OBJECTIVE

The objective of this study was to determine the effects of angiotensin-converting enzyme inhibition (ACEI) versus long-acting calcium-channel blockade (CCB) on atrial fibrillation (AF) in patients with hypertension.

BACKGROUND

Atrial fibrillation is the most common significant cardiac arrhythmia, and angiotensin II has been implicated in its pathophysiology.

METHODS

This was a retrospective, longitudinal cohort study from a database of 8 million people in the U.S. Patients age > or =18 years with hypertension were eligible if they filled a prescription for either an ACEI or a CCB between January 1995 and June 1999. The use of all other antihypertensive medications was permitted. Patient chronic disease burden was assessed using a modified Charlson index. Patients were matched on a propensity score generated from a logistic regression model. A survival analysis approach was used to compare the incidence of AF between groups. The final cohorts were evaluated until June 2002, and the average follow-up was 4.5 years.

RESULTS

After cohort matching, 10,926 patients were included in the analysis and divided equally into the ACEI and CCB groups. Mean patient age was 65 years. The adjusted hazards ratio (95% confidence interval [CI]) in the ACEI versus CCB groups for the entire follow-up period was 0.85 (95% CI: 0.74 to 0.97) for new-onset AF, and the adjusted incidence ratio for AF-related hospitalizations was 0.74 (95% CI: 0.62 to 0.89).

CONCLUSIONS

Angiotensin-converting enzyme inhibition was associated with a reduced incidence of AF for patients with hypertension in a usual care setting. These results need to be confirmed in a large-scale randomized clinical trial.