Coronary angiography-derived microcirculatory resistance predicts adverse cardiovascular events in elderly with unstable angina post-percutaneous coronary intervention.

BACKGROUND

Coronary microvascular dysfunction (CMD) has been increasingly recognized as a critical determinant of adverse cardiovascular outcomes. The coronary angiography-derived index of microcirculatory resistance (caIMR) has emerged as a promising noninvasive tool for CMD assessment, yet its prognostic value in elderly patients with unstable angina (UA) following percutaneous coronary intervention (PCI) remains insufficiently explored.

METHODS

This single-center retrospective cohort study enrolled 348 elderly UA patients (age ≥65 years) who underwent PCI between June 2022 and February 2024. Patients were stratified by post-PCI caIMR using a cutoff value of 2.50 mmHg s/cm. The primary endpoint was major adverse cardiovascular events (MACE), including myocardial infarction, stroke, heart failure, angina rehospitalization, and cardiovascular death. Multivariable Cox regression and subgroup analyses were performed to evaluate the prognostic consistency of caIMR across different patient characteristics.

RESULTS

Patients with caIMR ≥2.50 mmHg s/cm demonstrated significantly higher MACE rates. Multivariable analysis confirmed caIMR as an independent predictor, with diabetes mellitus also showing predictive value. Subgroup analyses revealed consistent prognostic value of caIMR regardless of hypertension status or diabetes.

CONCLUSION

Noninvasive caIMR assessment effectively stratifies post-PCI risk in elderly UA patients.