Tsuboi Y, Tanaka H, Nishio R, Sawa T, Terashita D, Nakayama K,
Satomi-Kobayashi S, Sakai Y, Emoto N, Hirata KI.

J Cardiopulm Rehabil Prev. 2017 Sep;37(5):341-346

PURPOSE: Pulmonary arterial hypertension (PAH) and chronic thromboembolic
pulmonary hypertension (CTEPH) are the main subgroups of pulmonary hypertension
(PH). Despite differences in their etiologies, both diseases are characterized by
vascular remodeling, resulting in progressive right heart failure. Noninvasive
periodic evaluation of exercise tolerance has become increasingly important.
Cardiopulmonary exercise testing (CPET) and a 6-minute walk test (6MWT) are now
both recommended for evaluating exercise tolerance, but there is insufficient
knowledge about possible differences in the associations of exercise tolerance
with right heart catheterization (RHC) data for patients with PAH and CTEPH.
METHODS: A retrospective study was performed with 57 patients with PH (24 with
PAH and 33 with CTEPH) all of whom underwent echocardiography, CPET, 6MWT, and
RHC.
RESULTS: For both patients with PAH and CTEPH, peak heart rate during CPET was
significantly higher than that from 6MWT, whereas minimum peripheral oxygen
saturation during CPET and 6MWT was similar. For patients with PAH, significant
correlations were observed between peak (Equation is included in full-text
article.)O2 and cardiac index (CI) (r = 0.59; P = .002) and between (Equation is
included in full-text article.)E/(Equation is included in full-text article.)CO2
slopes and CI (r =-0.46, P = .02), as well as a nonsignificant correlation
tendency for peak (Equation is included in full-text article.)O2 and pulmonary
vascular resistance (PVR) and for (Equation is included in full-text
article.)E/(Equation is included in full-text article.)CO2 and PVR (r =-0.39; P =
.05; and r = 0.39; P = .06, respectively). For patients with CTEPH, however, a
significant correlation was observed only between (Equation is included in
full-text article.)E/(Equation is included in full-text article.)CO2 slopes and
CI (r =-0.38; P = .02).
CONCLUSION: PH etiology should be considered when assessing exercise tolerance,
whereas CPET can be effective in addition to hemodynamic assessment by means of
RHC for periodic evaluation during followup.