Sato Shuji, Shimizu Kazuhiro, Ito Takuro, Tsubono Masakazu, Ogawa Akihiro, Sasaki Takeshi, Takahashi Mao, Noro Mahito, Shirai Kohji
Department of Cardiology, Toho University Sakura Medical Center, Chiba, Japan.
Department of Rehabilitation, Toho University Sakura Medical Center, Chiba, Japan.
Int Med Case Rep J. 2021 Mar 29;14:191-197. doi: 10.2147/IMCRJ.S303997. eCollection 2021.
The role of arterial stiffness in the pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is unclear. The cardio-ankle vascular index (CAVI) is a novel arterial stiffness index reflecting stiffness of the arterial tree from the origin of the aorta to the ankle, independent from blood pressure at the time of measurement. CAVI reflects functional stiffness, due to smooth muscle cell contraction or relaxation, and organic stiffness, due to atherosclerosis. Here, we report the case of a patient with an increased CAVI due to CTEPH and the improvement after riociguat administration and balloon pulmonary angioplasty (BPA).
A 65-year-old man suffered from dyspnea on exertion, and he was diagnosed with distal CTEPH. The mean pulmonary artery pressure (mPAP) was 51 mmHg, and the initial CAVI was 10.0, which is high for patient's age. In addition to right ventricular dysfunction, left ventricular dysfunction was observed as reduced global longitudinal strain (GLS-LV). After riociguat administration, CAVI decreased to 9.1 and GLS-LV improved from -10.3% to -17.3%, although pulmonary hypertension remained (mPAP 41 mmHg). Subsequently, a total of five BPA sessions were performed. Six months after the final BPA, mPAP decreased to 19 mmHg and GLS-LV improved to 19.3%. The patient was symptom free and his 6-minute walk distance improved from 322 m to 510 m. CAVI markedly decreased to 5.8, which is extremely low for his age.
These observations suggested that arterial stiffness as measured by CAVI was increased in CTEPH, potentially deteriorating cardiac function because of enhanced afterload. The mechanism of the increase of CAVI in this case of CTEPH was obscure; however, riociguat administration and BPA might improve the pathophysiology of CTEPH partly by decreasing CAVI.
动脉僵硬度在慢性血栓栓塞性肺动脉高压（CTEPH）病理生理学中的作用尚不清楚。心踝血管指数（CAVI）是一种新型动脉僵硬度指数，反映从主动脉起源到脚踝的动脉树僵硬度，与测量时的血压无关。CAVI反映了由于平滑肌细胞收缩或舒张引起的功能性僵硬度以及由于动脉粥样硬化引起的器质性僵硬度。在此，我们报告一例因CTEPH导致CAVI升高的患者，以及在使用利奥西呱和球囊肺动脉血管成形术（BPA）后病情改善的情况。
一名65岁男性，活动时出现呼吸困难，被诊断为远端CTEPH。平均肺动脉压（mPAP）为51 mmHg，初始CAVI为10.0，对于该患者年龄来说偏高。除右心室功能障碍外，还观察到左心室功能障碍，表现为整体纵向应变（GLS-LV）降低。使用利奥西呱后，CAVI降至9.1，GLS-LV从-10.3%改善至-17.3%，尽管肺动脉高压仍然存在（mPAP 41 mmHg）。随后，总共进行了5次BPA治疗。最后一次BPA治疗6个月后，mPAP降至19 mmHg，GLS-LV改善至19.3%。患者无症状，6分钟步行距离从322 m提高到510 m。CAVI显著降至5.8，对于他的年龄来说极低。
这些观察结果表明，CTEPH患者中通过CAVI测量的动脉僵硬度增加，可能由于后负荷增加而使心脏功能恶化。该例CTEPH患者中CAVI升高的机制尚不清楚；然而，使用利奥西呱和BPA可能通过降低CAVI部分改善CTEPH的病理生理学。
