Proteomics and recurrence of atrial fibrillation: a pilot study nested in the PREDIMAR trial.

Introduction: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia worldwide. Although catheter ablation is the most efficacious therapy, relapses occur frequently (30%) in the first year after ablation. Novel biomarkers of recurrence are needed for a better prediction of recurrence and management of AF. In this pilot study, we aimed to analyze the baseline proteome of subjects included in a case-control study to find differential proteins associated with AF recurrence.

Methods: Baseline serum proteomics (354 proteins) data from 16 cases (recurrent AF) and 17 controls (non-recurrent) were obtained using MS/MS analysis. False discovery rate was performed using a nonlinear fitting method for the selection of proteins. Logistic regression models were used to further analyze the association between differentially expressed proteins and AF recurrence Results: Ten proteins were differentially represented in cases vs controls. Two were upregulated in the cases compared to the controls: keratin type I cytoskeletal 17 (FC=2.14; p=0.017) and endoplasmic bifunctional protein (Fold-change [FC]=1.65; p=0.032). And eight were downregulated in the cases compared to the controls: C4bpA (FC=0.64; p=0.006), coagulation factor XI (FC=0.83; p=0.011), CLIC1 (FC=0.62; p=0.017), haptoglobin (FC=0.37; p=0.021), Ig alpha-2 chain C region (FC=0.49; p=0.022), C4bpB (FC=0.73; p=0.028), N-acetylglucosamine-1-phosphotransferase subunit gamma (FC=0.61; p=0.033) and platelet glycoprotein Ib alpha chain (FC=0.84; p=0.038).

Conclusion: This pilot study identifies ten differentially expressed serum proteins associated with AF recurrence, offering potential biomarkers for improved prediction and management.