Long-Term Mortality in Patients With Radiation-Associated Coronary Artery Disease Treated With Percutaneous Coronary Intervention

Abstract

Background: The incidence and predictors of long-term mortality after percutaneous coronary intervention (PCI) for radiation-associated coronary artery disease are unknown.

Methods and results: In this observational study of 314 patients (age, 65.2±11.4 years; 233 [74%] women) treated with PCI, 157 patients with previous external beam radiation therapy (XRT) were matched 1:1 with 157 comparison patients with atherosclerotic coronary artery disease without previous XRT, based on age, sex, lesion artery, and PCI type. The primary end point was all-cause mortality, and the secondary end point was cardiovascular mortality. After follow-up of 6.6±5.5 years, there were 101 deaths; 59 in the XRT group and 42 in the comparison group (P=0.04). On Cox proportional hazards multivariable survival analysis, previous XRT remained an independent predictor of all-cause mortality (hazard ratio [HR] 1.85; 95% confidence interval [CI], 1.21-2.85; P=0.004) and cardiovascular mortality (HR, 1.70; 95% CI, 1.06-2.89; P=0.03). Additional independent predictors of increased all-cause mortality included balloon angioplasty or bare-metal stent placement compared with drug-eluting stent placement (HR, 2.50; 95% CI, 1.61-3.97; P<0.0001), SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) score of ≥11 (the sample median; HR, 1.99; 95% CI, 1.32-3.04; P<0.001), New York Heart Association functional class ≥3 (HR, 1.83; 95% CI, 1.15-2.91; P=0.012), history of smoking (HR, 1.88; 95% CI, 1.10-3.09; P=0.022), and age ≥65 years (HR, 1.70; 95% CI, 1.07-2.07; P=0.024).

Conclusions: Compared with patients with typical atherosclerotic coronary artery disease, patients with radiation-associated coronary artery disease are at higher risk for mortality after PCI. Previous XRT exposure is independently associated with increased all-cause and cardiovascular mortality in patients treated with PCI.

Keywords: coronary artery disease; mortality; percutaneous coronary intervention; radiation oncology; survival.