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WESTPORT, CT (Reuters Health) – Expanding the criteria for lung transplants in patients with cystic fibrosis would make it more likely that those who could benefit most would undergo the surgery, according to an analysis of data from the CF Foundation Patient Registry (CFFPR). An added benefit would be a significantly shorter wait time for donated lungs.

Currently, patient selection depends primarily on percent predicted forced expiratory volume in 1 second (FEV-1%), Dr. Theodore G. Liou, of the University of Utah in Salt Lake City, and colleagues note in The Journal of the American Medical Association for December 5. The problem with this criterion, the researchers propose, is that it does not identify the high-mortality population for which lung transplants were originally intended.

Dr. Liou's team previously developed a new model that includes several clinical features that affect CF, including age, gender, weight, pancreatic sufficiency, diabetes mellitus, number of acute exacerbations, and infection.

Using data from the CFFPR, the investigators stratified patient into five groups according to 5-year predicted survival based on the new model. They then compared the effect of using the FEV-1% criterion versus the new model for selecting candidates for lung transplantation.

A total of 11,630 patients served as the control group, and the investigators predicted their 5-year survival rate beginning in January 1993. For 468 patients who underwent bilateral lung transplantation between 1992 and 1997, the 5-year survival rate was predicted from the date of the procedure.

For patients whose predicted survival rate was <30%, lung transplantation was associated with slightly decreased survival during the first 6 months following surgery, compared with controls. By 2 years, however, a survival advantage was evident, and this benefit increased with time.

The survival benefit was deemed equivocal for patients with 30% to <50% predicted survival. For those with a 50% predicted survival or better, transplantation actually increased their mortality rate.

The researchers estimate that on average, each year 154 individuals enter the group considered by the new model to have a 5-year survival rate <30%, "approximately 1.5 times the number of lung transplants performed each year for CF." Using an FEV-1% cutoff of less than 30% identified 1458 patients as potential recipients.

Pointing out in an editorial that the FEV-1% criterion was developed on the basis of patients from only one clinical center, Dr. Janet R. Maurer praises the prediction model of Liou et al., which has been validated in large populations. Dr. Maurer, of CIGNA HealthCare in Bloomfield, Connecticut, suggests that clinicians access the Web site http://www.jhsph.edu/Publications/JEPI/liou.htm for assistance in making the calculations using the new prediction model.