Led by Dr. Anushka Patel, of Royal Prince Alfred Hospital in Sydney, Australia, the authors of the study examined mortality and cardiovascular risks associated with atrial fibrillation in more than 11,000 patients with Type 2 diabetes. The researchers also sought to determine whether the effects of blood pressure lowering on cardiovascular events differ between diabetics with and without atrial fibrillation.
Study participants were randomly assigned to a fixed combination of perindopril and indapamide or placebo. At baseline, 847 patients (7.6%) had atrial fibrillation. Over a mean follow-up of 4.3 years, 879 patients died, with 53% of the deaths due to cardiovascular causes.
According to the article, 15% of the deaths occurred in patients with atrial fibrillation. After multiple adjustments, associations were observed between atrial fibrillation and increased risks of all-cause mortality (hazard ratio [HR] 1.61; p < 0.0001), cardiovascular death (HR 1.77; p < 0.0001), and death from heart failure (HR 1.68; p = 0.0002). Patients with atrial fibrillation also had a higher risk of major cerebrovascular events (HR 1.68; p = 0.0008).
“Routine blood pressure lowering using a fixed combination of perindopril-indapamide produced similar relative risk reductions in cardiovascular and all-cause mortality in patients with and without atrial fibrillation,” the investigators report. “However,” they add, “because of their higher risks of these events, the absolute benefits of this blood pressure-lowering treatment appear much greater in patients with atrial fibrillation.”
The researchers estimated that five years of active blood pressure lowering treatment would prevent one death among every 39 patients with atrial fibrillation or among every 84 patients without the arrhythmia. To prevent one cardiovascular death, the number needed to treat for five years is 42 patients with atrial fibrillation versus 120 patients without it.
Eur Heart J 2009;30:1128-1135.