A Study of Glycemic Control in Left Ventricular Assist

Study Overview
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Brief Summary
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The study is being conducted to understand if the hemoglobin A1c, a measurement of control of blood sugars over a 3-month time, is valid in patients with Left Ventricular Assist Devices (LVADs) in place. To understand whether it is an adequate measurement, the investigators will compare the A1c to results from a continuous glucose monitor (CGM) measurement of blood sugars. By monitoring blood sugars continuously, the investigators will also assess whether they can get better control of blood sugars with a CGM, including avoiding low blood sugars.

Official Title
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GLYcemic Control Evaluation by Continuous Glucose Monitor Compared With a1C in Left Ventricular Assist Device-supported Patients (GLYCEM1C-LVAD)

Conditions
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Hypoglycemia, Type 2 Diabetes Mellitus, Hyperglycemia

Intervention / Treatment
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* Device: Freestyle Libre 3 Continuous Glucose Monitor (CGM)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Prior implantation of contemporary, centrifugal flow LVAD (HeartWare or HeartMate 3) at any time after 2010 Diagnosis of type II diabetes mellitus Any antihyperglycemic regimen Greater than 3 months out from LVAD implantation Capable of utilizing smartphone device for LibreLink app for uploading glycemic data Patients may be enrolled who have preexisting CGM in place. Exclusion Criteria: Type I diabetics Unable to return at 3 month evaluation Unwillingness to participate

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Left Ventricular Assist Device (LVAD) supported Type 2 Diabetes Mellitus (T2DM) Subjects<br>Subjects diagnosed with T2DM who have a LVAD will be provided a Freestyle Libre 3 CGM. | Device: Freestyle Libre 3 Continuous Glucose Monitor (CGM)<br>* Subjects will be provided a Freestyle Libre 3 CGM for monitoring of blood glucose levels throughout participation in the study (approximately 3 months). CGM data will be uploaded to the LibreLink app on a weekly basis for review of glucose control and consultation with a diabetes-trained provider for any values outside of normal ranges. Adjustments to diet and medication therapy (antihyperglycemic therapy) will be made during consultations to improve episodes of hypoglycemia or severe hyperglycemia that were observed.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Average glucose values based on continuous glucose monitoring | Average level of blood sugar reported in mg/dL obtained via the Freestyle Libre 3 CGM over a 3 month period. | 3 months | 
| Estimated average glucose (eAG) values based on hemoglobin-A1c lab values | Estimated average level of blood sugar reported in mg/dL based on conversion of hemoglobin-A1c lab values (eAG=28.7*A1C - 46.7) collected at the 3-month visit. | 3 months | 
| Estimated average glucose (eAG) values based on fructosamine lab values | Estimated average level of blood sugar reported in mg/dL based on conversion of fructosamine lab values (eAG= 28.7*(0.017 x fructosamine + 1.61) - 46.7) collected at the 3-month visit. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of adjustments of antihyperglycemic agents | Number of adjustments made to diet and medication therapy based on consultation from a trained diabetes specialist to improve episodes of hypoglycemia or severe hyperglycemia following review of glucose levels obtained via the Freestyle Libre 3 CGM. | 3 months | 
| Number of hypoglycemic unawareness episodes | Number of hypoglycemia unawareness episodes defined as periods where subjects did not know that they had low blood sugar according to Freestyle Libre 3 CGM generated alerts. | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Left Ventricular Assist Device (LVAD)