Role of Cardiac Biomarkers in Prediction of Outcome in Atrial Fibrillation Patients Undergoing Catheter Ablation
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Observational

Summary: 
      The purpose of this study is to assess if pre-ablation levels of inflammatory biomarkers
      serve as independent predictors of procedure outcome To evaluate the inflammatory activation
      following catheter ablation by measuring serum-biomarker levels 24-hours after the procedure
      and examine the predictive role in procedure success To study the association of certain
      biomarkers with specific types of AF (paroxysmal or persistent or long standing persistent)
    

Detailed description: 
      Specific Aim: The purpose of this prospective study is to evaluate the role of inflammatory
      biomarkers in predicting procedure-outcome in AF patients undergoing catheter ablation.

      Background: 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.

      Myriad Rules-Based Medicine, Inc (Myriad RBM) in Austin, TX 78759 has developed biomarker
      panels that have been validated to detect early signs of inflammation. Myriad RBM will
      process the blood samples on a preliminary panel of 77 biomarkers, identified to be possible
      predictors of procedural outcome in RFCA in AF patients.

      Study design:

      This study will assess a panel of 77 biomarkers in human serum samples that have been
      identified by the pilot study results as the potential predictors of procedural outcome in
      catheter ablation for AF. The study population will consist of 150 volunteering patients with
      AF undergoing RFCA. Blood samples will be collected at two time points from each patient; one
      at baseline and the other in the morning after the procedure.

      Study Procedure:

      For each patient, one 8.5 ml tube of whole blood will be collected via venipuncture before
      and the morning after the ablation procedure.

      Ablation Procedure:

      Standard radiofrequency catheter ablation procedure will occur in accordance with the
      physician's discretion.

      Blood sample collection:

      The whole blood sample will be collected in a Serum Separator Tube (SST) using BD
      venipuncture procedure, and labeled with an anonymous patient identifier. Only clinical
      research staff will be able to identify study participants.

      Following collection, the samples will be centrifuged for 15 minutes at 900Xg at room
      temperature, within two hours of collection. Plasma, located as a clear straw-color fluid at
      the top of the specimen, would be transferred to another sterile tube and stored at -200 C.
      Samples will be picked up weekly by the RBM team to be stored at -800 C until the end of the
      study, when all samples will be simultaneously analyzed.

      Limited information will also be recorded such as age, gender, height, weight, caffeine
      intake and information about medications, smoking history, family history of atrial
      fibrillation (if known), and information about the outcome of the procedure. Researchers at
      RBM will be blinded to the patient history and demographic data.

      After this study is complete the researchers at RBM will store any leftover blood. The
      researchers may use the leftover samples in future unspecified research studies, which may or
      may not be related to the AF procedure. Even if the blood sample is used for other studies,
      the researchers will not have a way to identify the patient.

      Follow-Up:

      At the 6 and 12 month time points, information will be collected from the medical record
      regarding recurrence of AF.

      Risk Analysis:

      Minor risks associated with a venous blood draw may include fainting or bruising, pain or
      discomfort and a 1/1000 risk of infection at the site where blood is drawn.
    

Intervention name(s): Radio-frequency catheter ablation
Intervention type(s): Procedure
Other intervention name(s): RFCA
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients undergoing catheter ablation for atrial fibrillation
      
Biospecimen description: 
      Plasma from whole blood
    
Keywords: atrial fibrillation, catheter ablation, blood-biomarkers