This multicenter, prospective, observational study aims to address two primary objectives.

The first objective is to demonstrate that hospital-acquired pneumonia (nosocomial pneumonia) following cardiac surgery can be predicted using artificial intelligence (AI), and to develop a personalized risk calculator for its development.

The second objective is to demonstrate that hospital-acquired pneumonia can serve as a risk factor for a 1-year composite cardiovascular and pulmonary outcome after cardiac surgery, and to develop a personalized risk calculator for this composite outcome.

The composite outcome will include the occurrence of any of the following events:

• Respiratory death
• Hospitalization for respiratory diseases
• Development of oxygen dependence
• New-onset asthma, COPD, or interstitial lung disease
• Initiation or intensification of bronchodilator or corticosteroid therapy
• Cardiovascular death
• Acute myocardial infarction
• Unstable angina
• Myocardial revascularization
• Acute ischemic stroke
• Transient ischemic attack
• Acute heart failure
• Hospitalization for decompensated heart failure
• New-onset atrial fibrillation or ventricular tachycardia
• Initiation or intensification of antiarrhythmic therapy Both objectives will be addressed using artificial intelligence technologies applied during the data analysis phase.

This is a non-interventional study. Patient evaluation and treatment are conducted in strict accordance with approved standards of medical care for the respective conditions. No experimental or unregistered (not approved for use in the Russian Federation) medical or diagnostic procedures will be performed during this study.