ACE Inhibitors, ARBs Lower AF Risk in Hypertension

January 08, 2014

COPENHAGEN, DENMARK (updated) — Results from a large retrospective study suggest that controlling the activation of the renin-angiotensin system (RAS) with antihypertensive medications reduces the risk of atrial fibrillation[1].

Compared with beta-blockers and diuretics, the use of ACE inhibitors and angiotensin-receptor blockers (ARBs) was associated with a significantly reduced risk of atrial fibrillation. Compared with these other agents, however, the use of ACE inhibitors and ARBs did not reduce the risk of stroke.

"The main finding of this study is that ACE inhibitors and ARBs, when used as monotherapy in hypertensive patients without heart failure, ischemic heart disease, diabetes mellitus, and hyperthyroidism at baseline, possibly can contribute to the prevention of atrial fibrillation in the long term compared with monotherapy with a beta-blocker," write Dr Sarah Marott (Copenhagen University Hospital, Denmark) and colleagues December 17, 2013 in the European Heart Journal.

The researchers point out that all classes of antihypertensive drugs may potentially reduce the risk of atrial fibrillation, but ACE inhibitors and ARBs might be particularly beneficial, given their effect on atrial remodeling. To date, however, randomized controlled trial data have shown mixed results with regard to these two drug classes on atrial fibrillation.

Large Retrospective Cohort Study

In their analysis, the Danish group matched individuals free from atrial fibrillation taking ACE-inhibitor monotherapy with 48 658 patients taking beta-blockers, 69 630 taking diuretics, 57 646 taking calcium-channel antagonists, and 20 158 taking ARB monotherapy. Conversely, they matched individuals taking ARB monotherapy with 20 566 patients taking a beta-blocker, 20 832 taking a diuretic, 20 232 taking a calcium-channel antagonist, and 20 158 taking ACE-inhibitor monotherapy.

All individuals were free of conditions such as heart failure, ischemic heart disease, and diabetes, among others, as these conditions predispose patients to atrial fibrillation.

Compared with a beta-blocker and diuretic, the use of an ACE inhibitor reduced the incidence of atrial fibrillation 88% and 49%, respectively. There was no reduction in the incidence of atrial fibrillation when those treated with ACE inhibitors were compared with those who received calcium-channel antagonists. When the same analysis was repeated with ARBs, ARB use reduced the risk of atrial fibrillation 90% and 57%, respectively, when compared with beta-blockers and diuretics. Similarly, there was no reduction in risk when ARBs were compared with calcium-channel antagonists.

When the ARB-treated patients were compared with those who received an ACE inhibitor, the risk of atrial fibrillation was reduced 32%. None of the five medication classes tested differed with regard to the risk of stroke.

Despite the findings, Marott and colleagues emphasize the limitations of their retrospective report. For example, they point out that patients might have been prescribed beta-blockers because the treating physician felt that atrial fibrillation could develop. On the whole, however, they suggest that controlling the activation of the RAS could be protective in terms of preventing atrial fibrillation.

To heartwire , Dr Franz Messerli (St Luke's-Roosevelt Hospital, New York, NY) took issue with the conclusions, stating the activity of RAS was not assessed in the study and can be considered only an extrapolation. He pointed out that beta-blockers also inhibit the RAS while calcium-channel blockers have been documented to stimulate the RAS and sympathetic nervous system. Despite this, there was no difference in the incidence of AF risk among those treated with calcium-channel blockers and RAS inhibitors, whereas the largest difference in AF incidence was observed between beta-blockers and RAS inhibitors. He told heartwire that if conclusions should be drawn for the analysis it's that controlling the activation of the RAS "has no effect on the risk of atrial fibrillation."

The authors report no conflicts of interest.


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