title: Accuracy of noninvasive ejection fraction measurement in a large community-based clinic.
abstract: OBJECTIVE
  Compare the agreement of two dimensional echocardiography (echocardiography) and electrocardiogram (ECG)-gated single photon emission computed tomography (SPECT), with left ventricular contrast angiography (angiography) for the evaluation of left ventricular ejection fraction (LVEF).
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  American College of Cardiology National Cardiovascular Data Registry(TM) (ACC-NCDR).
  
  
  METHODS
  Patients from a large, community-based clinic in central Wisconsin.
  
  
  METHODS
  Consecutive patients (1999-2002) were identified from the ACC-NCDR dataset who underwent angiography and echocardiography or SPECT within 1 month of each other for evaluation of LVEF. Noninvasive LVEF values were compared to those obtained by angiography using the paired t-test. Regression analysis was used to assess the relation between the compared methods. Bland-Altman analyses were performed to assess the agreement between LVEF values obtained by the noninvasive techniques and angiography. Sensitivity and specificity of detecting depressed LVEF were determined for noninvasive techniques. Regression equations were determined for estimating angiographic values from the echocardiographic or SPECT values.
  
  
  RESULTS
  Five hundred thirty-four patients underwent 542 angiographic studies: SPECT in all 534 patients, combined SPECT and echocardiographic studies in 201 patients, and combined angiographic and echocardiographic studies in 202 patients. Correlation of angiographic LVEFs with both echocardiographic and SPECT LVEFs was significant (r = 0.70 and r = 0.69, respectively; p < 0.0001). Echocardiographic LVEFs were lower than those determined by angiography (49% +/- 1.0% versus 54% +/- 1.0%; p < 0.0001). SPECT LVEFs were also lower than angiographic LVEFs (49% +/- 0.6% versus 57% +/- 0.6%; p < 0.0001). For 201 patients who underwent both SPECT and echocardiography, SPECT LVEFs were lower (47% +/- 1.0% for SPECT versus 49% +/- 1.0% for echocardiography; p < 0.05). Bland-Altman analysis revealed widely varying differences between techniques with broad confidence intervals. Nonetheless, sensitivity and specificity for determining LVEFs of <40% for SPECT and echocardiography were 90% and 86%, and 75% and 89%, respectively. LVEF of < or = 35% was correctly assessed by both SPECT and echocardiography. Sensitivity and specificity for SPECT were 82% and 89%, and 81% and 88% for echocardiography.
  
  
  CONCLUSIONS
  At our institution, LVEFs obtained noninvasively by echocardiography or SPECT are lower than angiographic LVEFs with widely fluctuating differences. Regression equations can be used to correct the noninvasive readings. Although lower, noninvasive techniques appear to accurately assess depressed LVEFs (<40% and <35%). The accuracy of noninvasive techniques for the evaluation of LVEF should be considered when managing and determining prognoses of patients with cardiac conditions. Individual institutions should determine the validity of the noninvasive techniques they use to assess LVEF.
authors: Department of Cardiology, Marshfield Clinic, Marshfield, WI 54449, USA.
authors: Dana E
authors: DE
authors: Habash-Bseiso
authors: Roxann
authors: R
authors: Rokey
authors: Charles J
authors: CJ
authors: Berger
authors: Andrew W
authors: AW
authors: Weier
authors: Po-Huang
authors: PH
authors: Chyou
mesh_terms: D000368:Aged; D000554:Ambulatory Care Facilities; D015331:Cohort Studies; D003151:Community Health Centers; D017023:Coronary Angiography; D003935:Diagnostic Techniques, Cardiovascular / Q000706:statistics & numerical data; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013318:Stroke Volume; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014922:Wisconsin