Department of Internal Medicine (K.T., A.D., J.A., H.A.G., W.S., N.S., J.W., H.G., M.J.R.).
Department of Pneumology, Kerckhoff Heart, Rheuma, and Thoracic Center, Bad Nauheim, Germany (H.A.G.).
Circ Heart Fail. 2019 Jan;12(1):e005512. doi: 10.1161/CIRCHEARTFAILURE.118.005512.
Right ventricular (RV) maladaptation and failure determine outcome in pulmonary hypertension. The adaptation of RV function to loading (RV-pulmonary arterial coupling) is defined by a ratio of end-systolic to arterial elastances (Ees/Ea). How RV-pulmonary arterial coupling relates to pulmonary hypertension severity and onset of RV failure (defined by excessive volume increase and ejection fraction [EF] decrease) is not exactly known.
We performed cardiac magnetic resonance (CMR) imaging within 24 hours of a diagnostic right heart catheterization and invasive measurement of RV pressure-volume loops in 42 patients with pulmonary hypertension. Median (interquartile range) Ees and Ea were 0.49 (0.35-0.74) and 0.74 (0.45-1.04) mm Hg/mL, respectively; Ees/Ea was 0.73 (0.47-1.07). End-diastolic elastance (Eed) was 0.14 (0.06-0.24) mm Hg/mL. RV EF was 39±13%. End-systolic volume and end-diastolic volume/body surface area (BSA) were 62 (45-101) and 104 (83-143) mL/m, respectively. Ees/Ea decreased with increasing RV end-diastolic volume/BSA, mass/BSA, and pulmonary arterial stiffness, and with decreasing EF, from 0.89 to 1.09 in the least impaired tertiles to 0.55 to 0.61 in the most impaired tertiles. Eed increased with increasing RV mass/BSA, end-diastolic volume/BSA, and T1 mapping and with decreasing EF. Receiver operating characteristic analysis identified an Ees/Ea cutoff of 0.805 associated with onset of RV failure defined by increased RV volumes with EF <35%.
RV-pulmonary arterial coupling (Ees/Ea) has considerable reserve, from normal values of 1.5-2 to <0.8, and has the ability to detect pending RV failure in patients with pulmonary hypertension. Clinical Trial Registration URL: https://www.clinicaltrials.gov . Unique identifier: NCT03403868.
右心室（RV）适应不良和衰竭决定了肺动脉高压的预后。RV 功能对负荷的适应（RV-肺动脉耦联）由收缩末期到动脉弹性的比值（Ees/Ea）来定义。RV-肺动脉耦联与肺动脉高压的严重程度以及 RV 衰竭的发生（定义为容量过度增加和射血分数[EF]降低）之间的关系尚不清楚。
我们对 42 例肺动脉高压患者在诊断性右心导管检查后 24 小时内进行了心脏磁共振（CMR）成像，并进行了 RV 压力-容积环的有创测量。中位（四分位间距）Ees 和 Ea 分别为 0.49（0.35-0.74）和 0.74（0.45-1.04）mmHg/mL，Ees/Ea 为 0.73（0.47-1.07）。舒张末期弹性（Eed）为 0.14（0.06-0.24）mmHg/mL。RV EF 为 39±13%。收缩末期容积和舒张末期容积/体表面积（BSA）分别为 62（45-101）和 104（83-143）mL/m。Ees/Ea 随 RV 舒张末期容积/BSA、质量/BSA 和肺动脉僵硬度的增加而降低，随 EF 的降低而降低，从 EF 最低的三分位数的 0.89 到 1.09 降至 EF 最高的三分位数的 0.55 到 0.61。Eed 随 RV 质量/BSA、舒张末期容积/BSA、T1 映射和 EF 的降低而增加。接受者操作特征分析确定 Ees/Ea 截断值为 0.805，与 EF<35%的 RV 容量增加定义的 RV 衰竭开始相关。
RV-肺动脉耦联（Ees/Ea）具有相当大的储备，从正常的 1.5-2 到<0.8，并且具有在肺动脉高压患者中检测即将发生 RV 衰竭的能力。临床试验注册网址：https://www.clinicaltrials.gov。唯一标识符：NCT03403868。
