Pulmonary Vascular Capacitance is Associated with Vasoreactivity and Long-Term Response to Calcium Channel Blockers in Idiopathic Pulmonary Arterial Hypertension.
This study aimed to identify the relationship between pulmonary vascular capacitance (PVC) and vasoreactivity in patients with idiopathic pulmonary arterial hypertension (IPAH), and the value of PVC in predicting long-term response to CCB treatment.



Pulmonary vasodilator testing with inhaling iloprost was performed in 308 newly diagnosed IPAH patients. Acute vasodilator-responsive patients accepted CCBs treatment. Patients who benefit from long-term CCB were defined as those being in World Health Organization (WHO) functional class II or I after at least 1 year on CCB monotherapy.



PVC had significant correlations with WHO function class, 6-min walk distance, mean pulmonary arterial pressure, and pulmonary vascular resistance (r = -0.363, p < 0.001; r = 0.333, p < 0.001; r = -0.514, p < 0.001; r = -0.739, p < 0.001). Thirty-five acute vasodilator-responsive IPAH patients (11.4 %) displayed less severe disease and a higher baseline PVC (1.5 ± 0.6 vs. 1.1 ± 0.7 ml/mmHg, p = 0.003). During acute vasodilator testing, PVC increased significantly by mean of 79 ± 48 % and reached to a higher absolute value of 2.6 ± 1.5 ml/mmHg compared with non-responsive patients (1.4 ± 1.5 ml/mmHg, p < 0.001). Furthermore, PVC increased more during acute vasodilator testing in the 24 patients who benefit from long-term CCB treatment (1.4 ± 1.3 vs. 0.5 ± 0.4 ml/mmHg, p = 0.004). The OR of increased PVC during vasodilator testing for predicting patients with long-term response to CCB was 1.24 (95 % CI 1.02-1.50, p = 0.031) as assessed by multivariable logistic regression analysis.



PVC was higher in acute vasodilator-responsive IPAH patients and may be a predictor of long-term response to CCBs therapy.
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Xiao-Ling
XL
Cheng
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Jian-Guo
JG
He
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Zhi-Hong
ZH
Liu
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Qing
Q
Gu
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Xin-Hai
XH
Ni
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Zhi-Hui
ZH
Zhao
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China.
Qin
Q
Luo
State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beilishi Road, Xicheng District, Beijing, 100037, China. xiongcmfw@163.com.
Chang-Ming
CM
Xiong
D000328:Adult; D062186:Arterial Pressure; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D002302:Cardiac Output; D065627:Familial Primary Pulmonary Hypertension / Q000188:drug therapy* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D016285:Iloprost / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011651:Pulmonary Artery / Q000503:physiopathology*; D012720:Severity of Illness Index; D013997:Time Factors; D018924:Vascular Capacitance; D014655:Vascular Resistance; D014664:Vasodilation / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology; D000070857:Walk Test; D055815:Young Adult
D002121:Calcium Channel Blockers; D014665:Vasodilator Agents; D016285:Iloprost
Calcium channel blockers; Iloprost; Pulmonary vascular capacitance; Vasoreactivity