Current Approach to Treatment of Primary Pulmonary Hypertension

¹ The University of Colorado Health Sciences Center, Department of Medicine, Division of Cardiology, Cardiovascular Pulmonary Research Laboratory, and Clinical Research Center, Denver.

Based upon our experience with a cohort of 46 patients referred to the UCHSC from April, 1980 to April, 1987 for evaluation and treatment of PPH, we currently assess acute pulmonary vasoreactivity as defined by the patient's response to intravenous PGI₂ during the initial diagnostic catheterization. A 3 to 5 day trial of high dose oral diltiazem treatment (720 mg/day maximum) is given while monitoring the patient in the clinical research center to detect significant side effects including arrhythmias, orthostatic systemic hypotension, arterial desaturation, and worsened right ventricular dysfunction. We believe it is necessary to recatheterize each patient to establish the efficacy of calcium antagonist treatment prior to discharge. Those patients who are responsive to diltiazem are discharged and followed in our pulmonary hypertension clinic. Since an occasional patient will deteriorate after several weeks of therapy, repeat right heart catheterization after 8 weeks of treatment is used to determine which patients should be continued on diltiazem for chronic therapy. Approximately 30 percent of our patients with PPH have been improved on diltiazem treatment. Most patients who have a good response to treatment after eight weeks continue to benefit from longterm treatment. It appears that the response to an acute infusion of PGI₂ is useful in safely identifying those PPH patients who are likely to benefit from vasodilator therapy. Debilitated patients who are unresponsive to PGI₂ and vasodilator therapy are considered potential candidates for cardiopulmonary transplantation.