Clinical characteristics and predictors of mortality in patients with refractory angina due to obstructive and non-obstructive chronic coronary syndromes: a contemporary retrospective cohort study
Bibliographic record
Abstract
Abstract Background Refractory angina (RA) is a major global cardiovascular healthcare challenge due to the increasing burden of chronic coronary syndromes (CCS) worldwide and an ageing population [1, 2]. Patients suffer from persistent life-limiting angina despite maximal guideline-directed treatment; experience a poor quality of life; and incur significant excess healthcare costs. RA represents a large unmet clinical need with few contemporary data on the clinical characteristics and outcomes of these patients. Purpose This study investigated the characteristics and prognosis of patients with RA due to both obstructive and non-obstructive CCS. Methods Retrospective single-centre observational cohort study of patients diagnosed with RA, managed in a tertiary cardiac centre with a dedicated specialist angina service, between May 1995 to August 2023. Mortality was obtained from a national healthcare database and patient characteristics from hospital electronic records. Statistical analyses included descriptive statistics, Kaplan-Meier survival, univariate and multivariate Cox proportional hazard regression analyses. Results 558 patients (mean age 61±12) were included (Table 1). Most were males (n=350; 63%), had raised BMI (median 28 [25-31]), and a Canadian Cardiovascular Society Class of ≥2 (n=495; 85%). Hypertension (63%), dyslipidaemia (61%) and current/former smoking (63%) were the most common cardiovascular risk factors. Rates of diabetes mellitus (40%) and previous myocardial infarction (MI, 41%) were similar. Previous CABG±PCI (43%) was more prevalent than PCI alone (27%). 87% had a normal LVEF ≥50%. 68 patients died over a median follow-up of 6 years. 5-year mortality rate was 7.4% (95%CI: 0.89-0.95) and 10-years, 14% (95%CI: 0.82-0.89). On multivariate analysis, age (hazard ratio [HR] 1.1; P<0.01), diabetes mellitus (HR 2.2; P<0.01) and a reduced LVEF (41-49%: HR 2.4; <40%: HR 2.7; both P<0.01) were independent predictors of mortality. Prior revascularisation (PCI or CABG) was associated with a worse 5-year (9.3 vs. 2.8%) and 10-year (18 vs. 2.8%) mortality compared to those with no revascularisation (P=0.0001; Figure 1). Conclusion In an analysis of the clinical characteristics and outcomes of patients with RA from a contemporary single centre cohort, diabetes mellitus, a modifiable risk factor and impaired left ventricular function were major predictors of mortality. Prior revascularisation also conferred a significantly worse prognosis. Compared to previous US and European cohorts [3, 4], we observed lower rates of MI and revascularisation. Whilst patients with RA with no obstructive epicardial coronary disease contributed to an overall improved mortality rate, mortality in patients with prior revascularisation and obstructive CCS was also better than previously reported and support the favourable prognosis of RA. These findings inform the understanding of the treatment priorities for patients with RA.Table 1.Patient demographics Figure 1.Kaplan-Meier survival analysis
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 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 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".