Should patients with connective tissue disease undergo exercise Doppler echocardiography?

We read with the great interest the recently published article by Kovacs et al 1 (August 2010) indicating that exercise Doppler echocardiography (EDE) can be a useful, noninvasive screening tool to detect an increase in systolic pulmonary artery pressure (PAP) during exercise in patients with connective tissue disease. However, in our opinion, there are some interesting issues to be discussed. According to the recent European Society of Cardiology guidelines on pulmonary hypertension (PH), the defi nition of PH on exercise is not supported by published data. 2 Thus, no defi nition of exercise-induced PH can be provided currently. Moreover, US guidelines are consistent with this statement. 3 However, recently published data indicate that more attention should be paid to an exaggerated increase of systolic PAP during exercise, which is suggested to be a marker of early pulmonary vasculopathy in connective tissue disease. Kovacs et al 1 revealed that EDE showed a systolic PAP . 40 mm Hg during exercise in 26 of 52 patients with connective tissue disease. In our unpublished observations, an increase in systolic PAP of . 20 mm Hg at EDE was recorded in 11 (17%) of 65 patients with systemic sclerosis. In all of the 11 patients with increased systolic PAP, subsequent right-sided heart catheterization (RHC) confi rmed systolic PAP increase during exercise. In our opinion, EDE is a potentially useful test to detect “exercise-induced PH” that may represent an intermediate stage between a physiologic response and manifest PH. Importantly, an elevated systolic PAP on exercise can be caused not only by pulmonary vasculopathy but also by a signifi cant increase in pulmonary venous pressure. Among patients reported by Kovacs et al, 1 RHC revealed an elevation of pulmonary arterial wedge pressure . 20 mm Hg in 33% of subjects with exerciseinduced PAP increase. In our group of 16 patients with systemic sclerosis (11 subjects with exercise-induced PH and fi ve with PH at rest), RHC showed an elevated pulmonary arterial wedge pressure in 12 (75%) of them. These fi ndings may suggest a latent leftventricular fi lling dysfunction. Interestingly, these observations suggest that left-ventricular diastolic dysfunction in patients with connective tissue disease is more frequent than previously believed. Our data indicate that left-ventricular preload reduction using small doses of diuretics may be benefi cial for such patients. In our opinion, Kovacs et al 1 are perfectly right that EDE is a useful, noninvasive method to detect systolic PAP increase during exercise in patients with connective tissue disease. However, it should be remembered that RHC still remains the golden standard for assessment of PH.