PURPOSE: Lung transplantation is a treatment option for patients with end-stage COPD; though, a survival benefit has not been proven. This may be in part due to difficulties with the selection of appropriate recipients as traditional markers of disease severity do not reliably predict survival. The IC/TLC ratio is a newly described measure of hyperinflation that performs well as a predictor of COPD survival. The aim of this study is to compare survival following lung transplantation to the predicted survival of COPD patients using the IC/TLC ratio.
METHODS: We reviewed the records of 122 subjects who underwent lung transplantation for COPD at our institution between 1991 and 2006. Demographic data was collected, and a pre-transplant IC/TLC ratio was calculated. Actual post-transplant Kaplan-Meier survival curves were constructed. Survival at 50 months was compared to predicted values using Fisher’s Exact test.
RESULTS: The mean age of recipients was 56 years, and most were Caucasian (n=118) and female (n=69). 71 subjects had an IC/TLC ≤25%, while 51 subjects had an IC/TLC >25% prior to transplantation. Actual survival of lung transplant recipients with an IC/TLC ≤25% was greater than the predicted survival without transplantation (63% vs. 37% at 50 months; p<0.0001). Actual survival among the 51 subjects with an IC/TLC >25% was less than the predicted survival without transplantation (57% vs. approximately 78% at 50 months; p=0.0017). There was no difference in post-transplant survival between IC/TLC groups.
CONCLUSION: Lung transplantation offers a distinct survival advantage for COPD patients with an IC/TLC ≤25%. For those with IC/TLC ratio >25% the same advantage does not exist, and transplantation may actually worsen survival.
CLINICAL IMPLICATIONS: The IC/TLC ratio may be a useful measure for the appropriate selection of candidates for lung transplantation in COPD.
DISCLOSURE: Shirley Jones, None.