Microvascular ischemia in hypertrophic cardiomyopathy: new insights from high-resolution combined quantification of perfusion and late gadolinium enhancement.
Microvascular ischemia in hypertrophic cardiomyopathy: new insights from high-resolution combined quantification of perfusion and late gadolinium enhancement.
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DOI：
10.1186/s12968-016-0223-8
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发表时间：
2016-01-14
期刊：
影响因子：
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通讯作者：
Chiribiri A
中科院分区：
文献类型：
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作者：
Villa AD;Sammut E;Zarinabad N;Carr-White G;Lee J;Bettencourt N;Razavi R;Nagel E;Chiribiri A
微血管缺血是肥厚型心肌病（HCM）的标志之一，并与不良结局相关。然而，心肌纤维化，在心血管磁共振（CMR）上被视为晚期钆增强（LGE），可导致高达30%的HCM患者的静息灌注缺陷，可能导致高估缺血负荷。我们研究了左心室（LV）瘢痕对总LV缺血负荷的影响，采用新的高分辨率灌注分析技术结合LGE定量。30例HCM和心外膜冠状动脉通畅的患者接受了CMR，并对节段和高分辨率数据进行了费米约束定量灌注分析。后者在逐像素的基础上针对纤维化的存在进行校正。与节段性分析相比，高分辨率定量被证明对微血管缺血的检测更敏感。LGE区域与心肌灌注储备（MPR）显著降低相关，导致高估未校正灌注图上的总缺血负荷。使用阈值MPR为1.5，LGE的存在导致高估了28%的缺血负荷。在校正灌注图后，纤维化患者的缺血负荷更严重，这与该亚组中更严重的疾病一致。LGE是评估HCM患者缺血负荷的重要混杂因素。LGE校正的高分辨率定量分析能够独立评估微血管缺血和纤维化，在评估HCM患者时应使用。
Microvascular ischemia is one of the hallmarks of hypertrophic cardiomyopathy (HCM) and has been associated with poor outcome. However, myocardial fibrosis, seen on cardiovascular magnetic resonance (CMR) as late gadolinium enhancement (LGE), can be responsible for rest perfusion defects in up to 30 % of patients with HCM, potentially leading to an overestimation of the ischemic burden. We investigated the effect of left ventricle (LV) scar on the total LV ischemic burden using novel high-resolution perfusion analysis techniques in conjunction with LGE quantification. 30 patients with HCM and unobstructed epicardial coronary arteries underwent CMR with Fermi constrained quantitative perfusion analysis on segmental and high-resolution data. The latter were corrected for the presence of fibrosis on a pixel-by-pixel basis. High-resolution quantification proved more sensitive for the detection of microvascular ischemia in comparison to segmental analysis. Areas of LGE were associated with significant reduction of myocardial perfusion reserve (MPR) leading to an overestimation of the total ischemic burden on non-corrected perfusion maps. Using a threshold MPR of 1.5, the presence of LGE caused an overestimation of the ischemic burden of 28 %. The ischemic burden was more severe in patients with fibrosis, also after correction of the perfusion maps, in keeping with more severe disease in this subgroup. LGE is an important confounder in the assessment of the ischemic burden in patients with HCM. High-resolution quantitative analysis with LGE correction enables the independent evaluation of microvascular ischemia and fibrosis and should be used when evaluating patients with HCM.