Beta-blockers, ACEI/ARBs improve survival in revascularized AMI patients

Both beta-blockers (BBs) and angiotensin converting enzyme inhibitors/angiotensin receptor blockers (ACEI/ARBs) reduce mortality risk in patients with acute myocardial infarction (AMI) managed with revascularization, according to a recent Singapore study.

Moreover, combining both medication types seems to yield the best results, minimizing all-cause mortality and heart failure (HF) hospitalization.

“Our study findings conflict with that of other contemporary observation studies, highlighting continuing knowledge gaps in the appropriate use of BB and ACEI/ARB among patients with AMI in the current treatment era,” researchers said.

A total of 15,073 AMI patients (median age, 58 years; 83.2 percent male) were included in the present analysis, most of which had ST-elevation myocardial infarction (STEMI). All patients underwent in-hospital revascularization. More patients were on BB than ACEI/ARB medication (87.7 percent vs 74.2 percent); 66.8 percent were taking both, while <5 percent (n=742) were on neither medication. [Sci Rep 2020;10:15184]

Major adverse cardiovascular events (MACEs), defined as a composite of all-cause mortality and hospitalization for HF or MI, occurred in 11.1 percent (n=1,671) of patients at the 12-month follow-up. In terms of individual components, 4.0 percent were hospitalized for MI, 5.1 percent were admitted for HF, and 3.5 percent died.

Use of BBs at discharge significantly lowered the risk of the composite MACE endpoint (adjusted hazard ratio [HR], 0.80, 95 percent confidence interval [CI], 0.70–0.93) and all-cause mortality (adjusted HR, 0.69, 95 percent CI, 0.55–0.88).

In comparison, ACEI/ARB use lowered the likelihood of all-cause mortality (adjusted HR, 0.80, 95 percent CI, 0.66–0.98) and HF hospitalization (adjusted HR, 0.80, 95 percent CI, 0.68–0.95). Neither medication eased the risk of MI hospitalization.

Notably, taking both BBs and ACEI/ARBs had the strongest effect in reducing the risk of the composite MACE outcome (adjusted HR, 0.70, 95 percent CI, 0.57–0.86), as well as its all-cause mortality (adjusted HR, 0.55, 95 percent CI, 0.40–0.77) and HF hospitalization (adjusted HR, 0.64, 95 percent CI, 0.48–0.86) components. This analysis used the subgroup of patients who took neither medication as reference.

“Our study represents a contemporary national registry with high standards of background care in pharmacotherapy,” the researchers said. “In addition, 24-hour nationwide primary percutaneous coronary intervention has been the standard of care for STEMI in Singapore since 2007.”

“To our knowledge, our cohort is the largest registry of AMI who underwent in-hospital revascularization that study the association of BB and ACEI/ARB with MACE, allowing robust subgroup comparisons,” they added.

Nevertheless, the present findings show some degree of departure from the current literature, the researchers said. Although trials in the past have shown that ACEI/ARBs may protect against adverse outcomes in AMI patients, more contemporary observational studies have found the drug class to be of no particular benefit.

“While randomized trials of BB are ongoing in contemporarily managed AMI populations, we propose that the role ACEI/ARB treatment also be re-examined in randomized trials of patients with AMI who undergo early revascularization and are already receiving high levels of dual antiplatelet and lipid-lowering therapy,” they said.