Background: Lung-volume-reduction surgery is a proposed treatment for emphysema, but optimal selection criteria have not been defined. The National Emphysema Treatment Trial is a randomized, multicenter clinical trial comparing lung-volume-reduction surgery with medical treatment.
Methods: After evaluation and pulmonary rehabilitation, we randomly assigned patients to undergo lung-volume-reduction surgery or receive medical treatment. Outcomes were monitored by an independent data and safety monitoring board.
Results: A total of 1033 patients had been randomized by June 2001. For 69 patients who had a forced expiratory volume in one second (FEV1) that was no more than 20 percent of their predicted value and either a homogeneous distribution of emphysema on computed tomography or a carbon monoxide diffusing capacity that was no more than 20 percent of their predicted value, the 30-day mortality rate after surgery was 16 percent (95 percent confidence interval, 8.2 to 26.7 percent), as compared with a rate of 0 percent among 70 medically treated patients (P<0.001). Among these high-risk patients, the overall mortality rate was higher in surgical patients than medical patients (0.43 deaths per person-year vs. 0.11 deaths per person-year; relative risk, 3.9; 95 percent confidence interval, 1.9 to 9.0). As compared with medically treated patients, survivors of surgery had small improvements at six months in the maximal workload (P= 0.06), the distance walked in six minutes (P=0.03), and FEV1 (P<0.001), but a similar health-related quality of life. The results of the analysis of functional outcomes for all patients, which accounted for deaths and missing data, did not favor either treatment.
Conclusions: Caution is warranted in the use of lung-volume-reduction surgery in patients with emphysema who have a low FEV1 and either homogeneous emphysema or a very low carbon monoxide diffusing capacity. These patients are at high risk for death after surgery and also are unlikely to benefit from the surgery.