Amsallem Myriam, Boulate David, Aymami Marie, Guihaire Julien, Selej Mona, Huo Jennie, Denault Andre Y, McConnell Michael V, Schnittger Ingela, Fadel Elie, Mercier Olaf, Zamanian Roham T, Haddad Francois
Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California; Cardiovascular Institute, Stanford University School of Medicine, Stanford, California; Division of Cardiothoracic Surgery, Marie Lannelongue Hospital, Le Plessis Robinson, France.
Division of Cardiothoracic Surgery, Marie Lannelongue Hospital, Le Plessis Robinson, France.
Am J Cardiol. 2017 Sep 1;120(5):874-882. doi: 10.1016/j.amjcard.2017.05.053. Epub 2017 Jun 16.
Right ventricular (RV) adaptation to pressure overload is a major prognostic factor in patients with pulmonary arterial hypertension (PAH). The objectives were first to define the relation between RV adaptation and load using allometric modeling, then to compare the prognostic value of different indices of load adaptability in PAH. Both a derivation (n = 85) and a validation cohort (n = 200) were included. Load adaptability was assessed using 3 approaches: (1) surrogates of ventriculo-arterial coupling (e.g., RV area change/end-systolic area), (2) simple ratio of function and load (e.g., tricuspid annular plane systolic excursion/right ventricular systolic pressure), and (3) indices assessing the proportionality of adaptation using allometric pressure-function or size modeling. Proportional hazard modeling was used to compare the hazard ratio for the outcome of death or lung transplantation. The mean age of the derivation cohort was 44 ± 11 years, with 80% female and 74% in New York Heart Association class III or IV. Mean pulmonary vascular resistance index (PVRI) was 24 ± 11 with a wide distribution (1.6 to 57.5 WU/m). Allometric relations were observed between PVRI and RV fractional area change (R = 0.53, p < 0.001) and RV end-systolic area indexed to body surface area right ventricular end-systolic area index (RVESAI) (R = 0.29, p < 0.001), allowing the derivation of simple ratiometric load-specific indices of RV adaptation. In right heart parameters, RVESAI was the strongest predictor of outcomes (hazard ratio per SD = 1.93, 95% confidence interval 1.37 to 2.75, p < 0.001). Although RVESAI/PVRI provided small incremental discrimination on multivariate modeling, none of the load-adaptability indices provided stronger discrimination of outcome than simple RV adaptation metrics in either the derivation or the validation cohort. In conclusion, allometric modeling enables quantification of the proportionality of RV load adaptation but offers small incremental prognostic value to RV end-systolic dimension in PAH.
右心室（RV）对压力超负荷的适应是肺动脉高压（PAH）患者的一个主要预后因素。目的首先是使用异速生长模型确定RV适应与负荷之间的关系，然后比较PAH中不同负荷适应性指标的预后价值。纳入了一个推导队列（n = 85）和一个验证队列（n = 200）。使用3种方法评估负荷适应性：（1）心室-动脉耦合指标（如RV面积变化/收缩末期面积），（2）功能与负荷的简单比值（如三尖瓣环平面收缩期位移/右心室收缩压），以及（3）使用异速生长压力-功能或大小模型评估适应比例的指标。使用比例风险模型比较死亡或肺移植结局的风险比。推导队列的平均年龄为44±11岁，80%为女性，74%为纽约心脏协会III或IV级。平均肺血管阻力指数（PVRI）为24±11，分布范围较广（1.6至57.5 WU/m）。观察到PVRI与RV面积分数变化（R = 0.53，p < 0.001）以及体表面积指数化的RV收缩末期面积（RVESAI）之间存在异速生长关系（R = 0.29，p < 0.001），从而能够推导RV适应的简单比例负荷特异性指标。在右心参数中，RVESAI是结局的最强预测指标（每标准差的风险比 = 1.93，95%置信区间1.37至2.75，p < 0.001）。尽管RVESAI/PVRI在多变量模型中提供了小幅度的增量判别，但在推导队列或验证队列中，没有一个负荷适应性指标比简单的RV适应指标对结局的判别能力更强。总之，异速生长模型能够量化RV负荷适应的比例，但对PAH患者的RV收缩末期维度仅提供小幅度的增量预后价值。
