2018 JACC CI (Aptoglobin and STEMI detcetd by CMR)

OBJECTIVES This study aimed to evaluate the correlation between different haptoglobin (Hp) phenotypes and
myocardial infarction characteristics as detected by cardiac magnetic resonance (CMR) in consecutive patients after
ST-segment elevation myocardial infarction (STEMI).
BACKGROUND Hp is a plasma protein that prevents iron-mediated oxidative tissue damage. CMR has emerged as the
gold standard technique to detect left ventricular ejection fraction (LVEF), extent of scar with late gadolinium
enhancement (LGE) technique, microvascular obstruction (MVO), and myocardial hemorrhage (MH) in patients with
STEMI treated by primary percutaneous coronary intervention (pPCI).
METHODS One hundred forty-five consecutive STEMI patients (mean age 62.2
10.3 years; 78% men) were prospectively
enrolled and underwent Hp phenotyping and CMR assessment within 1 week after STEMI.
RESULTS CMR showed an area at risk (AAR) involving 26.6
19.1% of left ventricular (LV) mass with a late LGE extent
of 15.2
13.1% of LV mass. MVO and MH occurred in 38 (26%) and 12 (8%) patients, respectively. Hp phenotypes 1-1, 2-
1, 2-2 were observed in 15 (10%), 62 (43%), and 68 (47%), respectively. Multivariable analysis demonstrated that body
mass index, Hp2-2, diabetes, and peak troponin I were independent predictors of MVO with Hp2-2 associated with the
highest odds ratio (OR) (OR: 5.5 [95% confidence interval [CI]: 2.1 to 14.3; p < 0.001]). Hp2-2 significantly predicted
both the presence (area under the curve [AUC]: 0.63 [95% CI: 0.53 to 0.72; p ¼ 0.008]) and extent of MVO (AUC: 0.63
[95% CI: 0.54 to 0.72; p ¼ 0.007]).
CONCLUSIONS Hp phenotype is an independent predictor of MVO. Therefore, Hp phenotyping could be used for risk
stratification and may be useful in assessing new therapies to reduce myocardial reperfusion injury in patients with STEMI.

【研究目的】本研究旨在评估连续纳入的ST段抬高型心肌梗死（ST-segment elevation myocardial infarction, STEMI）患者中，不同结合珠蛋白（haptoglobin, Hp）表型与心脏磁共振（cardiac magnetic resonance, CMR）检测到的心肌梗死特征之间的相关性。

【研究背景】Hp是一种可预防铁介导的氧化性组织损伤的血浆蛋白。目前，心脏磁共振已成为检测接受直接经皮冠状动脉介入治疗（primary percutaneous coronary intervention, pPCI）的STEMI患者左心室射血分数（left ventricular ejection fraction, LVEF）、晚期钆增强（late gadolinium enhancement, LGE）技术评估的瘢痕范围、微血管阻塞（microvascular obstruction, MVO）及心肌出血（myocardial hemorrhage, MH）的金标准成像技术。

【研究方法】本研究前瞻性纳入145例连续就诊的STEMI患者（平均年龄62.2±10.3岁；男性占78%），所有患者均在STEMI发病后1周内完成Hp表型分型及CMR评估。

【研究结果】CMR检查显示，患者的风险区域（area at risk, AAR）占左心室（left ventricular, LV）质量的26.6%±19.1%，晚期钆增强累及的左心室质量范围为15.2%±13.1%。38例（26%）患者出现MVO，12例（8%）患者出现MH。Hp表型1-1、2-1、2-2的检出例数分别为15例（10%）、62例（43%）及68例（47%）。多变量分析显示，体重指数（body mass index, BMI）、Hp2-2表型、糖尿病及肌钙蛋白I峰值水平是MVO的独立预测因素，其中Hp2-2表型对应的比值比（odds ratio, OR）最高（OR=5.5，95%置信区间[CI]：2.1~14.3；P<0.001）。Hp2-2表型可显著预测MVO的发生（受试者工作特征曲线下面积[AUC]=0.63，95%CI：0.53~0.72；P=0.008）及MVO的累及范围（AUC=0.63，95%CI：0.54~0.72；P=0.007）。

【研究结论】Hp表型是MVO的独立预测因素。因此，Hp表型分型可用于风险分层，或可用于评估旨在减轻STEMI患者心肌再灌注损伤的新型治疗方案。