ABSTRACT
PURPOSE: 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. PATIENTS AND METHODS: 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. RESULTS: 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. CONCLUSION: 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.
Subject(s)
Captopril/therapeutic use , Cardiovascular Diseases/drug therapy , Hemodynamics/drug effects , Nifedipine/therapeutic use , Scleroderma, Systemic/drug therapy , Administration, Oral , Adult , Captopril/administration & dosage , Captopril/pharmacology , Cardiac Catheterization , Cardiovascular Diseases/diagnosis , Cardiovascular Diseases/physiopathology , Exercise Test , Female , Humans , Male , Middle Aged , Nifedipine/administration & dosage , Nifedipine/pharmacology , Prospective Studies , Scleroderma, Systemic/diagnosis , Scleroderma, Systemic/physiopathology , Vascular Resistance/drug effectsABSTRACT
Lung involvement in systemic sclerosis may be due in part to a functional abnormality of the pulmonary vasculature. To investigate the possible role of a pulmonary vasospastic process in this disorder, 21 non-smoking patients who had no evidence of cardiac disease or pulmonary hypertension were evaluated with pulmonary function tests prior to administration of nifedipine, 30 minutes after a single oral dose of nifedipine (20 mg), and after 4 weeks of treatment with nifedipine (10 mg 3 times daily). Treatment with nifedipine did not significantly change any of the pulmonary function values, except for the carbon monoxide diffusing capacity (DLCO). The linear trend between the individual DLCO values at baseline and their changes immediately following the initial 20-mg dose of nifedipine (r = -0.603, P = 0.02) and after 4 weeks of treatment (r = -0.636, P = 0.01) showed that the lower the DLCO value at baseline, the greater the improvement caused by nifedipine. These findings support the hypothesis of a potentially reversible pulmonary vasospasm in systemic sclerosis and suggest that nifedipine may be useful in the treatment of lung disease in these patients; however, further studies are needed.
