Abstract 18855: Outcomes after Coronary Artery Bypass Graft Surgery in Patients Treated with Thoracic Radiotherapy for Cancer
Introduction: Thoracic external beam radiation therapy (XRT) for cancer is associated with a multitude of long-term cardiotoxic side effects. Previous studies have suggested worse outcomes in XRT-treated cancer survivors who undergo revascularization with CABG, but sample sizes have been small. In addition, XRT after CABG is thought to portend decreased patency and survival. We aimed to examine outcomes after CABG in patients with XRT compared with to those without XRT.
Methods: We identified all patients who were treated with both CABG (between 1999 and 2013) and curative thoracic XRT for cancer (between 1971 and 2013) (>30 Gray). Baseline clinical characteristics and comorbidities at time of CABG, as well as long-term outcomes after CABG and XRT were compared with propensity matched control cohorts.
Results: A total of 38 patients underwent CABG following XRT [Group 1] (mean age 67.9, 63% female) and 43 patients underwent XRT after CABG [Group 2] (mean age 69.3, 63% female). Compared with propensity-matched controls (Group 1: n=141; Group 2: n=167), baseline clinical and demographic characteristics between cases and controls were similar in both groups, except a lower incidence of triple vessel disease in XRT cases in Group 2 (64 vs 80%, p=0.02). For Group 1, there was no significant difference in all-cause survival in long-term follow-up after CABG (Fig. 1, p=0.72). Meanwhile, Group 2 cases had significantly higher all-cause mortality following XRT (Fig. 2, p<0.001).
Conclusions: Patients previously treated with thoracic XRT who subsequently undergo CABG for coronary artery disease have a similar overall mortality rate compared to patients without prior XRT. This suggests that CABG is an effective method of revascularization in these patients. The higher mortality rates in CABG patients who subsequently develop disease requiring thoracic XRT is likely due to oncologic rather than cardiovascular causes, but more data are necessary to evaluate this finding.
Author Disclosures: J.J. Liang: None. T.T. Sio: None. J.M. Stulak: None. R.J. Lennon: None. A. Prasad: None. R.C. Miller: None. G.S. Sandhu: None.
- © 2014 by American Heart Association, Inc.