Lack of tight association between quality of life and exercise capacity in pulmonary arterial hypertension.

Background: In pulmonary arterial hypertension (PAH) health-related quality of life (HRQOL) has been investigated over the short-term (weeks) but little is known about patient's perspective over the medium and long term.

Objective: To analyze how patients on specific PAH therapies do over one year of observation in terms of HRQOL, and to investigate if possible associations between the exercise capacity (EC) and HRQOL persist over the medium term.

Methods: Thirty-four patients on PAH therapies (bosentan and/or sildenafil) were enrolled (age 14 to 58 years, median 35.5 years, functional class II or III), and evaluated at baseline, and 3, 6, 9 and 12 months subsequently using the six-minute walk test and the SF-36 HRQOL questionnaire.

Results: The six minute walked distance did not change over the follow-up (387-432 meters, median values, p=0.2775), the same for the functional class and peripheral oxygen saturation. The SF-36 scores also remained stable, with physical health always worse than mental health. Of 40 possible associations between EC and HRQOL, only 12 were significant (30%, p<0.05). Prediction of severely depressed HRQOL based on a walked distance of <235 meters was >90% specific but <43% sensitive.

Conclusion: Patients with PAH who remain stable in terms of EC also seem to do so in terms of HRQOL. However, EC and HRQOL are not consistently tied over time, and should be analyzed as different perspectives in the individual patient.