Trial Outcomes & Findings for Head-up Tilt Test in Patients With Reflex Syncope and Asystolic Response Who Received a Dual-chamber Pacemaker With the Closed Loop Stimulation (CLS) and Participated in the BIOSync Trial (NCT NCT06038708)

NCT ID: NCT06038708

Last Updated: 2025-02-03

Results Overview

Instantaneous measurement of heart rate value at specific time-points/stages during HUTT examination. Changes in Heart rate were investigated across four stages of the HUTT: baseline (Stage 1), pre-syncopal phase (Stage 2), maximum heart rate/pacing rate (Stage 3), and syncope or lowest Systolic Blood Pressure (Stage 4).

• Recruitment status: COMPLETED
• Target enrollment: 20 participants
• Primary outcome timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes
• Results posted on: 2025-02-03

Participant Flow

Participant milestones

Measure	DDD-CLS Patients Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Overall Study STARTED	20
Overall Study COMPLETED	20
Overall Study NOT COMPLETED	0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Race and Ethnicity were not collected from any participant.

Baseline characteristics by cohort

Measure	DDD-CLS Patients n=20 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Age, Continuous	68.3 years STANDARD_DEVIATION 11.9 • n=20 Participants
Sex: Female, Male Female	4 Participants n=20 Participants
Sex: Female, Male Male	16 Participants n=20 Participants
Region of Enrollment Italy	20 Participants n=20 Participants

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Instantaneous measurement of heart rate value at specific time-points/stages during HUTT examination. Changes in Heart rate were investigated across four stages of the HUTT: baseline (Stage 1), pre-syncopal phase (Stage 2), maximum heart rate/pacing rate (Stage 3), and syncope or lowest Systolic Blood Pressure (Stage 4).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Heart Rate [Bpm] at Specific Time-points During Head-up Tilt Test (HUTT) Examination Heart rate at baseline (Stage 1)	70 beats per minute Standard Deviation 7
Heart Rate [Bpm] at Specific Time-points During Head-up Tilt Test (HUTT) Examination Heart rate at pre-syncopal phase (Stage 2)	88 beats per minute Standard Deviation 12
Heart Rate [Bpm] at Specific Time-points During Head-up Tilt Test (HUTT) Examination Heart rate at maximum HR/pacing rate (Stage 3)	105 beats per minute Standard Deviation 14
Heart Rate [Bpm] at Specific Time-points During Head-up Tilt Test (HUTT) Examination Heart rate at syncope or lowest Systolic Blood Pressure (Stage 4)	95 beats per minute Standard Deviation 13

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Instantaneous measurement of blood pressure at specific time-points during HUTT examination. Changes in Systolic blood pressure were investigated across four stages of the HUTT: baseline (Stage 1), pre-syncopal phase (Stage 2), maximum heart rate/pacing rate (Stage 3), and syncope or lowest Systolic Blood Pressure (Stage 4).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Systolic Blood Pressure at Specific Time-points During Head-up Tilt Test (HUTT) Examination Systolic blood pressure at baseline (Stage 1)	143 mmHg Standard Deviation 20
Systolic Blood Pressure at Specific Time-points During Head-up Tilt Test (HUTT) Examination Systolic blood pressure at pre-syncopal phase (Stage 2)	108 mmHg Standard Deviation 19
Systolic Blood Pressure at Specific Time-points During Head-up Tilt Test (HUTT) Examination Systolic blood pressure at maximum heart rate/pacing rate (Stage 3)	99 mmHg Standard Deviation 21
Systolic Blood Pressure at Specific Time-points During Head-up Tilt Test (HUTT) Examination Systolic blood pressure at syncope or lowest Systolic Blood Pressure (Stage 4)	63 mmHg Standard Deviation 17

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Instantaneous measurement of stroke volume at specific time-points during HUTT examination

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Stroke Volume [ml] at Specific Time-points During Head-up Tilt Test (HUTT) Stroke volume at time of maximum spontaneous heart rate	54.6 ml Standard Deviation 10.4
Stroke Volume [ml] at Specific Time-points During Head-up Tilt Test (HUTT) Stroke volume at time of maximum CLS pacing rate	47 ml Standard Deviation 8.4
Stroke Volume [ml] at Specific Time-points During Head-up Tilt Test (HUTT) Stroke volume at time of recovery of basic pacing rate or spontaneous rhythm after pacing	77.9 ml Standard Deviation 34.5

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Instantaneous measurement of peripheral resistance at specific time-points during HUTT examination

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Peripheral Resistance [Dyn·s/cm5] at Specific Time-points During Head-up Tilt Test (HUTT) Peripheral Resistance at time of maximum spontaneous heart rate	1262.5 dyn*s/cm^5 Standard Deviation 377
Peripheral Resistance [Dyn·s/cm5] at Specific Time-points During Head-up Tilt Test (HUTT) Peripheral Resistance at time of maximum CLS pacing rate	1226.2 dyn*s/cm^5 Standard Deviation 350.4
Peripheral Resistance [Dyn·s/cm5] at Specific Time-points During Head-up Tilt Test (HUTT) Peripheral Resistance at time of recovery of basic pacing rate or spontaneous rhythm after pacing	1183.8 dyn*s/cm^5 Standard Deviation 347.3

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Recording of a specific time-point during HUTT examination. This time was collected as hours:minutes:seconds (e.g. 00:35:34).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Time of Maximum Spontaneous Heart Rate	22.7 minutes Interval 21.6 to 24.6

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Recording of a specific time-point during HUTT examination. This time was collected as hours:minutes:seconds (e.g. 00:35:34).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Time of Pacing Onset	22.9 minutes Interval 22.0 to 24.4

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Recording of a specific time-point during HUTT examination. This time was collected as hours:minutes:seconds (e.g. 00:35:34).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Time of Recovery of Spontaneous Rhythm After Pacing	29.2 minutes Interval 26.4 to 32.5

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Recording of a specific time-point during HUTT examination. This time was collected as hours:minutes:seconds (e.g. 00:35:34).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Time of Syncope	24.0 minutes Interval 22.9 to 25.2

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Recording of a specific time-point during HUTT examination. This time was collected as hours:minutes:seconds (e.g. 00:35:34).

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Time of Tilt-down	25.3 minutes Interval 23.4 to 37.6

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Interval from maximum pacing rate to basic rate or spontaneous rhythm

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Duration of the Recovery Phase [Minutes]	5.0 minutes Interval 3.3 to 8.3

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Calculation of the rate of change of heart rate from the time of maximum pacing rate to the time of basic rate or spontaneous rhythm recovery

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Slope in Heart Rate [Bpm/Minute] During the Recovery Phase	-6.0 bpm/minute Standard Deviation 3.0

PRIMARY outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Calculation of the rate of change of systolic blood pressure from the time of maximum pacing rate to the time of basic rate or spontaneous rhythm recovery

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Slope in Systolic Blood Pressure (mmHg Per Minute) During the Recovery Phase	6.2 mmHg per minute Standard Deviation 11.5

POST_HOC outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Time interval from CLS pacing onset to syncope or lowest blood pressure [minutes]

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Onset of CLS Pacing	1.7 minutes Interval 1.5 to 3.4

POST_HOC outcome

Timeframe: From the start to the end of the HUTT examination, assessed up to 45 minutes

Total duration of CLS pacing (interval from pacing onset to recovery of basic rate or spontaneous rhythm) [minutes]

Outcome measures

Measure	DDD-CLS Patients n=14 Participants Patients with reflex syncope and positive cardioinhibitory response to Head-Up Tilt Test (HUTT) with a dual-chamber pacing system equipped with the CLS algorithm.
Duration of CLS Pacing	5.0 minutes Interval 3.3 to 8.3

Adverse Events

DDD-CLS Patients

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Paola Napoli, Clinical Project Manager

BIOTRONIK Italy

Phone: 3357369277

Email: paola.napoli@biotronik.com

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place