Patients undergoing carotid revascularization procedures are at increased risk for the development of short- and long-term cardiac complications. Increased values of high-sensitive troponin may be useful in a timely selection of those patients. Still, contemporary literature doesn't provide enough data to answer the following questions: "Can high-sensitive troponin predict adverse cardiac outcomes perioperatively in carotid surgery?", "Should these cardiac biomarkers be routinely sampled in all patients undergoing carotid revascularization?" and "Can elevated levels of high-sensitive troponin preoperatively designate patients in whom the risk of surgical treatment (at a given moment) is greater than the benefit of the surgery?".

The aims of the study are: 1) to determine the incidence of elevated troponin levels pre- and postoperatively in patients undergoing CEA/CAS; 2) to assess whether elevated troponin levels pre- and postoperatively can predict the occurrence of myocardial infarction and death in these patients; 3) to demonstrate whether routine pre- and postoperative troponin measurement is justified in all or only in a particular subpopulation of patients, and 4) to assess whether, in this regard, a difference between patients undergoing CEA and CAS procedures exists.

A prospective, multicenter cohort study would include approximately 240 consecutive patients undergoing CEA/CAS procedures, under the conditions of regional/general and local anesthesia, during the period from April, to August 2022. Patients admitted due to emergency procedure for immediate surgical treatment (the same day), patients with preoperative anemia (due to any reason, hemoglobin level < 10 g/dL), in whom concomitant or "staged" cardiac surgery or vascular procedure is planned, who had an acute coronary event in the previous 3 months, patients undergoing multiple CEA/CAS during the study period, as well as those patients with conditions that may lead to increased troponin levels (end-stage kidney disease, sepsis, acute pericarditis and myocarditis, advanced heart failure, chemotherapy, systemic inflammatory diseases, and critical limb ischemia) would be excluded from the study. Using a pre-designed questionnaire, standard demographic and clinical data (related to comorbidities, chronic therapy, habits, previous surgery, and characteristics of carotid disease) would be collected. Intraoperative data (type of carotid intervention, type of anesthesia technique, and shunt placement), as well as data regarding the postoperative course, would be obtained from the database implemented in daily practice and patients' medical records. High-sensitive troponin would be measured in all patients, according to the following plan: 1) preoperatively - one day before the planned intervention and 2) postoperatively - 8 hours after the operation and on the first day after the operation. Troponin samples would be frozen and analyzed only after the patient's hospital discharge. Also, ECG would be recorded immediately following troponin measurement (a day before the planned intervention, 8 hours and 24 hours after the intervention). Patients operated on at the Clinic for Vascular and Endovascular Surgery of the University Clinical Center of Serbia would be operated under the conditions of regional anesthesia - a combination of deep and superficial cervical plexus block (which is a regular practice at this Institution), or local infiltrative anesthesia (for CAS procedures), while patients in other Hospital would be treated under the conditions of general anesthesia (Collaborators - to be defined). Clinical outcomes of interest: myocardial injury, myocardial infarction, stroke, cardiac-related death, and the all-cause mortality, would be recorded perioperatively, until hospital discharge (2 days following the procedure). Myocardial infarction, stroke, cardiac-related death, and the all-cause mortality would be recorded preoperatively and up to 2 days following the procedure, one month after, one and two years following surgery (at regular postoperative check-ups or by telephone interview with the patient, or a member of his family). Myocardial injury would be defined in accordance with the current Fourth Universal Definition of Myocardial Infarction, published by the European Society of Cardiology, as the existence of at least one elevated troponin value above the 99th percentile of the upper reference limit. In accordance with the same recommendations, acute myocardial infarction would be defined as the existence of an increase and/or decrease in troponin levels and clinical signs of acute myocardial ischemia. The indication for surgery or stenting procedure would be made based on the European Society of Vascular Surgery guidelines.

Following Institutional Ethics Committee approval (Approval No. 455/39, dated 07 May 2026), the follow-up period for study participants was extended from 2 years to 5 years. No other protocol changes were made.

Inclusion Criteria:

• Extracranial carotid stenosis greater than 50% (NASCET) in the carotid bifurcation or internal carotid artery assessed by ultrasound in whom carotid revascularisation is planned;
• The ability of the patient for follow-up examinations;
• Personally signed informed consent

Exclusion Criteria:

• Patients admitted due to emergency procedure for immediate surgical treatment (the same day);
• Patients with preoperative anemia (due to any reason, hemoglobin level < 10 g/dL);
• Patients in whom concomitant or "staged" cardiac surgery or vascular procedure is planned,
• Patients who had an acute coronary event in the previous 3 months;
• Patients undergoing multiple CEA/CAS during the study period;
• Patients with end-stage kidney disease;
• Patients with sepsis:
• Patients with acute pericarditis/myocarditis;
• Patients with advanced heart failure;
• Patients on chemotherapy,
• Patients with systemic inflammatory diseases;
• Patients with critical limb ischemia;

Patients with extracranial carotid stenosis greater than 50% (NASCET) in the carotid bifurcation or internal carotid artery assessed by ultrasound in whom carotid revascularisation is planned;