Outcomes from Quantitative Flow Ratio-Guided Complete Revascularization and Angiography-Guided Percutaneous Coronary Intervention in Patients with ST-Segment Elevation Myocardial Infarction

Abstract

BACKGROUND Quantitative flow ratio (QFR) is a non-invasive angiographic tool that provides functional assessment of coronary stenosis without the need for pressure wires or hyperemia. This prospective study aimed to evaluate the procedural and inpatient treatment outcomes of QFR-guided percutaneous coronary intervention (PCI) compared with that of angiography-guided PCI in patients with ST-elevation myocardial infarction (STEMI) undergoing staged revascularization of non-culprit lesions. MATERIAL AND METHODS This randomized prospective single-center study was conducted at the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics (July 2020-June 2021). After successful culprit-lesion PCI for STEMI, 124 participants with residual angiographically significant non-culprit stenosis (50-75%) were randomized to QFR-guided (n=62) or angiography-guided PCI (n=62). Procedural characteristics, fluoroscopy time, contrast usage, stent number/length, and inpatient treatment outcomes were compared between groups using SPSS 28.0 software. RESULTS Compared with PCI guided by visual estimation alone, the QFR-guided PCI group showed significant reductions in fluoroscopy time (median 6.2 vs 8.0 min, P=0.009), contrast volume (median 100 vs 120 mL, P=0.038), number of stents implanted (median 1.5 vs 2.0, P=0.002), and stent length (median 28 vs 45 mm, P<0.001). No significant differences were found between the groups in terms of periprocedural complications or length of inpatient stay. CONCLUSIONS QFR-guided PCI of the non-culprit lesion resulted in shorter fluoroscopy time, lower contrast volume, and a smaller number and average length of implanted stents. These findings highlight the potential of QFR to enhance procedural efficiency and reduce unnecessary stenting in clinical practice without compromising patient outcomes.

Figure 1

Patient selection into this study with a case example. Figure represents a case from our study of a 72-year-old man who was admitted to our center with acute chest pain. Electrocardiography confirmed an inferior ST-elevation myocardial infarction (A). Coronary angiography revealed a total occlusion of the right coronary artery (B), and the patient underwent an index culprit lesion percutaneous coronary intervention (PCI) to restore blood flow in the occluded artery (C). Coronary angiography also identified an approximately 75% stenosis in the left anterior descending artery (LAD) (white arrowhead) (D). A quantitative flow ratio of the LAD was performed, yielding a result of 0.74, indicating that the stenosis was hemodynamically significant (E). The LAD was treated during a staged procedure 3 months after the index PCI (F).

Figure 2

Fluoroscopy time (min) in quantitative flow ratio (QFR)-guided and angiography-guided percutaneous coronary intervention (PCI) groups during second-stage stenting procedure. This box plot illustrates the significantly shorter fluoroscopy time in the QFR-guided group than in the angiography group during the second-stage stenting procedure (6.59±0.42 min vs 10.88±1.24 min). P=0.009, based on the nonparametric Mann-Whitney test.

Figure 3

Contrast volume (mL) in quantitative flow ratio (QFR)-guided and angiography-guided percutaneous coronary intervention (PCI) groups during second-stage stenting procedure. This box plot illustrates the significantly lower contrast volume used in the QFR-guided group than in the angiography group during the second-stage stenting procedure (116.45±4.38 mL vs 148.23±9.19 mL). P=0.038, based on the nonparametric Mann-Whitney test.

Figure 4

Stents implanted (units) in quantitative flow ratio (QFR)-guided and angiography-guided percutaneous coronary intervention (PCI) groups during second-stage stenting procedure. This bar chart illustrates the statistically significant difference in the number of stents implanted between the QFR-guided and angiography-guided PCI groups during the second-stage stenting procedure, showing that the QFR method was associated with fewer stents per procedure (1.69±1.0 vs 2.26±0.14). χ²=10.971; lls=4; P=0.027; *, ** P<0.05, based on the χ² independence test.

Figure 5

Length of implanted stents (mm) in quantitative flow ratio (QFR)-guided and angiography-guided percutaneous coronary intervention (PCI) groups during second-stage stenting procedure. This box plot illustrates the significantly shorter implanted stent length in the QFR-guided group than in the angiography group during the second-stage stenting procedure (33.18±2.26 mm vs 47.69±3.11 mm). P<0.001, based on the nonparametric Mann-Whitney test.