Comorbidities can affect disease progression and/or response to treatment in various conditions. Comorbid conditions are prevalent in patients with pulmonary arterial hypertension (PAH); however, their effect on patient outcomes remains unknown.
We evaluated the effect on functional class (FC), 6-minute walk test distance (6MWD), and survival of the 7 most common comorbid conditions at enrollment in patients with PAH from the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL): hypertension, clinical depression, type II diabetes mellitus (diabetes), obesity, chronic obstructive pulmonary disease (COPD), sleep apnea, and thyroid disease.
Patients with COPD or diabetes had the shortest 6MWD at enrollment (304.5 and 304.6 m, respectively) versus other comorbidities. Adjusted linear regression for 6MWD at enrollment revealed significant reductions among hypertensive, obese, diabetic, and COPD patients (P<.001). A larger proportion of obese or COPD patients were FC III/IV versus FC I/II at enrollment (P<.001). There was a greater risk of death among patients with diabetes (hazard ratio [HR], 1.73; 95% CI, 1.40–2.13; P<.001) or COPD (HR, 1.59; 95% CI, 1.34–1.90; P<.001) but a reduced risk in obese patients (HR, 0.73; 95% CI, 0.61–0.86; P<.001).
Compared with other analyzed comorbidities in PAH patients, hypertension, obesity, diabetes, and COPD were associated with significantly worse 6MWD; obesity and COPD with worse FC; and diabetes and COPD with increased risk of death. Further investigation of the effects of treating these comorbidities in patients with PAH is warranted.