Inhaled nitric oxide in the preoperative evaluation of pulmonary hypertension in heart transplant candidates

Objective: The goal of this study was to evaluate the efficacy of 100% oxygen and inhaled nitric oxide UNO) in decreasing pulmonary vascular resistance (PVR) and transpulmonary gradient (TPG) in dilated cardiomyopathy patients being evaluated for orthotopic heart transplantation (OHT); who, despite maximal intravenous (IV) dilator therapy, had persistent moderate-to-severe pulmonary hypertension. Design: A prospective nonrandomized clinical study. Setting: University hospital, major transplant center. Participants: Twenty-one adult patients undergoing OHT evaluation. Interventions: One hundred percent oxygen and iNO at 20 and 40 ppm were sequentially administered to the patients once they were optimized with IV vasodilators and inotropes. Measurements and Main Results: Although no significant change was noted with oxygen, iNO 20 ppm reduced the mean pulmonary artery pressure (44.1 +/- 1.7 to 38.6 +/- 1.8 mmHg, p < 0.05), PVR index (823 +/- 47 to 621 +/- 55 dyne/s/ m(2)/cm(5), p < 0.05), TPG (22.4 +/- 1.4 to 17.0 +/- 1.5 mmHg, p < 0.05), and right ventricular stroke work index (14.7 +/- 1.2 to 11.1 +/- 1.2 g. m/m(2)/beat, p < 0.05). In 13 of 21 patients, PVR decreased by greater than 25% after iNO therapy. Nine of these patients had PVR and TPG decrease to levels considered acceptable for OHT listing. Conclusions: iNO can further improve right ventricular hemodynamics even after presumed optimization with IV vasodilators and serves as a test of PVR reversibility during the preoperative assessment of OHT candidates. (c) 2007 Elsevier Inc. All rights reserved.