NT-proBNP Selected Prevention of Cardiac Events in Diabetic Patients

Overview

Purpose and rationale The purpose of this study is to evaluate the effect of high dose Renin-Angiotensin System (RAS)-antagonists and beta-blocker treatment for the primary prevention of cardiac events in a population of patients with Type 2 diabetes mellitus (T2DM) with no evidence of a preexisting cardiac disease. An additional aim is to demonstrate an interaction between concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP as a surrogate of imminent cardiac risk) and treatment effects and the economic impact of the intervention overall and in the biomarker stratified subgroups. Primary objective Superiority of high dose treatment with RAS-antagonists and beta-blockers compared to conventional therapy regarding the reduction of unplanned hospitalization or death due to a cardiac event in T2DM patients with a NT-proBNP \> 125pg/ml. There is an additional eye-substudy for Viennese sites only. The purpose of this sub-study is to evaluate the effect of high dose RAS-antagonists and beta blocker treatment on early subclinical signs of diabetic micro-angiopathy and neuropathy. An additional aim will be the evaluation of the possible impact of the cardiovascular risk factor NT-proBNP on the onset and progression of diabetic retinopathy.

Purpose and rationale The purpose of this study is to evaluate the effect of high dose Renin-Angiotensin System (RAS)-antagonists and beta-blocker treatment for the primary prevention of cardiac events in a population of patients with Type 2 diabetes mellitus (T2DM) with no evidence of a preexisting cardiac disease. An additional aim is to demonstrate an interaction between concentrations of amino-terminal pro-B type natriuretic peptide (NT-proBNP as a surrogate of imminent cardiac risk) and treatment effects and the economic impact of the intervention overall and in the biomarker stratified subgroups. Primary objective Superiority of high dose treatment with RAS-antagonists and beta-blockers compared to conventional therapy regarding the reduction of unplanned hospitalization or death due to a cardiac event in T2DM patients with a NT-proBNP \> 125pg/ml. Co-primary objective Superiority of high dose treatment with RAS-antagonists and beta-blockers compared to conventional therapy regarding the reduction of unplanned hospitalization or death due to a cardiac event in T2DM patients in the whole population Secondary objective Dependency of treatment efficacy (reduction of unplanned hospitalization or death due to a cardiac event in T2DM patients) on the NT-proBNP concentration (interaction effect between NT-proBNP concentrations and treatment). Population The study population will consist of patients with T2DM without any history or signs of cardiac disease. Patients from approximately 20 centers worldwide will be included into the study and randomized 1:1 to intensive or conventional therapy. It is estimated that about 3000 patients have to be screened In order to include 2400 patients. The screen failure rate is anticipated to be approximately 20%. Investigational and reference therapy All eligible patients will be randomized to receive either a high dose of RAS-antagonists and beta-blockers (as defined in the section investigational drugs) on top of standard diabetes therapy or solely standard diabetes therapy. The use of RAS-antagonist and beta-blocker therapy at randomization is allowed in the control group (with the exception of maximal dosage), but prescription or titration during the study period is not encouraged. However, if the investigators feel that further prescription or up-titration is required a thorough justification is mandatory. Every attempt should be made to use other blood pressure lowering drugs than RAS-antagonists or beta-blockers in the control group. Study design This study is a randomized open-label, parallel group, active-controlled, two-arm, long-term morbidity and mortality trial to evaluate the efficacy and safety of high dose RAS-antagonist and beta-blocker therapy (as defined in the section investigational drugs) compared to standard diabetes therapy in patients with diabetes without any history or sign of a cardiac disease. The goal is to include 2400 patients. The observation period is planned to last for two years. However, the trial is event driven and will continue until predefined event rate is reached. The total trial duration is expected to last for four years (two years of recruitment and a two year observation period after last patient in). Every patient will remain in the study for two years after randomization. Visit 1 Screening At the first visit eligibility to enter the study will be assessed by the investigator. All inclusion/exclusion criteria will be evaluated. Informed consent will be obtained. Demographic data and drug prescription will be assessed. Blood will be obtained. Blood chemistry will be assessed locally. NT-proBNP will be determined by a point of care system locally. The investigator will be blinded to the result, which will be sent to the central computer. Blood will be obtained for the core lab, centrifuged and stored at -80° Celsius at the local unit. Vital signs will be obtained. Randomization will be performed electronically, this way randomization can be performed immediately. Visit 2 (3 months) At visit 2 vital signs will be obtained. Blood will be drawn. Blood chemistry parameters will be assessed locally for safety reason. Drug prescription will be documented. Visit 3 (12 months) At visit 3 vital signs will be obtained. Blood will be drawn. Blood chemistry parameters will be assessed locally for safety reason. Drug prescription will be documented. Visit 4 EOS (end of study) (24 months) At visit 4 vital signs will be obtained. Blood will be drawn. Blood chemistry parameters will be assessed locally for safety reason. Additional blood samples will be sent to the core laboratory. Drug prescription will be documented. Visit 1-4 is mandatory for all patients. Long-term follow-up Patients with be further followed by population register or telephone contact respectively until completion of the study to determine long-term mortality and hospitalizations. Unscheduled visits for the treatment group The treatment group will have additional visits for up-titration of RAS-antagonists and beta- blocker between visit 1 and visit 2. The frequency is up to the treating physician and dependent on the titration steps. A visit is not mandatory for each titration step. Patients will receive a logbook by the investigator, with weekly up- titration steps of the drugs. Additionally, patients will receive a diary for daily documentation of blood pressure, heart rate and symptoms if measurement is technically feasible for the patient. Based on own measurements, these data and laboratory results the investigator will decide if further up-titration of medication is possible. Systolic blood pressure should not decrease permanently below 100 mmHg and heart not below 60bpm permanently. Recommended drugs and recommended dosages are outlined in the section "Treatment". At each visit, blood chemistry for eGFR, creatinine, blood urea nitrogen (BUN), sodium and potassium will be obtained for safety reason. Details of the eye-substudy: The PONTIAC Eye Study is a masked longitudinal follow up of previously 1:1 randomized study patients participating in the PONTIAC 2 study. It is planed to include 130 consecutive patients for biannually visits over a study period of 2 years. Study patients (n=130) will be assigned to the Department of Ophthalmology and Optometry of the Medical University Vienna once they are included in the PONTIAC 2 Study in one of the participating Centers in Vienna. The investigators will be masked to the patient's randomization. The primary objective of the sub-study is: Superiority of the treatment arm with RAS-antagonists and beta-blockers compared to conventional therapy regarding thickness-change in the retinal nerve fiber layer or outer nuclear layer measured in spectral domain optical coherence tomography.