title: Paradoxical low-flow, low-gradient aortic stenosis despite preserved left ventricular ejection fraction: new insights from weights of operatively excised aortic valves.
abstract: OBJECTIVE
  We reported that patients with small aortic valve area (AVA) and low flow despite preserved left ventricular ejection fraction (LVEF), i.e. 'paradoxical' low flow (PLF), have worse outcomes compared with patients with normal flow (NF), although they generally have a lower mean gradient (MG). The aortic valve weight (AVW) excised at the time of valve replacement is a flow-independent marker of stenosis severity. The objective of this study was to compare the AVW of patients with PLF and MG<40 mmHg with the AVW of patients with NF and MG≥40 mmHg.
  
  
  RESULTS
  We recruited 250 consecutive patients undergoing valve replacement (Cohort A) for severe stenosis. Among them, 33 (13%) were in PLF [LVEF > 50% but stroke volume index (SVi) ≤ 35 mL/m(2)] with MG < 40 mmHg (PLF-LG group) and 105 (42%) were in NF (LVEF > 50% and SVi > 35 mL/m(2)) with MG ≥ 40 mmHg (NF-HG group). Despite a much lower MG (29 ± 7 vs. 53 ± 10 mmHg; P < 0.0001), patients in the PLF-LG group had a similar AVA (0.73 ± 0.12 vs. 0.69 ± 0.13; P = 0.19) compared with those in the NF-HG group. The AVW [median (interquartile): 1.90 (1.63-2.50) vs. 2.60 (1.66-3.32)] and prevalence of bicuspid phenotype (15 vs. 42%) were lower in the PLF-LG group than in the NF-HG group. However, AVWs analysed separately in the tricuspid and bicuspid valves were similar in both groups [tricuspid valves: 1.80 (1.63-2.50) vs. 2.30 (1.58-3.00) g; P = 0.26 and bicuspid valves: 2.72 (1.73-3.61) vs. 2.60 (2.10-3.55) g; P = 0.93]. When using cut-point values of AVW established in another series of non-consecutive patients (n = 150, Cohort B) with NF and concordant Doppler-echocardiographic findings, we found that the percentage of patients with evidence of severe stenosis in Cohort A was 70% in patients with PLF-LG and 86% in patients with NF-HG.
  
  
  CONCLUSIONS
  The aortic valve weight data reported in this study provide evidence that a large proportion of patients with PLF and low-gradient have a severe stenosis and that the gradient may substantially underestimate stenosis severity in these patients. A multi-parametric approach including all Doppler-echocardiographic parameters of valve function as well as other complementary diagnostic tests may help correctly identify these patients.
authors.affiliation: Department of Cardiology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, 2725 Chemin Sainte-Foy, Québec, Canada G1V-4G5.
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Clavel
authors.affiliation: Department of Cardiac Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Nancy
authors.initials: N
authors.lastname: Côté
authors.affiliation: Department of Cardiac Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Patrick
authors.initials: P
authors.lastname: Mathieu
authors.affiliation: Department of Cardiology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, 2725 Chemin Sainte-Foy, Québec, Canada G1V-4G5.
authors.forename: Jean G
authors.initials: JG
authors.lastname: Dumesnil
authors.affiliation: Department of Cardiac Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Audrey
authors.initials: A
authors.lastname: Audet
authors.affiliation: Department of Cardiac Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Andrée
authors.initials: A
authors.lastname: Pépin
authors.affiliation: Department of Pathology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Christian
authors.initials: C
authors.lastname: Couture
authors.affiliation: Department of Cardiac Surgery, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Dominique
authors.initials: D
authors.lastname: Fournier
authors.affiliation: Department of Pathology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Trahan
authors.affiliation: Department of Pathology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Pagé
authors.affiliation: Department of Cardiology, Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, 2725 Chemin Sainte-Foy, Québec, Canada G1V-4G5 philippe.pibarot@med.ulaval.ca.
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
mesh_terms: D000368:Aged; D001021:Aortic Valve / Q000002:abnormalities / Q000473:pathology* / Q000601:surgery; D001024:Aortic Valve Stenosis / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D000082882:Bicuspid Aortic Valve Disease; D015331:Cohort Studies; D015150:Echocardiography, Doppler; D005260:Female; D006349:Heart Valve Diseases / Q000473:pathology; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000473:pathology; D009929:Organ Size / Q000502:physiology; D012727:Sex Characteristics; D013318:Stroke Volume / Q000502:physiology; D014261:Tricuspid Valve / Q000473:pathology
keywords: Aortic stenosis; Echocardiography; Low flow; Surgery
references.citation: Circ Cardiovasc Imaging. 2012 Jan;5(1):27-35
references.pmid: 22109983
references.citation: Circulation. 2007 Jun 5;115(22):2856-64
references.pmid: 17533183
references.citation: J Am Coll Cardiol. 2012 Jan 17;59(3):235-43
references.pmid: 22240128
references.citation: J Heart Valve Dis. 2008 Jan;17(1):81-8
references.pmid: 18365573
references.citation: J Am Coll Cardiol. 2013 Dec 17;62(24):2329-38
references.pmid: 24076528
references.citation: Circulation. 2013 Sep 17;128(12):1349-53
references.pmid: 23956211
references.citation: J Am Coll Cardiol. 2012 Oct 2;60(14):1259-67
references.pmid: 22657269
references.citation: Eur Heart J. 2012 Oct;33(19):2451-96
references.pmid: 22922415
references.citation: Circulation. 2011 Sep 27;124(13):e360; author reply e362-3
references.pmid: 21947940
references.citation: Ann Thorac Surg. 2011 Jun;91(6):1808-15
references.pmid: 21619977
references.citation: J Am Coll Cardiol. 2012 Nov 6;60(19):1845-53
references.pmid: 23062546
references.citation: Heart. 2011 May;97(9):721-6
references.pmid: 20720250
references.citation: Eur Heart J. 2013 Jul;34(25):1906-14
references.pmid: 23533186
references.citation: JACC Cardiovasc Imaging. 2013 Feb;6(2):175-83
references.pmid: 23489531
references.citation: Circulation. 2013 Sep 10;128(11 Suppl 1):S235-42
references.pmid: 24030412
references.citation: J Thorac Cardiovasc Surg. 2012 Dec;144(6):1421-7
references.pmid: 22336754
references.citation: Circulation. 2013 Aug 6;128(6):622-31
references.pmid: 23812184
references.citation: Eur J Clin Invest. 2011 Nov;41(11):1172-9
references.pmid: 21988540
references.citation: Circulation. 2011 Mar 1;123(8):887-95
references.pmid: 21321152
references.citation: J Am Coll Cardiol. 2011 Jul 19;58(4):402-12
references.pmid: 21757118
references.citation: Eur Heart J. 2010 Feb;31(3):281-9
references.pmid: 19737801
references.citation: Ann Thorac Surg. 2008 Dec;86(6):1781-9
references.pmid: 19021976
references.citation: Circulation. 2013 Oct 15;128(16):1781-9
references.pmid: 24048203
references.citation: J Am Coll Cardiol. 2004 Nov 2;44(9):1847-55
references.pmid: 15519018