Kings College London, BHF Centre of Excellence, Division of Imaging Sciences, London, UK.
JACC Cardiovasc Imaging. 2009 Nov;2(11):1285-91. doi: 10.1016/j.jcmg.2009.07.009.
To determine whether noninvasive assessment of pulmonary artery flow (Qp) by cardiac magnetic resonance (CMR) would predict pulmonary vascular resistance (PVR) in patients with congenital heart disease characterized by an unrestricted left-to-right shunt.
Patients with an unrestricted left-to-right shunt who are at risk of obstructive pulmonary vascular disease require PVR evaluation preoperatively. CMR cardiac catheter (XMR) combines noninvasive measurement of Qp by phase contrast imaging with invasive pressure measurement to accurately determine the PVR.
Patients referred for clinical assessment of the PVR were included. The XMR was used to determine the PVR. The noninvasive parameters, Qp and left-to-right shunt (Qp/Qs), were compared with the PVR using univariate regression models.
The XMR was undertaken in 26 patients (median age 0.87 years)-ventricular septal defect 46.2%, atrioventricular septal defect 42.3%. Mean aortic flow was 2.24 +/- 0.59 l/min/m(2), and mean Qp was 6.25 +/- 2.78 l/min/m(2). Mean Qp/Qs was 2.77 +/- 1.02. Mean pulmonary artery pressure was 34.8 +/- 10.9 mm Hg. Mean/median PVR was 5.5/3.0 Woods Units (WU)/m(2) (range 1.7 to 31.4 WU/m(2)). The PVR was related to both Qp and Qp/Qs in an inverse exponential fashion by the univariate regression equations PVR = exp(2.53 - 0.20[Qp]) and PVR = exp(2.75 - 0.52[Qp/Qs]). Receiver-operator characteristic (ROC) analysis was used to determine cutoff values for Qp and Qp/Qs above which the PVR could be regarded as clinically acceptable. A Qp of > or =6.05 l/min/m(2) predicted a PVR of < or =3.5 WU/m(2) with sensitivity 72%, specificity 100%, and area under the ROC curve 0.90 (p = 0.002). A Qp/Qs of > or =2.5/1 predicted a PVR of < or =3.5 WU/m(2) with sensitivity 83%, specificity 100%, and area under the curve ROC 0.94 (p < 0.001).
Measurement of Qp or left-to-right shunt noninvasively by CMR has potential to predict the PVR in patients with an unrestricted left-to-right shunt and could potentially determine operability without having to undertake invasive testing.
通过心脏磁共振（CMR）评估肺动脉流量（Qp），确定其能否预测左向右分流不受限的先天性心脏病患者的肺血管阻力（PVR）。
存在阻塞性肺血管疾病风险的左向右分流不受限的患者需要术前评估 PVR。CMR 心导管术（XMR）结合相位对比成像的无创 Qp 测量与侵入性压力测量，可准确确定 PVR。
纳入接受 PVR 临床评估的患者。采用 XMR 确定 PVR。采用单变量回归模型，将无创参数 Qp 和左向右分流（Qp/Qs）与 PVR 进行比较。
26 例患者接受了 XMR 检查（中位年龄 0.87 岁），其中室间隔缺损占 46.2%，房室间隔缺损占 42.3%。平均主动脉流量为 2.24±0.59L/min/m2，平均 Qp 为 6.25±2.78L/min/m2。平均 Qp/Qs 为 2.77±1.02。平均肺动脉压为 34.8±10.9mmHg。平均/中位 PVR 为 5.5/3.0 伍德单位（WU）/m2（范围 1.7 至 31.4 WU/m2）。PVR 与 Qp 和 Qp/Qs 呈负指数关系，单变量回归方程为 PVR=exp（2.53-0.20[Qp]）和 PVR=exp（2.75-0.52[Qp/Qs]）。使用受试者工作特征（ROC）分析确定 Qp 和 Qp/Qs 的截断值，以便将 PVR 视为临床可接受的水平。Qp>或=6.05L/min/m2 预测 PVR<或=3.5WU/m2，其敏感性为 72%，特异性为 100%，ROC 曲线下面积为 0.90（p=0.002）。Qp/Qs>或=2.5/1 预测 PVR<或=3.5 WU/m2，敏感性为 83%，特异性为 100%，ROC 曲线下面积为 0.94（p<0.001）。
CMR 无创性测量 Qp 或左向右分流有预测左向右分流不受限患者 PVR 的潜力，可潜在确定手术可行性，无需进行有创性检查。
