Reduced exercise capacity and stress-induced pulmonary hypertension in patients with scleroderma

Objectives: We sought to determine the incidence of stress-induced pulmonary artery (PA) systolic hypertension in a referral population of patients with scleroderma, and to examine the relation between stress-induced pulmonary systolic hypertension and exercise capacity in this population. Background: Early detection of patients with scleroderma at risk for pulmonary hypertension (PHTN) could lead to more timely intervention and thus reduce morbidity and improve mortality. The change in PA systolic pressure (PASP) with exercise provides a possible tool for such detection. Methods: Sixty-five patients with scleroderma (9 men and 56 women; mean age 51 +/- 12 years [SD]), normal resting PASP, and normal resting left ventricular function underwent exercise Doppler echocardiography using a standard Bruce protocol. Tricuspid regurgitation velocity was measured before and after exercise. Exercise variables including workload achieved in metabolic equivalents (METS), total exercise time, percentage of target heart rate achieved, and PASP at rest and within 60 s after exercise were recorded. Results: Thirty patients (46%) demonstrated an increase in PASP to > 35 mm Hg plus an estimated right atrial pressure of 5 mm Hg. Postexercise PASP inversely correlated to both the maximum workload achieved (r = -0.34, p = 0.006) and exercise time (r = -0.31, p = 0.01). In women, the correlation was more significant (r = -0.38, p = 0.003). Patients in the lowest quartile of exercise time, with the least cardiac workload achieved, produced the highest postexercise PASP. Conclusion: Stress-induced PHTN is common in patients with scleroderma, even when resting PASP is normal. Stress Doppler echocardiography identifies scleroderma patients with an abnormal rise in PASP during exertion. Peak PASP is linearly related to exercise time and maximum workload achieved. Measurement of PASP during exercise may prove to be a useful tool for the, identification of future resting PHTN.