Cardiac impact of inhaled therapy in the largest randomised placebo-controlled trial in COPD history: have we reached the SUMMIT?

COPD mortality and exacerbations in the placebo group of clinical trials over two decades: a systematic review and meta-regression

A decreasing trend in exacerbation rates has been observed in COPD. Because mortality is linked to exacerbations, it is of interest to investigate whether a similar time trend is also present in mortality rates.

We performed a systematic review of placebo groups in published randomised controlled trials. Mortality rate was modelled based on a Poisson distribution for the event counts. Adding information on mortality as well as on newly published studies on a previous database, we performed a meta-regression.

Among the 56 included studies representing 14 166 patients, an annual decrease in mortality rates of 6.1% (−0.6%, 12.6%) (p=0.073) was observed. Consistent results were obtained in subgroups as well as when adjusting for potential confounders. The correlation between exacerbation rate and mortality rate was positive but weak as well as insignificant.

In summary, analysis of randomised controlled trials in COPD patients showed a decrease in mortality in the placebo arms over the last two decades. This effect is comparable to the previously observed decrease in annual exacerbation rate. Albeit insignificant, our results suggest that care is needed in the design of new trials or when comparing results from trials published many years apart.

Analysis of the placebo arms of controlled trials in COPD patients showed a decrease in mortality of 6% over the last two decades. This is comparable to the decrease in exacerbations. However, the decrease in mortality was insignificant.https://bit.ly/3opvouS

Impact of pre-enrolment medication use on clinical outcomes in SUMMIT

In mortality trials including patients with COPD and heightened cardiovascular risk, patients' treatments before entering the trial may affect the effects of inhaled medications during the studyhttp://ow.ly/WRRb30nwyIE

The impact of prior treatment on results of clinical trials in chronic obstructive pulmonary disease (COPD) has been debated. We used data from the Study to Understand Mortality and Morbidity in COPD Trial to examine the impact of prior treatment on the effects of randomised study drugs on mortality and exacerbations.

We used data on 16 417 patients with moderate COPD and heightened cardiovascular risk and information on prior medications to examine the effects of fluticasone furoate (FF), vilanterol (VI) and combined FF/VI compared to placebo on moderate and severe exacerbation as well as mortality. The study was event-driven with a median study exposure of 1.8 years. This study was registered with ClinicalTrials.gov, number NCT01313676.

There were no consistent associations between treatment prior to study entry and the effects of FF, VI or FF/VI on exacerbations during the study. However, patients taking inhaled corticosteroids and one or more bronchodilators prior to study entry seemed to have a better effect of active treatments than of placebo on mortality (hazard ratio for FF/VI 0.65, 95% CI 0.48–0.89). Survival in those randomised to placebo was independent of treatment prior to study enrolment.

Prior treatment appears to affect treatment effects on mortality but not exacerbations in a randomised controlled trial of patients with COPD and heightened cardiovascular risk.