Yang Weiguang, Marsden Alison L, Ogawa Michelle T, Sakarovitch Charlotte, Hall Keeley K, Rabinovitch Marlene, Feinstein Jeffrey A
1 Department of Pediatrics (Cardiology), Stanford University, Stanford, CA, USA.
2 Department of Bioengineering, Stanford University, Stanford, CA, USA.
Pulm Circ. 2018 Jul-Sep;8(3):2045894018780534. doi: 10.1177/2045894018780534. Epub 2018 May 16.
Pulmonary arterial hypertension (PAH) is characterized by elevated pulmonary artery pressures (PAP) and pulmonary vascular resistance (PVR). Optimizing treatment strategies and timing for transplant remains challenging. Thus, a quantitative measure to predict disease progression would be greatly beneficial in treatment planning. We devised a novel method to assess right ventricular (RV) stroke work (RVSW) as a potential biomarker of the failing heart that correlates with clinical worsening. Pediatric patients with idiopathic PAH or PAH secondary to congenital heart disease who had serial, temporally matched cardiac catheterization and magnetic resonance imaging (MRI) data were included. RV and PA hemodynamics were numerically determined by using a lumped parameter (circuit analogy) model to create pressure-volume (P-V) loops. The model was tuned using optimization techniques to match MRI and catheterization derived RV volumes and pressures for each time point. RVSW was calculated from the corresponding P-V loop and indexed by ejection fraction and body surface area (RVSW) to compare across patients. Seventeen patients (8 boys; median age = 9.4 years; age range = 4.4-16.3 years) were enrolled. Nine were clinically stable; the others had clinical worsening between the time of their initial matched studies and their most recent follow-up (mean time = 3.9 years; range = 1.1-8.0 years). RVSW and the ratio of pulmonary to systemic resistance (Rp:Rs) values were found to have more significant associations with clinical worsening within one, two, and five years following the measurements, when compared with PVR index (PVRI). A receiver operating characteristic analysis showed RVSW outperforms PVRI, Rp:Rs and ejection fraction for predicting clinical worsening. RVSW correlates with clinical worsening in pediatric PAH, shows promising results towards predicting adverse outcomes, and may serve as an indicator of future clinical worsening.
肺动脉高压（PAH）的特征是肺动脉压（PAP）和肺血管阻力（PVR）升高。优化移植的治疗策略和时机仍然具有挑战性。因此，一种预测疾病进展的定量指标对于治疗规划将非常有益。我们设计了一种新方法来评估右心室（RV）搏功（RVSW），将其作为与临床病情恶化相关的衰竭心脏的潜在生物标志物。纳入了患有特发性PAH或先天性心脏病继发PAH的儿科患者，他们有连续的、时间匹配的心脏导管检查和磁共振成像（MRI）数据。通过使用集总参数（电路类比）模型在数值上确定RV和PA血流动力学，以创建压力-容积（P-V）环。使用优化技术对模型进行调整，以匹配每个时间点MRI和导管检查得出的RV容积和压力。RVSW由相应的P-V环计算得出，并通过射血分数和体表面积（RVSW）进行指数化，以便在患者之间进行比较。共纳入17例患者（8名男孩；中位年龄 = 9.4岁；年龄范围 = 4.4 - 16.3岁）。9例临床稳定；其他患者在首次匹配研究时与最近一次随访之间出现临床病情恶化（平均时间 = 3.9年；范围 = 1.1 - 8.0年）。与肺血管阻力指数（PVRI）相比，发现RVSW以及肺与体循环阻力之比（Rp:Rs）值在测量后的1年、2年和5年内与临床病情恶化的关联更为显著。受试者工作特征分析表明，在预测临床病情恶化方面，RVSW优于PVRI、Rp:Rs和射血分数。RVSW与儿科PAH的临床病情恶化相关，在预测不良结局方面显示出有前景的结果，并且可能作为未来临床病情恶化的指标。
