Periprocedural Assessment of Coronary Microcirculatory Function to Predict Clinical Outcomes After Elective...

Percutaneous coronary intervention (PCI) could restore epicardial blood flow through the stent-based angioplasty. However, coronary microcirculatory function also affects 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.

Data from 1768 patients with stable coronary artery disease undergoing elective PCI were analyzed. The primary end point was major adverse cardiac events (MACE) comprising death and nonfatal myocardial infarction.

The median angio-IMR was 11.3 (interquartile range, 7.7-15.0) and 17.0 (interquartile range, 14.1-20.4) before and after PCI (P<0.001), respectively. During a median follow-up period of 20 months, MACE occurred in 53 patients (3.0%). Periprocedural angio-IMR changes (Δangio-IMR) exhibited superior predictive power for MACE compared with post-PCI angio-IMR alone. Specifically, Δangio-IMR>10 was independently associated with an increased risk of MACE (adjusted hazard ratio, 2.43 [95% CI, 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 versus 0.635, P<0.05).

Δangio-IMR was a predictor of MACE in patients with stable coronary artery disease undergoing elective PCI. Incorporating Δangio-IMR could enhance the identification of patients at high risk of MACE.