Quantitative Flow Ratio for Assessment of Non-Culprit Coronary Artery Lesions During Percutaneous Coronary Intervention (PCI) in 79 Patients Diagnosed with ST-Elevation Myocardial Infarction (STEMI): A Study from a Single Center in Lithuania.

BACKGROUND Approximately half of the patients requiring percutaneous coronary intervention (PCI) for ST-elevation myocardial infarction (STEMI) have additional stenotic coronary artery (CA) lesions in non-infarct-related arteries (non-IRA). This study from a single center in Lithuania aimed to evaluate the use of the quantitative flow ratio (QFR) in assessing non-IRA lesions during PCI in 79 patients diagnosed with STEMI. MATERIAL AND METHODS We prospectively included 105 vessels of 79 patients with worldwide STEMI criteria and ≥1 intermediate (35-75%) lesion in non-IRA between July 2020 and June 2021. For all included patients, QFR analyses were performed twice, during the index PCI (QFR 1) and during a staged procedure ≥3 months later (QFR 2). The QFR analyses were performed with the QAngio-XA 3D and £0.80 were used as cut-off values for PCI. The primary endpoint was a head-to-head numerical agreement between 2 measurements. RESULTS An excellent numerical agreement was found in all investigated lesions, r=0.931, p<0.001, left anterior descending (LAD) r=0.911, p<0.001, left circumflex (LCx) r=0.977, p<0.001, and right coronary artery (RCA) 0.946, p<0.001. Clinical treatment decision-making showed amazing agreement between the 1st and the 2nd QFR analyses, r=0.980, p<0.001. There was 1 disagreement between QFR 1 and QFR 2. CONCLUSIONS The findings from this support previous studies and showed that the QFR is a practical quantitative method to evaluate non-IRA lesions, which in this study included STEMI patients during PCI following occlusive CA stenosis.