Inhalers used to treat COPD carry no excess cardiovascular risk – a finding that could finally quash long-held concerns about use of the drugs in COPD patients who also have cardiovascular disease.

Researchers from the SUMMIT trial – the largest COPD outcome trial and the first to specifically enrol patients with, or at greater risk of, CVD – say the findings should reassure physicians that the drugs can be prescribed safely among the large number of patients who have been diagnosed with both conditions.

They investigated the efficacy of the once daily long acting beta₂-agonists (LABA) vilanterol, alone or in combination with inhaled corticosteroids (ICS), ICS alone, and placebo in 16,485 patients with moderate COPD and either established CVD or a high risk for the condition.

More than half of the study population had overt CVD including 51% with coronary artery disease, 17% with a history of myocardial infarction, 19% with peripheral arterial disease, and 10% with prior stroke.

There was no difference in the risk of the composite CV endpoint – sudden death, acute coronary syndrome, stroke, or transient ischaemic attack – between any of the treatment groups (HR 0.93, 95% CI 0.75 to 1.14).

Neither was there any difference between groups on treatment adverse CV events including palpitations and arrhythmias.

Whether these results represent a class effect applicable to other LABA, ICS or combination thera­pies is not yet known the authors cautioned however, they said the findings provide some of the most robust clinical trial evidence to date that an ICS, LABA and their combination appear to be safe, even among patients with CVD.

According to the researchers, the unclear safety-benefit profile of COPD therapy in patients with coexisting CVD has lingered after early trials and meta analyses gave rise to fears that LABA inhalers could heighten the risk of CV events.

But while a number of studies since have been able to explain some of those observations – shared risk factors, overlapping biological pathways and common genetic predispositions – the optimal management of patients diagnosed with both illnesses continues to be a matter of debate, because findings from newer studies are mixed, they argue.

The SUMMIT investigators noted that their findings were of ‘key clinical relevance’ because the overlap between COPD and CVD was so common.

“[Our] results indi­cate that healthcare providers should be reassured about treating patients for COPD as clinically indicated (ie, to reduce exacerba­tions) even if they are also at heightened CVD risk,” they said.