The New England Journal of Medicine has published the results of a study that aimed to assess the efficacy of leukotriene receptor antagonists (LTRA) in controlling asthma as a first-line treatment compared to inhaled corticosteroids (ICS) or as an add-on treatment compared to long acting beta agonists (LABA). This study has been reported in the general media (Daily Mail and Daily Telegraph)
The trial was operated as two parallel, randomised, open-label studies that ran for 2 years in several centres. 306 patients were involved in the ICS versus LTRA study with 158 given an ICS and 148 given LTRA. 352 patients were involved in the LABA versus LTRA study with 182 given LABA and 170 given LTRA. Participants were aged 12 to 80 years old and had poor quality of life or asthma control.
Patients were enrolled and efficacy was assessed using the Mini Asthma Quality of Life Questionnaire (MiniAQLQ) or the Asthma Control Questionnaire (ACQ).
At a predefined early assessment conducted at 2 months, LTRA was equivalent to the comparator treatment however at the full 2 year follow up equivalence could not be demonstrated. Additionally, interpretation may be difficult due to a large proportion of crossover between treatment arms seen in the study. In the LABA versus LTRA study, a quarter of patients assigned to treatment with LTRA were either switched to or co-prescribed a LABA.
Unfortunately, media reporting of this study has exaggerated the findings with headlines stating, "Pills better for treating asthma than inhalers" and "Once-a-day asthma pill 'is more effective than inhaler'".
Action: Clinicians should be aware of this study and the exaggerated media reporting. This study provides no reason to deviate from the current British Thoracic Society Asthma Guideline.
The British Medical Journal has published the results of a meta-analysis that aimed to assess the cardiovascular safety of angiotensin receptor blockers (ARBs).
The results of some previous trials indicated a possibility that ARBs may increase the risk of myocardial infarction. This review identified 37 randomised clinical trials included 147,020 participants and had a total follow-up of 485,166 patient years. The trials included both placebo and active comparator designs. The analysis was performed on all studies and the differing design type were also analysed separately. Studies were required to have at least 100 participants and run for at least 12 months. Data were collected and analysed for several outcomes including myocardial infarction, death, cardiovascular death, angina pectoris, stroke, heart failure and new onset diabetes.
This review found that when ARBs are compared with either placebo or a control treatment there is a lesser risk of stroke, heart failure and new onset diabetes. It was also found that when ARBs are compared to placebo, and despite lower average blood pressures, there is no decrease in the risk of myocardial infarction or cardiovascular death.
The authors note that, "unlike angiotensin converting enzyme inhibitors seem not to have any special “cardioprotective” effects". They also conclude that, "this large and comprehensive analysis produced firm evidence to refute the hypothesis that angiotensin receptor blockers increase the risk of myocardial infarction".
There are some limitations to this analysis. A lack of data from the studies meant that no correction could be made for the dose of drugs used or compliance with assigned treatment. Additionally, this was not an analysis of individual patient data and therefore clinically relevant differences could have been overlooked.
Action: This analysis provides some reassurance that ARBs do not cause cardiovascular harms. However, this analysis found no beneficial effect on the rate of cardiovascular death or myocardial infarction when compared to placebo. ARBs therefore remain an alternative for consideration in patients who are angiotensin converting enzyme inhibitor (ACEI) intolerant.