Long-Term Mortality Evaluated in Patients With Radiation-Associated CAD Treated With PCI

June 20, 2016—A study of the incidence and predictors of long-term mortality after percutaneous coronary intervention (PCI) for radiation-associated coronary artery disease was published by Grant W. Reed, MD, et al online in Circulation: Cardiovascular Interventions.

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 endpoint was all-cause mortality, and the secondary endpoint was cardiovascular mortality. 

As summarized in Circulation: Cardiovascular Interventions, there were 101 deaths at follow-up of 6.6 ± 5.5 years with 59 deaths in the XRT group and 42 deaths in the comparison group (P = .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 = .004) and cardiovascular mortality (HR, 1.7; 95% CI, 1.06–2.89; P = .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 < .0001), SYNTAX score of ≥ 11 (the sample median; HR, 1.99; 95% CI, 1.32–3.04; P < .001), New York Heart Association functional class ≥ III (HR, 1.83; 95% CI, 1.15–2.91; P = .012), history of smoking (HR, 1.88; 95% CI, 1.1–3.09; P = .022), and aged 65 years or older (HR, 1.70; 95% CI, 1.07–2.07; P = .024), reported the investigators.
 
Compared with patients with typical atherosclerotic coronary artery disease, patients with radiation-associated coronary artery disease are at higher risk for mortality after PCI; additionally, previous XRT exposure is independently associated with increased all-cause and cardiovascular mortality in patients treated with PCI, concluded the investigators in Circulation: Cardiovascular Interventions.