Volatilome and Single-Lead Electrocardiogram Optimize Ischemic Heart Disease Diagnosis Using Machine Learning Models

Other illness

• Failure to complete the stress test due to reasons unrelated to cardiac conditions;
• Post-enrollment development of conditions or identification of pathologies listed in the exclusion criteria.

Other

• Poor recording quality of single-channel electrocardiogram (ECG) and/or plethysmography data;
• Voluntary withdrawal of consent to continue participation in the study;

• Age ≥40 years;
• Absence of acute exacerbations of psychiatric disorders or cognitive impairments that would preclude study participation;
• Provision of written informed consent for study participation, blood sample collection, and anonymous publication of research results;
• Pre-test probability of ischemic heart disease between 1% and 33%.
  • Non-inclusion criteria:
• Pregnancy and breastfeeding;
• Diabetes mellitus;
• Presence of acute myocardial ischemia (acute coronary syndrome or myocardial infarction within the preceding 48 hours) or a history of myocardial infarction;
• Active infectious or non-infectious inflammatory diseases in the acute/exacerbation phase;
• Connective tissue diseases (regardless of disease activity);
• Respiratory disorders (e.g., bronchial asthma, chronic bronchitis, cystic fibrosis, or other conditions associated with significant respiratory dysfunction);
• Acute pulmonary thromboembolism involving the pulmonary artery or its branches;
• Aortic dissection;
• Hemodynamically significant decompensated cardiac valvular defects\*\*;
• Active malignancy;
• Decompensated chronic heart failure (NYHA class III-IV) or acute heart failure;
• Neurological disorders (e.g., Parkinson's disease, multiple sclerosis, acute psychosis, Guillain-Barré syndrome);
• Cardiac arrhythmias or conduction abnormalities contraindicating stress testing;
• Musculoskeletal disorders precluding exercise testing (e.g., bicycle ergometry);
• Allergy to radiocontrast agents and/or adenosine triphosphate (ATP);
• Chronic kidney disease with an estimated glomerular filtration rate (eGFR) \<30 mL/min/1.73 m² (CKD-EPI formula);
• Severe hepatic insufficiency and/or Child-Pugh class B or C liver cirrhosis.