To identify risk factors for poor functional outcome at one year following lung transplantation.
We conducted a cohort study of 321 consecutive lung transplant recipients between October 1991 and August 2002 at a tertiary-care academic medical center. We defined poor functional outcome as inability to achieve a normal minimum age-appropriate six-minute walk distance within one year following lung transplantation. The following recipient risk factors were evaluated: age, gender, race, diagnosis, body mass index, smoking history, depression medications, marital status, education level, working status, cytomegalovirus serology, osteoporosis and type of lung transplant. Risk factors were assessed individually for association with functional outcome and adjusted for confounding using multivariable logistic regression models.
Among those who survived one year, 25.6% (95% confidence interval [CI], (19.8, 31.2)) did not achieve a normal six-minute walk distance. Multivariable analysis demonstrated that the following risk factors were independently associated with poor functional outcome at one year: recipient female gender (adjusted odds ratio [OR] = 4.32; (95% CI, (1.96, 9.5); p<0.0001) and recipient body mass index of greater than 27 (adjusted OR= 3.72; (95% CI, (1.7, 8.1); p=0.001). Recipient diagnosis of interstitial lung disease compared to other diagnoses was associated with good functional outcome at one year (adjusted OR= 0.26; (95% CI, (0.08, 0.8); p=0.03).
Poor functional outcome following lung transplantation is common. Recipient female gender and recipient body mass index are independently associated with poor functional outcome following lung transplantation. Patients who survive one year, who carry a pre-transplant diagnosis of interstitial lung disease have better functional outcomes following lung transplantation.
Future investigations into the mechanism of poor functional outcome in female recipients and those with higher BMI are justified. Future studies should seek to validate these findings as well as to broaden the functional outcomes for which risk factors are identified. Reliable association of risk factors with poor functional outcome would permit a more rational approach to organ allocation.
J.S. Sager, None.