• Trading off harms and benefits – distinctions matter for beta-blockers in the elderly

    Such an important study in JAMA Internal Medicine. “Association of β-Blockers With Functional Outcomes, Death, and Rehospitalization in Older Nursing Home Residents After Acute Myocardial Infarction“:

    Importance  Although β-blockers are a mainstay of treatment after acute myocardial infarction (AMI), these medications are commonly not prescribed for older nursing home residents after AMI, in part owing to concerns about potential functional harms and uncertainty of benefit.

    Objective  To study the association of β-blockers after AMI with functional decline, mortality, and rehospitalization among long-stay nursing home residents 65 years or older.

    Design, Setting, and Participants  This cohort study of nursing home residents with AMI from May 1, 2007, to March 31, 2010, used national data from the Minimum Data Set, version 2.0, and Medicare Parts A and D. Individuals with β-blocker use before AMI were excluded. Propensity score–based methods were used to compare outcomes in people who did vs did not initiate β-blocker therapy after AMI hospitalization.

    Main Outcomes and Measures  Functional decline, death, and rehospitalization in the first 90 days after AMI. Functional status was measured using the Morris scale of independence in activities of daily living.

    Beta blockers are so “standard of care” after having a heart attack, I barely think about them when I hear about them. But they aren’t used as much for older nursing home residents because of concerns over how much they might really benefit versus how much they might harm them. This study, therefore, sought to look at how beta-blockers were associated with mortality and rehospitalization as well as with functional harms.

    It was a cohort study of nursing home residents, age 65 years or older, who had suffered from an acute myocardial infarction. The researchers used propensity scores to compare how those treated with beta blockers fared versus those not treated with beta blockers. The main outcomes of interest were independence in activities of daily living, rehospitalization in the 90 days after their MI, and death.

    The cohort consisted of more than 11,000 women and more than 4500 men, with an average age of 83 years. The propensity matching left an analysis of about 55oo users of beta-blockers versus about 11,000 non-users.

    Those who used beta blockers had about the same rate of rehospitalization as those who didn’t (HR 1.06, 95% CI 0.98-1.14). So no difference there.

    Those who used beta blockers had a significantly lower rate of death (HR 0.74, 95% CI 0.67-0.83). So a definite benefit to beta blockers there.

    Those who used beta blockers had a significantly higher rate of functional decline (OR 1.14, 95% CI 1.02-1.28). So a definite harm there.

    BUT – that’s when it gets interesting. Those who had moderate to severe cognitive impairment or severe functional dependency to begin with were even more likely to experience functional decline (OR 1.32-1.34). But those with intact cognition or mild dementia showed no real decline (OR 1.03). The same was true for people with in the best (OR 0.99) or intermediate (1.05) tertiles of functional independence.

    The benefit in mortality, though, was the same for all subgroups of functioning and ccognition

    In other words, the definite benefits seen for those over 65 who have an acute MI are the same – and real – for all people. But the harms in terms of loss of functional independence seem confined to those who have at least moderate cognitive impairment or a severe functional dependence already. For the latter group, there are clearly tradeoffs to using beta blockers. They gain a reduction in mortality, but at a real cost of further loss of independence of living.

    But if you’re over 65, have little cognitive impairment and moderate or less functional dependence, then treatment with beta blockers may extend your life and not really harm your independence. That’s an important distinction – and one worth discussing with your doctor.

    This is all fascinating to me because beta-blockers in the elderly were one of those clear “don’t do it so widely” things before. We may need to reevaluate that. But we need RCT evidence, not just cohort studies. We also need to know when to stop beta-blocker therapy as people cognitively or functionally decline. More research is necessary. This is clearly a complicated issue.


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