The importance of incidental coronary artery calcification seen on breast radiation therapy planning scans in women after 60 years old

Introduction Radiotherapy (RT) is an established treatment for breast cancer. A planning chest computed tomography (CT) scan must be obtained prior to RT and is rarely evaluated by a radiologist. Purpose The objective of this study was to determine whether the presence of coronary artery calcification (CAC) detected on planning CT correlates with adverse cardiovascular outcomes in female patients older than 60 years. Methods Planning CT scans performed between 2016 and 2020 in women with left-sided breast cancer aged > 60 years were selected for the study. A radiologist visually assessed all CT scans to qualitatively determine the presence of CAC. The women were divided into two groups: A) presence of CAC and B) absence of CAC. All patients were contacted by telephone to complete a standardized and validated questionnaire to assess all-cause mortality, cardiovascular mortality, and nonfatal major adverse cardiovascular events (MACE), with a minimum follow-up of 60 months. Variables such as hypertension, diabetes mellitus, dyslipidemia, smoking status, and type of prior chemotherapy were also evaluated. Results Among the 334 patients evaluated (69.00 ± 6.93 years), 161 (48.2%) had CAC (Group A) and 173 did not (Group B). The mean follow-up was 78.02 ± 14.32 months. All-cause mortality, cardiovascular mortality, and MACE in Groups A and B were 45 vs. 30 (RR 1.61; CI 1.08–2.43; p = 0.025), 43 vs. 11 (RR 4.2; CI 2.28–7.83; p < 0.0001), and 23 vs. 11 (RR 2.25; CI 1.15–4.42; p = 0.0188), respectively. Patients in Group A were older (71.5 vs. 67.2 years, p < 0.0001) and had a higher prevalence of hypertension (105 vs. 92; RR 1.32; CI 1.04–1.70; p = 0.02). After multivariate logistic regression analysis, the presence of coronary calcification was independently associated with all-cause mortality (OR 1.97; CI 1.16–3.38; p = 0.008), cardiovascular mortality (OR 4.3; CI 1.66–13.35; p < 0.0001), and MACE (OR 2.86; CI 1.24–6.88; p = 0.01). No differences were observed among the other variables analyzed. Conclusion The presence of CAC identified on planning CT is an independent predictor of mortality and fatal and nonfatal adverse cardiovascular events in women older than 60 years. Assessment of CAC at the time of planning CT may represent an opportunity to stratify cardiovascular risk in this subgroup of patients and to initiate measures aimed at mitigating these unfavorable outcomes.