Impact of Thoracic Radiation on Patients Undergoing Cardiac Surgery

Prior thoracic radiation has been associated with worse outcomes after cardiac surgery. This study sought to report long-term outcomes in patients undergoing surgery for radiation-associated heart disease. This was an observational study of open cardiac surgeries from 2011 and 2018. Patients with a history of malignancy that required thoracic radiation were identified, and this cohort was matched against a non-irradiated comparison group via Mahalanobis distance matching. Kaplan-Meier survival estimation and multivariable Cox regression analysis was performed to assess the long-term impact of thoracic radiation in patients undergoing cardiac surgery. Of the 15,284 patients receiving cardiac surgery in this time-frame, 269 were identified with a history of thoracic radiation for prior malignancy. Patients with prior radiation had increased 1-year and 5-year mortality (P < 0.001), despite no difference for 30-day mortality (P = 0.719), compared to non-irradiated patients. Mahalanobis distance matching yielded 269 equitably matched pairs. On multivariable analysis, patients with prior radiation demonstrated significantly increased hazard of death, as compared to the non-irradiated group (hazard ratio 1.40, 95% confidence interval: 1.02, 1.94, P = 0.038). Patients with radiation for breast cancer demonstrated a non-significant trend toward reduced hazard of death, as compared to patients with more extensive radiation exposure. There was an increase in long-term mortality in patients with prior radiation undergoing cardiac surgery, however open cardiac surgery can safely be performed in these patients with similar operative mortality. These findings may serve as a useful adjunct in shared decision-making for patients and surgeons alike.