FEV(1) as a guide to lung transplant referral in young patients with cystic fibrosis.

Forced expiratory volume in one second (FEV(1)) is widely used to guide referral of patients with cystic fibrosis (CF) for lung transplantation. We reasoned that the best FEV(1) in a 6-month period (bFEV(1)) would be a useful marker of the need for transplant referral. We examined both the rate of decline and different threshold values of bFEV(1) as prognostic indicators in young CF patients. In a case-control analysis, rates of decline in and threshold values of bFEV(1) of 28 patients dying between ages 7-18 years from 1980-1997 were compared to those of 28 age- and gender-matched controls. The threshold analysis of bFEV(1) values was then applied to all patients under age 19 years followed in our clinic from 1993-1997. The rate of decline in bFEV(1) differed for cases and controls over the 4-year period prior to death, but not from years 2-4 prior to death, the time at which transplant referral decisions should be made. A bFEV(1) value of 50% predicted at 2 years prior to the death of the case selected 14 of 28 cases and one control. When applied to all pediatric patients followed from 1993-1997, a bFEV1 threshold of 50% predicted selected 2 of the 3 patients who died and 3 of the 140 patients who survived. Consideration of lung transplantation referral should begin when young CF patients have a best FEV(1) <50% predicted despite aggressive conventional treatment. Copyright 2000 Wiley-Liss, Inc.