Clinical relevance of the International Society for Heart and Lung Transplantation consensus classification of primary graft dysfunction after heart transplantation: Epidemiology, risk factors, and outcomes.

BACKGROUND: Primary graft dysfunction (P-GD) is the leading cause of early mortality after heart transplantation (HT). In this 2-center study we analyze outcomes and risk factors of P-GD according to the recent consensus conference classification endorsed by International Society for Heart and Lung Transplantation.

METHODS: We included all adult HTs performed between 1999 and 2013. P-GD was graded as mild, moderate, and severe, according to International Society for Heart and Lung Transplantation recommendations, and analyzed separately from secondary GD. The primary end point was the combined occurrence of in-hospital death or emergency retransplantation.

RESULTS: Early GD was found in 118 of 518 patients (23%), and 72 (13.9%) met the criteria for P-GD. Of these, 4 (5%) were mild, 33 (46%) moderate, and 35 (49%) severe and mostly characterized by biventricular involvement (78%). The end point occurred in 53 patients (10.2%). Overall, GD was a strong predictor of death-graft loss (odds ratio, 15.9; 95% confidence interval, 7.9-33.5; p < 0.01), with non-significant worse outcomes in P-GD (37%) vs secondary GD (27%) patients (p = 0.2). The study end point was more frequent in severe P-GD patients (65%) than in moderate (12%) or mild (0%; p < 0.01). Several known risk factors influenced the risk for P-GD, and the combination of specific donor and recipient risk factors accounted for approximately 22-times increased odds for P-GD. Donor age, recipient diabetes, ischemic time, and post-operative dialysis predicted non-recovery from P-GD.

CONCLUSIONS: Consensus-defined P-GD identifies patients at major risk for early death and graft loss after HT, although the "mild" grade appeared under-represented and clinically irrelevant. The amplified negative effect of donor and recipient factors on P-GD risk underscores the need for appropriate donor-recipient match.