T1 Mapping in HIV Patients With High and Low CD4+ Cell Counts

Study Overview
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Brief Summary
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HIV-infection is associated with an increased risk for cardiovascular disease. Especially patients with low CD4+ counts have a higher incidence of structural heart disease. Myocardial T1 relaxation time, as well as T1-derived extracellular volume fraction are relatively new methods for non-invasive myocardial tissue characterization, including diffuse myocardial fibrosis. In our study HIV-patients with high and low CD4+ counts are examined on a 3T MRI scanner (Ingenia 3T, Philips Medical, Best, Netherlands). Scanning protocol includes common SSFP sequences, STIR imaging and LGE [Late gadolinium enhancement]. All HIV patients are treated in the HIV outpatient clinic of the hospital's Internal Medicine department and have an unremarkable history of cardiac disease. Patients are recruited from all over Germany. In order to obtain reference values, a subgroup of healthy, age-matched controls is included in this study. Aim of this study is to show differences in T1- and ECV-values in the investigated subgroups. In addition, we also want to create cut-off values for healthy and affected myocardium in asymptomatic HIV-infected patients. This study could show whether myocardial T1 mapping is a potential screening parameter for beginning heart disease as part of an HIV-infection, and whether an application in routine diagnostic is reasonable.

Official Title
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Myocardial T1-mapping and T1-derived Extracellular Volume Fraction (ECV) in HIV-infection Patients With Chronic High and Low CD4+ Counts and in a Healthy Control Group

Conditions
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Heart Diseases, HIV

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: chronic HIV infection no known cardiac disease no cardiovascular risk factors Exclusion Criteria: contraindications to MRI (e.g. metal implants) chronic kidney disease

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| HIV patients with high CD4+ cell counts<br>HIV Infection, Chronic high CD4+ cell counts (>500 /μl), No known cardiac disease | |
| HIV patients with low CD4+ cell counts<br>HIV Infection, Chronic low CD4+ cell counts (<200 /μl), No known cardiac disease | |
| Control Group<br>No known cardiac disease. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Native T1 Relaxation Times | T1 relaxation times will be directly obtained form the T1 maps through ROI analysis. T1 maps will be analyzed using a segmental approach. T1 relaxation times are given in [ms]. | Measurement will be performed within 2 weeks after MRI scan | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Extracellular volume fraction (ECV) | Hematocrit corrected ECV will be calculated using pre- and post-contrast T1 values for myocardium and blood pool using following formula: ECV= (1⁄T1 myocardium post contrast-1⁄T1 myocadium pre contrast)/(1⁄T1 blood post contrast-1⁄ T1 blood pre contrast) x (1-hematocrit). ECV is given in percentage. | Measurement will be performed within 2 weeks after MRI scan |