title: Prognostic value of capnography during rest and exercise in patients with heart failure.
abstract: New variables obtained from cardiopulmonary exercise testing (CPX) have received attention in recent years, in particular the partial pressure of end-tidal carbon dioxide (P(ET) CO(2) ). The purpose of this study was to therefore comprehensively assess the ability of resting and exercise P(ET) CO(2) to predict major cardiac events in a heart failure (HF) cohort referred for CPX. A total of 963 patients with systolic HF undergoing symptom-limited CPX were included in the analysis. Resting and exercise P(ET) CO(2) along with other CPX variables were determined, and patients were followed for major adverse events. With regard to resting measures, multivariate analysis revealed that left ventricular ejection fraction was the most robust prognostic marker (P<.001) while resting P(ET) CO(2) added significant predictive value and was retained in the regression (P<.001). When exercise data were considered, the multivariate analysis revealed that the P(ET) CO(2) apex during exercise added predictive value and was retained (P<.05). In what is the largest evaluation of P(ET) CO(2) in the assessment of systolic HF patients to date, the authors substantiate prior (smaller) studies showing prognostic utility of P(ET) CO(2) , both as a resting measure (an important potential screening tool) and during exercise. These data add to the rationale to incorporate P(ET) CO(2) as a routine monitoring component in HF management.
authors.affiliation: Physical Therapy Program, Department of Orthopaedics and Rehabilitation, School of Medicine, University of New Mexico, Albuquerque, NM 87131-0001, USA. rarena@salud.unm.edu
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.forename: Marco
authors.initials: M
authors.lastname: Guazzi
authors.forename: Jonathan
authors.initials: J
authors.lastname: Myers
authors.forename: Paul
authors.initials: P
authors.lastname: Chase
authors.forename: Daniel
authors.initials: D
authors.lastname: Bensimhon
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Cahalin
authors.forename: Mary Ann
authors.initials: MA
authors.lastname: Peberdy
authors.forename: Euan
authors.initials: E
authors.lastname: Ashley
authors.forename: Erin
authors.initials: E
authors.lastname: West
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Forman
mesh_terms: D000328:Adult; D000368:Aged; D019296:Capnography / Q000379:methods*; D015331:Cohort Studies; D018450:Disease Progression; D005080:Exercise Test; D054143:Heart Failure, Systolic / Q000175:diagnosis* / Q000401:mortality / Q000601:surgery; D016027:Heart Transplantation / Q000706:statistics & numerical data; D006353:Heart-Assist Devices / Q000706:statistics & numerical data; D006801:Humans; D008137:Longitudinal Studies; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D013318:Stroke Volume