Long-term effects of upstream therapy on paroxysmal atrial fibrillation in patients without overt heart diseases.

Most paroxysmal atrial fibrillation (PAF) ultimately becomes chronic atrial fibrillation (CAF), even in the presence of antiarrhythmic drugs. Upstream therapies such as calcium channel blockers (CCB), angiotensin-converting enzyme inhibitors (ACEI), or statins have attracted attention for treating AF patients. We have previously reported that ACEI inhibited the progression of PAF to CAF. CCB and statins were also reported to inhibit the development of AF, but the follow-up periods in several of the papers appeared to be too short to allow a clear verdict on the antiarrhythmic effects. We therefore conducted a retrospective analysis of the relationship between long-term treatment (over 5 years) with an ACEI, CCB, or statin and outcome in patients with PAF (n = 125).The follow-up period was 7.7 +/- 3.1 years. Class I antiarrhythmic drugs were prescribed for 76.6% of the patients, ACEI for 36.0%, CCB for 47.2%, and statins for 20.0%. We assessed the cardiac rhythm from the medical records or electrocardiograms and determined the time from the first visit to the development of CAF. Kaplan-Meier analysis showed that the use of an ACEI significantly decreased the cumulative probability of CAF, while class I antiarrhythmics, CCB, and statins did not inhibit progression to CAF. Multivariate analysis showed that only ACEI was related to a reduced progression to CAF (odds ratio, 0.112; 95% confidence interval, 0.034 to 0.374, P = 0.001). Class I antiarrhythmic drugs, CCBs, and statins showed no such association.ACEI thus appear to be superior to CCB or statins with respect to upstream therapy.