Percutaneous Coronary Intervention Outcomes in Patients With Prior Thoracic Radiation Therapy: A Systematic Review and Meta-Analysis

Background: Thoracic radiation predisposes patients to accelerated coronary artery disease. There is a paucity of data in both short-term and long-term outcomes following revascularization in patients who have undergone thoracic radiation. Methods: We performed a search of the Medline, Cochrane, and Scopus databases for studies that compared outcomes in cancer patients who have undergone thoracic radiation and percutaneous coronary intervention (PCI). The primary outcome of our meta-analysis was all-cause mortality. Secondary outcomes included cardiac mortality, myocardial infarction (MI), and restenosis. Results: The analysis included four observational studies with a total of 13,941 patients for the primary outcome of all-cause mortality. There were a total of 1,322 patients analyzed for cardiac mortality, 13,103 for MI, and 10,530 for restenosis. The longest follow-up for the primary outcome was 16 years. There was statistically significant higher risk of all-cause mortality in patients who underwent thoracic radiation (risk ratio (RR): 1.29, 95% confidence interval (CI): 1.08 - 1.54, P = 0.004). There was no statistically significant difference in cardiac mortality (RR: 1.15, 95% CI: 0.83 - 1.61, P = 0.40), MI (RR: 1.01, 95% CI: 0.20 - 5.08, P = 0.99), and restenosis (RR: 1.92, 95% CI: 0.24 - 15.35, P = 0.54). Conclusion: In this meta-analysis, we found a higher risk of all-cause mortality in patients with a history of thoracic radiation undergoing PCI, likely from underlying malignancy itself.