Effect of a national guideline on postoperative troponin surveillance: a retrospective cohort study
Bibliographic record
Abstract
Purpose: We aimed to evaluate the effect of the 2017 Canadian Cardiovascular Society (CCS) guidelines on troponin surveillance after noncardiac surgery. Methods: This was a single-centre, retrospective, observational study. Patients aged 40 yr or older undergoing intermediate- to high-risk elective noncardiac surgery between 2016 and 2021 were included. We compared the number and percentage of troponin tests ordered before and after the guidelines were published and compared patient characteristics, specifically cardiovascular comorbidity, using odds ratio’s (OR) with 95% confidence intervals (CIs). Outcomes were myocardial injury, myocardial infarction (MI), and in-hospital mortality. Results: The cohort included 36,386 patients and the median age was 63 yr. Between 2016 and 2018, troponin surveillance was done in 2,461 (13%) of the 19,046 patients, compared with 2,398 (14%) of the 17,340 patients who had surgery between 2019 and 2021 (OR, 1.08; 95% CI, 1.02 to 1.15). Patients who had surgery in the second period had less cardiovascular comorbidity; the adjusted OR for troponin surveillance was 1.14 (95% CI, 1.07 to 1.21). In the two periods, troponin was elevated in 561 (2.9%) and 470 (2.7%) patients, an MI was documented in 54 (0.3%) and 36 (0.2%) patients, and 95 (0.5%) and 73 (0.4%) patients died, respectively. After adjustment for baseline differences in the two periods, the ORs for MI and mortality were 0.83 (95% CI, 0.54 to 1.27) and 0.88 (95% CI, 0.64 to 1.19), respectively. Conclusion: Although the odds of troponin ordering were slightly but significantly higher after publication of the CCS guidelines, the odds for detecting an MI and for mortality did not change.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".