Single-centre prospective study to characterize causes of dyspnea in stable patients with coronary artery disease and evaluate the possibility to determine the cause of dyspnea before in-depth examination.

Stable patients with dyspnea and coronary artery disease will be included in this single-centre prospective study. In addition to routine clinical examination patients will be interviewed to determine the nature of shortness of breath, angina, presence of chronic heart failure or anxiety using the Medical Research Council Dyspnea scale, the visual analog scale of dyspnea, Borg scale, modified "dictionary" of dyspnea, G. Rose questionnaire, Seattle Angina Questionnaire, Framingham criteria for chronic heart failure and the SHOCK scale. During the subsequent in-depth examination including thyroid hormones, NT-proBNP, hsTroponin, ECG monitoring, six-minute walk test, stress-echo with a diastolic stress test, spirometry and coronary angiography (if necessary) main reason for dyspnea will be established. Possibilities of early (before in-depth examination) determination the reason for dyspnea in stable patients with coronary artery disease will be evaluated.

Inclusion Criteria:

1. Stable patients with shortness of breath and established diagnosis of coronary artery disease (at least 1 of the following signs):

   • history of myocardial infarction;
   • typical angina without suspected other cause of pain;
   • myocardial ischemia documented by ECG changes during symptoms and/or by results of the stress test;
   • coronary artery stenosis >50% according to coronary angiography.

2. Signed informed consent.

Exclusion Criteria:

1. Acute coronary syndrome (myocardial infarction, unstable angina) in the previous month.
2. Hospitalization with decompensation of CHF in the previous 6 months (including CHF decompensation as the main reason for current hospitalization).
3. Diseases with an unfavourable prognosis (terminal CKD, CHF NYHA IV, a lung disease with severe respiratory failure).
4. Contraindications to bicycle stress echocardiography.
5. Atrial Fibrillation at the time of hospitalization, when the decision not to restore the sinus rhythm.
6. Mental illnesses and disorders, dementia, drug or alcohol dependence.
7. Known oncological diseases.

Stable patients with dyspnea and established coronary artery disease.