Bradycardia, Sinus Node Dysfunction
Conditions
Keywords
Single chamber pacing, Dual chamber pacing, MRI, MR scans
Brief summary
The objective of the SAMURAI Clinical Study is to collect data to confirm the safety, performance and effectiveness of the ImageReady System for use in the Magnetic Resonance Imaging (MRI) environment when used in accordance with the Conditions of Use included in the Boston Scientific MRI Technical Guide
Interventions
RADIATIONMRI
The study-specified MRI scan includes RF- and gradient-intensive sequences designed to test the ImageReady System in the MR environment
DEVICEImageReady System implant
Pacemaker and lead(s) implant
Sponsors
Boston Scientific Corporation
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Subject must have the ImageReady System as their initial (de novo) pacing system implant * Subject has a Class I or II indication for implantation of a single or dual chamber pacemaker according to the ACC/AHA/HRS, or ESC guidelines, as appropriate per geography * Subject is able and willing to undergo an MRI scan without intravenous sedation * Subject is willing and capable of providing informed consent (which can include the use of a legally authorized representative (LAR) for documentation of informed consent) and participating in all testing/ visits associated with this clinical study at an approved clinical study center and at the intervals defined by this protocol * Subject is age 18 or above, or of legal age to give informed consent specific to state and national law
Exclusion criteria
* Subject has or has had any pacing or ICD system implants * Subject has any MR Unsafe implants or devices with an unknown MR status, including MR Unsafe sternal wires, neurostimulators, biostimulator, metals or alloys, per labeling of each implant * Subject has any MR Conditional implants or devices that impact the ability to conduct this protocol * Subject needs or will need another MR scan within 14 weeks of system implant, other than that required by the SAMURAI Study * Subject has a known or suspected sensitivity to dexamethasone acetate (DXA) * Subject has a mechanical tricuspid heart valve * Subject is enrolled in any other concurrent study, with the exception of local mandatory governmental registries and observational studies/registries\* that are not in conflict and do not affect the following: * Schedule of procedures for the SAMURAI Study (i.e. should not cause additional or missed visits); * SAMURAI Study outcome (i.e. involve medications that could affect pacing thresholds); * Conduct of the SAMURAI Study per GCP/ ISO 14155:2011/ local regulations * Subjects with documented permanent or persistent AF where the physician intends to implant a dual chamber pulse generator (single chamber VVIR pulse generators are acceptable) * Subject is currently on the active heart transplant list * Subject has documented life expectancy of less than 12 months * Women of childbearing potential who are or might be pregnant at the time of study enrollment or ImageReady MR Conditional Pacing System implant (method of assessment upon physician's discretion) * Subjects currently requiring dialysis
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of Participants Without MR Scan-related Complications | MRI Visit + 1 Month | The primary safety endpoint for SAMURAI will be assessed for all subjects randomized to the MRI Group who undergo any portion of the MRI scan sequences. Safety will be confirmed by evaluating the MRI scan-related Complication-free rate (CFR) between the MR Scan and the MRI Visit + 1 Month Visit. |
| Success Rate for Threshold Measurement at 1 Month Post-MRI Scan or Control Group Visit | MRI + 1 Month Visit | The MRI scan can result in damage to cardiac tissue surrounding lead electrodes due to RF field-induced heating, which in turn may cause elevated pacing thresholds. Primary Effectiveness Endpoint 1 will evaluate any chronic effects from lead heating that will be seen through increased pacing threshold at the MRI Visit + 1 Month follow-up. Subjects with an increase in pacing thresholds s 0.5V (at 0.5 ms) from pre-MR Scan/Control Group visit to MRI/Control visit + 1 Month follow-up were considered a success. A success rate was calculated for both the MRI and the Control Groups. |
| Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit | MRI + 1 Month Visit | The MRI scan can result in damage to cardiac tissue surrounding lead electrodes due to Radiofrequency (RF) field-induced heating. Primary Effectiveness Endpoint 2 will evaluate any chronic effects from lead heating that will be seen through decreased sensed amplitude at the MRI Visit + 1 Month follow-up. Data were analyzed separately by chamber, Right Atrium (RA) and Right Ventricle (RV), for this endpoint. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Proportion of Participants Without ImageReady System-related Complications | 3 months post implant | Overall safety of the ImageReady System will be confirmed by evaluating system-related complications that occur from system implant through 3 months post implant for all subjects who underwent an implant procedure and and reached 91 days of follow-up. |
Countries
Australia, Canada, China, Israel, Malaysia, Singapore, United States
Participant flow
Recruitment details
363 patients were consented and enrolled in this study. 11 patients were withdrawn pre-implantation. 352 patients underwent the implantation procedure and 348 patients were successfully implanted. 1 patient died prior to randomization.
Participants by arm
| Arm | Count |
|---|---|
| MRI Group Those subjects randomized to the MRI Group will undergo a study-specific MRI scan 6-9 weeks post-implant.
MRI: The study-specified MRI scan includes RF- and gradient-intensive sequences designed to test the ImageReady System in the MR environment
ImageReady System implant: Pacemaker and lead(s) implant | 229 |
| Control Group Those subjects randomized to the Control Group will not undergo s study-specific MRI scan. All follow-up time requirements are the same for the two groups.
ImageReady System implant: Pacemaker and lead(s) implant | 118 |
| Total | 347 |
Baseline characteristics
| Characteristic | MRI Group | Control Group | Total |
|---|---|---|---|
| Age, Continuous | 69.0 years STANDARD_DEVIATION 13 | 70.4 years STANDARD_DEVIATION 11.9 | 69.4 years STANDARD_DEVIATION 12.8 |
| Region of Enrollment Australia | 0 Participants | 1 Participants | 1 Participants |
| Region of Enrollment Canada | 6 Participants | 2 Participants | 8 Participants |
| Region of Enrollment China | 7 Participants | 3 Participants | 10 Participants |
| Region of Enrollment Israel | 21 Participants | 13 Participants | 34 Participants |
| Region of Enrollment Malaysia | 21 Participants | 8 Participants | 29 Participants |
| Region of Enrollment Singapore | 12 Participants | 8 Participants | 20 Participants |
| Region of Enrollment United States | 162 Participants | 83 Participants | 245 Participants |
| Sex: Female, Male Female | 102 Participants | 63 Participants | 165 Participants |
| Sex: Female, Male Male | 127 Participants | 55 Participants | 182 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 163 / 229 | 82 / 118 |
| serious Total, serious adverse events | 123 / 229 | 67 / 118 |
Outcome results
Primary
Proportion of Participants Without MR Scan-related Complications
The primary safety endpoint for SAMURAI will be assessed for all subjects randomized to the MRI Group who undergo any portion of the MRI scan sequences. Safety will be confirmed by evaluating the MRI scan-related Complication-free rate (CFR) between the MR Scan and the MRI Visit + 1 Month Visit.
Time frame: MRI Visit + 1 Month
Population: The primary safety endpoint for SAMURAI will be assessed for all subjects randomized to the MRI Group who underwent any portion of the MRI scan sequences and did not have a medically necessary scan performed prior to the MRI visit + 1 month follow-up.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MRI Group | Proportion of Participants Without MR Scan-related Complications | 100 Percentage of participants |
Primary
Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit
The MRI scan can result in damage to cardiac tissue surrounding lead electrodes due to Radiofrequency (RF) field-induced heating. Primary Effectiveness Endpoint 2 will evaluate any chronic effects from lead heating that will be seen through decreased sensed amplitude at the MRI Visit + 1 Month follow-up. Data were analyzed separately by chamber, Right Atrium (RA) and Right Ventricle (RV), for this endpoint.
Time frame: MRI + 1 Month Visit
Population: Right Atrium: a total of 78 Control Group subjects and 135 MRI Group subjects had paired sensed amplitude measurements and met the inclusion criteria. Right Ventricle: a total of 91 Control Group subjects and 152 MRI Group subjects had paired sensed amplitude measurements and met the inclusion criteria.
| Arm | Measure | Group | Value (NUMBER) |
|---|---|---|---|
| MRI Group | Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit | Right Atrium (RA) | 96.2 % of participants with success |
| MRI Group | Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit | Right Ventricle (RV) | 96.7 % of participants with success |
| Control Group | Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit | Right Atrium (RA) | 96.3 % of participants with success |
| Control Group | Success Rate for Sensed Amplitude Measurement at 1 Month Post-MRI Scan or Control Group Visit | Right Ventricle (RV) | 96.7 % of participants with success |
p-value: 0.0006Farrington-Manning score test
p-value: 0.0002Farrington-Manning score test
Primary
Success Rate for Threshold Measurement at 1 Month Post-MRI Scan or Control Group Visit
The MRI scan can result in damage to cardiac tissue surrounding lead electrodes due to RF field-induced heating, which in turn may cause elevated pacing thresholds. Primary Effectiveness Endpoint 1 will evaluate any chronic effects from lead heating that will be seen through increased pacing threshold at the MRI Visit + 1 Month follow-up. Subjects with an increase in pacing thresholds s 0.5V (at 0.5 ms) from pre-MR Scan/Control Group visit to MRI/Control visit + 1 Month follow-up were considered a success. A success rate was calculated for both the MRI and the Control Groups.
Time frame: MRI + 1 Month Visit
Population: For the per-protocol analysis, a total of 96 Control Group subjects and 167 MRI Group subjects had paired threshold measurements and met the inclusion criteria.
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MRI Group | Success Rate for Threshold Measurement at 1 Month Post-MRI Scan or Control Group Visit | 98.2 % of participants with success |
| Control Group | Success Rate for Threshold Measurement at 1 Month Post-MRI Scan or Control Group Visit | 97.9 % of participants with success |
p-value: <0.0001Farrington-Manning score test
Secondary
Proportion of Participants Without ImageReady System-related Complications
Overall safety of the ImageReady System will be confirmed by evaluating system-related complications that occur from system implant through 3 months post implant for all subjects who underwent an implant procedure and and reached 91 days of follow-up.
Time frame: 3 months post implant
| Arm | Measure | Value (NUMBER) |
|---|---|---|
| MRI Group | Proportion of Participants Without ImageReady System-related Complications | 94.5 Percentage of participants |