缺血介导的下乳头肌功能障碍作为功能性二尖瓣反流的标志物。
Ischemia-Mediated Dysfunction in Subpapillary Myocardium as a Marker of Functional Mitral Regurgitation.
机构信息
Division of Cardiology, Weill Cornell Medicine, New York, New York, USA; Division of Cardiology, Columbia University Irving Medical Center, New York, New York, USA.
Division of Cardiology, Weill Cornell Medicine, New York, New York, USA.
出版信息
JACC Cardiovasc Imaging. 2021 Apr;14(4):826-839. doi: 10.1016/j.jcmg.2021.01.007. Epub 2021 Mar 17.
OBJECTIVES
The goal of this study was to test whether ischemia-mediated contractile dysfunction underlying the mitral valve affects functional mitral regurgitation (FMR) and the prognostic impact of FMR.
BACKGROUND
FMR results from left ventricular (LV) remodeling, which can stem from myocardial tissue alterations. Stress cardiac magnetic resonance can assess ischemia and infarction in the left ventricle and papillary muscles; relative impact on FMR is uncertain.
METHODS
Vasodilator stress cardiac magnetic resonance was performed in patients with known or suspected coronary artery disease at 7 sites. Images were centrally analyzed for MR etiology/severity, mitral apparatus remodeling, and papillary ischemia.
RESULTS
A total of 8,631 patients (mean age 60.0 ± 14.1 years; 55% male) were studied. FMR was present in 27%, among whom 16% (n = 372) had advanced (moderate or severe) FMR. Patients with ischemia localized to subpapillary regions were more likely to have advanced FMR (p = 0.003); those with ischemia localized to other areas were not (p = 0.17). Ischemic/dysfunctional subpapillary myocardium (odds ratio: 1.24/10% subpapillary myocardium; confidence interval: 1.17 to 1.31; p < 0.001) was associated with advanced FMR controlling for infarction. Among a subgroup with (n = 372) and without (n = 744) advanced FMR matched (1:2) on infarct size/distribution, patients with advanced FMR had increased adverse mitral apparatus remodeling, paralleled by greater ischemic/dysfunctional subpapillary myocardium (p < 0.001). Although posteromedial papillary ischemia was more common with advanced FMR (p = 0.006), subpapillary ischemia with dysfunction remained associated (p < 0.001), adjusting for posteromedial papillary ischemia (p = 0.074). During follow-up (median 5.1 years), 1,473 deaths occurred in the overall cohort; advanced FMR conferred increased mortality risk (hazard ratio: 1.52; 95% confidence interval: 1.25 to 1.86; p < 0.001) controlling for left ventricular ejection fraction, infarction, and ischemia.
CONCLUSIONS
Ischemic and dysfunctional subpapillary myocardium provides a substrate for FMR, which predicts mortality independent of key mechanistic substrates.
目的
本研究旨在检验二尖瓣下缺血性收缩功能障碍是否会影响功能性二尖瓣反流（FMR）以及 FMR 的预后影响。
背景
FMR 是由左心室（LV）重构引起的，其可能源于心肌组织改变。压力心脏磁共振可以评估左心室和乳头肌的缺血和梗死；但其对 FMR 的相对影响尚不确定。
方法
在 7 个部位对已知或疑似冠状动脉疾病的患者进行扩张型心脏磁共振检查。对 MRI 病因/严重程度、二尖瓣装置重构和乳头肌缺血情况进行中心分析。
结果
共纳入 8631 例患者（平均年龄 60.0±14.1 岁，55%为男性）。27%的患者存在 FMR，其中 16%（n=372）存在严重（中度或重度）FMR。局限于心尖下区域的缺血患者更有可能出现严重的 FMR（p=0.003）；而局限于其他区域的缺血患者则不然（p=0.17）。缺血/功能障碍的心尖下心肌（优势比：1.24/10%心尖下心肌；置信区间：1.17 至 1.31；p<0.001）与 FMR 控制梗死相关。在一个亚组中（n=372）和另一个亚组中（n=744）进行了配对（1:2），以比较梗死大小/分布，存在严重 FMR 的患者具有更多的不良二尖瓣装置重构，同时伴有更多的心尖下缺血/功能障碍心肌（p<0.001）。尽管伴有严重 FMR 的患者中更常见后内侧乳头肌缺血（p=0.006），但伴有功能障碍的心尖下缺血仍然与严重 FMR 相关（p<0.001），即使调整了后内侧乳头肌缺血的影响（p=0.074）。在随访期间（中位时间为 5.1 年），整个队列中共有 1473 例死亡；严重 FMR 使死亡风险增加（风险比：1.52；95%置信区间：1.25 至 1.86；p<0.001），这一结果独立于左心室射血分数、梗死和缺血等关键机制。
结论
缺血和功能障碍的心尖下心肌为 FMR 提供了基础，其预测死亡率的能力独立于关键的机制基础。
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