Left ventricular ejection fraction response after atrial fibrillation ablation: Clinical predictors and development of the PACED score

BACKGROUND: Catheter ablation for atrial fibrillation (AF) in left ventricular systolic dysfunction (LVSD) improves outcomes, yet left ventricular ejection fraction (LVEF) response is difficult to prospectively predict. OBJECTIVE: This study aimed to identify preprocedural predictors of LVEF response after AF ablation in patients with LVSD and develop a pragmatic score to stratify patients. METHODS: This multicenter cohort study included patients with AF and an LVEF of <50% undergoing index ablation. The primary endpoint was responder status defined as ≥10% increase in LVEF or improvement to ≥50% on follow-up echocardiography after the final ablation. Multivariable logistic regression modeling, stratified by follow-up rhythm, was used to identify predictors and derive a simplified scoring tool. RESULTS: Among 366 patients (aged 64.4 ± 10.6 years; 82% male), 70.8% were left ventricular responders at follow-up. Predictors of nonresponse in the sinus rhythm subgroup included heart failure etiology, QRS duration of >105 ms, paroxysmal AF, and type 2 diabetes. These were incorporated into the PACED score, which stratified response (score <2, 87% probability of response; score ≥3, 71% of nonresponse) with good discrimination (c-statistic 0.83; 95% confidence interval 0.77-0.89). In the largest contemporary multicenter cardiac magnetic resonance subcohort, late gadolinium enhancement was more frequent among nonresponders (84.6% vs 53.6%; P < .001). Guideline-directed medical therapy at baseline was not independently associated with recovery. CONCLUSION: LVEF response post-AF ablation in patients with LVSD can be accurately predicted precatheter ablation with a bedside score. Left ventricular response depends primarily on substrate and conduction characteristics rather than pharmacotherapy in a guideline-directed medical therapy-optimized cohort. Late gadolinium enhancement on cardiac magnetic resonance is associated with an increased chance of being a nonresponder to ablation.