Abstract 4138477: Small Vessels, Big Challenges: Clinical and Demographic Correlates of Failure to Respond to Optimal Medical Therapy in Patients with Microvascular Angina
Bibliographic record
Abstract
Background: Microvascular angina (MVA), resulting from coronary microvascular dysfunction, affects 40-50% of patients with exertional chest pain or dyspnea and a normal coronary angiogram. This condition significantly impairs quality of life and elevates the risk of major cardiac events, including myocardial infarction, stroke and death. MVA is classified as 'structural' (coronary flow reserve [CFR] <2.5&index of microcirculatory resistance [IMR] >25) or 'functional' (CFR <2.5&IMR <25). Current treatments are empirical, necessitating further investigation. Methods: This single-centre, retrospective study conducted in South Wales from 2019-24 examined MVA cases confirmed via national electronic health records. The Canadian Cardiovascular Society (CCS) angina grade was assessed at diagnosis and post optimal medical therapy (OMT) during clinic visits. Ordinal logistic regression was used to identify independent correlates of higher CCS grade, considering baseline LDL, age, diffuse epicardial disease, sex, hypertension, kidney function, smoking status and HbA1c levels as covariates. Results: Among 64 identified MVA cases (median age 69 yrs, IQR 61.3-77.8; 68.8% male), 81.3% had structural MVA, 6.3% functional MVA and 12.5% mixed disease. Coronary vessel testing was performed on 1, 2 or 3 vessels in 29.7% (n=19), 53.1% (n=34; 21 positive [+ve] in 2 vessels, 13 +ve in 1 vessel) and 17.2% (n=11; 5 +ve in 3 vessels, 5 +ve in 2 vessels, 1 +ve in 1 vessel) of cases, respectively. The LAD was most commonly affected vessel (82.8%). At diagnosis, 79.7% had CCS grade III or higher (Fig 1). Post OMT, 45.3% achieved CCS grade 0-I, 31.8% CCS grade II and 15.6% remained at CCS grade III (refractory angina). Medications included ranolazine (84.4%), beta-blockers (70.3%) and calcium channel blockers (28.1%). Ordinal logistic regression analysis (X 2 =0.27, p=0.033) identified baseline LDL (95% CI [0.16, 1.26]; p=0.011), age (95% CI [-0.12, -0.001]; p=0.045), diffuse epicardial disease (95% CI [0.016, 2.13]; p=0.047) and male sex (95% CI [0.066, 2.36]; p=0.038) as independent correlates of higher CCS grade, signifying poor response to OMT. Conclusion: MVA manifests regionally, underscoring the need for multi-territory testing. Although tailored OMT proved effective for many, 15.6% of patients continued to experience refractory symptoms (CCS grade III). This highlights the necessity for alternative therapeutic strategies to improve patient outcomes in this challenging condition.
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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) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.003 | 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".