title: Impact of valvuloarterial impedance on 2-year outcome of patients undergoing transcatheter aortic valve implantation.
abstract: BACKGROUND
  Elderly patients with severe aortic stenosis undergoing transcatheter aortic valve implantation (TAVI) often have increased calcification and fibrosis of the aorta. Indices that account for the severity of valvular obstruction and systemic vascular impedance may better assess total left ventricular afterload. The aims of the present study were to evaluate changes in valvuloarterial impedance (Zva), systemic arterial compliance, and systemic vascular resistance after TAVI and to investigate the prognostic value of these parameters.
  
  
  METHODS
  A total of 116 patients (49% men; mean age, 81 ± 8 years) with symptomatic severe aortic stenosis underwent TAVI. Zva, systemic arterial compliance, and systemic vascular resistance were measured at baseline and 1 and 12 months after TAVI. The primary end point was all-cause mortality.
  
  
  RESULTS
  After TAVI, there was a significant reduction in Zva (from 5.40 ± 1.52 mm Hg/mL/m(2) at baseline to 4.13 ± 1.17 mm Hg/mL/m(2) at 1 month and 4.35 ± 1.38 mm Hg/mL/m(2) at 1 year, P < .001). Systemic arterial compliance (from 0.57 ± 0.27 to 0.57 ± 0.28 and 0.53 ± 0.27 mL/m(2)/mm Hg, P = .408) and systemic vascular resistance (from 1,938 ± 669 to 1,856 ± 888 and 1,871 ± 767, dyne·s·cm(-5), P = .697) did not change significantly over time. During a median follow-up period of 25 months, survival rates of patients with baseline Zva ≥ 5 mm Hg/mL/m(2) were lower compared with those with Zva < 5 mm Hg/mL/m(2) (82% vs 91%, respectively, log-rank P = .04). On multivariate Cox proportional-hazards analysis, baseline Zva was independently associated with all-cause mortality (hazard ratio, 1.48; 95% confidence interval, 1.05-2.07; P = .025).
  
  
  CONCLUSIONS
  In patients undergoing TAVI, there is a significant postprocedural reduction in Zva, but there is no reduction in systemic arterial compliance or vascular resistance. Baseline Zva is an independent predictor of overall mortality at 2-year follow-up.
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
authors.forename: Spyridon
authors.initials: S
authors.lastname: Katsanos
authors.forename: Kai Hang
authors.initials: KH
authors.lastname: Yiu
authors.forename: Marie-Annick
authors.initials: MA
authors.lastname: Clavel
authors.forename: Josep
authors.initials: J
authors.lastname: Rodés-Cabau
authors.forename: Darryl
authors.initials: D
authors.lastname: Leong
authors.forename: Frank
authors.initials: F
authors.lastname: van der Kley
authors.forename: Nina
authors.initials: N
authors.lastname: Ajmone Marsan
authors.forename: Jeroen J
authors.initials: JJ
authors.lastname: Bax
authors.forename: Philippe
authors.initials: P
authors.lastname: Pibarot
authors.forename: Victoria
authors.initials: V
authors.lastname: Delgado
mesh_terms: D000369:Aged, 80 and over; D001021:Aortic Valve / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000601:surgery*; D001024:Aortic Valve Stenosis / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D006328:Cardiac Catheterization; D015150:Echocardiography, Doppler; D005260:Female; D006350:Heart Valve Prosthesis; D019918:Heart Valve Prosthesis Implantation / Q000379:methods* / Q000401:mortality; D006801:Humans; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate; D014655:Vascular Resistance