Pulmonary fibrosis on multidetector computed tomography and mortality in patients with radiation-associated cardiac disease undergoing cardiac surgery

Objective: In the long-term, malignancy-associated thoracic radiation leads to varying degrees of pulmonary fibrosis and radiation-associated cardiac disease, often requiring cardiothoracic surgery. We sought to determine whether pulmonary fibrosis affects mortality in patients with radiation-associated cardiac disease undergoing cardiothoracic surgery. Methods: We studied 117 patients (aged 63 +/- 15 years, 71% were women) with radiation-associated cardiac disease receiving multimodality imaging who underwent cardiothoracic surgery (21% redo) between 2000 and 2003. Some 50% of patients had breast cancer, 28% of patients had Hodgkin's lymphoma, 9% of patients had lung cancer, and 13% of patients had other cancers. Time from radiation was 18 +/- 12 years. Clinical, pulmonary function, angiographic, and echocardiographic parameters were recorded. On multidetector chest computed tomography, ascending aortic calcification and degree of pulmonary fibrosis (in 5 lobes for a score of 15: 0 none, 1 linear streaks, 2 moderate fibrosis, and 3 severe fibrosis with traction bronchiectasis) were recorded. Results: Mean European System for Cardiac Operative Risk Evaluation was 7.9 +/- 3, and forced expiratory volume at 1 minute/forced vital capacity ratio was 0.75 +/- 0.2. Mean left ventricular ejection fraction was 49% +/- 12%, and right systolic ventricular pressure was 42 +/- 5mm Hg. Some 27% of patients had severe aortic stenosis, and 46% of patients had II+ or greater mitral regurgitation. On multidetector chest computed tomography, mean pulmonary fibrosis score was 3.5 +/- 3, and 59% of patients had ascending aortic calcification. Isolated coronary artery bypass was performed in 17% of patients; the rest were combination surgeries. At 6.3 +/- 0.4 years, there were 59 deaths (50%) (3% died 1 month postoperatively). Forty-five patients (39%) had pulmonary complications in follow-up. Increasing pulmonary fibrosis score (hazard ratio, 1.11; 95% confidence interval, 1.02-1.20; P=.02), worse European System for Cardiac Operative Risk Evaluation (hazard ratio, 1.10; 95% confidence interval, 1.01-1.21; P=.04), and lack of beta-blocker (hazard ratio, 0.54; 95% confidence interval, 0.31-0.94, P=.008) and aspirin (hazard ratio, 0.54; 95% confidence interval, 0.31-0.94; P=.03) independently predicted mortality. Conclusions: In patients with radiation-associated cardiac disease undergoing cardiothoracic surgery, worsening pulmonary fibrosis is associated with increased mortality.