Arterial Stiffness and Hemodynamics in Cardiac Surgery

NCT ID: NCT06911593

Last Updated: 2025-04-04

Basic Information

• Recruitment Status: COMPLETED
• Total Enrollment: 121 participants
• Study Classification: OBSERVATIONAL
• Study Start Date: 2022-10-01
• Study Completion Date: 2023-09-01

Brief Summary

Background:

Hypotension during the induction of anesthesia is a significant clinical condition associated with increased perioperative morbidity and mortality. This study aims to evaluate whether hypotension occurring during anesthesia induction can be predicted using arterial stiffness and stiffness index parameters measured by ultrasonography. Additionally, the study investigates potential associations between arterial stiffness parameters and intraoperative hemodynamic variables, vasoactive drug use, length of stay in the hospital and intensive care unit (ICU), and mortality.

Methods:

This prospective study was conducted in patients scheduled for elective open cardiac surgery. The predictive value of arterial stiffness, measured by ultrasonography, for identifying hypotension during anesthesia induction was assessed. Carotid-femoral pulse wave velocity (PWV) and stiffness index (β index) were used as indicators of arterial stiffness.

Detailed Description

Background:

Hypotension during anesthesia induction is a serious clinical condition that may lead to adverse perioperative outcomes such as myocardial ischemia, renal hypoperfusion, and neurological complications. In cardiac surgery, hypotension during induction can compromise myocardial perfusion and increase the risk of ischemic events. In patients with significant coronary artery disease, a sudden drop in systemic blood pressure can reduce coronary perfusion pressure, potentially resulting in left ventricular dysfunction and hemodynamic instability. Therefore, careful hemodynamic management and appropriate use of vasopressors during anesthesia induction are critical to improving perioperative outcomes in open cardiac surgery.

Arterial stiffness refers to the reduced elasticity of arterial walls due to loss of elastic tissue. It increases with age and is associated with a higher risk of cardiovascular disease. Arterial stiffness can be assessed using ultrasonography (USG) or applanation tonometry. Ultrasonographic pulse wave velocity (PWV) measurements are comparable to those obtained via tonometry. Arterial stiffness has become nearly synonymous with PWV, but research on stiffness index and ultrasonographic stiffness measurements remains limited. The predictive role of arterial stiffness in anesthesia-induced hypotension has not been adequately evaluated. This study was designed to address this gap by evaluating whether arterial stiffness and stiffness index measured by USG can predict hypotension during anesthesia induction. Exploratory analyses also examined associations with intraoperative hemodynamic changes, vasoactive drug use, ICU and hospital stay, and mortality.

Methods:

This prospective study was conducted between October 1, 2022, and May 1, 2023, at a university hospital. Ethical approval was obtained from the institutional review board. Patients scheduled for elective cardiac surgery were evaluated. Arterial stiffness and stiffness index values measured by ultrasonography, along with intraoperative and postoperative clinical data, were analyzed. Informed consent was obtained from all participants.

Participants:

Patients aged 18-85 years scheduled for elective cardiac surgery were included. Exclusion criteria included arrhythmia, end-stage renal disease, left ventricular ejection fraction <35%, reoperation, emergency surgery, body mass index >40 kg/m², and incomplete data. Upon arrival in the operating room, standard monitoring was initiated, including ECG, SpO₂, and invasive arterial pressure via radial artery cannulation under local anesthesia. All arterial stiffness measurements were performed by a single clinician after sedation with midazolam and fentanyl. Measurements were conducted in the supine position, followed by anesthesia induction and central venous catheterization. Hemodynamic parameters, hypotension episodes, and vasoactive agent use were recorded throughout the surgical procedure. After surgery, participants were transferred to the intensive care unit.

Measurements - Pulse Wave Velocity (PWV):

A 3-lead ECG was connected to the patient. Measurements were taken in the supine position with the head turned to the left. A sector probe was placed at the bifurcation of the right sternocleidomastoid muscle to visualize Doppler waveforms of the carotid artery. A linear probe was used to measure maximum and minimum diameters of the carotid artery. The femoral artery was imaged below the inguinal ligament. Doppler signals were recorded from both sites simultaneously with ECG. The time delay between the ECG R-wave and the start of the Doppler waveform was measured across three cardiac cycles and averaged. The distance between the measurement points was divided by the delay time to calculate PWV (m/s). This value represented arterial stiffness.

The stiffness index (β) was calculated using the maximum and minimum diameters of the carotid artery and systolic/diastolic blood pressure values:

β = [ln(Systolic BP / Diastolic BP)] / [(Systolic Diameter - Diastolic Diameter) / Diastolic Diameter] The vasoactive inotropic score (VIS) was used to assess the degree of vasopressor and inotropic support. A VIS ≥10 is considered an independent risk factor for increased morbidity and mortality.

Data Collection:

Baseline systolic, diastolic, and mean arterial pressures and heart rate values were recorded pre-induction, pre-intubation, and within the first 10 minutes post-intubation. Additional hemodynamic parameters such as systolic pressure variation (SPV), pulse pressure variation (PPV), and central venous pressure (CVP) were also collected. Intraoperative hypotension was defined as systolic arterial pressure (SAP) <90 mmHg. Thresholds of <80 mmHg and <70 mmHg were also explored. The types and doses of vasoactive and inotropic agents used during surgery, including during cardiopulmonary bypass, were recorded. VIS values were calculated and analyzed in relation to arterial stiffness parameters.

Conditions

Hypotension; Anesthesia-Induced Hypotension; Arterial Stiffness; Cardiovascular Diseases

Study Design

• Observational Model Type: OTHER
• Study Time Perspective: PROSPECTIVE

Study Groups

Single group

In our study, a single group was analyzed without comparisons to another group. Ultrasonographic measurements were performed within a single patient cohort.

Doppler ultrasonography

Intervention Type: DIAGNOSTIC_TEST

The delay time was determined as the time difference between the onset of the Doppler waveform and the R-wave on the electrocardiogram(ECG) of the USG device. The distance between the carotid and femoral arteries, where imaging was performed, was then measured. This distance was divided by the delay time to calculate the carotid-femoral pulse wave velocity(PWV) in meters per second, which was considered a measure of arterial stiffness.

Interventions

Doppler ultrasonography

The delay time was determined as the time difference between the onset of the Doppler waveform and the R-wave on the electrocardiogram(ECG) of the USG device. The distance between the carotid and femoral arteries, where imaging was performed, was then measured. This distance was divided by the delay time to calculate the carotid-femoral pulse wave velocity(PWV) in meters per second, which was considered a measure of arterial stiffness.

Intervention Type: DIAGNOSTIC_TEST

Eligibility Criteria

Inclusion Criteria

• Patients aged between 18 and 85 who underwent elective cardiac surgery

Exclusion Criteria

• Arrhythmia
• End-stage renal failure on dialysis
• Left ventricular ejection fraction <35%
• Reoperation
• Emergency surgery
• Body mass index >40
• Missing data

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Necmettin Erbakan University

OTHER

Sponsor Role: collaborator

Konya City Hospital

OTHER

Sponsor Role: lead

Responsible Party

Mustafa Aydemir

Specialist, Department of Anesthesiology and Reanimation

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

NecmettinEU

Konya, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

2022/3982

Identifier Type: -

Identifier Source: org_study_id