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 VÌO2 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.
EXPRESS: The association of six minute walk work and other clinical measures to cardiopulmonary exercise test parameters in pulmonary vascular disease