Predictive value of the average three-vessel microvascular resistance in patients with non-ST-segment elevation myocardial infarction after percutaneous coronary intervention.

Objectives: We investigated the predictive value of the average microvascular resistance of the three main vessels (3VA-AMR) for the prognosis of patients with non-ST-segment elevation myocardial infarction (NSTEMI) after percutaneous coronary intervention (PCI).

Methods: This study was conducted on patients with NSTEMI who underwent PCI between March 1, 2021, and February 28, 2022, at Fujian Medical University Union Hospital. Quantitative flow ratio (QFR) analysis was conducted on all patients' PCI angiography images to assess postoperative QFR and angio-based microvascular resistance (AMR) for three main vessels. All enrolled patients were devided into two groups based on the criteria for coronary microvascular dysfunction (CMD): high 3VA-AMR group and low 3VA-AMR group. The primary outcome was 2-year major adverse cardiac events (MACEs), including cardiovascular death, myocardial infarction, and ischemia-driven revascularization.

Results: A total of 290 patients were included in the final analysis. Compared with the low 3VA-AMR group, the three vessels of high 3VA-AMR group showed lower area stenosis (49.46 ± 13.70 % vs. 52.93 ± 15.43 %，P = 0.001), higher QFR value (0.92 ± 0.05 vs. 0.88 ± 0.09, P < 0.001), and higher AMR value (274.50 [257.33-301.42] mmHg*s/m vs. 208.00 [182.00-231.83] mmHg*s/m, P < 0.001). The incidence of 2-year MACEs was significantly higher in the high 3VA-AMR group than in the low 3VA-AMR group (21.90 % vs. 10.27 %, P = 0.007). Univariate and multivariate Cox regression analyses confirmed that 3VA-AMR was independently associated with 2-year MACEs (HR:1.007, 95 % CI:1.004-1.010, P < 0.001). The Kaplan-Meier method further confirmed the difference in 2-year MACE risk between two groups. Receiver operating characteristic curve analysis showed a significant correlation between 3VA-AMR and MACE (area under the curve: 0.701, P < 0.001).

Conclusions: 3VA-AMR was an independent risk factor for 2-year MACEs in NSTEMI patients. Compared with target-vessel AMR, 3VA-AMR demonstrated superior predictive value for 2-year MACEs following PCI.