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

Abstract

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. 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. 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 ± 5 mm 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. In patients with radiation-associated cardiac disease undergoing cardiothoracic surgery, worsening pulmonary fibrosis is associated with increased mortality.