Fang et al prospectively observed 126 patients undergoing lung transplant at 9 U.S. centers. PA pressure was obtained invasively in the OR just after transplant. Those who developed grade 3 primary graft dysfunction at 72 hours (1' endpoint) had mPAP of 38.5 mm Hg, compared to 29.6 for those who did not; the relationship persisted after multivariate analysis. Cardiopulmonary bypass attenuated the relationship. Mortality rates were higher in the high mPAP group but didn't achieve significance. CHEST 2011;139:182-187.