Relevance of post-MI use of beta-blockers and MRA, reveals new study

USA: The effects of beta-blocker therapy on survival after myocardial infarction (MI), when analyzed dichotomously, on (all doses) did not demonstrate overall improvement versus off beta‐blocker therapy. Mineralocorticoid receptor antagonists (MRA) have a proven benefit for patients with LV dysfunction after STEMI but continue to be underused. 

These are the conclusion from two recent studies published in the Journal of the American Heart Association. The studies explored the use of two older classes of drugs in patients who have had an MI and raise questions about their relevance in the current era, following decades of advancements in care. 

"There appeared to be a dose dependence of the benefit of beta‐blocker therapy on survival, even beyond 1 year after myocardial infarction, with benefit noted at one quarter the dose targeted in clinical trials demonstrating the benefit of beta‐blocker therapy," wrote the authors of beta-blockers analysis. "There is a signal for continued benefit of beta‐blocker therapy that requires further elucidation in prospective trials."

It is necessary to consider the roll of beta-blocker therapy, given the tremendous advances that have been made in the management of acute MI and psot-MI treatments. However, the relevant question is no longer whether all patients with acute MI should be treated with beta‐blockers.

The OBTAIN study9 and this substudy support the need for a new paradigm that addresses which patients should be treated, for how long, and at what dose. An important role for personalized medicine in the management of this diverse patient population must be incorporated. Further randomized clinical trials are required to prospectively test dosing and treatment durations for beta‐blocker therapy following acute MI.

"Clinicians need to be continuously reevaluating what they're doing in this setting, in which the mix of available treatments changes frequently," Ricky Turgeon, PharmD (University of British Columbia, Vancouver, Canada), senior author of the MRA analysis told TCTMD

"When we get newer therapies, we need to not forget about the old therapies and understand how these all interplay and interact together," he said. "With all of the new interventions that are coming out for these patients, and with increasing complexity with the different antithrombotics and other therapies, we need to really not look at this as a sort of grocery list of therapies that we could use, but really see which combination is optimal for patients."

"In our contemporary regional STEMI cohort, only 1 in 4 MRA‐eligible patients were prescribed an MRA within 3 months following hospitalization, despite high‐quality evidence that early use reduces mortality. Aside from lower LVEF and calendar year, MRA utilization was not associated with any patient‐ or institutional‐level characteristics, suggesting unexplained variability in clinical practice," wrote the study authors. "Novel decision‐support tools are required to optimize guideline‐directed therapy decisions during hospitalization and follow‐up to target this gap in post‐STEMI care." 

Reference:

1) The study titled, "One‐Year Landmark Analysis of the Effect of Beta‐Blocker Dose on Survival After Acute Myocardial Infarction," is published in the Journal of the American Heart Association.

DOI: https://www.ahajournals.org/doi/full/10.1161/JAHA.120.019017

2) The study titled, "Predictors of the Use of Mineralocorticoid Receptor Antagonists in Patients With Left Ventricular Dysfunction Post‐ST‐Segment–Elevation Myocardial Infarction is published in the Journal of the American Heart Association.

DOI: https://www.ahajournals.org/doi/full/10.1161/JAHA.120.019167