An acute increase in lung allocation score (LAS) of more than five units in the month before lung transplant is a strong and independent predictor of post-transplant death according to a new study.
Using a Cox proportional hazards model, a LAS increase of more than 5 in the 30 days before surgery was associated with a 31% increased risk for post-transplant death (hazard ratio, 1.31, 95% CI 1.11 to 1.54, P=0.001) compared with patients with LAS increases of 5 or less (reference group), reported Wayne Tsuang, MD, of Duke University Medical Center, and colleagues, in Annals of Internal Medicine.
"We show, for the first time to our knowledge, that the trajectory of pre-transplant LAS change offers important prognostic information about post-transplant survival beyond that captured by the LAS-T (score at transplant)," the authors wrote.
The lung allocation score has been used in the U.S. since 2005 to determine which patients in need of lung transplants will get them.
The system allocates organs on the basis of a patient's risk of death without a transplant and chance of survival following the procedure based on a predictive model that includes more than a dozen health variables and patient characteristics.
The model is used to predict the patient's chance of survival over the next year with and without a lung transplant, and the LAS is calculated and normalized to reflect a range of 0 to 100. The higher the LAS score, the higher a patient rises on the organ waiting list.
Since the adoption of the LAS system, the wait list for lung transplants has been cut in half, because there is no longer an incentive to place patients on the list early to accrue time. The death rate while waiting for a transplant has also declined because sicker patients are given priority.