Inhaled iloprost to control pulmonary artery hypertension in patients undergoing mitral valve surgery: a prospective, randomized-controlled trial.
BACKGROUND
Pulmonary hypertension (PHT) is common in patients undergoing mitral valve surgery and is an independent risk factor for the development of acute right ventricular (RV) failure. Inhaled iloprost was shown to improve RV function and decrease RV afterload in patients with primary PHT. However, no randomized-controlled trials on the intraoperative use of iloprost in cardiac surgical patients are available. We therefore compared the effects of inhaled iloprost vs. intravenous standard therapy in cardiac surgical patients with chronic PHT.


METHODS
Twenty patients with chronic PHT undergoing mitral valve repair were randomized to receive inhaled iloprost (25 microg) or intravenous nitroglycerine. Iloprost was administered during weaning from cardiopulmonary bypass (CPB). Systemic and pulmonary haemodynamics were assessed with pulmonary artery catheterization and transoesophageal echocardiography. Milrinone and/or inhaled nitric oxide were available as rescue medication in case of failure to wean from CPB.


RESULTS
Inhaled iloprost selectively decreased the pulmonary vascular resistance index after weaning from CPB (208 +/- 108 vs. 422 +/- 62 dyn.s/cm(5)/m(2), P<0.05), increased the RV-ejection fraction (29 +/- 3% vs. 22 +/- 5%, P<0.05), improved the stroke volume index (27 +/- 7 vs. 18 +/- 6 ml/m(2), P<0.05) and reduced the transpulmonary gradient (10 +/- 4 vs. 16 +/- 3 mmHg, P<0.05). In all patients receiving inhaled iloprost, weaning from CPB was successful during the first attempt. In contrast, three patients in the control group required re-institution of CPB and had to be weaned from CPB using rescue medication.


CONCLUSIONS
In patients with pre-existing PHT undergoing mitral valve surgery, inhaled iloprost is superior to intravenous nitrogylycerine by acting as a selective pulmonary vasodilator, reducing RV afterload and moderately improving RV-pump performance.
Rex
S
S
Department of Anaesthesiology, University Hospital, Rheinisch-Westfälische Technische Hochschule Aachen, Aachen, Germany. srex@ukaachen.de
Schaelte
G
G
Metzelder
S
S
Flier
S
S
de Waal
E E C
EE
Autschbach
R
R
Rossaint
R
R
Buhre
W
W
D000280:Administration, Inhalation; D000368:Aged; D002303:Cardiac Output, Low / Q000188:drug therapy / Q000209:etiology; D002315:Cardiopulmonary Bypass; D002407:Catheterization, Swan-Ganz; D017548:Echocardiography, Transesophageal; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000209:etiology; D016285:Iloprost / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D020105:Milrinone / Q000627:therapeutic use; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D016343:Monitoring, Intraoperative; D005996:Nitroglycerin / Q000008:administration & dosage / Q000627:therapeutic use; D011183:Postoperative Complications / Q000188:drug therapy / Q000209:etiology; D011446:Prospective Studies; D013318:Stroke Volume / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use*; D018497:Ventricular Dysfunction, Right / Q000000981:diagnostic imaging / Q000209:etiology / Q000517:prevention & control
D014665:Vasodilator Agents; D005996:Nitroglycerin; D016285:Iloprost; D020105:Milrinone