NEW YORK (Reuters Health) – When it comes to preventing atrial fibrillation, not all antihypertensive agents are created equal. New research suggests that angiotensin-converting enzyme (ACE) inhibitors, angiotensin II-receptor blockers (ARBs), and beta-blockers are all superior to calcium channel blockers in the reducing the risk.
Compared with calcium channel blockers, each of these agents reduces the risk of this common arrhythmia by around 25%, the findings indicate.
Hypertension is one of the primary predisposing factors for atrial fibrillation. However, little information is available regarding prevention of atrial fibrillation, and current opinions differ on the effect of various blood-pressure-lowering drugs on risk for the arrhythmia, authors point out in the January 19th Annals of Internal Medicine.
Senior author Dr. Christoph R. Meier, from University Hospital Basel, Switzerland, looked into this issue using the UK’s General Practice Research Database. Their nested case-control analysis included patients ages 20 to 79 undergoing treatment for hypertension and excluded patients with risk factors for atrial fibrillation (history of any arrhythmia, congestive heart failure, ischemic and valvular heart disease, thyrotoxicosis, alcoholism, or chronic obstructive pulmonary disease).
From a study population of around 680,000 patients, 4661 cases were first diagnosed with atrial fibrillation between 1998 and 2008. The authors matched 18642 control patients for age, gender, general practice, and calendar time. Diagnosis and treatment of hypertension had to precede the index date, at which time nearly two-thirds of patients were at least 70 years old. Forty-seven percent of patients were male.
The investigators note that they focused their analysis “on patients who received only one type of antihypertensive drug (with or without a diuretic), because these patients were likely to have mild to moderate hypertension that required only monotherapy.”
Models were adjusted for body mass index and smoking status, as well as comorbidities or drugs that could affect the risk of arrhythmia. The reference group of patients were treated with calcium-channel blockers.
In comparison, current use of other antihypertensives for at least a year was associated with a lower risk of atrial fibrillation. Adjusted odds ratios were 0.75 for ACE inhibitors, 0.71 for ARBs, and 0.78 for beta-blockers (p < 0.004 for each).
Patients who received other drugs along with ACE inhibitors or ARBs did not have lower risk of atrial fibrillation.
Dr. Meier’s team acknowledges that a limitation of the study is lack of data regarding blood pressure control. Moreover, “general health status and severity of hypertension may have differed across patients who used different antihypertensive study drugs.”
Ann Intern Med 2010;152:78-84.
