title: Elevated left ventricular filling pressure estimated by E/E' ratio after exercise predicts development of new-onset atrial fibrillation independently of left atrial enlargement among elderly patients without obvious myocardial ischemia.
abstract: OBJECTIVE
  To determine whether elevated left ventricular (LV) filling pressure estimated by raised Doppler E velocity to tissue Doppler E' velocity ratio (E/E') after exercise is associated with increased risk of new-onset atrial fibrillation (AF) in non-ischemic elderly patients.
  
  
  BACKGROUND
  Prognostic importance of exercise induced LV diastolic dysfunction remains uncertain.
  
  
  METHODS
  We studied 147 elderly patients (73 ± 5 years) who underwent treadmill stress echocardiography. Patients with exercise induced LV wall motion abnormality were not included. Doppler and tissue Doppler measurements were done before treadmill exercise and immediately after the post-stress image acquisition, and E/E' ratio was measured. Raised E/E' was defined as E/E'≥ 15, and left atrial (LA) enlargement was defined as LA volume index ≥ 34 ml/m(2). Using Cox proportional hazards regression analysis, predictor of new-onset AF was determined. Using Kaplan-Meier analysis, we evaluated association between raised post-exercise E/E' or LA enlargement with new-onset AF.
  
  
  RESULTS
  During the follow-up period (median=67 months), there were 25 new-onset AF. Cox proportional hazards regression analysis demonstrated that male gender [hazard ratio (HR) 3.294; p=0.0117], LA enlargement (HR 3.576; p=0.0017), and raised post-exercise E/E' (HR 3147; p=0.0068) were the best predictors of new-onset AF. Kaplan-Meier survival plot demonstrated that patients with both LA enlargement and raised post-exercise E/E' developed new-onset AF most frequently. There was no significant difference in outcome between patients with isolated raised post-exercise E/E' or isolated LA enlargement.
  
  
  CONCLUSIONS
  Raised E/E' ratio after exercise provides significant prognostic information for predicting new-onset AF in non-ischemic elderly patients. This prognostic value of raised post-exercise E/E' is independent of and incremental to the LA enlargement.
authors.affiliation: Takagi Cardiology Clinic, Kyoto, Japan. Electronic address: tcardiol@qb4.so-net.ne.jp.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Takagi
authors.affiliation: Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Takagi
authors.affiliation: Nishinomiya Watanabe Cardiovascular Center, Nishinomiya, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Yoshikawa
mesh_terms: D000368:Aged; D001281:Atrial Fibrillation / Q000175:diagnosis* / Q000503:physiopathology*; D006332:Cardiomegaly; D018618:Echocardiography, Doppler, Color; D005080:Exercise Test / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006325:Heart Atria / Q000473:pathology; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D017202:Myocardial Ischemia; D011379:Prognosis; D016016:Proportional Hazards Models; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Atrial fibrillation; Diastolic function; Doppler echocardiography; Exercise stress echocardiography; Tissue Doppler echocardiography