The association of six‐minute walk work and other clinical measures to cardiopulmonary exercise test parameters in pulmonary vascular disease

Abstract

In pulmonary vascular disease (PVD) exercise abnormalities can include reduced exercise capacity, reduced oxygen pulse (O2 pulse) and elevated VE/VCO2. The association of clinical measures such as 6 minute walk work (6MWW), haemodynamics, lung function and echocardiogram to peak VO2, O2 pulse and VE/VCO2 has not been fully investigated in PVD Aims: To determine the relationship of 6MWW and other clinical measures to peak VO2, peak O2 pulse and VE/VCO2. Additionally, to investigate the ability to predict peak VO2 from 6MWW and other clinical parameters. Methods: Clinical data was retrospectively analysed from 63 chronic thromboembolic pulmonary hypertension (CTEPH) and 54 chronic thromboembolic disease (CTED) patients. 6 minute walk test measures, haemodynamics, lung function and echocardiographic measures were correlated with peak VO2, peak O2 pulse and VE/VCO2. Predictive equations were developed to predict peak V̇O2 in both CTEPH and CTED cohorts and subsequently validated. Results: A number of clinical parameters correlated to peak VO2, peak O2 pulse and VE/VCO2. 6MWW and TLCO demonstrated the strongest correlation to peak VO2 and peak O2 pulse. The validation of the predictive equations showed a variable level of agreement between measured peak VO2 and calculated peak VO2 from the predictive equations. Conclusion: 6MWW and additionally a number of clinical test parameters were associated to peak VO2, peak O2 pulse and VE/VCO2. 6MWW and TLCO were particularly highly correlated to peak VO2 and similarly to peak O2 pulse. The validation of the predictive equations showed a variable level of agreement and therefore may have limited clinical applicability.

Use of six‐minute walking test to predict peak oxygen consumption in pulmonary vascular disease

“…The CPET is an incremental test that measures maximum or peak exercise capacity, whereas the 6MWT is usually a submaximal test since it is not incremental. Although our group demonstrated that, in patients with PH, this test represents a maximum capacity, 14 it could not be confirmed that this is the case with all the patients evaluated by Robertson et al, 1 since approximately only half of them, showed PH. It is likely the group with CTED, with a mean pulmonary artery pressure of 16 ± 6 mmHg, behaves like the rest of the population and the 6MWT is a submaximal exercise.…”

“…Furthermore, our data showed that the response to exercise in PH patients indicates cardiovascular limitation due to increased right ventricular afterload. However, in the supplementary material shown by Robertson et al 1 notable differences in the hemodynamic profile of both populations can be seen and conclusions are not so clear.…”

“…4,5 Nevertheless, to achieve a reliable, reproducible and useful equation in clinical practice, certain test execution conditions standardized by the scientific societies must be met. 6,7 Having said that, in the Robertson et al 1 study, there are certain aspects of test execution that deserve attention. One of our main concerns is that two different protocols were used for this study to perform the 6MWT.…”

“…To the Editor, We read with interest the recent article by Robertson et al 1 determining the relationship between 6-min walk work (6MWW) and the clinical measurements of cardiopulmonary exercise test (CPET) and investigating the ability to predict peak oxygen consumption (VO 2peak) from 6MWW. To meet their objective, Robertson et al1retrospectively analysed 63 chronic thromboembolic pulmonary hypertension (PH) and 54 chronic thromboembolic diseases (CTED) patients.…”

O Papel do teste cardiopulmonar de exercício no diagnóstico diferencial da dispneia em paciente com hipertensão arterial pulmonar primária

“…As informações do TCPE comprovaram o acometimento vascular pulmonar causado pela HAP primária, com repercussão cardíaca, evidenciado pela alteração do comportamento do pulso de oxigênio ao esforço, aumento significativo da relação VE/VCO2 slope, alto VE/VCO2 nadir, baixo PETCO2 pico(Guazzi, et. al., 2017;Robertson, et. al., 2021;Thirapatarapong, et.…”