Respiratory and Haemodynamic Effects of Conscious Sedation With Dexmedetomidine for a TAVI Procedure

Respiratory and Haemodynamic Effects Comparison of Conscious Sedation With Dexmedetomidine Versus Sedation With Remifentanil-propofol for a TAVI Procedure: a Prospective, Randomised, Single-blind Study

Transcatheter aortic valve implantation (TAVI) is now the standard procedure for elderly patients with severe aortic stenosis. This patient group is characterised by increased frailty, multiple comorbidities and limited physiological reserve, exposing them to an increased risk of intraoperative complications.

The majority of TAVI procedures are now performed under conscious sedation, in order to limit the risks associated with general anaesthesia and to promote a faster recovery. However, this strategy carries a risk of intraoperative respiratory events, notably bradypnoea, oxygen desaturation and airway obstruction, particularly in elderly patients with comorbidities.

The anaesthetic strategy, and in particular the type of sedation used, is likely to influence intraoperative respiratory and haemodynamic tolerance. Traditionally used agents, such as propofol combined with opioids, can induce dose-dependent respiratory depression. Conversely, dexmedetomidine, an α2-adrenergic receptor agonist, has a distinct pharmacological profile, characterised by sedation with a theoretically limited respiratory impact.

However, comparative data regarding the impact of different sedation strategies on intraoperative respiratory tolerance during TAVI remain limited, justifying the conduct of this study.

Dexmedetomidine is a selective α2-adrenergic receptor agonist, used in anaesthesia and intensive care for its sedative and anxiolytic properties. It induces what is known as 'cooperative' sedation, characterised by the maintenance of relative alertness, the possibility of interacting with the patient and, above all, a limited impact on spontaneous breathing.

Physiologically, dexmedetomidine differs from conventional sedatives, such as propofol and opioids, in causing less respiratory depression, making it a particularly attractive option for conscious sedation. This property is essential in elderly and comorbid patients, particularly during procedures such as TAVI, where maintaining spontaneous ventilation is a major concern.

Several clinical studies, particularly in procedural sedation and interventional cardiology, suggest that the use of dexmedetomidine is associated with better respiratory tolerance, with a reduction in episodes of desaturation, bradypnoea and the need for airway interventions, compared with strategies based on propofol and opioids.

However, data specific to the context of TAVI under conscious sedation remain limited, particularly regarding the prospective and standardised assessment of intraoperative respiratory events.

This study therefore aims to address this knowledge gap by assessing the effect of dexmedetomidine, compared with standard sedation using propofol-remifentanil, on intraoperative respiratory tolerance in patients undergoing TAVI under conscious sedation.

Study Overview

• Status: Recruiting
• Conditions: TAVI(Transcatheter Aortic Valve Implantation)
• Intervention / Treatment: Drug: Sedation with dexmedetomidine; Drug: sedation propofol and remifentanil

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Celine Boudart, MD PhD; Phone Number: +3225553919; Email: celine.boudart@hubruxelles.be

Study Locations

• Belgium
  • Brussels, Belgium, 1070
    • Recruiting
    • HUB Erasme
    • Contact: Celine Boudart; Phone Number: +3225553919; Email: celine.boudart@hubruxelles.be

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• -aged 60 or over,
• undergoing transfemoral TAVI,
• treated under sedation without general anaesthesia,
• having given their written informed consent,
• with sufficient command of French to undertake cognitive tests.

Exclusion Criteria:

• whose first language is not English,
• who have a contraindication to dexmedetomidine,
• who require conversion to general anaesthesia during the procedure,
• or who present with major haemodynamic instability (shock, uncontrolled arrhythmia).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: sedation dexmedetomidine	Drug: Sedation with dexmedetomidine; Loading dose (optional depending on tolerance): 0.5 µg/kg administered as a slow infusion over 10 minutes (no direct bolus to avoid bradycardia). Maintenance infusion: 0.2 to 0.7 µg/kg/h. Start at 0.4 µg/kg/h. Adjust in increments of 0.1-0.2 µg/kg/h depending on the level of sedation observed. Target: RASS -2 to 0 (patient calm, arable to verbal stimulation). Adjustment of sedation: If agitation/discomfort: Increase Dexdor by 0.1 µg/kg/h.; If persistent: sufentanil bolus 2.5-5 µg. If significant drowsiness/bradycardia: Reduce by 0.1 µg/kg/h.; If bradycardia < 45 bpm: Pacemaker in place by surgical team If hypotension (SBP < 90 mmHg): → Reduce flow rate and administer crystalloids ± vasopressor (noradrenaline)
Active Comparator: sedation propofol-remifentanil	Drug: sedation propofol and remifentanil; Propofol and remifentanil will be administered via target-controlled infusion (TCI) pumps in accordance with standard pharmacokinetic models: Sedation will be titrated to maintain a RASS score between -2 and 0 (patient calm, arousable to verbal stimulation). Start the infusion at the lower target (propofol 0.5 µg/mL; remifentanil 1.0 ng/mL). Gradually adjust every 2-3 minutes based on RASS, signs of discomfort or pain, and haemodynamic and respiratory stability. If agitation/discomfort: Increase Propofol by 0.2 µg/ml and Remifentanil by 0.3 ng/ml If hypoventilation (EtCO₂ > 50 or FR < 8) : Reduce Propofol by 0.2 µg/ml or Remifentanil by 0.3 ng/ml. If bradycardia < 45 bpm: Pacing If hypotension (SBP < 90 mmHg): Reduce the infusion rate and administer crystalloids ± a vasopressor (noradrenaline) Maximum remifentanil dose: 2.5 ng/mL Maximum propofol dose: 1.5 µg/mL

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
the occurrence of an intraoperative respiratory event during a TAVI procedure performed under sedation	Oxygen desaturation, defined as: moderate desaturation with an SpO₂ ≤ 95%,; severe/significant desaturation with an SpO₂ ≤ 90%, Bradypnoea, defined as a respiratory rate < 10 breaths per minute, Impaired ventilation as evidenced by capnography, measured using the CapnoLine® device, including: a reduction in waveform amplitude,; respiratory irregularity,; or any abnormality consistent with hypoventilation or airway obstruction. Respiratory monitoring will be carried out continuously throughout the procedure, including monitoring of oxygen saturation, respiratory rate and capnography	during sedation for TAVI procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postoperative cognitive function	Changes in the MoCA (Montreal Cognitive Assessment) score between the preoperative period (performed the day before de TAVI procedure) and the postoperative period (performed between 24 and 48 hours after TAVI procedure). The MoCA is a rapid cognitive screening test, scored out of 30, used to identify mild or more severe cognitive impairment. A score of 30/30 indicates the absence of cognitive impairment. The lower the score, the more severe the cognitive impairment. Here, we will examine the difference between the pre- and post-measurements, which will be calculated statistically using the score.	the day before TAVI procedure and between 24 and 48 hours postoperatively.
Intraoperative blood pressure stability	Variations blood pressure during the procedure. Blood pressure will be measured in mm Hg using an arterial catheter. Need for vasopressors or corrective interventions.	during sedation and TAVI procedure
Heart Rate stability during procedure	Variations in haert rate (beat per minute) during the procedure. Need for corrective interventions.	during sedation and TAVI procedure
Comfort and quality of sedation	Assessment of patient comfort, of the anaesthetist and the operating cardiologist using Visual Analog Scale (ranging from 0 to 10). A score of 0 indicates complete dissatisfaction, whilst a score of 10 indicates maximum satisfaction	Day 0 (at the completion of the TAVI procedure)
Length of hospital stay	Hospital length of stay (in days) defined as the time from completion of the TAVI procedure until hospital discharge	up to 30 days
Tolerance and safety	Occurrence of intra- and post-operative adverse events related to sedation, from the start of the sedation for TAVI procedure until the hospital discharge	up to 30 days

Collaborators and Investigators

• Sponsor: Erasme University Hospital
• Investigators: Principal Investigator: celine Boudart, HUB - Erasme

Study record dates

Study Major Dates

• Study Start (Actual): April 22, 2026
• Primary Completion (Estimated): May 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: April 2, 2026
• First Submitted That Met QC Criteria: April 9, 2026
• First Posted (Actual): April 16, 2026

Study Record Updates

• Last Update Posted (Actual): April 30, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: dexmedetomidine; sedation; TAVI
• Additional Relevant MeSH Terms: Organic Chemicals; Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Azoles; Acids, Acyclic; Carboxylic Acids; Imidazoles; Piperidines; Propionates; Remifentanil; Dexmedetomidine
• Other Study ID Numbers: HUB2025720

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No