CA in AF With LVSD With and Without LV Fibrosis: Results From the CAMERA-MRI II Trial

Catheter ablation (CA) improves outcomes in atrial fibrillation (AF) with left ventricular systolic dysfunction (LVSD), but the influence of LV fibrosis remains unclear.

This study sought to compare outcomes of CA in patients with AF and LVSD stratified by the presence or absence of LV late gadolinium enhancement (LGE) on cardiac magnetic resonance.

Patients from the CAMERA-MRI II (Catheter Ablation Versus Medical Rate Control of the Atrial Fibrillation With Systolic Heart Failure and Myocardial Fibrosis-an MRI Guided Multi-Centre Randomised Controlled Clinical Trial) randomized study were classified as LGE positive (LV LGE burden ≥5%) or LGE negative (<5%) and all underwent CA. Outcomes at 12 months included change in left ventricular ejection fraction (LVEF), LVEF normalization, AF burden, functional capacity, and heart failure hospitalization.

Eighty patients underwent CA (40 LGE positive and 40 LGE negative). Both groups demonstrated substantial improvement in LVEF (LGE positive: ΔLVEF +20.3 ± 11.0%; LGE negative: +21.7 ± 11.8%; P = 0.578 for between-group difference in change). Unadjusted 12-month LVEF was lower in LGE-positive patients (49.1 ± 11.3% vs 54.5 ± 9.0%; P = 0.019); however, after adjustment for baseline cardiac magnetic resonance and markers of baseline disease severity, LGE status was not independently associated with 12-month LVEF (P = 0.849). Fewer LGE-positive patients achieved LVEF normalization (LVEF ≥50% in 52% vs 82% in LGE negative; P = 0.004), whereas arrhythmia-free survival and AF burden reduction were comparable. Improvements in biomarkers, functional status, and quality of life occurred in both groups. Higher LGE burden (>20%) was associated with attenuated LVEF recovery.

In AF with LVSD, CA is associated with substantial improvement in LV systolic function and clinical status regardless of LGE status. Absolute 12-month LVEF and normalization rates are lower in LGE-positive patients, consistent with greater baseline disease severity, whereas higher scar burden appears to modulate the magnitude of recovery and may inform expectations regarding outcomes.