Carvedilol and metoprolol are both able to preserve myocardial function in type 2 diabetes. Issue 5 (13th March 2020)

• Record Type: Journal Article
• Authors: Bussey, Carol T.; Babakr, Aram A.; Iremonger, Rachael R.; van Hout, Isabelle; Wilkins, Gerard T.; Lamberts, Regis R.; Erickson, Jeffrey R.
• Is Part Of: Physiological reports. Volume 8:Issue 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-03-13
• Subjects: carvedilol -- metoprolol -- myocardial -- Type 2 diabetes -- β‐blocker; Physiology -- Periodicals; 571
• DOI: 10.14814/phy2.14394
• Languages: English
• ISSNs: 2051-817X

Abstract

Abstract: Purpose: Increasing cohorts of patients present with diabetic cardiomyopathy, and with no targeted options, treatment often rely on generic pharmaceuticals such as β‐blockers. β‐blocker efficacy is heterogenous, with second generation β‐blocker metoprolol selectively inhibiting β1 ‐AR, while third generation β‐blocker carvedilol has α1 ‐AR inhibition, antioxidant, and anti‐apoptotic actions alongside nonselective β‐AR inhibition. These additional properties have led to the hypothesis that carvedilol may improve cardiac contractility in the diabetic heart to a greater extent than metoprolol. The present study aimed to compare the efficacy of metoprolol and carvedilol on myocardial function in animal models and cardiac tissue from patients with type 2 diabetes and preserved ejection fraction. Methods: Echocardiographic examination of cardiac function and assessment of myocardial function in isolated trabeculae was carried out in patients with and without diabetes undergoing coronary artery bypass grafting (CABG) who were prescribed metoprolol or carvedilol. Equivalent measures were undertaken in Zucker Diabetic Fatty (ZDF) rats following 4 weeks treatment with metoprolol or carvedilol. Results: Patients receiving carvedilol compared to metoprolol had no difference in cardiac function, and no difference was apparent in myocardial function between β‐blockers. Both β‐blockers similarly improved myocardial function in diabetic ZDF rats treated for 4 weeks, without significantly affecting in vivo cardiac function. Conclusions: Metoprolol and carvedilol were found to have no effect on cardiac function in type 2 diabetes with preserved ejection fraction, and were similarly effective in preventing myocardial dysfunction in ZDF rats. Abstract : In this manuscript, we present data comparing the effects of carvedilol and metoprolol on in vivo and in vitro cardiac function in both diabetic and non‐diabetic human patients, as well as in a rat model of type 2 diabetes (Zucker Diabetic Fatty rats). Our data demonstrate that both carvedilol and metoprolol are able to improve the contractility of cardiac muscle from diabetic humans and rats, as well as preserving cardiac function in both models. Importantly, we saw no extra improvement in individuals or animals that received carvedilol over those who received metoprolol, suggesting that any improvement in health outcomes provided by carvedilol (as seen in the COMET study) are not derived from differences in the contractile function of the cardiac muscle.