Exercise-Echocardiography–Derived Pulmonary Artery Pressure Slope in Borderline and Mild to Moderate Pulmonary Arterial Hypertension

Objective: Examine pulmonary artery systolic pressure (PASP) response to exercise in isolated borderline and mild to moderate pulmonary arterial hypertension (PAH).Methods: Doppler stress echocardiography was performed in 32 healthy volunteers with resting PASP of 29 mm Hg or less, 39 with resting PASP between 30 and 40 mm Hg, and 7 with resting PASP between 41 and less than 60 mm Hg. All subjects had otherwise normal echocardiograms.Results: Rate of increase in PASP with exercise was positively associated with resting PASP (P 0.001), increased age (P 0.001), and estrogen use among women (P = 0.001). On multivariate analysis, PASP slope was independently related (P = 0.03) to resting PASP and inversely associated with exercise time (P 0.001).Conclusions: Patients with borderline and mild to moderate resting PAH have an exaggerated PASP response to exercise. PASP slope is a strong independent predictor of exercise time. Outcome studies are needed to determine the prognostic significance of this finding.