A systematic review including 7 studies with a total of 24,849 subjects was abstracted in DARE. There was a significant difference in the development of atrial fibrillation (new-onset or recurrence post-cardioversion) in favour of treatment with ACEIs or ARBs compared with control (OR 0.57, 95% CI: 0.39 to 0.82). There was significant heterogeneity across the studies. A subgroup analysis of studies that included higher risk patients (those with left ventricular dysfunction or previous documented atrial fibrillation; n=7,250) showed that there was a significant benefit of treatment with ACEIs or ARBs compared with control (OR 0.42, 95% CI: 0.27 to 0.66).
Comment: The quality of evidence is downgraded by inconsistency (variability in results across studies) and by indirectness (combining ACEIs and ARBs in the meta-analysis may not be appropriate).