Noninvasive assessment of pulmonary vascular resistance by echocardiography in chronic thromboembolic pulmonary hypertension.
BACKGROUND
Pulmonary vascular resistance (PVR) is an important parameter in the management of patients with chronic thromboembolic pulmonary hypertension (CTEPH), and numerous noninvasive methods for PVR prediction have been proposed. However, a systematic evaluation of the methods that are specific for CTEPH has not been conducted. We compared a variety of echocardiography-derived prediction indices with direct right heart catheterization (RHC) to identify the most reliable noninvasive indicator of PVR in patients with CTEPH.


METHODS
Echocardiography and RHC were performed sequentially in 40 patients (mean age: 62.4±11.4 years; 30 females) with CTEPH. We measured the peak flow velocity of tricuspid regurgitation (TRV), tricuspid regurgitation pressure gradient (TRPG), right ventricular outflow tract (RVOT) time-velocity integral (TVIRVOT), left ventricular outflow tract (LVOT) time-velocity integral (TVILVOT), cardiac output at RVOT (CORVOT), and the LVOT (COLVOT) using echocardiography. The parameters TRV/TVIRVOT, TRV/TVILVOT, TRV/CORVOT, TRV/COLVOT, TRPG/TVIRVOT, TRPG/TVILVOT, TRPG/CORVOT, and TRPG/COLVOT were then calculated to predict the PVR. Finally, correlations between these echocardiographic predictors of PVR and the PVR data obtained from RHC (PVRRHC) were assessed.


RESULTS
The mean pulmonary arterial pressure and PVRRHC were 32.1±11.4mmHg and 5.4±2.9 Wood units, respectively. TRV/TVIRVOT, TRV/TVILVOT, TRV/COLVOT, TRPG/TVIRVOT, TRPG/TVILVOT, TRPG/CORVOT, and TRPG/COLVOT were all significantly correlated with the PVRRHC, and TRPG/COLVOT was the most strongly correlated with the PVRRHC (r=0.807, p<0.001).


CONCLUSIONS
Echocardiographic measurement of TRPG/COLVOT is a reliable noninvasive predictor of PVR in CTEPH patients.
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan. Electronic address: daikasai6075@yahoo.co.jp.
Hajime
H
Kasai
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Akane
A
Matsumura
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Toshihiko
T
Sugiura
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; Department of Advanced Medicine in Pulmonary Hypertension, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan.
Ayako
A
Shigeta
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan; Department of Advanced Medicine in Pulmonary Hypertension, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuou-ku, Chiba 260-8670, Japan.
Nobuhiro
N
Tanabe
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Ryogo
R
Ema
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Yoriko
Y
Sakurai
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Misuzu
M
Yahaba
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Yukiko
Y
Matsuura
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Naoko
N
Kawata
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Seiichiro
S
Sakao
Department of Respirology, Graduate School of Medicine, Chiba University, Chiba 260-8670, Japan.
Koichiro
K
Tatsumi
D000368:Aged; D002908:Chronic Disease; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000150:complications* / Q000503:physiopathology; D014655:Vascular Resistance
Chronic thromboembolic pulmonary hypertension; Echocardiography; Pulmonary vascular resistance; noninvasive