Ki Hong Choi1, Neng Dai2, YinLiang Li2, Juwon Kim1, Doosup Shin3, Seung Hun Lee4, Hyun Sung Joh1, Hyun Kuk Kim5, Ki-Hyun Jeon6, Sang Jin Ha7, Sung-Mok Kim8, Mi Ja Jang1, Taek Kyu Park1, Jeong Hoon Yang1, Young Bin Song1, Joo-Yong Hahn1, Joon-Hyung Doh9, Eun-Seok Shin10, Seung-Hyuk Choi1, Hyeon-Cheol Gwon1, Joo Myung Lee11. 1. Division of Cardiology, Department of Internal Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 2. Department of Cardiology, Zhongshan Hospital, Fudan University, Shanghai Institute of Cardiovascular Diseases, Shanghai, China. 3. Division of Cardiovascular Medicine, Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa, USA. 4. Division of Cardiology, Department of Internal Medicine, Chonnam National University Hospital, Gwangju, Korea. 5. Department of Internal Medicine and Cardiovascular Center, Chosun University Hospital, University of Chosun College of Medicine, Gwangju, Korea. 6. Division of Cardiology, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea. 7. Division of Cardiology, Department of Internal Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine, Gangneung, Korea. 8. Department of Radiology, Cardiovascular Imaging Center, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. 9. Department of Medicine, Inje University Ilsan Paik Hospital, Goyang, Korea. 10. Department of Cardiology, Ulsan Medical Center, Ulsan, Korea. 11. Division of Cardiology, Department of Internal Medicine, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: drone80@hanmail.net.
Abstract
OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy and prognostic implications of angiography-derived index of microcirculatory resistance (angio-IMR) in patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: The index of microcirculatory resistance (IMR) is a reliable invasive measure of coronary microvascular dysfunction in patients with STEMI. A functional coronary angiography-derived method to estimate IMR is a wire- and hyperemic agent-free alternative to IMR. METHODS: The study population consisted of 2 independent cohorts. The diagnostic cohort comprised patients with IMR from the culprit vessel immediately after successful primary percutaneous coronary intervention (n = 31). The prognostic cohort was patients with STEMI who were successfully treated with primary percutaneous coronary intervention and followed for 10 years from the index procedure (n = 309). Angio-IMR was calculated using computational flow and pressure simulation. The primary outcome was a composite of cardiac death and readmission for heart failure over 10 years of follow-up. RESULTS: In the diagnostic cohort, angio-IMR correlated well with IMR (R = 0.778; P < 0.001). Sensitivity, specificity, accuracy, and area under the curve of angio-IMR to predict IMR >40 U were 75.0%, 84.2%, 80.6%, and 0.899 (95% confidence interval: 0.786-0.949), respectively. In the prognostic cohort, patients with angio-IMR >40 U showed significantly higher risk for cardiac death or readmission for heart failure than did those with angio-IMR ≤40 U (46.7% vs 16.6%; adjusted hazard ratio: 2.909; 95% CI: 1.670-5.067; P < 0.001). Angio-IMR >40 U was an independent predictor of cardiac death or readmission for heart failure (hazard ratio: 2.173; 95% CI: 1.157-4.079; P = 0.016) and showed incremental prognostic value compared with a model with clinical risk factors only (C index = 0.726 vs 0.666 [P < 0.001], net reclassification index = 0.704 [P < 0.001]). CONCLUSIONS: Angio-IMR showed high correlation and diagnostic accuracy to predict IMR. Patients with STEMI with angio-IMR >40 U showed a significantly higher risk for cardiac death or readmission for heart failure than those with preserved angio-IMR values. (Prognostic Implication of Angiography-Derived IMR in STEMI Patients; NCT04628377).
OBJECTIVES: The aim of this study was to evaluate the diagnostic accuracy and prognostic implications of angiography-derived index of microcirculatory resistance (angio-IMR) in patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: The index of microcirculatory resistance (IMR) is a reliable invasive measure of coronary microvascular dysfunction in patients with STEMI. A functional coronary angiography-derived method to estimate IMR is a wire- and hyperemic agent-free alternative to IMR. METHODS: The study population consisted of 2 independent cohorts. The diagnostic cohort comprised patients with IMR from the culprit vessel immediately after successful primary percutaneous coronary intervention (n = 31). The prognostic cohort was patients with STEMI who were successfully treated with primary percutaneous coronary intervention and followed for 10 years from the index procedure (n = 309). Angio-IMR was calculated using computational flow and pressure simulation. The primary outcome was a composite of cardiac death and readmission for heart failure over 10 years of follow-up. RESULTS: In the diagnostic cohort, angio-IMR correlated well with IMR (R = 0.778; P < 0.001). Sensitivity, specificity, accuracy, and area under the curve of angio-IMR to predict IMR >40 U were 75.0%, 84.2%, 80.6%, and 0.899 (95% confidence interval: 0.786-0.949), respectively. In the prognostic cohort, patients with angio-IMR >40 U showed significantly higher risk for cardiac death or readmission for heart failure than did those with angio-IMR ≤40 U (46.7% vs 16.6%; adjusted hazard ratio: 2.909; 95% CI: 1.670-5.067; P < 0.001). Angio-IMR >40 U was an independent predictor of cardiac death or readmission for heart failure (hazard ratio: 2.173; 95% CI: 1.157-4.079; P = 0.016) and showed incremental prognostic value compared with a model with clinical risk factors only (C index = 0.726 vs 0.666 [P < 0.001], net reclassification index = 0.704 [P < 0.001]). CONCLUSIONS: Angio-IMR showed high correlation and diagnostic accuracy to predict IMR. Patients with STEMI with angio-IMR >40 U showed a significantly higher risk for cardiac death or readmission for heart failure than those with preserved angio-IMR values. (Prognostic Implication of Angiography-Derived IMR in STEMI Patients; NCT04628377).