Analysis of the Canadian database of patients with Chronic Total Occlusion - Percutaneous Coronary Intervention
Bibliographic record
Abstract
Background: Chronic total occlusions (CTOs) are complete blockages of coronary arteries observed in roughly one out of every 5 patients with coronary artery disease (CAD). Percutaneous coronary intervention (PCI) is a minimally invasive procedure used to treat CAD. However, its chances of success were initially reported to be lower in patients with CTO. Recent improvements in technology and techniques have improved these chances. Furthermore, centres with higher volumes tend to report better outcomes. The available evidence to date is largely drawn from registry studies in the United States and Japan. Given the potential for variation in patient characteristics, practice patterns and outcomes across settings, there is a need to examine the Canadian experience in CTO PCI.Objectives: 1)To characterize patients undergoing CTO PCI in Canada2)To estimate the impact of previously reported risk factors for procedural success and complications in this population. 3)To examine characteristics of patients receiving antegrade vs. retrograde CTO PCI4)To estimate the impact of risk factors for procedural success and complications among subjects who received antegrade vs. retrograde CTO PCI Methods: This thesis reports on the first analysis of the Canadian CTO PCI registry (CCTOP), the first multicentre Canadian cohort of patients who underwent CTO-PCI in one of six major participating tertiary care centres during 2014 to 2019. A review of the literature is provided, including registry studies from other jurisdictions. Descriptive statistics were used to summarize demographic and clinical characteristics of patients, and characteristics of CTO-PCI procedures applied in CCTOP. The outcomes of interest included short-term procedural success of CTO-PCI, defined as technical success without major complication within 30 days and complications. Logistic regression and classification and regression tree (CART) models were used to estimate the association between each risk factors for procedural success. Results: A total 1194 consecutive patients were examined among whom 549 underwent antegrade-only (46 %) and 525 underwent retrograde (44%) CTO-PCI procedures. Procedural success was high overall (n=928, 88%). It was higher for antegrade vs. retrograde procedures as expected (91% vs. 81%). Important predictors of an unsuccessful CTO-PCI included presence of a prior Coronary Artery Bypass Graft (CABG) procedure (OR, 0.46, [95% CI, 0.22,0.94]), severely reduced Left Ventricular Ejection Fraction (LVEF) (OR, 0.29, [95% CI, 0.10,0.88]), collateral that were not crossed(OR, 0.10, [95% CI, 0.04,0.29]), ambiguity in the proximal cap(OR, 0.50, [95% CI, 0.25,0.99]). Classification and Regression Trees (CART) analysis did not identify any interactions between the risk factors studied.Conclusions: This analysis demonstrates that the Canadian experience with CTO-PCI is comparable to other major centres worldwide in terms of the high overall success and low risk of complications. Further, it shows that retrograde procedures can be attempted with a high level of success for certain groups of patients
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.002 | 0.010 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.008 | 0.016 |
| Science and technology studies | 0.002 | 0.000 |
| Scholarly communication | 0.002 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".