Early beta-blocker use may reduce 30-day mortality in patients with acute MI
Patients receiving early beta-blockers had a 30-day mortality rate of 2.3%, compared with 8.6% in those who did not, the study found.
Providing beta-blockers to patients with acute myocardial infarction (MI) within the first 48 hours of hospitalization may reduce 30-day mortality, but the survival benefits appear to dwindle after 1 year of use, a recent study found.
Using a national French registry, researchers assessed all-cause mortality in 2,679 consecutive patients with acute MI (without heart failure or left ventricular dysfunction) admitted to 223 centers in 2005. They analyzed 30-day mortality in relation to early beta-blocker use (≤48 hours of admission), 1-year mortality in relation to prescription at discharge, and 5-year mortality in relation to 1 year of use. Results of the prospective cohort study were published online on Sept. 20 by The BMJ.
Of 2,679 patients, 2,050 (76.5%) received early beta-blockers, and these patients were younger than those who did not, with a lower GRACE risk score and fewer comorbidities. Patients receiving early beta-blockers had a 30-day mortality rate of 2.3%, compared with 8.6% in those who did not (crude hazard ratio [HR], 0.26 [P<0.001]; adjusted HR, 0.46 [P=0.008]).
Of 2,217 patients discharged from the hospital, 1,783 (80.4%) were prescribed beta-blockers at discharge. Those who received beta-blockers were younger and had fewer comorbidities than those who did not. At 1 year, mortality rate was 3.4% in patients who were discharged with beta-blockers, compared to 7.8% in those who were not (crude HR, 0.43 [P<0.001]; adjusted HR, 0.77 [P=0.32]).
Beta-blockers were still being used in 1,230 of 1,383 patients (88.9%) alive at 1 year with prescription details available. Most patient characteristics were similar between those who discontinued beta-blockers and those who did not, except that patients who discontinued used other secondary prevention drugs less frequently. At 5 years, mortality was 7.6% in patients continuing beta-blockers at 1 year, compared with 9.2% in those who stopped (crude HR, 0.79 [P=0.41]; adjusted HR, 1.19 [P=0.57]).
Conversely, when assessing 5-year mortality of study participants who also received statins, researchers found significant differences between those who continued taking statins at 1 year and those who discontinued them. Five-year mortality was 5.8% in 1,120 patients who continued taking statins at 1 year, compared to 16.9% in the 136 patients (10.8%) who stopped (crude HR, 0.32 [P<0.001]; adjusted HR, 0.42 [P=0.001]).
The authors noted limitations to the study, such as its observational nature and how the most severely ill patients less often receive beta-blockers at the acute stage. They also could not account for potentially unmeasured confounders and did not perform a formal sample size calculation for their analysis.