Ratio of Mixed Venous Oxygen Saturation-to-Pulmonary Capillary Wedge Pressure: Insights from the Veterans Affairs Clinical Assessment, Reporting, and Tracking Program

Dustin Hillerson, Richard Charnigo, Sun Moon Kim, Amrita Iyengar, Matthew Lane, Naoki Misumida, Andrew R. Kolodziej, Gbolahan O. Ogunbayo, Ahmed Abdel-Latif, John C. Gurley, David C. Booth

Research output: Contribution to journalArticlepeer-review


Background: Hemodynamic values from right heart catheterization aid diagnosis and clinical decision-making but may not predict outcomes. Mixed venous oxygen saturation percentage and pulmonary capillary wedge pressure relate to cardiac output and congestion, respectively. We theorized that a novel, simple ratio of these measurements could estimate cardiovascular prognosis. Methods: We queried Veterans Affairs' databases for clinical, hemodynamic, and outcome data. Using the index right heart catheterization between 2010 and 2016, we calculated the ratio of mixed venous oxygen saturation-to-pulmonary capillary wedge pressure, termed ratio of saturation-to-wedge (RSW). The primary outcome was time to all-cause mortality; secondary outcome was 1-year urgent heart failure presentation. Patients were stratified into quartiles of RSW, Fick cardiac index (CI), thermodilution CI, and pulmonary capillary wedge pressure alone. Kaplan-Meier curves and Cox proportional hazards models related comparators with outcomes. Results: Of 12 019 patients meeting inclusion criteria, 9826 had values to calculate RSW (median 4.00, interquartile range, 2.67-6.05). Kaplan-Meier curves showed early, sustained separation by RSW strata. Cox modeling estimated that increasing RSW by 50% decreases mortality hazard by 19% (estimated hazard ratio, 0.81 [95% CI, 0.79-0.83], P<0.001) and secondary outcome hazard by 28% (hazard ratio, 0.72 [95% CI, 0.70-0.74], P<0.001). Among the 3793 patients with data for all comparators, Cox models showed RSW best associated with outcomes (by both C statistics and Bayes factors). Furthermore, pulmonary capillary wedge pressure was superior to thermodilution CI and Fick CI. Multivariable adjustment attenuated without eliminating the association of RSW with outcomes. Conclusions: In a large national database, RSW was superior to conventional right heart catheterization indices at assessing risk of mortality and urgent heart failure presentation. This simple calculation with routine data may contribute to clinical decision-making in this population.

Original languageEnglish
Pages (from-to)E008838
JournalCirculation: Heart Failure
Issue number2
StatePublished - Feb 1 2022

Bibliographical note

Funding Information:
The authors are grateful to Dr Susan S. Smyth and the peer reviewers for review of the article. This material is based upon work supported, in part, by the Department of Veterans Affairs, Veterans Health Administration, and Office of Research and Development, along with resources and the facilities at the Lexington VA Medical Center. The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government.

Funding Information:
Dr Abdel-Latif is supported by National Institutes of Health grant R01 HL124266. The other authors report no conflicts.

Publisher Copyright:
© 2022 Lippincott Williams and Wilkins. All rights reserved.


  • cardiac catheterization
  • diagnosis
  • heart failure
  • hemodynamics
  • outcome assessment

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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