• To identify serum biomarkers that correlate with procedure outcome in AF patients undergoing catheter ablation [ Time Frame: 3-months post-procedure ] [ Designated as safety issue: No ]
  

• To identify the biomarkers which correlate with different types of AF, namely paroxysmal, persistent or long-standing persistent [ Designated as safety issue: No ]
  
• To identify candidate biomarkers that can predict fluid retention in the immediate post-ablation period. [ Designated as safety issue: No ]
  

AF is the most common arrhythmia in clinical practice, affecting > 2.3 million people in US. It increases dramatically with age and is seen in as many as 9% of individuals by the age of 80 (1). A major cause of stroke, AF is also associated with a 2-fold increase in mortality (1).

Symptomatic AF has been demonstrated to be consistently associated with elevated inflammatory activity in the atrial tissue as evidenced by the facts that AF occurs in 40% of patients following cardiac bypass surgery and 50% of patients undergoing valvular surgery (2). Recent studies have also demonstrated that elevated CRP level can increase the risk of AF up to 31% (2). Oxidative damage experienced during AF leads to myocardial necrosis which in turn induces low-grade inflammation resulting in eventual fibrosis of the atrial myocardium. Thus, inflammation can be responsible for adverse structural and electrical remodeling of the cardiac tissue which can further perpetuate the existence, maintenance, and recurrence of this arrhythmia.

Radiofrequency catheter ablation (RFCA) has evolved as a promising curative therapy for drug-refractory AF. However, the recurrence of AF after RFCA is a common clinical problem, occurring in 25-50% of patients in the follow-up period (3) and some patients undergo multiple ablation procedures before being cured of the arrhythmia. Published retrospective studies have demonstrated that systemic inflammation generated during AF ablation is associated with fewer early arrhythmia recurrences (4). Therefore, measurement of inflammatory markers within 24 hours of RFCA could be helpful in further exploration of any association between the degree of inflammatory activation and procedure outcome.

Systemic inflammatory activation is characterized by increased circulating levels of several biomarkers for prolonged periods. Thus, examination of these biomarkers at 3-months post-procedure may provide critical insight into understanding the role of inflammation in achievement of long-term success of catheter ablation in AF patients.

Rules-Based Medicine, Inc (RBM) at 3300 Duval Road Austin, TX 78759 has developed biomarker panels that have been validated to detect early signs of inflammation. RBM will process the blood samples on a preliminary panel of ~40 biomarkers which are presumed to be possible predictors of procedural outcomes in RFCA in AF patients.