Diagnostic value of angiography-derived index of microcirculatory resistance (AMR) for coronary microcirculatory dysfunction (CMD) and its prognostic significance in patients with chronic coronary syndromes in the smoking population

Abstract

This study aims to analyze the prognostic significance of angiographic microvascular resistance (AMR) derived from functional coronary angiography in diagnosing coronary microvascular dysfunction (CMD) among patients with chronic coronary syndrome (CCS), particularly focusing on the prognostic significance of CMD in smokers. Additionally, this study assesses the prognostic significance of the diagnostic accuracy of the AMR index for CMD in CCS patients within the smoking population. Seventy-five CCS patients were studied for IMR measurement between June 2018 and December 2020, classified into CMD and non-CMD groups. Pearson correlation analyzed AMR and IMR relationship, while ROC curves determined AMR's predictive value for CMD with optimal cutoff value. An additional 223 CCS patients were included for AMR measurements. The study's primary endpoint was MACE occurrence, followed up through telephone calls. COX one-way analysis and Kaplan-Meier analysis evaluated the association between AMR and MACE risk. In the study, 52% of patients were diagnosed with CMD, and the AUC under the AMR curve for predicted IMR ≥ 25 was 0.90 (95% CI: 0.79-0.95). The CMD group had a higher proportion of female patients, smokers, and those with hypertension and diabetes mellitus compared to the non-CMD group (all P < .05). The CMD group exhibited higher AMR values than the non-CMD group (3.20 ± 0.5 vs 1.95 ± 0.45, P < .01), with a significant correlation between AMR and IMR (R2 = 0.81, P