Temporal Trends of the Prevalence of Angina With No Obstructive Coronary Artery Disease (ANOCA)

Background: Angina with no obstructive coronary artery disease (ANOCA) is a common entity. There is still under-recognition of this condition, but it is unclear if the referral patterns for chest pain diag-nosis have changed. We aimed to determine if the prevalence of pa-tients diagnosed with ANOCA by means of coronary angiography has changed over time.Methods: A population-based cohort of patients who had their first coronary angiogram for a chest pain syndrome in Alberta from 1995 to 2020 was extracted retrospectively from the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease (APPROACH) database. A temporal trend analysis was performed to compare patients with ANOCA vs obstructive coronary artery disease (CAD), and the predictors of ANOCA were investigated. Results: In our analysis, 121,066 patients were included (26% ANOCA, 31% female, overall mean age 62 years). The percentages of ANOCA vs obstructive CAD ranged from 24.2% to 26.7% in all patients (P < 0.001), from 19.4% to 21.4% in patients with acute coronary syndromes (P = 0.002), and from 30.6% to 37.5% in patients with stable angina (P < 0.001). Independent predictors of ANOCA were female sex (odds ratio [OR] 3.34, 95% confidence interval [CI] 3.05-3.66), younger age (OR 0.96, 95% CI 0.95-0.96), history of atrial fibrillation (OR 2.18, 95% CI 1.73-2.73), and stable angina (vs myocardial infarction: OR 0.25, 95% CI 0.23-0.28; vs unstable angina: OR 0.79, 95% CI 0.70-0.89). Traditional cardiovascular risk factors were associated with obstructive CAD.Conclusions: There remained a high prevalence of ANOCA detected during invasive coronary angiography, which remained stable over time. This study demonstrates an opportunity to exclude obstructive CAD with less invasive testing, particularly in women.