Prevalence of Coronary Microvascular Dysfunction and Epicardial Spasm in Patients With Angina and Myocardial Bridge
Bibliographic record
Abstract
Background: Myocardial bridges (MB) are prevalent but not universally associated with angina. The mechanisms linking MB and angina are poorly defined. The objective of this study was to determine the prevalence of epicardial spasm, microvascular spasm, and/or endothelium-independent coronary microvascular dysfunction (CMD) in patients with MB which might explain symptoms. Methods: Patients with known MB and chest pain at the University of Chicago Medical Center between 2020-2023 were included. All patients underwent dobutamine testing with measurement of resting full-cycle ratio to determine hemodynamic significance (resting full-cycle ratio ≤0.76). Endothelium-independent CMD was defined as coronary flow reserve <2.0 or index of microvascular resistance ≥25 on adenosine testing. Microvascular spasm was defined as chest pain and electrocardiogram changes with nonischemic fractional flow reserve with acetylcholine. Epicardial spasm was defined as dynamic stenosis of >90% of the epicardial vessel or ischemic fractional flow reserve (≤0.8) with acetylcholine. Results: A total of 30 patients (mean age, 47 ± 10 years; 60% female) with MB were studied. Endothelium-independent CMD, microvascular spasm, and epicardial spasm occurred commonly in 60%, 29%, and 37% of patients respectively, with 77% having at least one abnormality. The MB was hemodynamically significant in 47% of patients, and the prevalence of these coexisting conditions was not affected by hemodynamic significance. Conclusions: Epicardial spasm, microvascular spasm, and endothelium-independent CMD are prevalent in patients presenting with known MB and chest pain irrespective of the hemodynamic significance of the bridge. Invasive coronary function testing may play an important role in uncovering alternative explanations for angina in patients with known MB.
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) | 0.000 | 0.056 |
| Bibliometrics | 0.000 | 0.000 |
| 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".