Functional pattern of baseline lung allograft dysfunction after lung transplantation.

Baseline lung allograft dysfunction (BLAD) is predictor of death and chronic lung allograft dysfunction (CLAD) after lung transplantation. However, it may be distinct risk factors and prognosis depending on functional pattern of BLAD. Our objective was to verify these hypotheses. This retrospective study was conducted with lung transplants done in our center between 2010 and 2019. Forced expiratory volume in the first second [FEV1] and forced vital capacity [FVC] > 80% predicted defined normal baseline function. Failure to meet these criteria defined BLAD which was then characterized according to its functional pattern. Restrictive and obstructive groups were compared to non-BLAD group. Characteristics associated with death and CLAD were determined by multivariate regression. Of 171 recipients eligible for study, 111 (65%) had normal respiratory function, 22 (13%) had obstructive BLAD, 34 (20%) restrictive BLAD and 4 (2%) mixed BLAD. Patients with obstructive BLAD had older donor (55 ± 15 years vs 44 ± 16 years; p=0.007) with lower PaO2/FiO2 (386 ± 84 mm Hg vs 435 ± 84 mm Hg; p=0.03) than patients without BLAD, increased risk of death (hazard ratio [HR] 4.7; 95% confidence interval [CI] 2.11-10.5) but not of CLAD. Compared to patients without BLAD, patients with restrictive BLAD were more likely transplanted for fibrosis (30% vs 10%; p=0.053), had smaller implanted graft with smaller ratio of total lung capacity [TLC] implanted/ predicted TLC of recipient (0.88 ± 0.23 vs 1 ± 0.21; p<0.0001), had increased risks of death ([HR] 6.7 95% [CI] 3.23-13.9) and CLAD ([HR] 2.19 95% [CI] 1.25-3.84). There may be several kind of BLAD with distinct risk factors and prognosis. This need further invesigation.