Background: This study compared the results of exercise Doppler echocardiography (EDE) with right-sided heart catheterization (RHC) and evaluated the combination of EDE and cardiopulmonary exercise testing (CPET) as a screening method for early pulmonary vasculopathy in patients with connective tissue disease.
Methods: Patients (N = 52) with connective tissue disease (predominantly systemic sclerosis) and without known pulmonary arterial hypertension underwent both EDE and CPET. If systolic pulmonary arterial pressure (SPAP) was > 40 mm Hg during exercise or peak oxygen uptake (Vo(2)) was < 75% predicted, RHC was suggested.
Results: EDE showed an SPAP > 40 mm Hg during exercise in 26/52 patients. Additionally, CPET showed a peak Vo(2) < 75% predicted in 10/26 patients with SPAP <or= 40 mm Hg upon exercise. Accordingly, RHC was suggested to 36 patients. RHC was performed in 28 of these patients, revealing SPAP > 40 mm Hg in 25 patients (n = 1 at rest, n = 24 during exercise). SPAP values assessed by EDE showed no significant difference vs RHC at rest, 25 W, 50 W, and maximal exercise (difference [95% CI]: 0.3 [-2.7; 3.2], -1.3 [-7.1; 4.4], 0.9 [-7.7; 5.9], and -5.6 [-13.5; 2.2] mm Hg). Eight patients with exercise SPAP > 40 mm Hg had an exercise pulmonary arterial wedge pressure > 20 mm Hg, suggesting exercise-induced left ventricular diastolic dysfunction not detectable by EDE.
Conclusions: EDE appears to be a reasonable noninvasive method to detect SPAP increase during exercise in connective tissue disease. In combination with CPET, it may be a useful screening tool for early pulmonary vasculopathy, although RHC remains the gold standard for hemodynamic assessment.
Trial registration: clinicaltrials.gov; Identifier: NCT00609349 (Early Recognition of Pulmonary Arterial Hypertension).