Section of Cardiology, Department of Medicine, University of Chicago, Chicago, IL.
Section of Cardiology, Department of Medicine, University of Chicago, Chicago, IL.
Chest. 2012 Mar;141(3):642-650. doi: 10.1378/chest.11-0969. Epub 2011 Sep 1.
The pulmonary hypertension connection (PHC) equation predicts contemporary survival in idiopathic, heritable, and anorexigen-associated pulmonary arterial hypertension (PAH). The aim of this study is to validate the PHC equation in a prospective PAH population cohort and compare its predictability with the French equation.
We compared the rates of actual survival in patients prospectively followed for up to 3.5 years in four double-blind, randomized trials and their open-label extension studies with predicted survival calculated using the PHC equation [(P(t) = e((-A(x,y,z)t)), A(x,y,z) = e((-1.270-0.0148x + 0.0402y - 0.361z)), where P(t) is the probability of survival, t the time interval in years, x the mean pulmonary artery pressure, y the mean right atrial pressure, and z the cardiac index] and the French equation in patients with idiopathic, heritable, and anorexigen-associated PAH (n = 449).
Mean age was 44 ± 15 years, 77% were women, and 80% had World Health Organization (WHO) functional class III/IV symptoms. The mean 6-min walk distance (6MWD) was 354 ± 95 m. The baseline hemodynamics were as follows: mean right atrial pressure 10 ± 6 mm Hg, mean pulmonary artery pressure 59 ± 15 mm Hg, and cardiac output 4.1 ± 1.5 L/min. The 1-, 2-, and 3-year Kaplan-Meier survival rates were 89%, 80%, and 70%, respectively; the nonadjusted survival rates were 91%, 87%, and 84%, respectively. The expected survival predicted by both the PHC and the French equations was similar to the actual observed Kaplan-Meier survival and was within its 95% confidence limits. The PHC equation also performed well when used in patients with WHO functional class III/IV, cardiac output < 4 L/min, or 6MWD < 380 m.
Risk prediction equations (PHC and French) accurately predicted survival and may be useful for risk estimation in patients with idiopathic, heritable, and anorexigen-associated PAH in large cohort studies. Their use for survival prediction for individual patients needs further study.
肺动脉高压关联（PHC）方程可预测特发性、遗传性和食欲抑制剂相关性肺动脉高压（PAH）患者的当代生存率。本研究旨在前瞻性 PAH 患者队列中验证 PHC 方程，并比较其与法国方程的预测能力。
我们将在四项双盲、随机试验及其开放标签扩展研究中前瞻性随访长达 3.5 年的患者的实际生存率与使用 PHC 方程[（P(t) = e((-A(x,y,z)t))，A(x,y,z) = e((-1.270-0.0148x + 0.0402y - 0.361z))，其中 P(t)是生存率，t 是时间间隔（以年为单位），x 是平均肺动脉压，y 是平均右心房压，z 是心输出量]和法国方程预测的生存率进行比较，纳入特发性、遗传性和食欲抑制剂相关性 PAH 患者（n = 449）。
平均年龄为 44 ± 15 岁，77%为女性，80%有世界卫生组织（WHO）功能分级 III/IV 症状。平均 6 分钟步行距离（6MWD）为 354 ± 95 m。基线血流动力学参数如下：平均右心房压 10 ± 6 mmHg，平均肺动脉压 59 ± 15 mmHg，心输出量 4.1 ± 1.5 L/min。1、2、3 年的 Kaplan-Meier 生存率分别为 89%、80%和 70%；未经调整的生存率分别为 91%、87%和 84%。PHC 和法国方程预测的预期生存率与实际观察到的 Kaplan-Meier 生存率相似，且均在其 95%置信区间内。PHC 方程在 WHO 功能分级 III/IV、心输出量<4 L/min 或 6MWD<380 m 的患者中也表现良好。
风险预测方程（PHC 和法国）可准确预测生存率，在特发性、遗传性和食欲抑制剂相关性 PAH 的大型队列研究中可能有助于估计风险。但它们在个体患者的生存预测中的应用还需要进一步研究。
