Houston Methodist Hospital, Houston, TX, USA.
Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, USA.
Sci Rep. 2019 Dec 27;9(1):20168. doi: 10.1038/s41598-019-56213-4.
Measures of serum cardiac troponins and natriuretic peptides have become established as prognostic heart failure risk markers. In addition to detecting myocardial fibrosis through late gadolinium enhancement (LGE), extracellular volume fraction (ECV) measures by cardiac magnetic resonance (CMR) have emerged as a phenotypic imaging risk marker for incident heart failure outcomes. We sought to examine the relationship between cardiac troponins, natriuretic peptides, ECV and their associations with incident heart failure events in a CMR referral base. Mid short axis T1 maps were divided into 6 cardiac segments, each classified as LGE absent or present. Global ECV was derived from T1 maps using the area-weighted average of only LGE-absent segments. ECV was considered elevated if measured >30%, the upper 95% bounds of a reference healthy group without known cardiac disease (n = 28). Patients were dichotomized by presence of elevated ECV. High-sensitivity cardiac troponin T (hs-cTnT) and N-terminal B-type natriuretic peptide (NT-proBNP) were measured using serum samples acquired and stored at time of CMR scan, and patients were categorized into 3 groups for each blood marker based on recommended cutoff values. Subsequent heart failure admission and any death were ascertained. Relationships with ECV, hs-cTnT, and NT-proBNP were examined separately and as a composite with Cox proportional hazard models. Of 1,604 serial patients referred for a clinical CMR with myocardial T1 maps, 331 were eligible after exclusions and had blood available and were followed over a median 25.0 [interquartile range 21.8, 31.7] months. After adjustments for age (mean 57.3 [standard deviation (SD) 15.1 years), gender (61% male), and ethnicity (12.7% black), elevated ECV remained a predictor of a first composite heart failure outcome for patients with high levels of hs-cTnT (≥14 ng/L; hazard ratio [HR] 2.42 [95% confidence interval (CI) 1.17, 5.03]; p = 0.02) and NT-proBNP (≥300 pg/mL; HR 2.28 [95% CI 1.24, 4.29]; p = 0.01). Similar trends were seen for lower category levels of blood markers, but did not persist with minimal covariate adjustments. Elevated measures of ECV by CMR are associated with incident heart failure outcomes in patients with high hs-cTnT and NT-proBNP levels. This imaging marker may have a role for additional heart failure risk stratification.
血清心肌肌钙蛋白和利钠肽的测定已成为心力衰竭预后风险标志物。除了通过晚期钆增强（LGE）检测心肌纤维化外，心脏磁共振（CMR）的细胞外容积分数（ECV）测量也已成为心力衰竭事件发生的表型成像风险标志物。我们试图在 CMR 转诊基地中检查心肌肌钙蛋白、利钠肽、ECV 之间的关系及其与心力衰竭事件的相关性。中短轴 T1 图谱分为 6 个心脏节段，每个节段分为 LGE 无或有。通过 T1 图谱的面积加权平均值，仅从 LGE 无节段中得出 ECV。如果测量值>30%，即参考无已知心脏病的健康组（n=28）的上 95%界限，则认为 ECV 升高。根据存在升高的 ECV 将患者分为两组。使用 CMR 扫描时获得并储存的血清样本测量高敏心肌肌钙蛋白 T（hs-cTnT）和 N 末端 B 型利钠肽（NT-proBNP），并根据推荐的截断值将每个血液标志物的患者分为 3 组。随后确定心力衰竭入院和任何死亡情况。使用 Cox 比例风险模型分别检查与 ECV、hs-cTnT 和 NT-proBNP 的关系，并将其作为复合因素进行检查。在接受心肌 T1 图谱临床 CMR 检查的 1604 例连续患者中，排除后有 331 例符合条件，并且有血液样本可用，并随访中位数为 25.0 [四分位间距 21.8，31.7]个月。在校正年龄（平均 57.3 [标准差 15.1 岁]、性别（61%为男性）和种族（12.7%为黑人）后，对于 hs-cTnT 水平较高（≥14 ng/L；风险比 [HR] 2.42 [95%置信区间 1.17，5.03]；p=0.02）和 NT-proBNP 水平较高（≥300 pg/mL；HR 2.28 [95%置信区间 1.24，4.29]；p=0.01）的患者，升高的 ECV 仍然是首次复合心力衰竭结局的预测因素。对于血液标志物的较低类别水平，也存在类似的趋势，但在最小协变量调整后并未持续存在。在 hs-cTnT 和 NT-proBNP 水平较高的患者中，CMR 升高的 ECV 与心力衰竭事件的发生相关。该成像标志物可能对心力衰竭的进一步风险分层具有作用。
