Beta-blocker use following MI confirmed
A French observational study has found that use of a beta-blocker early after myocardial infarction (MI) (within 48 hours) is associated with a substantial reduction in 30-day mortality in people who do not have heart failure. However, continuing with beta-blockers was not associated with a significant reduction in mortality at 1 year. In addition, stopping beta-blocker treatment in the year after an MI did not appear to affect mortality at 5 years.
A total of 2679 people with MI who did not have heart failure or left ventricular systolic dysfunction ( LVSD) were included in the study. Data came from the nationwide French registry of Acute ST-elevation and non-ST-elevation Myocardial Infarction (Fast-MI), and from physicians, patients or their families, discharge letters and other supportive documents.
Key result are summarised in the Table. The beneficial effects seen from early beta-blocker use and 30-day mortality in people without heart failure or LVSD are consistent with the NICE guideline on myocardial infarction www.nice.org.uk/guidance/cg172, which recommends that people should be offered a beta-blocker as soon as possible after an MI, when they are haemodynamically stable. The lack of a detrimental effect on 5-year mortality from stopping beta-blocker treatment at 1 year in people without heart failure or LVSD suggests that it might be worth considering whether continued beta-blocker treatment needs to be reviewed in these people after a year. This is consistent with the NICE guideline, which recommends that beta-blocker treatment should be continued indefinitely only in people who have LVSD. However, the lack of a statistically significant reduction in mortality seen after a year in people who were discharged on beta-blockers adds uncertainty about the optimum duration of beta-blocker treatment after an MI.
Table: Key results from the study.
These results are consistent with recent NICE guidance and suggest that stopping beta-blocker treatment in the year after an MI does not appear to affect mortality at 5 years in contrast to the increase in 5-year mortality seen when statin treatment is stopped. However the limitations of using observational data to guide clinical decisions should be remembered.
Puymirat E, et al. β blockers and mortality after myocardial infarction in patients without heart failure: multicentre prospective cohort study. BMJ 2016;354:i4801. www.bmj.com/content/354/bmj.i4801