Heart rate response during 6-minute walking testing predicts outcome in operable chronic thromboembolic pulmonary hypertension
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
BACKGROUND: Six-minute walk test (6MWT) is routinely performed in chronic thromboembolic pulmonary hypertension (CTEPH) before pulmonary endarterectomy (PEA). However, the clinical relevance of heart rate response (ΔHR) and exercise-induced oxygen desaturation (EID) during 6MWT is remaining unknown. METHODS: Patients undergoing PEA in our center between 03/2013-04/2014 were assessed prospectively with hemodynamic and exercise parameters prior to and 1 year post-PEA. Patients with symptomatic chronic thromboembolic disease (mean pulmonary artery pressure (mPAP) <25 mmHg) and clinical relevant obstructive pulmonary disease were excluded. The following definitions were used: ΔHR = (peak HR - resting HR), percent heart rate reserve (HRR) = (peak HR -rest HR)/(220 - age - rest HR) x 100 and EID = SpO2 ≤88 %. RESULTS: Thirty-seven patients (of 116 patients screened) with mPAP of 43.2 ± 8.7 mmHg, pulmonary vascular resistance (PVR) of 605.5 ± 228.7 dyn*s/cm(5), cardiac index (CI) of 2.4 ± 0.5 l/min/m(2) and a 6MWT-distance of 404.7 ± 148.4 m and a peak VO2 of 12.3 ± 3.4 ml/min/kg prior to PEA were included. Baseline ΔHR during 6MWT was significantly associated with PVR 1 year post-PEA using linear regression analysis (r = 0.43, p = 0.01). Multivariate analysis indicated an association of HRR during 6MWT and residual PH with a hazard ratio of 1.06 (95 % Confidence interval for hazard ratio 0.99-1.14, p = 0.08). EID was observed commonly during 6MWT but no correlations to outcome parameters were found. CONCLUSIONS: This is the first prospective study to describe an association of ΔHR during 6MWT with pulmonary hemodynamics 1 year post-PEA. Our preliminary results indicate that HRR derived from 6MWT is of clinical significance. EID was commonly observed, albeit failed as a significant prognostic factor.
Date Issued
2016-07-04
Date Acceptance
2016-06-10
Citation
BMC Pulmonary Medicine, 2016, 16
ISSN
1471-2466
Publisher
BioMed Central
Journal / Book Title
BMC Pulmonary Medicine
Volume
16
Copyright Statement
© 2016 The Author(s). This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
License URL
Subjects
Chronic thromboembolic pulmonary hypertension
Heart rate response
Oxygen desaturation
Pulmonary endarterectomy
Respiratory System
1102 Cardiovascular Medicine And Haematology
Publication Status
Published
Article Number
96