title: Clinical utility and prognostic value of left atrial volume assessment by cardiovascular magnetic resonance in non-ischaemic dilated cardiomyopathy.
abstract: OBJECTIVE
  Echocardiographic studies have shown that left atrial volume (LAV) predicts adverse outcome in small heart failure (HF) cohorts of mixed aetiology. However, the prognostic value of LAV in non-ischaemic dilated cardiomyopathy (DCM) is unknown. Cardiovascular magnetic resonance (CMR) allows accurate and reproducible measurement of LAV. We sought to determine the long-term prognostic significance of LAV assessed by CMR in DCM.
  
  
  RESULTS
  We measured LAV indexed to body surface area (LAVi) in 483 consecutive DCM patients referred for CMR. Patients were prospectively followed up for a primary endpoint of all-cause mortality or cardiac transplantation. During a median follow-up of 5.3 years, 75 patients died and 9 underwent cardiac transplantation. After adjustment for established risk factors, LAVi was an independent predictor of the primary endpoint [hazard ratio (HR) per 10 mL/m(2) 1.08; 95% confidence interval (CI) 1.01-1.15; P = 0.022]. LAVi was also independently associated with the secondary composite endpoints of cardiovascular mortality or cardiac transplantation (HR per 10 mL/m(2) 1.11; 95% CI 1.04-1.19; P = 0.003), and HF death, HF hospitalization, or cardiac transplantation (HR per 10 mL/m(2) 1.11; 95% CI 1.04-1.18; P = 0.001). The optimal LAVi cut-off value for predicting the primary endpoint was 72 mL/m(2). Patients with LAVi >72 mL/m(2) had a three-fold elevated risk of death or transplantation (HR 3.00; 95% CI 1.92-4.70; P < 0.001). LAVi provided incremental prognostic value for the prediction of transplant-free survival (net reclassification improvement 0.17; 95% CI 0.05-0.29; P = 0.002).
  
  
  CONCLUSIONS
  LAVi is a powerful independent predictor of transplant-free survival and HF outcomes in DCM. Assessment of LAV improves risk stratification in DCM and should be incorporated into routine CMR examination.
authors.affiliation: Royal Brompton Hospital, London SW3 6NP, UK.
authors.forename: Ankur
authors.initials: A
authors.lastname: Gulati
authors.forename: Tevfik F
authors.initials: TF
authors.lastname: Ismail
authors.forename: Andrew
authors.initials: A
authors.lastname: Jabbour
authors.forename: Nizar A
authors.initials: NA
authors.lastname: Ismail
authors.forename: Kishen
authors.initials: K
authors.lastname: Morarji
authors.forename: Aamir
authors.initials: A
authors.lastname: Ali
authors.forename: Sadaf
authors.initials: S
authors.lastname: Raza
authors.forename: Jahanzaib
authors.initials: J
authors.lastname: Khwaja
authors.forename: Tristan D H
authors.initials: TD
authors.lastname: Brown
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Liodakis
authors.forename: Arun J
authors.initials: AJ
authors.lastname: Baksi
authors.forename: Rameen
authors.initials: R
authors.lastname: Shakur
authors.forename: Kaushik
authors.initials: K
authors.lastname: Guha
authors.forename: Michael
authors.initials: M
authors.lastname: Roughton
authors.forename: Ricardo
authors.initials: R
authors.lastname: Wage
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Cook
authors.forename: Francisco
authors.initials: F
authors.lastname: Alpendurada
authors.forename: Ravi G
authors.initials: RG
authors.lastname: Assomull
authors.forename: Raad H
authors.initials: RH
authors.lastname: Mohiaddin
authors.forename: Martin R
authors.initials: MR
authors.lastname: Cowie
authors.forename: Dudley J
authors.initials: DJ
authors.lastname: Pennell
authors.forename: Sanjay K
authors.initials: SK
authors.lastname: Prasad
mesh_terms: D000328:Adult; D000368:Aged; D002306:Cardiac Volume / Q000502:physiology*; D002311:Cardiomyopathy, Dilated / Q000401:mortality / Q000503:physiopathology* / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006325:Heart Atria / Q000503:physiopathology*; D016027:Heart Transplantation; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors
keywords: Cardiovascular magnetic resonance; Dilated cardiomyopathy; Left atrial volume; Prognosis