Abstract
Abstract Background Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with a prothrombotic state and impaired fibrinolysis. Plasminogen activator inhibitor-1 (PAI-1), a key regulator of the fibrinolytic system, is linked to increased cardiovascular risk when elevated. Catheter ablation is a well-established treatment for restoring sinus rhythm in AF. Previous studies show that PAI-1 levels decrease 1–3 months post-ablation, indicating potential therapeutic relevance. Objective To evaluate whether within-patient differences in PAI-1 levels predict procedural success following catheter ablation for AF. Methods 70 AF patients aged ≥60 years (35 paroxysmal, 35 persistent) undergoing ablation were prospectively enrolled. PAI-1 levels were measured pre-procedure and 1–3 months post-ablation. Differences were correlated with ablation modality, AF type, recurrence and sex. Analyses included Spearman’s correlation, ROC curves, and diagnostic performance metrics. Difference thresholds were determined using interpolation, Highest-Density-Interval, and Bayesian analysis. Results Overall, PAI-1 levels decreased significantly post-ablation (t=15.1, p<0.00001); weak to moderate differences were observed by sex (t=2.14, p<0.05) and AF type (t=4.26, p<0.0001). Post-ablation PAI-1 difference (–14 to –3.48 ng/mL) predicted a recurrence rate of 4.2–22.5%, with 92% sensitivity, 65% specificity, 87% PPV, 76% NPV, and 84% accuracy. Conclusion In patients aged ≥60 years, within-patient PAI-1 differences of –14 to –3.48 ng/mL may help predict ablation outcomes. Although limited by small sample size, mechanistic rationale suggests that greater reductions in PAI-1 may be associated with improved procedural performance.