title: Cardiac CT assessment of left ventricular mass in mid-diastasis and its prognostic value.
abstract: OBJECTIVE
  To determine the influence of cardiac motion on measurements of left ventricular (LV) mass obtained with 64-slice computed tomography (CT) and to elucidate the prognostic value of LV mass on major adverse cardiac events (MACE) and all-cause mortality. Increased LV mass has been linked with MACE. Although Cardiac CT allows measurement of LV anatomy, it is susceptible to motion artefacts often requiring image acquisition during diastasis. There is a need to understand variability in LV mass measurements across phases of the cardiac cycle, and whether mid-diastolic measurements have prognostic value.
  
  
  RESULTS
  The study comprised two equally sized cohorts of patients that had undergone retrospectively gated cardiac CT: patients who had MACE and/or all-cause death at follow-up and a matched (age, sex, and risk factors) event-free cohort. LV mass was measured at mid-diastole, end-diastole, and end-systole. Correlation and agreement between phases were determined. The incremental value of mid-diastolic hypertrophy (LVH) over the National Cholesterol Education Programme (NCEP) risk was performed for LV mass indices normalized to body surface area (LVMIBSA) or weight (LVMIWeight). Of 166 patients, 31.3% experienced MACE and 28.9% died of any cause (follow-up 22.9 ± 13.4 months). LV mass at all cardiac phases were strongly correlated (r > 0.94). Mean mid-diastolic LVMIBSAwas higher in the cohort with events (93.7 vs. 80.7 g/m2, P= 0.008) as was LVMIWeight(2.26 vs. 1.88 g/kg, P = 0.001). LVMIBSAand LVMIWeighthad prognostic value incremental to NCEP with 1.85 and 2.47 hazard ratios, respectively.
  
  
  CONCLUSIONS
  Measurement of LV mass can be obtained by cardiac CT images obtained at mid-diastasis. LV mass measurements obtained at mid-diastasis have prognostic value.
authors: Division of Nuclear Medicine, The Ottawa hospital, 1053 Carling Ave, Ottawa, ON, Canada, Canada, K1Y 4E9 rklein@toh.on.ca.
authors: Ran
authors: R
authors: Klein
authors: Faculty of Science, University of Ottawa, Ottawa, ON, Canada.
authors: Emmanuelle S
authors: ES
authors: Ametepe
authors: Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, Canada K1Y 4W7.
authors: Yeung
authors: Y
authors: Yam
authors: Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, Canada K1Y 4W7.
authors: Girish
authors: G
authors: Dwivedi
authors: Division of Cardiology, University of Ottawa Heart Institute, 40 Ruskin St., Ottawa, ON, Canada K1Y 4W7.
authors: Benjamin J
authors: BJ
authors: Chow
mesh_terms: D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D015637:Gated Blood-Pool Imaging / Q000379:methods; D006801:Humans; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000401:mortality* / Q000503:physiopathology; D007091:Image Processing, Computer-Assisted; D053208:Kaplan-Meier Estimate; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods*; D015588:Observer Variation; D011379:Prognosis; D016016:Proportional Hazards Models; D012372:ROC Curve; D012042:Registries; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D016019:Survival Analysis; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology
keywords: LV mass; computed tomography; prognosis; prospective gating