Periprocedural assessment of coronary microcirculatory function to predict clinical outcomes after elective PCI

Background Percutaneous coronary intervention (PCI) could restore epicardial blood flow through the stent‐based angioplasty. However, coronary microcirculatory function also impacts clinical outcomes and can be quantified by the angiography‐derived index of microcirculatory resistance (angio‐IMR). The prognostic significance of periprocedural angio‐IMR in patients undergoing elective PCI remains unclear. This study aimed to assess angio‐IMR before and after PCI, as well as their association with long‐term prognosis. Methods Data from 1,768 patients with stable coronary artery disease (CAD) undergoing elective PCI were analyzed. The primary endpoint was major adverse cardiac events (MACE) comprising death and nonfatal myocardial infarction. Results The median angio‐IMR was 11.3 (interquartile range IQR, 7.7 ‐ 15.0) and 17.0 (IQR, 14.1 ‐ 20.4) before and after PCI (p 10 was independently associated with an increased risk of MACE (adjusted hazard ratio, 2.43; 95% confidence interval, 1.32 ‐ 4.49; p = 0.004). In comparison with periprocedural myocardial infarction, Δangio‐IMR > 10 could provide additional prognostic value in predicting MACE (area under the curve, 0.681 vs. 0.635, p < 0.05). Conclusions Δangio‐IMR was a predictor of MACE in patients with stable CAD undergoing elective PCI. Incorporating Δangio‐IMR could enhance the identification of patients at high risk of MACE.