Eplerenone might affect atrial fibrosis in patients with hypertension

Eplerenone is reported to reduce the development of atrial fibrillation (AF). The aim of this study was to clarify the mechanism of eplerenone for AF prevention from the viewpoint of P wave morphology, which is reported to correlate with atrial fibrosis.

Thirty-five patients with hypertension, who were randomized to receive eplerenone (n = 16) or amlodipine (n = 19) for 1 year, were evaluated. P wave signal-averaged electrocardiography was recorded at baseline and 1 year after entry, and P wave duration (Ad) and P wave dispersion (P-disp) were obtained. Serum levels of intact procollagen type I N-terminal propeptide (PINP) and N-terminal procollagen-III peptide (PIIIP) were also measured.

There were no significant differences in baseline clinical characteristics including Ad, P-disp, and the decrease in blood pressure at 1-year follow-up between the two groups. Ad and P-disp (mean ± standard deviation) significantly increased in patients on amlodipine after 1 year (140 ± 21 ms to 139 ± 19 ms vs 132 ± 10 ms to 136 ± 12 ms, P < 0.01 and 14 ± 7 ms to 9 ± 4 ms vs 12 ± 5 to 16 ± 8, P < 0.01, respectively). PINP was significantly more decreased in patients with eplerenone than amlodipine (56.6 ± 30.4 μg/mL to 46.6 ± 19.4 μg/mL vs 41.5 ± 16.2 μg/L to 48.7 ± 21.3 μg/L, P < 0.01). Percent changes of Ad, P-disp, PINP, and PIIIP were significantly smaller in patients with eplerenone than amlodipine (0.0 ± 4.7% vs 3.2 ± 4.4%, P < 0.05, - 28.6 ± 31.0% vs 46.3 ± 73.0%, P < 0.01, - 5.6 ± 38.1% vs 22.7 ± 42.7%, P < 0.05, and - 9.2 ± 25.1% vs 7.4 ± 19.0%, P < 0.05, respectively).

Eplerenone reduced the increase of Ad and P-disp with a decrease of PINP and PIIIP, which might translate into reduction of atrial fibrosis. This study showed that eplerenone may be useful as upstream therapy for AF in patients with hypertension.