title: Outcomes after percutaneous coronary intervention with stents in patients treated with thoracic external beam radiation for cancer.
abstract: OBJECTIVE
  The aim of this study was to assess outcomes after percutaneous coronary intervention (PCI) with stents in patients treated with thoracic external beam radiation therapy (EBRT).
  
  
  BACKGROUND
  Thoracic EBRT for cancer is associated with long-term cardiotoxic sequelae. The impact of EBRT on patients requiring coronary stents is unclear.
  
  
  METHODS
  We analyzed outcomes after PCI in cancer survivors treated with curative thoracic EBRT before and after stenting between 1998 and 2012. Reference groups were propensity-matched cohorts with stenting but no EBRT. Primary endpoint was target lesion revascularization (TLR), a clinical surrogate for restenosis. Secondary endpoints included myocardial infarction (MI) and cardiac and overall mortality.
  
  
  RESULTS
  We identified 115 patients treated with EBRT a median 3.6 years after stenting (group A) and 45 patients treated with EBRT a median 2.2 years before stenting (group B). Long-term mean TLR rates in group A (3.2 vs. 6.6%; hazard ratio: 0.6; 95% confidence interval: 0.2 to 1.6; p = 0.31) and group B (9.2 vs. 9.7%; hazard ratio: 1.2; 95% confidence interval: 0.4 to 3.4; p = 0.79) were similar to rates in corresponding control patients (group A: 1,390 control patients; group B: 439 control patients). Three years post-PCI, group A had higher overall mortality (48.6% vs. 13.9%; p < 0.001) but not MI (4.8% vs. 4.3%; p = 0.93) or cardiac mortality (2.3% vs. 3.6%; p = 0.66) rates versus control patients. There were no significant differences in MI, cardiac, or overall mortality rates in group B.
  
  
  CONCLUSIONS
  Thoracic EBRT is not associated with increased stent failure rates when used before or after PCI. A history of PCI should not preclude the use of curative thoracic EBRT in cancer patients or vice versa. Optimal treatment of cancer should be the goal.
authors.affiliation: Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jackson J
authors.initials: JJ
authors.lastname: Liang
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Terence T
authors.initials: TT
authors.lastname: Sio
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Joshua P
authors.initials: JP
authors.lastname: Slusser
authors.affiliation: Department of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Lennon
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
authors.forename: Robert C
authors.initials: RC
authors.lastname: Miller
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Gurpreet
authors.initials: G
authors.lastname: Sandhu
authors.affiliation: Cardiovascular Sciences, St. George's, University of London, London, United Kingdom. Electronic address: a.prasad@sgul.ac.uk.
authors.forename: Abhiram
authors.initials: A
authors.lastname: Prasad
mesh_terms: D000368:Aged; D003324:Coronary Artery Disease / Q000175:diagnosis / Q000401:mortality / Q000628:therapy*; D023903:Coronary Restenosis / Q000209:etiology / Q000401:mortality / Q000628:therapy; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D008910:Minnesota; D009203:Myocardial Infarction / Q000209:etiology / Q000401:mortality; D009369:Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D057216:Propensity Score; D016016:Proportional Hazards Models; D011475:Prosthesis Failure; D011878:Radiotherapy / Q000009:adverse effects; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
keywords: cancer; coronary artery stent; malignancy; radiation therapy; restenosis; survivorship