Beta blockers following acute MI may reduce mortality, increase functional decline in older adults

Nursing home residents who received beta blockers after an acute MI had a 26 percent relative reduction in 90-day mortality, according to a cohort study.

The use of beta blockers was also associated with a 14 percent relative increase in the odds of functional decline. The risk of functional decline was highest among adults with poor cognitive and functional status at baseline.

Lead researcher Michael A. Steinman, MD, of the University of California, San Francisco, and colleagues published their results online Dec. 12 in JAMA Internal Medicine.

“For nursing home residents with intact cognition or mild dementia and in those with nonsevere levels of functional dependency, we found substantial mortality benefit and no functional harms,” the researchers wrote. “Therefore, treatment is appropriate for most such patients. In contrast, for nursing home residents with extensive functional dependency or moderate to severe dementia, resolving the tradeoff between reduced mortality and increased risk for functional decline will depend on patient preferences, as expressed directly or through surrogate decision makers.”

This study included nursing home residents in the U.S. who were at least 65 years old and were hospitalized for acute MI from May 1, 2007, to March 31, 2010. They were required to have lived in a nursing home for at least 30 days before being hospitalized with acute MI and returned to a nursing home after hospital discharge. They also could not have used a beta blocker for at least four months.

The researchers obtained data from Medicare Part A and Part D claims, the Online Survey Certification and Reporting System and the Minimum Data Set, version 2.0, which consists of assessments of nearly all nursing home residents in the U.S.

The researchers used the Morris scale of independence in activities of daily living to measure functional status.

The initial cohort included 15,720 patients, including 8,953 new beta blocker users and 6,767 nonusers. The mean age was 83 years old, and 70.9 percent of the participants were women.

The researchers then performed propensity score matching, which yielded an additional 5,496 new beta blocker users and 5,496 nonusers. The mean age of these participants was 84 years old, while 70.9 percent were women.

Within three months of hospital discharge, 12.1 percent of participants had functional decline, 25.3 percent were rehospitalized and 14.0 percent died.

Beta blocker users were 14 percent more likely than nonusers to experience functional decline and 26 percent less likely to die. The rates of hospitalization were similar between users and nonusers.

Among participants with moderate or severe cognitive impairment or a high degree of functional dependence at baseline, the use of beta blockers was associated with a 32 percent to 34 percent increased odds of functional decline. Meanwhile, the use of beta blockers did not lead to a functional decline in participants with relatively preserved cognitive and functional abilities.

The researchers cited a few limitations of the study, including its observational design, which meant the study could be subject to confounding. They also excluded patients who died or were rehospitalized within 14 days of hospital discharge, so they mentioned the results pertained to the effect of beta blocker use on outcomes starting 14 days after discharge in adult survivors who remained in the nursing home until then.

“Decisions about treating older nursing home residents with [beta blockers] should consider the tradeoff between functional harms and mortality benefits,” the researchers wrote. “In this highly vulnerable group, understanding the importance that individual patients place on avoiding death and on avoiding functional decline will be critical to guiding decision making about use of these medications.”