ABC | Volume 114, Nº6, June 2020

Original Article Yang et al Chemotherapy-related coronary-artery disease Arq Bras Cardiol. 2020; 114(6):1004-1012 coronary vasculature by number of lesions and their functional impacts, locations and complexity. 16-18 It is an important tool for grading complexity of coronary artery disease (CAD) and for risk-stratifying patients who are being considered for revascularization. In addition, it has demonstrated good value as a predictor of major adverse cardiac events, including cardiac death. Higher SXscores, indicative of more- complex diseases, are hypothesized to represent a greater therapeutic challenge and to pose potentially worse cardiac prognoses. 16,17,19-21 Recent studies used SXscore to quantify the severity of CAD among cancer patients, which looked mostly at the effect of radiotherapy on CAD. 20,21 In the present study, we used SXscore to evaluate the complexity and severity of CAD among lung cancer patients to investigate the relationship between chemotherapy and CAD. We also observed the effect of radiotherapy and other risk factors on anatomical severity of coronary arteries among those patients. Methods Study design and patients We used a hospital-based cross-sectional study design. The study patients were admitted to Chinese PLA General Hospital to undergo coronary angiography (CAG) due to suspected angina pectoris or stenosed coronary artery, showed by computer tomography angiography, between 2010 and 2017. Furthermore, the patients should have previously received definite diagnoses of lung cancer. Patients who had previously undergone percutaneous coronary intervention were excluded. We thoroughly examined the patients’ electronic medical records for history of lung cancer, including diagnosis, age at time of diagnosis, location and treatment history (chemotherapy and radiotherapy). We reviewed sex, age at time of CAG, body mass index (BMI), family history of cardiovascular diseases (CVDs), tobacco use, hypertension, diabetes, hyperlipidemia and lipid profile. These data were extracted using a clinical-research data platform created by Xiliu Data. Some data were checked by telephone with the patients themselves or their families. Coronary angiography and SXscore From the baseline diagnostic angiogram, we separately scored each coronary lesion with stenosis ≥50% in a vessel ≥1.5 mm diameter. Next, we added the scores to provide the overall SXscore, which we had calculated prospectively using the SXscore algorithm (described in full elsewhere in the literature). 16,17,22 All angiographic variables pertinent to SXscore calculation were computed by two blinded experienced interventional cardiologists. When the SXscore of each patient differed between the two cardiologists, they would discuss the angiogram and come up with a common SXscore for each patient. Final SXscores were calculated per patient and saved in a dedicated database. Two representative examples with SXscores based on CAG are shown in Figure 1. In the study, a Sxscore of 22 was the upper tertile. We defined SXscore grades as SXlow (<22) or SXhigh (≥22). Through logistic-regression analysis, high SXscore grade was determined as positive if SXscore ≥22. Figure 1 – SXscore of coronary artery based on CAG. Representative CAGs of a patient with SXlow (SXscore = 2; A–B) and a patient with SXhigh (SXscore = 38; C–D). 1005