Prevalence of significant coronary artery disease in patients with severe aortic stenosis and the discriminatory performance of the coronary artery calcium score and echocardiographic parameters at a referral center in the Ecuadorian Andean highlands: a cross-sectional study

Severe aortic stenosis (AS) and coronary artery disease (CAD) share cardiovascular risk factors and partly common calcification pathways; reported concomitant CAD ranges from 25% to 75%. In Latin America, and particularly in high-altitude Andean populations, neither their coexistence nor the discriminatory performance of the coronary artery calcium (CAC) score and echocardiographic parameters has been characterized. Cross-sectional study reviewing the records of 390 consecutive adults with severe AS treated between January 2021 and March 2025 at a referral center in Quito, Ecuador (2,850 m). Coronary anatomy was assessed by computed tomography angiography (65.6%) or invasive coronary angiography (34.4%). Significant CAD was defined as ≥ 50% stenosis of the left main or ≥ 70% of a major epicardial artery. Associations were expressed as prevalence ratios (PR) by log-binomial regression, with Poisson regression as sensitivity analysis, and discrimination as the area under the ROC curve (AUC). Among 390 patients, the median age was 72 years (IQR 62–80), 59.7% were women and 90.5% were of mestizo ethnicity; hypertension (59.0%), obesity (57.7%) and chronic kidney disease (36.9%) were the most frequent comorbidities. Significant CAD was present in 12.1% (47/390), and affected patients were older (77 vs. 71 years; p < 0.001). The CAC score showed the highest discrimination (AUC 0.958, 95% CI 0.911–1.000), with no CAD-free participant reaching 400 Agatston units; aortic valve calcium was inversely associated (AUC 0.771). The classical low-flow, low-gradient (LFLG) phenotype was the strongest echocardiographic correlate (PR 5.95, 95% CI 3.53–10.03; p < 0.001), whereas very severe stenosis was inversely associated (PR 0.30, 95% CI 0.12–0.74; p = 0.009). In multivariable analysis, only the classical LFLG phenotype (adjusted PR 2.73, 95% CI 1.42–5.23; p = 0.003) and obesity (adjusted PR 2.42, 95% CI 1.21–4.84; p = 0.012) remained independent. The prevalence of concomitant significant CAD was lower than that reported in European and North American registries. Within this cohort, the CAC score showed the greatest discriminatory performance for significant CAD, and the classical LFLG phenotype was the most robust echocardiographic correlate. Aortic valve calcium was inversely related to CAD and is not a marker of coronary atherosclerotic burden.