Comparative effectiveness of angiotensin-receptor blockers for preventing macrovascular disease in patients with diabetes: a population-based cohort study

Background — Telmisartan, unlike other angiotensin-receptor blockers, is a partial agonist of peroxisome proliferator–activated receptor-γ, a property that has been associated with improvements in surrogate markers of cardiovascular health in small trials involving patients with diabetes. However, whether this property translates into a reduced risk of cardiovascular events and death in these patients is unknown. The researchers sought to explore the risk of myocardial infarction, stroke and heart failure in patients with diabetes who were taking telmisartan relative to the risk of these events occurring in patients taking other angiotensin-receptor.

Methods — The researchers conducted a populationbased, retrospective cohort study of Ontario residents with diabetes aged 66 years and older who started treatment with candesartan, irbesartan, losartan, telmisartan or valsartan between Apr. 1, 2001, and Mar. 31, 2011. The primary outcome was a composite of admission to hospital for acute myocardial infarction, stroke or heart failure. The researchers examined each outcome individually in secondary analyses, in addition to all-cause mortality.

Results — The researchers identified 54 186 patients with diabetes who started taking an angiotensinreceptor blocker during the study period. After multivariable adjustment, patients who took either telmisartan (adjusted hazard ratio [HR] 0.85, 95% confidence interval [CI] 0.74–0.97) or valsartan (adjusted HR 0.86, 95% CI 0.77–0.95) had a lower risk of the composite outcome compared with patients who took irbesartan. In contrast, no significant difference in risk was seen between other angiotensin-receptor blockers and irbesartan. In secondary analyses, the researchers found a reduced risk of admission to hospital for heart failure with telmisartan compared with irbesartan (adjusted HR 0.79, 95% CI 0.66– 0.96), but no significant differences in risk were seen between angiotensin-receptor blockers in the other secondary analyses.

Interpretation — Compared with other angiotensin-receptor blockers, telmisartan and valsartan were both associated with a lower risk of admission to hospital for acute myocardial infarction, stroke or heart failure among older adults with diabetes and hypertension. Telmisartan and val sartan may therefore be the preferred angiotensin-receptor blockers for use in these patients.