Predictors of operative mortality and cardiopulmonary morbidity in the National Emphysema Treatment Trial

Objective: We sought to identify predictors of operative mortality, pulmonary morbidity, and cardiovascular morbidity after lung volume reduction surgery. Methods: Univariate and multivariate logistic regression analyses were performed. Candidate predictors included demographic characteristics, physical condition characteristics, pulmonary function measures, measures of the distribution of emphysema as determined by radiologists and by means of computerized analysis of chest computed tomographic scans, and measures of exercise capacity, dyspnea, and quality of life. End points analyzed were operative mortality (death within 90 days of the operation), major pulmonary morbidities (tracheostomy, failure to wean, reintubation, pneumonia, and ventilator for <3 days), and cardiovascular morbidities (infarction, pulmonary embolus, or arrhythmia requiring treatment). Results: Five hundred eleven patients in the non-high-risk group of the National Emphysema Treatment Trial underwent lung volume reduction. The incidence of operative mortality was 5.5%, major pulmonary morbidity occurred in 29.8% of patients, and cardiovascular morbidity occurred in 20.0% of patients. Predictors for these end points are as follows: Relative odds P value Operative mortality Non-upper-lobe predominance (radiologist) 2.99 .009 Pulmonary morbidity Age in years 1.05 .02 FEV₁ % predicted 0.97 .05 Dlco % predicted 0.97 .01 Cardiovascular morbidity Age in years 1.07 .004 Oral steroid use 1.72 .04 Non-upper-lobe predominance (QIA α measure) 2.67 <.001 FEV₁, Forced expiratory volume in 1 second; Dlco, diffusion capacity; QIA, quantitative image analysis. Conclusions: Although lung volume reduction can be performed in selected patients with acceptable mortality, the incidence of major cardiopulmonary morbidity remains high. The lone predictor for operative mortality of lung volume reduction was the presence of non-upper-lobe- predominant emphysema, as assessed by the radiologist. Pulmonary morbidity can be expected in elderly patients who have a low diffusing capacity for carbon monoxide and forced expiratory volume in 1 second. When assessing morbidity, the computer-assisted chest computed tomographic analysis proved useful only in predicting cardiovascular complications.