Somewhat Charming Results from CHARISMA: Beta-Blockers Linked with Improved Outcomes in Some Patients
Journal Wrap | For patients with a prior myocardial infarction (MI), but without heart failure (HF), beta-blocker use was associated with a lower risk of recurrent MI and lower composite cardiovascular outcomes, according to results from the CHARISMA trial recently published in Circulation: Cardiovascular Quality and Outcomes. Patients without a prior MI, however, did not derive the same benefits.
While beta-blockers are "widely regarded as one of the most important therapies in clinical medicine of the 20th century," Sripal Bangalore, MD, MHA, and study co-authors wrote, their role in the long-term reduction of cardiovascular outcomes remains controversial. With this in mind, the researchers for the CHARISMA trial conducted a post-hoc analysis of participants without HF, including:
- 4,772 patients with prior MI
- 7,804 patients with known atherothrombosis
- 2,101 patients with risk factors for cardiovascular disease
Patients were stratified within their cohort based on baseline beta-blocker use.
Researchers conducted a propensity score analysis within each cohort to determine the effects of prior beta-blocker use and the primary study endpoint (a composite of nonfatal MI, stroke from any cause, or cardiovascular death).
After a median follow-up of 28 months, beta-blocker use was associated with a 31% lower risk of the primary outcome in the propensity score-matched prior MI cohort (70 [7.1%] vs. 100 [10.2%]; HR = 0.69, 95% CI 0.50-0.94; p = 0.021). This risk reduction was driven primarily by a reduction in recurrent MI risk (33 [3.4%] vs. 48 [4.9%]; HR = 0.62, 95% CI, 0.39-1.00; p = 0.049), although there was no reduction in mortality.
Additionally, researchers observed a trend toward elevated risk for stroke in individuals without MI who took beta-blockers, compared with those who did not use beta-blockers.
In the cohorts of patients with known atherothrombosis and with cardiovascular risk factors alone, beta-blocker use was not associated with a lower rate of cardiovascular events. The risk factor–alone cohort had a trend toward higher risk for stroke with beta-blocker use (3.5% for users vs. 1.5% for non-users; HR = 2.13; 95% CI 0.92-4.92). That risk became significant in the propensity score–adjusted regression models (HR = 2.69; 95% CI 1.33-5.44; p = 0.006).
"In patients without previous events but with multiple cardiovascular risk factors, there is a concern that these agents might increase the risk of stroke," the authors wrote. "Randomized controlled trials are needed to evaluate the efficacy of newer beta-blockers with vasodilating properties in patients without HF or left ventricular systolic dysfunction."
- Bangalore S, Bhatt D, Steg G, et al. Circ Cardiovasc Qual Outcomes. 2014 September 30. [Epub ahead of print]
Keywords: CardioSource WorldNews Interventions
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