History of stroke as a predictor of high left atrial fibrosis in patients with persistent atrial fibrillation-insight from the DECAAF II randomized trial.

Background: There is a strong relationship between left atrial (LA) remodeling and ischemic stroke (IS) risk in atrial fibrillation (AF) patients. The Efficacy of Delayed Enhancement MRI-Guided Ablation vs. Conventional Catheter Ablation of Atrial Fibrillation (DECAAF-II) is the biggest MRI-based, randomized, multicenter clinical trial performed on persistent AF patients. The aim of this study is to evaluate the relationship between history of stroke and atrial fibrosis in the DECAAF II population.

Methods: Persistent AF patients who underwent Late Gadolinium Enhancement Magnetic Resonance Imaging (LGE-MRI) were included in the study and divided into two different groups: those with a history of stroke and those without. Propensity score matching was performed to adjust for covariates. Atrial fibrosis was compared in both groups. Then, patients were divided into different fibrosis groups, using three different cut-offs of baseline atrial fibrosis: ≥ 15%, ≥ 20%, and ≥ 25%. Univariate logistic regression and adjusted multivariate analysis were performed to assess the effect of clinical characteristics and risk factors on baseline fibrosis.

Results: Eight-hundred forty-three patients were recruited in DECAAF II, of whom 70 (8.3%) had a history of stroke. Patients with history of stroke had a higher prevalence of hypertension (p = 0.043), diabetes (p = 0.014), and hyperlipidemia (p = 0.001). Seventy patients with no history of strokes were matched with patients with history of stroke to adjust for covariates using propensity score analysis. Patients in the stroke group had a significantly higher level of fibrosis than those without (20.2% vs. 8.1%, p = 0.017). Increased age was a significant predictor of all three baseline fibrosis classes (≥ 15%, ≥ 20%, and ≥ 25%). Additionally, history of stroke was found to be a predictor of baseline fibrosis ≥ 25% even after adjusting for other clinical characteristics and risk factors (OR = 1.98 [1.14-3.43], p = 0.01).

Conclusions: Left atrial fibrosis level greater than 25% correlates with the history of previous stroke episodes in patients with persistent atrial fibrillation.