Clinical outcome of coronary stenting after thoracic radiotherapy: a case-control study

Patients with lymphoma, lung or breast neoplasia show significant improvement in their disease-specific survival after radiotherapy (RT), but these benefits may be offset by delayed effects of irradiation of the heart. We compared clinical outcome after coronary stenting in patients with neoplastic disease and previous thoracic RT with matched patients without previous RT.

Single-centre retrospective case-control study. Patients and methods Each patient with former thoracic RT undergoing coronary stenting between June 1998 and June 2005 was matched to two control patients according to several known prognostic factors (gender, age, available follow-up, stented vessel, drug-eluting stent use, unstable coronary disease, renal insufficiency, diabetes, bifurcational disease, stent length and size and ejection fraction). Main outcome measures Major adverse cardiac events (MACE) were defined as the composite of cardiac death, acute myocardial infarction (AMI) and target lesion revascularisation (TLR) and were assessed at latest follow-up and compared using Cox regression analyses.

41 patients underwent coronary stenting at 6+/-4 years after RT. Clinical outcome at 5+/-2 years after stenting was compared with outcome in 82 matched patients. For all-cause mortality, the hazard ratio for RT versus no RT was 4.2 (95% CI 1.8 to 9.5; p=0.0006). For cardiac mortality, the estimated hazard ratio was 4.2 (95% CI 1.0 to 17.0; p=0.0451). No significant differences were detected in terms of AMI, TLR, MACE or stent thrombosis.

Our findings suggest an increased risk of all-cause and cardiac mortality in patients who underwent coronary stent implantation after previous thoracic RT. Verification in larger patient populations is warranted.