The study
Researchers studied 54,186 patients with diabetes, aged 66 years or older, who started treatment with an ARB – candesartan, irbesartan, losartan, telmisartan or valsartan – between 2001 and 2011.
They hypothesised that telmisartan could be associated with a lower risk of cardiovascular events than other ARBs, based on evidence from small studies that it is associated with greater improvements in surrogate markers of CV health compared to other drugs in the class.
The primary outcome was admission to hospital for acute MI, stroke or heart failure.
The findings
Patients were followed up for a total of 107,315 person-years of treatment. After taking into account multiple confounding variables, the team found treatment with telmisartan was associated with a 15% lower risk for the primary outcome relative to irbesartan, while valsartan was associated with a 14% lower relative risk.
By contrast, there was no difference in risk of the primary outcome between irbesartan and either losartan or candesartan.
What this means for GPs
The researchers said that if confirmed, their findings could suggest telmisartan and valsartan should be chosen above other ARBs for treating hypertension in older patients with diabetes.
‘Pending confirmatory data from additional observational studies or randomised controlled trials, we suggest that a class effect may not be assumed when using angiotensin-receptor blockers for the prevention of diabetes-related macrovascular complications or heart failure, and that telmisartan and valsartan may be the preferred drugs for this indication,’ they concluded.
But an accompanying commentary warns: ‘Although [the study] has generated some intriguing results, without appropriately designed randomised controlled trials, there is scant evidence to support preferring one drug in this class over another for patients with type 2 diabetes.’
CMAJ 2013; available online 8 July
