Cardiac Reoperations in Patients with Prior Thoracic Radiation: A Single-Center Analysis of Outcomes and Key Lessons

OBJECTIVES: Thoracic radiation therapy (TRT) increases the risk of primary and reoperative cardiac surgery (RCS). However, the impact of radiation extent on RCS is unknown. Thus, we examine the outcomes of RCS in patients with prior TRT, comparing mantle vs. non-mantle radiation. METHODS: The cohort comprised all adult patients with prior TRT who underwent RCS at a single center from March 2011 to March 2025. The cohort was matched (1:3) using baseline characteristics and operative components to patients who underwent RCS without prior TRT. Sub-analysis of TRT patients compared those with mantle vs. non-mantle radiation. RESULTS: 708 patients were included, comprising 177 in the TRT cohort (65 mantle, 112 non-mantle) and 531 in the matched no TRT cohort. Compared to matched controls, TRT patients had higher rates of postoperative renal failure requiring dialysis (17.9% vs 8.3%, RR 2.04 (95% CI 1.33 - 3.15), p=0.001) and hospital stay (28.2 vs. 19.8 days, MD 8.4 (95% CI 3.5 -13.3), p=0.01). Operative mortality was higher in the TRT cohort (11% vs. 5.5%, RR 2.28 (95% CI 1.34 - 3.86), p=0.01). In sub-analysis, mantle radiation patients had longer hospital stay compared to non-mantle radiation (35.3±35.4 vs 24.3±23.9 days, p=0.03), higher rate of mechanical circulatory support (13.8% vs 4.4%, p=0.026), delayed chest closure (12.3% vs. 2.6%, p=0.011), and operative mortality (15.4% vs. 8%, p=0.06). Mantle radiation patients had worse 1- and 5-year survival (60% vs. 86%; 36% vs. 61%, p=0.001). CONCLUSION: Prior TRT is associated with increased postoperative complications and operative mortality after RCS. Notably, mantle radiation appears to confer a greater risk than non-mantle radiation, with worse survival and a trend toward higher operative mortality, though larger studies are needed to confirm this observation.