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TSUKUBA, JAPAN. In my March 2003 research report Aldosterone: Villain of the Peace?, I speculated that excess aldosterone or
cortisol was implicated in the initiation of paroxysmal atrial fibrillation (AF)
episodes and was also responsible for fibrosis of the heart tissue, eventually leading
to persistent or permanent AF. I also suggested that blocking mineralocorticoid (MC)
receptors with aldosterone antagonists (spironolactone or eplerenone) may be effective
in preventing AF episodes. Now Japanese cardiologists report that the aldosterone
antagonist eplerenone (Inspra) is effective in preventing recurrence of AF in patients
with permanent (long-standing persistent) AF who have undergone radiofrequency (RF)
catheter ablation.
Their clinical trial included 161 patients who had been in sustained AF for anywhere
from 1 to 20 years (mean of 3.4 years). The average age was 60 years and 83% were male.
Only 12% of the group had structural heart disease, so the majority had lone AF. All
participants underwent an extensive RF catheter ablation using the double-Lasso technique
and an open-irrigation catheter. A right atrial flutter ablation was also included.
Following the procedure, 55 patients were assigned to receive eplerenone (dosage not specified,
but likely 25-50 mg/day). In addition, beta-blockers, ACE inhibitors, ARBs (angiotensin
receptor blockers), and calcium channel blockers were used equally in the group of 55 patients
receiving eplerenone and in the group of 106 patients not receiving eplerenone.
At the end of 24 months of follow-up, 47% of participants were still in normal sinus rhythm
(NSR). Those who had been in permanent AF for more than 3 years were significantly less
likely to be in NSR as were patients with an enlarged left atrium. Experiencing AF during
the first 3 months following the ablation (early recurrence) was also associated with a
significantly poorer outcome. Substantially more patients in the eplerenone group (60%)
were in NSR after 24 months than in the non-eplerenone group (40%).
The Japanese researchers conclude that eplerenone therapy substantially
increases the odds of maintaining NSR after a catheter ablation for permanent AF.
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