title: Two-dimensional strain for the assessment of left ventricular function in low flow-low gradient aortic stenosis, relationship to hemodynamics, and outcome: a substudy of the multicenter TOPAS study.
abstract: BACKGROUND
  Decision making in patients with low flow-low gradient aortic stenosis mainly depends on the actual stenosis severity and left ventricular function, which is of prognostic importance. We used 2-dimensional strain parameters measured by speckle tracking at rest and during dobutamine stress echocardiography to document the extent of myocardial impairment, its relationship with hemodynamic variables, and its prognostic value.
  
  
  RESULTS
  In 47 patients with low flow-low gradient aortic stenosis, global peak systolic longitudinal strain (PLS) and peak systolic longitudinal strain rate (PLSR) were analyzed. PLS and PLSR at rest and peak stress were -7.56±2.34% and -7.41±2.89% (P=NS) and -0.38±0.12 s(-1) and -0.53±0.18 s(-1) (P<0.001), respectively. PLS and PLSR inversely correlated with left ventricular ejection fraction at rest (rs=-0.52; P<0.0001 and -0.38; P=0.008) and peak stress (rs=-0.39; P=0.007 and -0.45; P=0.002). The overall 2-year survival rate was 60%. Univariate predictors of survival were peak stress left ventricular ejection fraction (P=0.0026), peak stress PLS (P=0.0002), peak stress PLSR (P<0.0001), and N-terminal pro-B-type natriuretic peptide (P<0.0001). Three hierarchically nested multivariable Cox regression models were constructed-model 1: The Society of Thoracic Surgeons score as an indicator of clinical risk (area under the receiver operating characteristic=0.59); model 2: model 1+N-terminal pro-B-type natriuretic peptide and peak stress left ventricular ejection fraction (area under the receiver operating characteristic=0.83; incremental P<0.0001); model 3: model 2+peak stress PLSR (area under the receiver operating characteristic=0.89; incremental P=0.035).
  
  
  CONCLUSIONS
  In patients with low flow-low gradient aortic stenosis, 2-dimensional strain parameters are strong predictors of outcome. Peak stress PLSR may add incremental prognostic value beyond what is obtained from N-terminal pro-B-type natriuretic peptide and peak stress left ventricular ejection fraction. A larger study is needed to confirm these findings.
authors.affiliation: Department of Internal Medicine II, Division of Cardiology, Medical University of Vienna, Vienna, Austria.
authors.forename: Philipp Emanuel
authors.initials: PE
authors.lastname: Bartko
authors.forename: Georg
authors.initials: G
authors.lastname: Heinze
authors.forename: Senta
authors.initials: S
authors.lastname: Graf
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Clavel
authors.forename: Aliasghar
authors.initials: A
authors.lastname: Khorsand
authors.forename: Jutta
authors.initials: J
authors.lastname: Bergler-Klein
authors.forename: Ian Gordon
authors.initials: IG
authors.lastname: Burwash
authors.forename: Jean Gaston
authors.initials: JG
authors.lastname: Dumesnil
authors.forename: Mario
authors.initials: M
authors.lastname: Sénéchal
authors.forename: Helmut
authors.initials: H
authors.lastname: Baumgartner
authors.forename: Raphael
authors.initials: R
authors.lastname: Rosenhek
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
authors.forename: Gerald
authors.initials: G
authors.lastname: Mundigler
mesh_terms: D000322:Adrenergic Agonists; D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000097:blood / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D004280:Dobutamine; D015150:Echocardiography, Doppler; D025401:Echocardiography, Stress; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology; D006439:Hemodynamics; D006801:Humans; D053208:Kaplan-Meier Estimate; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009200:Myocardial Contraction; D020097:Natriuretic Peptide, Brain / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D012720:Severity of Illness Index; D013314:Stress, Mechanical; D013318:Stroke Volume; D015996:Survival Rate; D013997:Time Factors; D016277:Ventricular Function, Left
chemical_list: D000322:Adrenergic Agonists; D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D004280:Dobutamine