. Secondary outcomes compared HF hospitalisations, arrhythmia outcomes and change in cardiac dimensions, biomarkers, functional status and QoL at 12m according to randomisation and between CA groups. Result(s): One hundred and twenty patients were enrolled (age 61.3+/-11.5 years, CMR LVEF 30.7+/-8.5%) and 98.3% completed 12m follow-up. Eighty LGE positive patients (mean LGE burden 12.6%) were randomised to CA (n=40) or MRC (n=40);40 LGE negative patients all underwent CA. At 12m, the LGE positive CA group experienced a significant improvement in LVEF (DELTALVEF +20.3+/-11.0%) compared to MRC (DELTALVEF +4.7+/-8.4%, p<0.001), which was comparable to the LGE negative group (+21.7+/-11.8%,p=0.578). In the LGE positive group, CA was associated with greater reverse remodeling, diminished AF burden, fewer HF hospitalisations and improvements in functional capacity and symptoms at 12m compared to MRC. Conclusion(s): Among LGE positive patients, CA was associated with more favourable outcomes including greater improvement in LVEF, functional capacity and symptoms with a reduction in AF burden and HF hospitalizations compared to MRC. Copyright © 2025