Effects of long-term infusion of prostacyclin on exercise performance in patients with primary pulmonary hypertension.
OBJECTIVE
To determine whether long-term IV prostacyclin (PGI(2)) use improves exercise capacity in patients with primary pulmonary hypertension (PPH).


METHODS
Cycle ergometry and the 6-min walk was used to evaluate the exercise performance of patients with PPH. The patients underwent serial exercise testing after starting continuous IV PGI(2) and were followed up for 19.5 +/- 7.5 months. Peak work, peak oxygen consumption (f1.gif" BORDER="0">O(2)), peak O(2) pulse, and distance walked in 6 min were used to evaluate performance.


BACKGROUND
PPH is characterized by medial hypertrophy and intimal proliferation of the pulmonary arterioles, leading to elevation of pulmonary artery pressure, right ventricular failure, and death. Palliative treatment consists of vasodilators, anticoagulants, cardiac glycosides, diuretics, and transplantation. PGI(2), a potent vasodilator and inhibitor of platelet aggregation, has been used for long-term treatment when conventional therapy has been unsuccessful.


METHODS
Sixteen patients with PPH (10 women, 6 men; mean age, 24 years).


RESULTS
At the initiation of PGI(2), peak work (+/- SD) was 35.5 +/- 11% of predicted; peak f1.gif" BORDER="0">O(2), 39 +/- 10.4%; peak O(2) pulse, 5.0 +/- 1.7 mL/min; and distance on the 6-min walk, 428 +/- 78 feet. At 18 to 27 months, peak work increased to 58.8 +/- 23% of predicted (p = 0.001), peak f1.gif" BORDER="0">O(2) increased to 52 +/- 15% of predicted (p = 0. 02), peak O(2) pulse increased to 7.1 +/- 3.0 mL/beat (p = 0.004), and performance on the 6-min walk increased to 526 +/- 62 feet (p = 0.001). There was a positive correlation between peak f1.gif" BORDER="0">O(2) and peak 6-min walk of 0.6 (p < 0.005) and between peak work and peak 6-min walk of 0.6 (p < 0.005).


CONCLUSIONS
Exercise capacity improved in our patients at up to 27 months of follow-up. Exercise testing is helpful in assessing the functional capacity of patients with PPH and may be useful in guiding therapy. Patients who deteriorate while receiving optimal conventional therapy should be considered for IV PGI(2) therapy.
Wax
D
D
Division of Pediatric Cardiology, Columbia University College of Physicians and Surgeons, New York, NY. d-wax@nwu.edu
Garofano
R
R
Barst
R J
RJ
D000293:Adolescent; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage* / Q000009:adverse effects; D002648:Child; D011464:Epoprostenol / Q000008:administration & dosage* / Q000009:adverse effects; D005080:Exercise Test / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology; D007262:Infusions, Intravenous; D008134:Long-Term Care; D016040:Lung Transplantation / Q000502:physiology; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood; D016896:Treatment Outcome
D000959:Antihypertensive Agents; D011464:Epoprostenol; D010100:Oxygen