title: Real-time physiologic biomarker for prediction of atrial fibrillation recurrence, stroke, and mortality after electrical cardioversion: A prospective observational study.
abstract: BACKGROUND
  Left atrial appendage emptying flow velocity (LAAEV) depends largely on left atrioventricular compliance and may play a role in mediating the perpetuation of atrial fibrillation (AF) and AF-related outcomes.
  
  
  METHODS
  We identified 3,251 consecutive patients with sustained AF undergoing first-time successful transesophageal echocardiography (TEE)-guided electrical cardioversion who were enrolled in a prospective registry between May 2000 and March 2012. Left atrial appendage emptying flow velocity was stratified into quartiles: ≤20.2, 20.3-33.9, 34-49.9, and ≥50 cm/s. Multivariate Cox regression models were used to identify independent predictors of AF recurrence, ischemic stroke, and all-cause mortality.
  
  
  RESULTS
  The mean (SD) age was 69 (12.6) years and 67% were men. Compared with the fourth quartile, patients in the first-third quartiles were significantly older, had higher CHA2DS2-VASc (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, stroke/transient ischemic attack [TIA], vascular disease, age 65-74 years, sex category) scores, greater frequency of atrial spontaneous echo contrast, and AF of longer duration. Kaplan-Meier analysis showed a decreased probability of event-free survival with decreasing quartiles of LAAEV. Five-year cumulative event rates across first-fourth quartiles were 83%, 80%, 73%, and 73% (P < .001) for first AF recurrence; 7.5%, 7.0%, 4.1%, and 4.0%, for stroke (P = .01); and 31.3%, 26.1%, 24.1%, and 19.4%, for mortality (P < .001), respectively. Multivariate Cox regression analysis revealed an independent association of the first and second quartiles with AF recurrence (P < .001 and P < .001, respectively) and stroke (P = .03, and P = .04, respectively), and of the first quartile with mortality (P = .003).
  
  
  CONCLUSIONS
  Patients with decreased LAAEV have an increased risk of AF recurrence, stroke, and mortality after successful electrical cardioversion. Real-time measurement of LAAEV by TEE may be a useful physiologic biomarker for individualizing treatment decisions in patients with AF.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN. Electronic address: melduni.rowlens@mayo.edu.
authors.forename: Rowlens M
authors.initials: RM
authors.lastname: Melduni
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Hon-Chi
authors.initials: HC
authors.lastname: Lee
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, FL.
authors.forename: Kent R
authors.initials: KR
authors.lastname: Bailey
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Fletcher A
authors.initials: FA
authors.lastname: Miller
authors.affiliation: Department of Health Sciences Research, Mayo Clinic, Rochester, FL.
authors.forename: David O
authors.initials: DO
authors.lastname: Hodge
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: James B
authors.initials: JB
authors.lastname: Seward
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Gersh
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN.
authors.forename: Naser M
authors.initials: NM
authors.lastname: Ammash
mesh_terms: D000368:Aged; D020517:Atrial Appendage / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001281:Atrial Fibrillation / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D001783:Blood Flow Velocity / Q000502:physiology*; D018572:Disease-Free Survival; D017548:Echocardiography, Transesophageal; D004554:Electric Countershock; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D053208:Kaplan-Meier Estimate; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D011446:Prospective Studies; D012008:Recurrence; D020521:Stroke / Q000453:epidemiology* / Q000209:etiology; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology