Cardiovascular Imaging Program, Division of Cardiovascular Medicine, Division of Cardiac Surgery, Heart and Vascular Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts.
Cardiology Branch, Division of Intramural Research, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland.
JAMA Cardiol. 2022 Jan 1;7(1):93-99. doi: 10.1001/jamacardio.2021.3396.
Impaired myocardial flow reserve (MFR) and stress myocardial blood flow (MBF) on positron emission tomography (PET) myocardial perfusion imaging may identify adverse myocardial characteristics, including myocardial stress and injury in aortic stenosis (AS).
To investigate whether MFR and stress MBF are associated with LV structure and function derangements, and whether these parameters improve after aortic valve replacement (AVR).
DESIGN, SETTING, AND PARTICIPANTS: In this single-center prospective observational study in Boston, Massachusetts, from 2018 to 2020, patients with predominantly moderate to severe AS underwent ammonia N13 PET myocardial perfusion imaging for myocardial blood flow (MBF) quantification, resting transthoracic echocardiography (TTE) for assessment of myocardial structure and function, and measurement of circulating biomarkers for myocardial injury and wall stress. Evaluation of health status and functional capacity was also performed. A subset of patients underwent repeated assessment 6 months after AVR. A control group included patients without AS matched for age, sex, and summed stress score who underwent symptom-prompted ammonia N13 PET and TTE within 90 days.
MBF and MFR quantified on ammonia N13 PET myocardial perfusion imaging.
LV structure and function parameters, including echocardiographic global longitudinal strain (GLS), circulating high-sensitivity troponin T (hs-cTnT), N-terminal pro-B-type natriuretic peptide (NT-pro BNP), health status, and functional capacity.
There were 34 patients with AS (1 mild, 9 moderate, and 24 severe) and 34 matched control individuals. MFR was independently associated with GLS and LV ejection fraction, (β,-0.31; P = .03; β, 0.41; P = .002, respectively). Stress MBF was associated with hs-cTnT (unadjusted β, -0.48; P = .005) and log NT-pro BNP (unadjusted β, -0.37; P = .045). The combination of low stress MBF and high hs-cTnT was associated with higher interventricular septal thickness in diastole, relative wall thickness, and worse GLS compared with high stress MBF and low hs-cTnT (12.4 mm vs 10.0 mm; P = .008; 0.62 vs 0.46; P = .02; and -13.47 vs -17.11; P = .006, respectively). In 9 patients studied 6 months after AVR, mean (SD) MFR improved from 1.73 (0.57) to 2.11 (0.50) (P = .008).
In this study, in AS, MFR and stress MBF were associated with adverse myocardial characteristics, including markers of myocardial injury and wall stress, suggesting that MFR may be an early sensitive marker for myocardial decompensation.
正电子发射断层扫描（PET）心肌灌注成像上的心肌血流储备（MFR）和应激心肌血流（MBF）受损可能识别出不良的心肌特征，包括主动脉瓣狭窄（AS）中的心肌应激和损伤。
研究 MFR 和应激 MBF 是否与 LV 结构和功能障碍相关，以及这些参数在主动脉瓣置换（AVR）后是否得到改善。
设计、地点和参与者：这是一项在马萨诸塞州波士顿进行的单中心前瞻性观察研究，2018 年至 2020 年期间，主要患有中度至重度 AS 的患者接受氨 N13 PET 心肌灌注成像以量化 MBF，接受经胸超声心动图（TTE）评估心肌结构和功能，并测量循环生物标志物以评估心肌损伤和壁应力。还进行了健康状况和功能能力的评估。一部分患者在 AVR 后 6 个月进行了重复评估。对照组包括年龄、性别和总和应激评分匹配的无 AS 患者，他们在 90 天内接受了症状诱发的氨 N13 PET 和 TTE。
氨 N13 PET 心肌灌注成像上的 MBF 和 MFR。
LV 结构和功能参数，包括超声心动图整体纵向应变（GLS）、循环高敏肌钙蛋白 T（hs-cTnT）、N 末端 pro-B 型利钠肽（NT-pro BNP）、健康状况和功能能力。
共纳入 34 例 AS 患者（1 例轻度、9 例中度和 24 例重度）和 34 例匹配的对照组个体。MFR 与 GLS 和 LV 射血分数独立相关（β，-0.31；P = .03；β，0.41；P = .002）。应激 MBF 与 hs-cTnT 相关（未调整的β，-0.48；P = .005）和 log NT-pro BNP 相关（未调整的β，-0.37；P = .045）。与高应激 MBF 和低 hs-cTnT 相比，低应激 MBF 和高 hs-cTnT 的组合与室间隔舒张末期厚度增加、相对壁厚度增加和 GLS 恶化相关（12.4mm 与 10.0mm；P = .008；0.62 与 0.46；P = .02；-13.47 与-17.11；P = .006）。在 9 例接受 AVR 治疗后 6 个月的患者中，平均（SD）MFR 从 1.73（0.57）增加至 2.11（0.50）（P = .008）。
在这项研究中，AS 中的 MFR 和应激 MBF 与不良的心肌特征相关，包括心肌损伤和壁应力的标志物，表明 MFR 可能是心肌失代偿的早期敏感标志物。
