Evidence for CV benefits of inhaled corticosteroids in COPD ‘lacking’
MedWire News: A systematic review and meta-analysis of published studies has failed to find strong evidence to suggest that treatment with inhaled corticosteroids (ICSs) reduces risk for myocardial infarction (MI), cardiovascular (CV) death, or overall mortality in patients with chronic obstructive pulmonary disease (COPD).
ICSs are widely used in the treatment of patients with COPD, and may potentially reduce CV events and mortality among this high-risk group by alleviating systemic inflammation, explain S Singh (Johns Hopkins University School of Medicine, Baltimore, Maryland, USA) and team.
They add: “CV and mortality benefits with ICSs have been reported in observational studies in patients with COPD. However, it remains uncertain whether this beneficial effect is seen in randomized controlled trials (RCTs).”
The researchers therefore searched the literature for observational studies and long-term RCTs of at least 24 weeks duration that included data on the effects of ICSs on MI rates and mortality in COPD patients.
In total, 23 RCTs involving 23,396 participants with COPD and 12 observational studies involving more than 400,000 COPD patients and controls were included in the final analysis.
Examination of the pooled data from the RCTs revealed no significant association between ICS treatment and a reduced relative risk (RR) for MI (RR=0.95), CV-related death (RR=1.02), or overall mortality (RR=0.96) compared with placebo.
Conversely, data from the observational studies revealed that ICS use was associated with a significant reduction in CV-related death (two studies: RR=0.79), and overall mortality (11 studies: RR=0.78).
However, the researchers found evidence for publication bias regarding mortality in the observational studies.
Singh and colleagues conclude: “Our meta-analysis has found conflicting evidence on the effects of ICS therapy on cardiovascular events and mortality in patients with COPD.
“We were unable to demonstrate a significant beneficial effect of ICS therapy on MI or CV death in RCTs. In contrast, our meta-analysis showed significant relative reductions (magnitude of around 20%) in the risk of CV and all-cause mortality with ICS-exposed patients in the observational studies.”
They add: “Further research to clarify these divergent findings is clearly needed.”
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By Mark Cowen