Carvedilol Versus Metoprolol in the Acute Phase of Myocardial Infarction:

Abstract

Beta-adrenergic blockers provide significant cardioprotection during acute ischemia and reperfusion. To further explore the effects of additional alpha-1-adrenoceptor blockade on autonomic modulation in acute myocardial infarction (AMI), carvedilol was compared with metoprolol in the setting of primary percutaneous coronary interventions (PCI). In a prospective study, 100 consecutive patients (61.1 +/- 11 years; 23 females) undergoing primary PCI for AMI were randomly assigned to metoprolol 200 mg/day vs carvedilol 25 mg/day. The first oral dose of study drug was administered upon hospital admission, and a 24-hour ambulatory electrocardiogram was recorded. A total of 40 recordings of patients assigned to metoprolol and 39 of patients assigned to carvedilol were eligible for analysis of heart rate turbulence. Turbulence onset (TO), turbulence slope (TS), and turbulence timing were measured after ventricular premature beats (VPBs). The mean value of the 10 preceding RR intervals (mean RR) before VPBs was also measured. There were no significant differences in mean age, gender distributions, TIMI perfusion grades, left ventricular ejection fraction, site and size of infarction, duration of ischemia, and mean 24-hour heart rate between the two groups. Though the mean RR were not significantly different (metoprolol 863.1 +/- 157 ms; carvedilol 839.6 +/- 151 ms), there was a trend toward lower values of TO in the carvedilol group (-0.015 +/- 0.016 vs -0.012 +/- 0.023%; P = NS) and significantly higher values for TS in the metoprolol group (6.96 +/- 5.8 vs 5.6 +/- 4.22; P < 0.05). Turbulence timing was similar in both groups (metoprolol 5.8 +/- 2.4 vs carvedilol 6.1 +/- 2.1). In patients undergoing direct PCI for AMI, treatment with carvedilol, in contrast to metoprolol, was associated with a higher early acceleration and a lower deceleration of heart rate after VPBs, indicating differing effects on baroreceptor response due to additional alpha-1-adrenoceptor blockade. These data offer new insights into effects of a broader antiadrenergic therapy on autonomic reflexes in the acute phase of AMI.

Heart Rate Turbulence: Standards of Measurement, Physiological Interpretation, and Clinical Use

“…Different effects of selective and nonselective antiadrenergic therapy on HRT were reported (80). In a randomized study comparing metoprolol (beta 1 -blocker) and carvedilol (beta 1 -, beta 2 -, alpha 1 -blocker) in the subacute phase of myocardial infarction (MI), there was a trend toward lower TO in the carvedilol group and significantly higher TS in the metoprolol group, indicating differential effects of additional alpha 1 -adrenoceptor blockade on baroreceptor response.…”

Comparison of Pyrroloquinoline Quinone and/or Metoprolol on Myocardial Infarct Size and Mitochondrial Damage in a Rat Model of Ischemia/Reperfusion Injury

“…Despite evidence that both high-dose PQQ (15 mg/kg) 7 and metoprolol 15,22 provide substantial cardioprotection during acute ischemia and reperfusion, to our knowledge no prior in vivo studies in intact animals have been performed using a β-blocker/antioxidant combination to prevent I/R damage. Thus, we set out to determine (1) whether metoprolol is as effective as low-dose (3 mg/kg) PQQ in reducing infarct size and (2) whether the cardioprotective effects of PQQ and metoprolol are additive.…”

Type of β-blocker use among patients with versus without diabetes after myocardial infarction

“…In head-to-head trials, carvedilol has been at least as effective as metoprolol in terms of anti-ischemic effects. 12–13 While there is no inherent reason to believe that medications such as labetolol or nebivolol would not be effective in reducing the risk of adverse ischemic events after an MI, this lack of outcomes data may have affected the practice patterns of some physicians; nevertheless, these medications constituted only a small fraction of DM-friendly beta blockers in our study (6%). Further qualitative research would be informative to better understand why physicians choose one beta-blocker over another after an MI.…”

“…29–31 Although confirmation in a larger study is needed, our results suggest that the metabolic differences between different beta-blockers may have clinically important implications. As such, treating DM patients with DM-friendly beta-blockers post-MI seems to be the optimal strategy, particularly since there is no downside in terms of their cardioprotective effects 12–13 or associated costs (e.g., carvedilol is available as a generic medication and as a $4/month drug at many pharmacies 14–15 ).…”

“…Given the multiple beta-blockers available—with varying metabolic effects, similar cardioprotective properties 12–13 , and equal costs 14–15 —we studied whether providers apply this concept in clinical practice. In addition, we evaluated whether prescription of beta-blockers with unfavorable glycometabolic profile is associated with worse glycemic control post-discharge.…”