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.