title: End-Tidal CO2 Predicts Reduction in Mitral Regurgitation in Patients Undergoing Percutaneous Mitral Valve Edge-to-Edge Repair.
abstract: OBJECTIVE
  We evaluated end-tidal CO2 (etCO2), which has been proposed to assess acute hemodynamic changes, to guide percutaneous edge-to-edge mitral valve repair (PMVR) with the MitraClip system.
  
  
  METHODS
  Thirty-nine patients (aged 78 ± 14 years) undergoing PMVR for moderate-to-severe mitral regurgitation (MR) of primary and secondary etiology were included. General anesthesia was maintained with sevoflurane and constant ventilation parameters to ensure stable etCO2 tension. MR grade was determined semiquantitatively by transesophageal echocardiography by 2 experienced operators blinded to etCO2 measurements. etCO2 levels were measured 3, 5, 10, and 15 min after final MitraClip placement.
  
  
  RESULTS
  Overall, etCO2 increased from 32.2 ± 1.7 before to 35.4 ± 3.0, 34.6 ± 2.6, and 34.2 ± 2.4 mm Hg 3, 5, and 10 min after implantation. A significant correlation was noted between the echocardiographic reduction in MR grade and the increase in etCO2. ANOVA for repeated measures confirmed a significant increase in etCO2 after clip implantation (corrected F = 20.0; p < 0.001) and revealed a significantly greater increase in etCO2 in patients with MR reduction ≥2 grades as compared to lesser MR reductions (F = 6.47; p = 0.015). Blood pressure changes did not correlate with the degree of MR reduction.
  
  
  CONCLUSIONS
  We observed a close correlation between the reduction in MR grade during PMVR and etCO2, which might evolve as a useful parameter to complement treatment guidance during PMVR.
authors.affiliation: Clinic III for Internal Medicine, Department of Cardiology, Heart Center, University of Cologne, Cologne, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Huntgeburth
authors.forename: Robert
authors.initials: R
authors.lastname: Schier
authors.forename: Roman
authors.initials: R
authors.lastname: Pfister
authors.forename: Henrik
authors.initials: H
authors.lastname: Ten Freyhaus
authors.forename: Kristina
authors.initials: K
authors.lastname: Dahlem
authors.forename: Kai
authors.initials: K
authors.lastname: Friedrichs
authors.forename: Stephan
authors.initials: S
authors.lastname: Baldus
authors.forename: Volker
authors.initials: V
authors.lastname: Rudolph
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002245:Carbon Dioxide / Q000097:blood*; D017548:Echocardiography, Transesophageal; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000379:methods*; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000097:blood* / Q000601:surgery*; D012372:ROC Curve; D016896:Treatment Outcome
chemical_list: D002245:Carbon Dioxide
keywords: End-tidal CO2; MitraClip; Mitral regurgitation; Percutaneous mitral valve edge-to-edge-repair; Procedural guidance