Cardiopulmonary hemodynamics in systemic sclerosis and response to nifedipine and captopril

This prospective study was performed to evaluate the response of the cardiopulmonary vasculature to two vasodilators in patients with systemic sclerosis and either minimal or no central hemodynamic abnormalities.

Twenty patients with systemic sclerosis, Raynaud's phenomenon (19 of 20 patients), and clinically normal cardiac function underwent right heart catheterization. Rest and exercise hemodynamic measurements, including cardiac output by thermodilution, were performed before and after oral administration of nifedipine 20 mg and captopril 25 mg.

Half of the patients had normal hemodynamics (Group A); the other half (Group B) had abnormal baseline elevations in pulmonary vascular resistance and four of them showed "borderline" pulmonary arterial hypertension. Group A, with significantly shorter disease duration compared with Group B, responded poorly to nifedipine and captopril. However, Group B had significant decreases in pulmonary vascular resistance (from 148 +/- 20 to normal levels of 94 +/- 21 dynes.second.cm-5) and pulmonary mean pressure in response to nifedipine treatment but not to captopril.

These observations show a short-term beneficial effect of nifedipine in the cardiopulmonary vasculature of patients with systemic sclerosis and suggest that a potentially reversible vasoconstrictive element is included in the vascular lesion of this disorder.