Allopurinol in Diabetes Mellitus and Multivessel Coronary Artery Disease

Overview

Atherosclerosis is a progressive disease of the arterial wall, arising from the combination of endothelial dysfunction and inflammation. This link is exacerbated in diabetic patients. Uric acid is known to generate oxidative stress and it's elevated levels has been shown to be associated with cardiac hypertrophy, inflammation, myocardial fibrosis and diastolic dysfunction. Allopurinol inhibits xanthine oxidase, an enzyme that regulates uric acid production. In observational studies it has been shown to reduce ischemia, inflammation and improve coronary flow. The aim of this study is to see whether treatment with Allopurinol in patients diagnosed with multivessel disease and undergoing treatment with either percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) , will reduce markers of inflammation and improve quality of life and major adverse cardiovascular effects (MACE).

This is a pilot study, PROBE design (prospective randomized open label blinded endpoints study), that will include 100 patients. Patients will be recruited during their hospitalization in the cardiology department of Ichilov- Tel-Aviv Sourasky Medical Center. It will include patients with known or newly diagnosed diabetes mellitus, hospitalized with diagnosis of acute coronary syndrome and multi-vessel coronary artery disease (CAD) that will be demonstrated by cardiac catheterization that the patients will undergo during their hospitalization in concordance with their diagnosis and practice guidelines. The decision about intervention with either PCI or CABG will be accepted by a heart team after the initial demonstration of multi-vessel disease. Study recruitment will take place either in the first 24 hours after PCI or before CABG. All patients will sign an informed consent and randomized before any intervention is done. After enrollment, patients will undergo the following baseline procedure (no later than 24 hours from PCI): 1. Physical examination and medical interview 2. Quality of life questionnaires (Seattle angina , EQ-5D) 3. Echocardiogram 4. Blood tests- see below for description 5. Endothelial function using the EndoPat® Blood sampling will be done via IV cannula that will be placed in an antecubital vein. Blood sample analyses will be performed using reagents, calibrators and control materials in the local labs of each participating site. A 40 ml blood sample will be obtained for the following blood tests 1. Full chemistry including: lipid levels, thyroid function, liver enzymes function, Troponin, BNP, HbA1c, uric acid, creatinine and glucose levels. 2. Blood count 3. Inflammatory biomarker (hs-CRP, fibrinogen, IL-6, IL-1B, IL-18, MMP, IL-10, IL-35, TNFa, AchE , PAI-1, MPO, cholinergic status.) 4. Endothelial function markers: Endothelin-1, I-CAM, V-CAM, superoxide dismutase ADMA, and oxidized LDL 5. Oxidative Stress- superoxide dismutase ADMA, and oxidized LDL, Plasma protein carbonyls. 6. Urine samples- microalbuminuria, albumin/creatinine. Uric acid. Endothelial function will be assessed using EndoPAT 2000 device (Itamar Medical Inc., Caesarea, Israel) that is a device that measures endothelial function using a sensor placed on the fingers. This device has been validated and used previously to assess peripheral arterial tone in other populations. EndoPAT bio-sensors are placed on the index fingers of both arms. EndoPAT quantifies the endothelium-mediated changes in vascular tone, elicited by a 5-minute occlusion of the brachial artery (using a standard blood pressure cuff). When the cuff is released, the surge of blood flow causes an endothelium-dependent Flow Mediated Dilatation (FMD). The dilatation, manifested as reactive hyperemia, is captured by EndoPAT as an increase in the PAT Signal amplitude. A post-occlusion to pre-occlusion ratio is calculated by the EndoPAT software, providing the EndoPAT index. In addition, the EndoPAT system will measure heart rate variability. After randomization and assessment as described above, the patients will receive treatment according to the study arm they were assigned to which will include either standard medical therapy alone, or standard medical therapy and allopurinol. Allopurinol will be given initially at 100 mg once daily dose, with dose escalation by 100 mg every 2 weeks till final dose of 300 mg daily will be reached. After discharge, patients will be assessed several times: 1. One month after in cardiology clinic. Assessment will include all the tests as in the pre study exam (see above). also, patients will be monitored for the possible side effects of allopurinol treatment. 2. Three months- in cardiology clinic. Assessment will include all the tests as in the pre study exam (see above).