Non-invasive measurement using cardiovascular magnetic resonance of changes in pulmonary artery stiffness with exercise
Non-invasive measurement using cardiovascular magnetic resonance of changes in pulmonary artery stiffness with exercise
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DOI：
10.1186/s12968-015-0213-2
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发表时间：
2015-12-13
影响因子：
6.4
通讯作者：
Chesler, Naomi C.
中科院分区：
文献类型：
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作者：
Forouzan, Omid;Warczytowa, Jared;Chesler, Naomi C.
背景：运动压力测试通常在临床环境中用于监测心脏和脉管系统的功能状态。大动脉僵硬度是动脉功能的一种测量方法，可以在运动压力期间进行无创量化。近端肺动脉僵硬度的变化与肺动脉高压 (PH) 的进展尤其相关，因为肺动脉 (PA) 僵硬度是目前右心室衰竭死亡率的最佳预测因子。方法：使用心血管磁共振 (CMR) 来研究运动应激对健康受试者 PA 脉搏波速度 (PWV) 和相对面积变化 (RAC) 的影响，这两种方法都是 PA 硬度的非侵入性测量。所有 21 名受试者（平均年龄 26 +/- 4 岁；13 名女性和 8 名男性）使用定制的 MR 兼容步进设备在扫描仪范围内以仰卧位进行锻炼（分为两个阶段的轻度至中度锻炼，每个阶段持续 3-4 分钟）。为了测量主 PA (MPA) 的横截面积和血流速度，采集了二维相衬 (2D-PC) CMR 图像。为了测量指标的再现性，CMR 图像由两名独立观察者进行了分析。使用组内相关性和 Bland-Altman 分析计算观察者间的一致性。 结果：从休息到最高运动水平，心输出量从 5.9 +/- 1.4 L/min 增加到 8.2 +/- 1.9 L/min (p < 0.05)，MPA PWV 从 1.6 +/- 0.5 m/s 增加到 3.6 +/- 1.4 m/s (p < 0.05)，MPA RAC 从 0.34 +/- 0.11 下降至 0.24 +/- 0.1 (p < 0.05)。虽然 PWV 从第一到第二运动阶段也有所增加（从 2.7 +/- 1.0 m/s 到 3.6 +/- 1.4 m/s，p < 0.05），但两个运动阶段之间 RAC 没有显着变化。我们发现观察者间对 MPA 流量、RAC 和 PWV 的量化具有良好的一致性。结论：这些结果表明，健康受试者的 MPA 硬度指标随着急性中度运动而增加，并且 CMR 运动压力在临床实践中为无创评估血管功能提供了巨大的潜力。
Background: Exercise stress tests are commonly used in clinical settings to monitor the functional state of the heart and vasculature. Large artery stiffness is one measure of arterial function that can be quantified noninvasively during exercise stress. Changes in proximal pulmonary artery stiffness are especially relevant to the progression of pulmonary hypertension (PH), since pulmonary artery (PA) stiffness is the best current predictor of mortality from right ventricular failure.Methods: Cardiovascular magnetic resonance (CMR) was used to investigate the effect of exercise stress on PA pulse wave velocity (PWV) and relative area change (RAC), which are both non-invasive measures of PA stiffness, in healthy subjects. All 21 subjects (average age 26 +/- 4 years; 13 female and 8 male) used a custom-made MR-compatible stepping device to exercise (two stages of mild-to-moderate exercise of 3-4 min duration each) in a supine position within the confines of the scanner. To measure the cross-sectional area and blood flow velocity in the main PA (MPA), two-dimensional phase-contrast (2D-PC) CMR images were acquired. To measure the reproducibility of metrics, CMR images were analyzed by two independent observers. Inter-observer agreements were calculated using the intraclass correlation and Bland-Altman analysis.Results: From rest to the highest level of exercise, cardiac output increased from 5.9 +/- 1.4 L/min to 8.2 +/- 1.9 L/min (p < 0.05), MPA PWV increased from 1.6 +/- 0.5 m/s to 3.6 +/- 1.4 m/s (p < 0.05), and MPA RAC decreased from 0.34 +/- 0.11 to 0.24 +/- 0.1 (p < 0.05). While PWV also increased from the first to second exercise stage (from 2.7 +/- 1.0 m/s to 3.6 +/- 1.4 m/s, p < 0.05), there was no significant change in RAC between the two exercise stages. We found good inter-observer agreement for quantification of MPA flow, RAC and PWV.Conclusion: These results demonstrate that metrics of MPA stiffness increase in response to acute moderate exercise in healthy subjects and that CMR exercise stress offers great potential in clinical practice to noninvasively assess vascular function.