International journal of general medicine
Development and Internal Validation of a Clinical Prediction Model for Coronary Slow Flow Phenomenon in Type 2 Diabetes: A Retrospective Observational Study
By Hu S, Yan CS, Xu T and 4 others.
Abstract
Background
Patients with type 2 diabetes mellitus (T2DM) may exhibit coronary slow flow phenomenon (CSFP) despite the absence of obstructive epicardial coronary stenosis. Dedicated prediction tools remain limited. This study aimed to develop and internally validate a model for estimating the probability of TIMI frame count (TFC)-defined CSFP in patients with T2DM.
Methods
Among 501 patients with T2DM undergoing coronary angiography at a single center in Xinjiang, China (2021-2025), 429 met eligibility criteria. CSFP was defined as maximum coronary stenosis <40% and TFC >27 frames in at least one major coronary artery. Patients were randomly divided into training (n = 300) and validation (n = 129) cohorts. Predictors selected by penalized regression were entered into multivariable logistic regression. Performance was assessed using area under the receiver operating characteristic curve (ROC-AUC), area under the precision-recall curve (AUC-PR), calibration, bootstrap-corrected concordance index, and decision curve analysis; additional analyses were complementary.