BHF Glasgow Cardiovascular Research Centre, Institute of Cardiovascular and Medical Sciences, University of Glasgow, Glasgow, United Kingdom.
West of Scotland Heart and Lung Centre, Golden Jubilee National Hospital, Clydebank, United Kingdom.
JCI Insight. 2016 May 5;1(6):e85768. doi: 10.1172/jci.insight.85768.
Failed myocardial reperfusion is common and prognostically important after acute ST-elevation myocardial infarction (STEMI). The purpose of this study was to investigate coronary flow reserve (CFR), a measure of vasodilator capacity, and the index of microvascular resistance (IMR; mmHg × s) in the culprit artery of STEMI survivors.
IMR ( = 288) and CFR ( = 283; mean age [SD], 60 [12] years) were measured acutely using guide wire-based thermodilution. Cardiac MRI disclosed left ventricular pathology, function, and volumes at 2 days ( = 281) and 6 months after STEMI ( = 264). All-cause death or first heart failure hospitalization was independently adjudicated (median follow-up 845 days).
Myocardial hemorrhage and microvascular obstruction occurred in 89 (42%) and 114 (54%) patients with evaluable T2*-MRI maps. IMR and CFR were associated with microvascular pathology (none vs. microvascular obstruction only vs. microvascular obstruction and myocardial hemorrhage) (median [interquartile range], IMR: 17 [12.0-33.0] vs. 17 [13.0-39.0] vs. 37 [21.0-63.0], < 0.001; CFR: 1.7 [1.4-2.5] vs. 1.5 [1.1-1.8] vs. 1.4 [1.0-1.8], < 0.001), whereas thrombolysis in myocardial infarction blush grade was not. IMR was a multivariable associate of changes in left ventricular end-diastolic volume (regression coefficient [95% CI] 0.13 [0.01, 0.24]; = 0.036), whereas CFR was not ( = 0.160). IMR (5 units) was a multivariable associate of all-cause death or heart failure hospitalization ( = 30 events; hazard ratio [95% CI], 1.09 [1.04, 1.14]; < 0.001), whereas CFR ( = 0.124) and thrombolysis in myocardial infarction blush grade ( = 0.613) were not. IMR had similar prognostic value for these outcomes as <50% ST-segment resolution on the ECG.
IMR is more closely associated with microvascular pathology, left ventricular remodeling, and health outcomes than the angiogram or CFR.
NCT02072850.
A British Heart Foundation Project Grant (PG/11/2/28474), the National Health Service, the Chief Scientist Office, a Scottish Funding Council Senior Fellowship, a British Heart Foundation Intermediate Fellowship (FS/12/62/29889), and a nonfinancial research agreement with Siemens Healthcare.
急性 ST 段抬高型心肌梗死（STEMI）后心肌再灌注失败很常见，且具有预后意义。本研究旨在探讨 STEMI 幸存者罪犯动脉的冠状动脉血流储备（CFR，反映扩张能力的指标）和微血管阻力指数（IMR；mmHg×s）。
使用基于导丝的热稀释法在急性期测量 IMR（=288）和 CFR（=283；平均年龄[标准差]，60[12]岁）。心肌 MRI 在 STEMI 后 2 天（=281）和 6 个月（=264）时显示左心室病理学、功能和容积。全因死亡或首次心力衰竭住院由独立裁判裁定（中位随访 845 天）。
在可评估 T2*-MRI 图谱的 281 例患者中，89 例（42%）和 114 例（54%）发生心肌出血和微血管阻塞。IMR 和 CFR 与微血管病理学相关（无 vs. 仅有微血管阻塞 vs. 微血管阻塞伴心肌出血）（中位数[四分位间距]，IMR：17[12.0-33.0] vs. 17[13.0-39.0] vs. 37[21.0-63.0]，<0.001；CFR：1.7[1.4-2.5] vs. 1.5[1.1-1.8] vs. 1.4[1.0-1.8]，<0.001），而心肌梗死溶栓分级则不然。IMR 是左心室舒张末期容积变化的多变量相关因素（回归系数[95%CI]0.13[0.01，0.24]；=0.036），而 CFR 不是（=0.160）。IMR（5 个单位）是全因死亡或心力衰竭住院的多变量相关因素（=30 例事件；风险比[95%CI]，1.09[1.04，1.14]；<0.001），而 CFR（=0.124）和心肌梗死溶栓分级（=0.613）则不然。IMR 在这些结局中的预后价值与心电图上<50%ST 段回落相似。
与造影或 CFR 相比，IMR 与微血管病理学、左心室重构和健康结局的相关性更密切。
NCT02072850。
英国心脏基金会项目资助（PG/11/2/28474）、英国国家医疗服务体系、苏格兰首席科学家办公室、英国心脏基金会中级奖学金、英国心脏基金会非金融研究协议与西门子医疗。
