biostudies-literatureZhao Mthe Scientific Research Project of Health Industry of Gansu Provincethe Gansu Provincial Talent Programthe Science and Technology Planning Project of Lanzhou Citythe Youth Doctoral Fund Project of the Department of Education in Gansu Provincethe Foundation for Scientific Research of the First Hospital of Lanzhou UniversityCivil-Military Integration Development of Gansu ProvinceScience and Technology Program of Gansu Province4242-4255https://www.ebi.ac.uk/biostudies/studies/S-EPMC12397152biostudies-literatureUnknown52(11)<h4>Objectives</h4>This study sought to elucidate the diagnostic performance and concordance between myocardial flow reserve (MFR) derived from dynamic single-photon emission computed tomography (D-SPECT) and quantitative flow ratio (QFR) in evaluating non-culprit ischemic lesions following ST-elevation myocardial infarction (STEMI). Additionally, the study investigated the integration of MFR with angiographic microvascular resistance (AMR) derived from coronary angiography to determine its utility in screening and stratifying non-culprit ischemic lesions.<h4>Background</h4>The diagnostic performance and agreement between MFR and QFR in evaluating non-culprit ischemic lesions in STEMI patients with multivessel disease are unknown.<h4>Methods</h4>This research encompassed a cohort of 106 STEMI patients with at least 1 intermediate non-culprit ischemic lesion, characterized by 40-80% diameter stenosis. After undergoing percutaneous coronary intervention, patients were evaluated using QFR and, approximately five days later, underwent D-SPECT to assess myocardial blood flow (MBF) and MFR. MFR was evaluated against QFR as a reference for diagnostic performance and agreement, including sensitivity analysis in vessels with normal microvascular function. Furthermore, MFR, combined with AMR, effectively screened and stratified non-culprit ischemic lesions. Non-culprit ischemic lesions were defined by QFR ≤ 0.80 and normal microvascular function by AMR < 255 mmHg*s/m.<h4>Results</h4>Among non-culprit lesions, MFR predicted a QFR ≤ 0.80 with a sensitivity of 85%, specificity of 86%, and accuracy of 86%. The positive predictive value was 56%, and the negative predictive value was 96%. The MFR cut-off was 1.93, with an area under the receiver operating characteristic curve of 0.90 (95% CI: 0.84 to 0.94). MFR showed similar diagnostic performance in patients with normal microcirculation. Moreover, low MFR with normal AMR indicated non-culprit ischemic lesions caused solely by epicardial narrowing, while low MFR with abnormal AMR indicated ischemic lesions complicated by microvascular dysfunction.<h4>Conclusion</h4>MFR derived from D-SPECT exhibits good diagnostic performance and moderate agreement in identifying non-culprit ischemic lesions in patients with STEMI. Combining AMR with MFR effectively screens and stratifies non-culprit ischemic lesions.<h4>Trial registration</h4>ChiCTR.org.cn. ChiCTR2200059934. Registered 13 May 2022.European journal of nuclear medicine and molecular imagingMyocardial flow reserve derived from D-SPECT for evaluating non-culprit ischemic lesions in STEMI patients: comparison with quantitative flow ratio.PMC12397152NO.ldyyyn2021-115NO.2025QNTD27NO.2060303NO.GSWSKY2020-64NO. 24JRRA293NO.2020-ZD-722022QB-011Zhang JChen MChen FXing EWa YLu AZhao YNiu XZhao MPan CWang TBai MBai LZhao JfalseMyocardial flow reserve derived from D-SPECT for evaluating non-culprit ischemic lesions in STEMI patients: comparison with quantitative flow ratio.<h4>Objectives</h4>This study sought to elucidate the diagnostic performance and concordance between myocardial flow reserve (MFR) derived from dynamic single-photon emission computed tomography (D-SPECT) and quantitative flow ratio (QFR) in evaluating non-culprit ischemic lesions following ST-elevation myocardial infarction (STEMI). Additionally, the study investigated the integration of MFR with angiographic microvascular resistance (AMR) derived from coronary angiography to determine its utility in screening and stratifying non-culprit ischemic lesions.<h4>Background</h4>The diagnostic performance and agreement between MFR and QFR in evaluating non-culprit ischemic lesions in STEMI patients with multivessel disease are unknown.<h4>Methods</h4>This research encompassed a cohort of 106 STEMI patients with at least 1 intermediate non-culprit ischemic lesion, characterized by 40-80% diameter stenosis. After undergoing percutaneous coronary intervention, patients were evaluated using QFR and, approximately five days later, underwent D-SPECT to assess myocardial blood flow (MBF) and MFR. MFR was evaluated against QFR as a reference for diagnostic performance and agreement, including sensitivity analysis in vessels with normal microvascular function. Furthermore, MFR, combined with AMR, effectively screened and stratified non-culprit ischemic lesions. Non-culprit ischemic lesions were defined by QFR ≤ 0.80 and normal microvascular function by AMR < 255 mmHg*s/m.<h4>Results</h4>Among non-culprit lesions, MFR predicted a QFR ≤ 0.80 with a sensitivity of 85%, specificity of 86%, and accuracy of 86%. The positive predictive value was 56%, and the negative predictive value was 96%. The MFR cut-off was 1.93, with an area under the receiver operating characteristic curve of 0.90 (95% CI: 0.84 to 0.94). MFR showed similar diagnostic performance in patients with normal microcirculation. Moreover, low MFR with normal AMR indicated non-culprit ischemic lesions caused solely by epicardial narrowing, while low MFR with abnormal AMR indicated ischemic lesions complicated by microvascular dysfunction.<h4>Conclusion</h4>MFR derived from D-SPECT exhibits good diagnostic performance and moderate agreement in identifying non-culprit ischemic lesions in patients with STEMI. Combining AMR with MFR effectively screens and stratifies non-culprit ischemic lesions.<h4>Trial registration</h4>ChiCTR.org.cn. ChiCTR2200059934. Registered 13 May 2022.2025-01-01T00:00:00Z2025 Sep2026-05-10T05:04:50.835Z2026-04-08T01:34:39.759ZS-EPMC123971524023779410.1007/s00259-025-07223-0