Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Nov 22;193(46):E1757-E1765.
doi: 10.1503/cmaj.202901.

Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario, Canada

Louise Y Sun  1 , Anna Chu  1 , Derrick Y Tam  1 , Xuesong Wang  1 , Jiming Fang  1 , Peter C Austin  1 , Christopher M Feindel  1 , Garth H Oakes  1 , Vicki Alexopoulos  1 , Natasa Tusevljak  1 , Maral Ouzounian  1 , Douglas S Lee  2 ; CorHealth Ontario Cardiac Surgery Risk Adjustment Task Group
Affiliations

Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario, Canada

Louise Y Sun et al. CMAJ. .

Abstract

Background: Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are the 2 most common cardiac surgery procedures in North America. We derived and externally validated clinical models to estimate the likelihood of death within 30 days of CABG, AVR or combined CABG + AVR.

Methods: We obtained data from the CorHealth Ontario Cardiac Registry and several linked population health administrative databases from Ontario, Canada. We derived multiple logistic regression models from all adult patients who underwent CABG, AVR or combined CABG + AVR from April 2017 to March 2019, and validated them in 2 temporally distinct cohorts (April 2015 to March 2017 and April 2019 to March 2020).

Results: The derivation cohorts included 13 435 patients who underwent CABG (30-d mortality 1.73%), 1970 patients who underwent AVR (30-d mortality 1.68%) and 1510 patients who underwent combined CABG + AVR (30-d mortality 3.05%). The final models for predicting 30-day mortality included 15 variables for patients undergoing CABG, 5 variables for patients undergoing AVR and 5 variables for patients undergoing combined CABG + AVR. Model discrimination was excellent for the CABG (c-statistic 0.888, optimism-corrected 0.866) AVR (c-statistic 0.850, optimism-corrected 0.762) and CABG + AVR (c-statistic 0.844, optimism-corrected 0.776) models, with similar results in the validation cohorts.

Interpretation: Our models, leveraging readily available, multidimensional data sources, computed accurate risk-adjusted 30-day mortality rates for CABG, AVR and combined CABG + AVR, with discrimination comparable to more complex American and European models. The ability to accurately predict perioperative mortality rates for these procedures will be valuable for quality improvement initiatives across institutions.

PubMed Disclaimer

Conflict of interest statement

Competing interests: Louise Sun received support from the Canadian Institutes of Health Research (CIHR) for article processing charges. Dr. Sun was named National New Investigator by the Heart and Stroke Foundation of Canada, and is supported by a Clinical Research Chair in Big Data and Cardiovascular Outcomes at the University of Ottawa. Douglas Lee is the Ted Rogers Chair in Heart Function Outcomes, University Health Network, University of Toronto. Dr. Lee also received a research grant from CorHealth Ontario and a foundation grant from the Canadian Institutes of Health Research (CIHR). Peter Austin is supported by a Mid-Career Investigator Award from the Heart and Stroke Foundation. Dr. Austin also reports receiving a CIHR Project Grant, paid to Sunnybrook Research Institute. No other competing interests were declared.

Figures

Figure 1:
Figure 1:
Flow diagram for the derivation cohort. Note: AVR = aortic valve replacement, CABG = coronary artery bypass graft, CIHI DAD = Canadian Institute for Health Information Discharge Abstract Database, OHIP = Ontario Health Insurance Plan. Note: Owing to small cell sizes, some exclusion criteria have been collapsed.
See this image and copyright information in PMC

References

    1. ElBardissi AW, Aranki SF, Sheng S, et al. . Trends in isolated coronary artery bypass grafting: an analysis of the Society of Thoracic Surgeons adult cardiac surgery database. J Thorac Cardiovasc Surg 2012;143:273–81. - PubMed
    1. Tam DY, Bakaeen F, Feldman DN, et al. . Modality selection for the revascularization of left main disease. Can J Cardiol 2019;35:983–92. - PubMed
    1. Shahian DM, Jacobs JP, Badhwar V, et al. . The Society of Thoracic Surgeons 2018 Adult Cardiac Surgery Risk Models: Part 1 – Background, design considerations, and model development. Ann Thorac Surg 2018;105:1411–8. - PubMed
    1. Nashef SA, Roques F, Sharples LD, et al. . EuroSCORE II. Eur J Cardiothorac Surg 2012;41:734–44, discussion 744–5. - PubMed
    1. Johnston A, Mesana TG, Lee DS, et al. . Sex differences in long-term survival after major cardiac surgery: a population-based cohort study. J Am Heart Assoc 2019; 8:e013260. - PMC - PubMed

Publication types

Grants and funding