title: Relationship Between QT Interval and Outcome in Low-Flow Low-Gradient Aortic Stenosis With Low Left Ventricular Ejection Fraction.
abstract: QT interval has been shown to be associated with cardiovascular events. There is no data regarding the association between QT interval and left ventricular (LV) function and prognosis in patients with low LV ejection fraction (LVEF), low-flow, low-gradient aortic stenosis (LF-LG AS). We aimed to examine the relationship between corrected QT interval (QTc) and LV function and outcome in these patients.
  
  
  
  Ninety-three patients (73±10 years; 74% men) with LF-LG AS (mean gradient <40 mm Hg and indexed aortic valve area ≤0.6 cm2/m2) and reduced LVEF (≤40%) were prospectively included in this analysis and 63 of them underwent aortic valve replacement within 3 months following inclusion. Prolonged QTcwas defined as QTc>450 ms in men and >470 ms in women. LV global longitudinal strain was measured by speckle tracking and expressed in absolute value |%|. QTccorrelated with the following: global longitudinal strain (r=-0.40, P=0.005), LVEF (r=-0.27, P=0.02), stroke volume (r=-0.35, P=0.007), and B-type natriuretic peptide (r=0.45, P=0.0006). During a median follow-up of 2.0 years, 49 patients died. Prolonged QTcwas associated with a 2-fold increase in all-cause mortality (hazard ratio=2.05; P=0.01) and cardiovascular mortality (hazard ratio=1.89; P=0.04). In multivariable analysis adjusted for EuroSCORE, aortic valve replacement, previous myocardial infarction, LVEF, and ß-blocker medication, prolonged QTcwas independently associated with all-cause mortality (hazard ratio=2.56; P=0.008) and cardiovascular mortality (hazard ratio=2.50; P=0.02).
  
  
  
  In patients with LF-LG AS and reduced LVEF, longer QTcinterval was associated with worse LV function and increased risk of death. Assessment of QTcmay provide a simple and inexpensive tool to enhance risk stratification in LF-LG AS patients.
  
  
  
  URL: https://www.clinicaltrials.gov. Unique identifier: NCT 01835028.
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Abdellaziz
authors: A
authors: Dahou
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Oumhani
authors: O
authors: Toubal
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Marie-Annick
authors: MA
authors: Clavel
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Jonathan
authors: J
authors: Beaudoin
authors: CHU Limoges, Hôpital Dupuytren Service Cardiologie, Limoges, France INSERM 1094, Faculté de médecine de Limoges, Limoges, France.
authors: Julien
authors: J
authors: Magne
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Patrick
authors: P
authors: Mathieu
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: François
authors: F
authors: Philippon
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Jean G
authors: JG
authors: Dumesnil
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Rishi
authors: R
authors: Puri
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Henrique B
authors: HB
authors: Ribeiro
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Éric
authors: É
authors: Larose
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada.
authors: Josep
authors: J
authors: Rodés-Cabau
authors: Institut Universitaire de Cardiologie et de Pneumologie de Québec/Québec Heart & Lung Institute, Laval University, Québec City, Québec, Canada philippe.pibarot@med.ulaval.ca.
authors: Philippe
authors: P
authors: Pibarot
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000503:physiopathology / Q000628:therapy*; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000503:physiopathology*; D015897:Comorbidity; D000072700:Conservative Treatment; D015150:Echocardiography, Doppler; D005260:Female; D005492:Folic Acid / Q000031:analogs & derivatives; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D011792:Quebec / Q000453:epidemiology; D013318:Stroke Volume; D014748:Vinca Alkaloids
chemical_list: C556242:EC 0489; D014748:Vinca Alkaloids; D005492:Folic Acid
keywords: B‐type natriuretic peptide; Doppler‐echocardiography; QT interval; aortic stenosis; left ventricular function; low‐flow low gradient; outcome; risk stratification