OBJECTIVE: Empirical results indicate an increased risk for cardiovascular (CV) adverse drug events (ADE) in chronic obstructive pulmonary disease (COPD) patients treated with beta-2-agonists (B2A) and muscarinic antagonists (MA). A systematic review (including a meta-analysis for drug classes with sufficient sample size) was conducted assessing the association between B2A or MA and acute myocardial infarctions (MI) in COPD patients.
METHODS: Comprehensive literature search in electronic databases (MEDLINE, Cochrane database) was performed (January 1, 1946-April 1, 2013). Results were presented by narrative synthesis including a comprehensive quality assessment. In the meta-analysis, a random effects model was used for estimating relative risk estimates for acute MI.
RESULTS: Eight studies (two systematic reviews, two randomized controlled trials, and four observational studies) were comprised. Most studies comparing tiotropium vs. placebo showed a decreased MI risk for tiotropium, whereas for studies with active control arms no clear tendency was revealed. For short-acting B2A, an increased MI risk was shown after first treatment initiation. For all studies, a good quality was found despite some shortcomings in ADE-specific criteria. A meta-analysis could be conducted for tiotropium vs. placebo only, showing a relative risk reduction of MI (0.74 [0.61-0.90]) with no evidence of statistical heterogeneity among the included trials (I(2) = 0%; p = 0.8090).
CONCLUSIONS: An MI-protective effect of tiotropium compared to placebo was found, which might be attributable to an effective COPD treatment leading to a decrease in COPD-related cardiovascular events. Further studies with effective control arms and minimal CV risk are required determining precisely tiotropium's cardiovascular risk.
