Effect of Metoprolol Succinate in Patients with Stable Angina and Elevated Heart Rate Receiving Low-Dose β-Blocker Therapy

Metabolomic profiling of metoprolol-induced cardioprotection in a murine model of acute myocardial ischemia

Metoprolol (Met) is widely applied in the treatment of myocardial infarction and coronary heart disease in clinic. However, the metabolic network in vivo affected by Met manipulation is still unclear and it's therapeutic molecular mechanisms were remained to be furthered elucidated except β1 adrenergic receptor. Myocardial infarction (MI) was induced by permanent CAL for 24 h in ICR mice. Myocardial infarct size, biochemical indicators such as creatine kinase (CK), lactate dehydrogenase (LDH), C-reactive Protein (CRP), tumor necrosis factor-α (TNF-α) and cardiac troponin I(cTn-I), cardiac function and myocardial pathological changes were detected to ensure the improvement of Met on MI. Subsequently, the significantly changed endogenous metabolites and the network in both serum and urine were screened and constructed through metabolomics by using HPLC-Q-TOF/MS. Finally, the potential regulatory enzymes that could be the possible new therapeutic targets of Met were selected and validated by western blotting and immunohistochemistry based on the screened differential metabolites and the enrichment analysis. Met effectively reduced the infarct size of myocardial infarction mice, improved the biochemical indicators, and ameliorated the cardiac function and pathological conditions. Our study further found that Met could regulate the pathways of glycine, serine and threonine metabolism, cysteine and methionine metabolism, purine and pyrimidine metabolism under the pathological conditions of MI. Moreover, several regulatory enzymes involved GATM, CSE and NT5E were demonstrated to be regulated by Met. This study constructed the regulatory metabolic network map of Met, elucidated the endogenous metabolic pathway regulated by Met, and validated the new potential therapeutic targets of Met in MI, which might provide a further reference for the clinical application of Met.

Impact of metoprolol standard dosing pathway in Chinese patients with acute coronary syndrome: protocol for a multicentre prospective study

INTRODUCTION

Metoprolol is the most frequently used β-receptor blockers; however, the prescribed dose in China is far less than the recommended doses in the guidelines. Based on the Chinese and International guidelines and the Chinese clinical practice, we are conducting this study (NCT03413410) to test the feasibility and tolerability of the metoprolol optimal dosing pathway by observing the percentage of patients achieving target dose in Chinese acute coronary syndrome (ACS) patients during hospitalisation.

METHODS AND ANALYSIS

A total of about 1000 patients aged ≥18 years, hospitalised for ACS will be enrolled from ~15 hospital sites in China between February 2018 and April 2019. The percentage of patients achieving the target metoprolol dosage at discharge is the primary endpoint. The secondary endpoints included the following: mean heart rate (HR) and blood pressure (BP) of the patients who have achieved target dose at discharge and during the follow-up period, percentage of patients experiencing bradycardia (HR <50 beats/min), hypotension (BP <90/60 mm Hg) and drug-related temporary heart failure worsening during hospitalisation and 1 month after discharge, respectively. We will also assess the proportion of patients reporting metoprolol-related adverse events and the leading causes for metoprolol discontinuation.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Ethics committee of the Chinese PLA General Hospital (number: S2017-112-01). Study findings will be disseminated through presentations at national and international conferences and submitted for publications in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov registry (NCT03413410).