Clinical and echocardiographic predictors of obstructive and non-obstructive coronary heart disease with limited instrumental diagnostics

Objective: To determine clinical and echocardiographic predictors of myocardial ischemia in non-obstructive coronary arteries (INOCA) in patients with stable angina/ischemia equivalents. Materials and Methods: The study was conducted between January 2025 and January 2026 inclusive among 100 patients with stable angina or ischemic equivalents. The average patient age was 61.22±10.24 years, and 53% were women (n=53). The average body mass index was 28.90±3.99 kg/m2. Based on the results of coronary angiography, patients were divided into three groups: with obstructive coronary artery disease (CAD), with INOCA, and with intact coronary arteries. Results: The INOCA phenotype (n=40) was characterized by a higher proportion of women (OR 3.95; 95% CI 1.50-10.42), a lower pre-test probability of obstructive CAD (46.04±14.76% vs. 64.28±10.87%, p<0.001), a higher LV ejection fraction (63.01±4.02% vs. 58.16±5.02%, p<0.001), preserved left ventricular systolic function, and a tendency toward more pronounced signs of diastolic dysfunction. A positive response to nitroglycerin was less common (OR 0.36; 95% CI 0.14-0.95) than in obstructive CAD. The most favorable echocardiographic profile was observed in the group of intact coronary arteries. This confirms the distinction between "non-obstructive ischemia" (INOCA) and no coronary pathology. Patients with intact coronary arteries (n=25) compared with the obstructive CAD group (n=35) were younger (54.52±12.41 vs. 66.49±7.16 years; p<0.001) and had a lower body mass index (BMI) (26.95±3.54 vs. 29.01±3.04 kg/m2; p=0.023). The pre-test probability of obstructive CAD in the intact arteries group was significantly lower (24.18±8.37% vs. 64.28±10.87%; p<0.001). Conclusion: A combination of clinical data, standard echocardiography, and nitrate testing can be used for pre-coronary angiography stratification of INOCA probability and optimization of patient management in the presence of persistent symptoms. It is also important to consider functional verification of the ischemic mechanism for subsequent mechanism-based patient management.