Different manifestation of irradiation induced coronary artery disease detected with coronary computed tomography compared with matched non-irradiated controls.

BACKGROUND AND PURPOSE: Patients who received chest irradiation for treatment of a malignancy are at increased risk for the development of coronary artery atherosclerosis. Little is known about the anatomical coronary artery plaque characteristics of irradiation induced coronary artery disease (CAD). This study aimed to evaluate potential differences in the presence, extent, severity, composition and location of CAD in patients treated with mediastinal irradiation compared with non-irradiated controls matched on age, gender and cardiovascular risk factors.

MATERIAL AND METHODS: Seventy-nine asymptomatic Hodgkin and non-Hodgkin lymphoma survivors, all treated with mediastinal irradiation with or without chemotherapy, who underwent coronary computed tomography angiography (CTA) to exclude or detect CAD were included. Patients were 1:3 matched with non-irradiated controls (n=237) for age, gender, diabetes, hypertension, hypercholesterolemia, family history of CAD and currently smoking. Mean age at cancer diagnosis was 26±9years and age at the time of coronary CTA was 45±11years.

RESULTS: More patients had an abnormal CTA (defined as any coronary artery atherosclerosis): 59% vs. 36% (P<0.001) and significantly more patients had two vessel CAD: 10% vs. 6% and three vessel/left main CAD: 24% vs. 9% compared with controls (overall P<0.001). The maximum stenosis severity among patients was less often <30% (53% vs. 68%) and more often >70% (7% vs. 0%) (overall P=0.001). Patients had more coronary artery plaques in proximal coronary artery segments: left main (17% vs. 6%, P=0.004), proximal left anterior descending artery (30% vs. 16%, P=0.004), proximal right coronary artery (25% vs 10%, P<0.001) and proximal left circumflex artery (14% vs 6%, P=0.022), whereas the number of plaques in non-proximal segments did not differ between groups.

CONCLUSIONS: Hodgkin and non-Hodgkin lymphoma survivors treated with mediastinal irradiation with or without chemotherapy showed a higher presence, greater severity, larger extent and more proximally located CAD compared with age, gender and risk factor matched non-irradiated controls. These findings represent features of higher risk CAD and may explain the worse cardiovascular outcome after chest irradiation.