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|
| General |
| Study Status |
Completed |
Application Number /
Requirement Number |
P060040 S005/ PAS002 |
| Date Original Protocol Accepted |
05/07/2010
|
| Date Current Protocol Accepted |
05/07/2010
|
| Study Name |
Heartmate II Bleeding Study
|
| Device Name |
THORATEC HEARTMATE II LEFT VENTRICULAR ASSIST SYSTEM
|
| General Study Protocol Parameters |
| Study Design |
Prospective Cohort Study
|
| Data Source |
External Registry
|
| Comparison Group |
Concurrent Control
|
| Analysis Type |
Descriptive
|
| Study Population |
Adolescent: 13-18 yrs,
Transit. Adolescent B (as adults) : 18-21 yrs,
Adult: >21
|
| Detailed Study Protocol Parameters |
| Study Objectives |
This study is a prospective non-randomized observational study,with a primary objective of comparing high molecular weight von Willebrand factor multimer levels in nonpulsatile versus pulsatile left ventricular assist device recipients.
|
| Study Population |
Study Population: Patients who are identified pre-implant in the INTERMACS database as "Bridge to Transplant (patient currently listed for transplant)" or "Possible Bridge to Transplant - Likely to be eligible" will be enrolled in the post market study. Patients implanted with the Heartmate II will comprise the study group and patients implanted with any other LVAD will comprise a concurrent comparator group.
|
| Sample Size |
10 nonpulsatile and 5 pulsatile (HeartMate XVE, Thoratec PVAD) for a total sample size of 15 patients
|
| Key Study Endpoints |
Primary endpoint is to examine the change high molecular weight mutlimer von Willebrand factor from pre-operative levels in nonpulsatile and pulsatile device recipients to 7 days post procedure. Secondary endpoint examine HMW multimer vWF levels in patients who experience a bleeding event.
|
| Follow-up Visits and Length of Follow-up |
All subjects will be assessed pre-procedure and 7days, 30 days and 6 months after device implantation (and/or preheart transplant and 7 days after heart transplant)
|
| Interim or Final Data Summary |
| Interim Results |
No safety data is available for this study.
|
| Actual Number of Patients Enrolled |
53 enrolled (36 included in analyses)
|
| Actual Number of Sites Enrolled |
2
|
| Patient Follow-up Rate |
18/52
|
| Final Safety Findings |
All non-pulsatile VAD patients demonstrated significant reductions in vWF HMW multimer levels following VAD placement. By 30 days postimplantation 100% of non-pulsatile patients tested had reduction in their HMWM levels and AvWS. Therefore, there are additional factors related to AVWF beyond decreased HMVM.
1. Higher vWF Ag levels pre-implant were measured in the pulsatile recipients versus non-pulsatile and decreased slightly by 30 days post-implant in both.
2. VWF Ag levels were higher in the bleeders at all time points in non-pulsatile patients; and both bleeders and non-bleeders had lower 30 day and 6 month vWF Ag levels compared to pre-implant levels.
3. P-selectin levels did not change significantly from baseline following non-pulsatile pump implantation. P-selectin levels were significantly lower in non-bleeders prior to implant and at 30 days post-implantation.
4. D-dimer levels declined following surgery but remained elevated through the 12 months follow up measurements.
|
| Study Strengths & Weaknesses |
Weaknesses: First, there were too few patients in the pulsatile group to power the study. Protocol deviations resulted in only 4 of the 10 pulsatile pumps being included. Of the 4 pulsatile pumps in the study, 3 patients recevied the HeartMate XVE and 1 received the Thoratec PVAD. Second, it was unclear if the loss of large mutlimers was inside or outside of the normal range of values for multimers seen in populations not included in the study.
Strengths: This study is hypothesis generating for future research to see if certain preoperative characteristics, such as high P-Selectin and high vWF levels, could help to identify patients who could be at an increased risk of bleeding postoperatively.
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| Recommendations for Labeling Changes |
None
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