Atrial Fibrillation (AF), Block Complete Heart, Chronotropic Incompetence
Conditions
Keywords
left bundle branch area pacing, closed loop stimulation, LBBAP, CLS, Rate adaptive pacing, cardiac pacing
Brief summary
This prospective, single-center, crossover study evaluated the effects of closed-loop stimulation (CLS) compared with conventional accelerometer-based rate-adaptive pacing (VVIR) in patients with permanent atrial fibrillation undergoing left bundle branch area pacing (LBBAP). Chronotropic responses were evaluated during standardized mental and physical stress testing. Heart rate distribution during daily activity, functional capacity, quality of life, and device-related parameters were also assessed.
Interventions
DEVICEClosed-Loop Stimulation
The pacemaker was programmed to closed-loop stimulation (CLS), an impedance-based rate-adaptive pacing algorithm that adjusts the pacing rate in response to changes in intracardiac impedance associated with cardiac contractile dynamics.
DEVICEAccelerometer-Based VVIR Pacing
The pacemaker was programmed to VVIR mode with accelerometer-based rate-adaptive pacing. The pacing rate was adjusted according to physical activity detected by the device's accelerometer.
Sponsors
Bartlomiej Wrobel
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Masking description
Participants were blinded to the programmed pacing mode. Investigators and outcome assessors were not blinded.
Intervention model description
Participants underwent two consecutive pacing periods, one with closed-loop stimulation (CLS) and one with accelerometer-based VVIR pacing. Seventeen participants started with CLS followed by VVIR, whereas 16 participants started with VVIR followed by CLS. The order of pacing modes was not randomized.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥18 years * Permanent atrial fibrillation * Chronotropic incompetence * Permanent pacemaker with left bundle branch area pacing (LBBAP) * Ventricular pacing burden \>50% * Ability to provide written informed consent
Exclusion criteria
* Age \<18 years * Inability or unwillingness to provide informed consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Heart Rate During Mental Stress | At the end of each 1-month pacing period | Change in heart rate (ΔHR) during the Paced Auditory Serial Addition Test (PASAT), calculated as the peak heart rate recorded during the test minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm). |
| Change in Heart Rate During Isometric Handgrip | At the end of each 1-month pacing period | Change in heart rate (ΔHR) during the 5-minute isometric handgrip test performed at 30% of maximal voluntary contraction, calculated as the peak heart rate recorded during the test minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm). |
| Change in Heart Rate During Treadmill Exercise | At the end of each 1-month pacing period | Change in heart rate (ΔHR) during the symptom-limited treadmill exercise test using the modified Bruce protocol, calculated as the peak heart rate achieved during exercise minus the baseline heart rate. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in beats per minute (bpm). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Exercise Duration During Treadmill Testing | At the end of each 1-month pacing period | Total exercise duration during the symptom-limited treadmill exercise test performed using the modified Bruce protocol. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed in seconds. |
| Metabolic Equivalents Achieved During Treadmill Testing | At the end of each 1-month pacing period | Exercise capacity during the symptom-limited treadmill exercise test using the modified Bruce protocol, expressed as metabolic equivalents (METs) achieved during the test. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing. |
| Heart Rate Score During Daily Activity | At the end of each 1-month pacing period | Heart Rate Score (HRS), defined as the percentage of all sensed and paced ventricular beats occurring in the most populated 10-beats-per-minute heart rate histogram bin. HRS was assessed from pacemaker-derived heart rate histograms under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing. Higher HRS values indicate a more concentrated heart rate distribution and less heart rate variation across histogram bins. The score ranges from 0% to 100%. |
| Health-Related Quality of Life Assessed With the EQ-5D-5L Index | At the end of each 1-month pacing period | Health-related quality of life was assessed using the EuroQol 5-Dimension 5-Level (EQ-5D-5L) descriptive system. Responses were converted to an EQ-5D-5L index value using the Polish value set. Index values range from -0.590 to 1.000, with higher values indicating better health-related quality of life. A value of 1 represents full health, 0 represents a health state equivalent to death, and negative values represent health states valued as worse than death. The outcome was compared between closed-loop stimulation (CLS) and accelerometer-based VVIR pacing. |
| Self-Rated Health Assessed With the EQ VAS | At the end of each 1-month pacing period | Self-rated health was assessed using the EuroQol Visual Analogue Scale (EQ VAS), ranging from 0 to 100, where 0 represents the worst health the participant can imagine and 100 represents the best health the participant can imagine. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing. |
| Patient-Reported Pacing-Mode Preference | At the end of the study, after completion of both 1-month pacing periods | At the end of the study, participants were asked during which of the two pacing periods they experienced better overall subjective well-being, or whether they had no preference. Responses were subsequently categorized according to the pacing mode programmed during the preferred period as preference for closed-loop stimulation (CLS), preference for accelerometer-based VVIR pacing, or no preference. |
| Ventricular Pacing Percentage | At the end of each 1-month pacing period | Ventricular pacing percentage was obtained from pacemaker interrogation and defined as the proportion of ventricular events that were paced during each study period. The outcome was assessed under both closed-loop stimulation (CLS) and accelerometer-based VVIR pacing and expressed as a percentage from 0% to 100%. |
Countries
Poland
Outcome results
None listed