TY - JOUR
T1 - Subendocardial and Transmural Myocardial Ischemia
T2 - Clinical Characteristics, Prevalence, and Outcomes With and Without Revascularization
AU - Gould, K. Lance
AU - Nguyen, Tung
AU - Kirkeeide, Richard
AU - Roby, Amanda E.
AU - Bui, Linh
AU - Kitkungvan, Danai
AU - Patel, Monica B.
AU - Madjid, Mohammad
AU - Haynie, Mary
AU - Lai, Dejian
AU - Li, Ruosha
AU - Narula, Jagat
AU - Johnson, Nils P.
N1 - Publisher Copyright:
© 2023 The Authors
PY - 2023/1
Y1 - 2023/1
N2 - Background: Subendocardial ischemia is commonly diagnosed but not quantified by imaging. Objectives: This study sought to define size and severity of subendocardial and transmural stress perfusion deficits, clinical associations, and outcomes. Methods: Regional rest-stress perfusion in mL/min/g, coronary flow reserve, coronary flow capacity (CFC), relative stress flow, subendocardial stress-to-rest ratio and stress subendocardial-to-subepicardial ratio as percentage of left ventricle were measured by positron emission tomography (PET) with rubidium Rb 82 and dipyridamole stress in serial 6,331 diagnostic PETs with prospective 10-year follow-up for major adverse cardiac events with and without revascularization. Results: Of 6,331 diagnostic PETs, 1,316 (20.7%) had severely reduced CFC with 41.4% having angina or ST-segment depression (STΔ) >1 mm during hyperemic stress, increasing with size. For 5,015 PETs with no severe CFC abnormality, 402 (8%) had angina or STΔ during stress, and 82% had abnormal subendocardial perfusion with 8.7% having angina or STΔ >1 mm during dipyridamole stress. Of 947 cases with stress-induced angina or STΔ >1 mm, 945 (99.8%) had reduced transmural or subendocardial perfusion reflecting sufficient microvascular function to increase coronary blood flow and reduce intracoronary pressure, causing reduced subendocardial perfusion; only 2 (0.2%) had normal subendocardial perfusion, suggesting microvascular disease as the cause of the angina. Over 10-year follow-up (mean 5 years), severely reduced CFC associated with major adverse cardiac events of 44.4% compared to 8.8% for no severe CFC (unadjusted P < 0.00001) and mortality of 15.2% without and 6.9% with revascularization (P < 0.00002) confirmed by multivariable Cox regression modeling. For no severe CFC, mortality was 3% with and without revascularization (P = 0.90). Conclusions: Reduced subendocardial perfusion on dipyridamole PET without regional stress perfusion defects is common without angina, has low risk of major adverse cardiac events, reflecting asymptomatic nonobstructive diffuse coronary artery disease, or angina without stenosis. Severely reduced CFC causes angina in fewer than one-half of cases but incurs high mortality risk that is significantly reduced after revascularization.
AB - Background: Subendocardial ischemia is commonly diagnosed but not quantified by imaging. Objectives: This study sought to define size and severity of subendocardial and transmural stress perfusion deficits, clinical associations, and outcomes. Methods: Regional rest-stress perfusion in mL/min/g, coronary flow reserve, coronary flow capacity (CFC), relative stress flow, subendocardial stress-to-rest ratio and stress subendocardial-to-subepicardial ratio as percentage of left ventricle were measured by positron emission tomography (PET) with rubidium Rb 82 and dipyridamole stress in serial 6,331 diagnostic PETs with prospective 10-year follow-up for major adverse cardiac events with and without revascularization. Results: Of 6,331 diagnostic PETs, 1,316 (20.7%) had severely reduced CFC with 41.4% having angina or ST-segment depression (STΔ) >1 mm during hyperemic stress, increasing with size. For 5,015 PETs with no severe CFC abnormality, 402 (8%) had angina or STΔ during stress, and 82% had abnormal subendocardial perfusion with 8.7% having angina or STΔ >1 mm during dipyridamole stress. Of 947 cases with stress-induced angina or STΔ >1 mm, 945 (99.8%) had reduced transmural or subendocardial perfusion reflecting sufficient microvascular function to increase coronary blood flow and reduce intracoronary pressure, causing reduced subendocardial perfusion; only 2 (0.2%) had normal subendocardial perfusion, suggesting microvascular disease as the cause of the angina. Over 10-year follow-up (mean 5 years), severely reduced CFC associated with major adverse cardiac events of 44.4% compared to 8.8% for no severe CFC (unadjusted P < 0.00001) and mortality of 15.2% without and 6.9% with revascularization (P < 0.00002) confirmed by multivariable Cox regression modeling. For no severe CFC, mortality was 3% with and without revascularization (P = 0.90). Conclusions: Reduced subendocardial perfusion on dipyridamole PET without regional stress perfusion defects is common without angina, has low risk of major adverse cardiac events, reflecting asymptomatic nonobstructive diffuse coronary artery disease, or angina without stenosis. Severely reduced CFC causes angina in fewer than one-half of cases but incurs high mortality risk that is significantly reduced after revascularization.
KW - coronary flow capacity
KW - coronary flow reserve
KW - coronary physiology
KW - microvascular dysfunction
KW - myocardial perfusion
KW - positron emission tomography
KW - revascularization
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U2 - 10.1016/j.jcmg.2022.05.016
DO - 10.1016/j.jcmg.2022.05.016
M3 - Article
C2 - 36599572
AN - SCOPUS:85144267388
SN - 1936-878X
VL - 16
SP - 78
EP - 94
JO - JACC: Cardiovascular Imaging
JF - JACC: Cardiovascular Imaging
IS - 1
ER -