부산대학교 도서관

Shuji Sato,1 Kazuhiro Shimizu,1 Takuro Ito,1 Masakazu Tsubono,1 Akihiro Ogawa,2 Takeshi Sasaki,3 Mao Takahashi,1 Mahito Noro,1 Kohji Shirai4 1Department of Cardiology, Toho University Sakura Medical Center, Chiba, Japan; 2Department of Rehabilitation, Toho University Sakura Medical Center, Chiba, Japan; 3Department of Clinical Functional Physiology, Toho University Sakura Medical Center, Chiba, Japan; 4Department of Internal Medicine, Mihama Hospital, Chiba, JapanCorrespondence: Kazuhiro ShimizuDepartment of Cardiology, Toho University Sakura Medical Center, 564-1 Shimoshizu, Sakura City, Chiba, 285-8741, JapanTel +81-43-462-8811Fax +81-43-462-8820Email k432@sakura.med.toho-u.ac.jpBackground: 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).Case Presentation: 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.Conclusion: 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.Keywords: cardio-ankle vascular index, chronic thromboembolic pulmonary hypertension, arterial stiffness, ventricular afterload