Myocardial Metabolism in Patients With Dilated Cardiomyopathy

Study Overview
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Brief Summary
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Dilated cardiomyopathy (DCM) is characterized by a metabolic shift from fat to carbohydrates and failure to increase myocardial glucose uptake in response to workload increments. The investigators aimed at verifying whether this pattern is influenced by the presence of abnormal glucose tolerance (AGT).

Detailed Description
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A catheter is advanced into the coronary sinus by fluoroscopy to withdraw venous blood. A unipolar pacing catheter is positioned into the right atrium. Arterial sampling is done from the femoral artery introducer catheter. The study protocol consisted of 3 steps (Rest, Pacing and Recovery), during which timed blood samples are collected to measure plasma NEFA and glucose. After the instrumentation is completed, Rest arterio-venous sampling is performed at time -15 min and 0 min. After the 0 min, heart rate is increased by atrial pacing to 110 bpm for 3 minutes and to 130 bpm for 3 additional minutes and arterio-venous sampling is repeated at the end of each step (at time 3 and 6 min). Pacing is then stopped and at time 1, 5, 15 and 30 min into the Recovery period other pairs of arterial and venous samples are withdrawn.

Official Title
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Abnormal Glucose Tolerance is Associated With a Reduced Myocardial Metabolic Flexibility in Patients With Dilated Cardiomyopathy

Conditions
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Type 2 Diabetes, Dilated Cardiomyopathy

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: For patients with dilated cardiomyopathy: Myocardial left ventricular ejection fraction (LVEF) <40% left ventricular end-diastolic diameter (LVEDD) >56 mm For patients without dilated cardiomyopathy: LVEF >50% LVEDD <56 mm. Exclusion Criteria: NYHA class IV Atrial fibrillation Previous myocardial infarction Valvular heart disease Myocarditis Pericarditis Severe to moderate systemic arterial hypertension Fasting hyperglycaemia (>7.0 mmol/l) Treated diabetes, autoimmune diseases, neoplasia, kidney, liver or respiratory failure

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 69 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 |
| --- | --- |
| DCM-AGT<br>Subjects with both dilated cardiomyopathy (DCM) and abnormal glucose tolerance (AGT, either impaired glucose tolerance or type 2 diabetes). | |
| DCM-NGT<br>Subjects with dilated cardiomyopathy (DCM) and normal glucose tolerance (NGT). | |
| N-AGT<br>Subjects without dilated cardiomyopathy (N) with abnormal glucose tolerance (AGT, either impaired glucose tolerance or type 2 diabetes). | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Myocardial metabolic responses to stress in humans | The investigators aimed at evaluating myocardial NEFA and glucose uptake. | Arterio-venous sampling will be performed in about an hour during three experimental condition: rest (time -15 and 0 min), pacing (3 and 6 min), and recovery (1, 5, 15 and 30 min). |