title: Increased plasma homocysteine predicts arrhythmia recurrence after minimally invasive epicardial ablation for nonvalvular atrial fibrillation.
abstract: OBJECTIVE
  Minimally invasive epicardial ablation via right minithoracotomy is an emerging option for patients with drug-refractory nonvalvular atrial fibrillation. To guide the development of rational treatment algorithms, factors predisposing to recurrence of arrhythmia need to be quantified and eventually treated. We addressed the association of the plasma levels of homocysteine and the recurrence of atrial fibrillation after minimally invasive ablation.
  
  
  METHODS
  We obtained peripheral blood samples from 104 patients at follow-up after arrhythmia surgery; the homocysteine concentration was expressed as micromoles per liter. Prospective follow-up was conducted through electrocardiogram Holter monitoring (average 18.5 ± 5.8 months). Stratified analysis (high vs low homocysteine) was based on the cutoff value for the last quartile of homocysteine concentration (16 μmol/L). Time-to-event and diagnostic performance analyses were performed.
  
  
  RESULTS
  The rate of freedom from atrial fibrillation was 89.4% at the end of follow-up. Elevated circulating homocysteine level, persistent type of atrial fibrillation, and increased left atrial dimension independently predicted the recurrence of atrial fibrillation during the follow-up (adjusted Cox regression). Patients with a high homocysteine level were more likely to have atrial fibrillation recurrence (stratified Kaplan-Meier, P < .001). The cutoff value for elevated homocysteine (16 μmol/L) yielded a good diagnostic performance in the prediction of atrial fibrillation recurrence (area under the receiver operating characteristic curve, 0.807).
  
  
  CONCLUSIONS
  The homocysteine level measured during the follow-up reliably predicts the risk of recurrence after epicardial ablation of nonvalvular atrial fibrillation via minithoracotomy. Specific treatments to reduce plasma homocysteine could be considered in the future in these patients.
authors.affiliation: Department of Cardiac Surgery, Anthea Hospital, GVM Care & Research, Bari, Italy. Electronic address: gnasso@libero.it.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Nasso
authors.forename: Raffaele
authors.initials: R
authors.lastname: Bonifazi
authors.forename: Vito
authors.initials: V
authors.lastname: Romano
authors.forename: Mario Siro
authors.initials: MS
authors.lastname: Brigiani
authors.forename: Flavio
authors.initials: F
authors.lastname: Fiore
authors.forename: Francesco
authors.initials: F
authors.lastname: Bartolomucci
authors.forename: Mauro
authors.initials: M
authors.lastname: Lamarra
authors.forename: Khalil
authors.initials: K
authors.lastname: Fattouch
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Rosano
authors.forename: Mario
authors.initials: M
authors.lastname: Gaudino
authors.forename: Roberta
authors.initials: R
authors.lastname: Spirito
authors.forename: Carlo
authors.initials: C
authors.lastname: Gaudio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Speziale
mesh_terms: D000368:Aged; D019540:Area Under Curve; D001281:Atrial Fibrillation / Q000150:complications / Q000175:diagnosis / Q000601:surgery*; D015415:Biomarkers / Q000097:blood; D017115:Catheter Ablation / Q000009:adverse effects; D015716:Electrocardiography, Ambulatory; D005260:Female; D006710:Homocysteine / Q000097:blood*; D006801:Humans; D020138:Hyperhomocysteinemia / Q000097:blood / Q000150:complications*; D053208:Kaplan-Meier Estimate; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012372:ROC Curve; D012008:Recurrence; D018570:Risk Assessment; D012307:Risk Factors; D013908:Thoracotomy / Q000009:adverse effects; D013997:Time Factors; D016896:Treatment Outcome; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; D006710:Homocysteine