atrial fibrillation ( af ) is the most common sustained cardiac arrhythmia and a major cause of substantial mortality and morbidity from stroke , thromboembolism , and heart failure , leading to an impaired quality of life.1 - 5 ) with the increase of elderly population in the developed world , the prevalence of af is increasing , resulting in a major public health problem.6 ) maintenance of sinus rhythm is the main therapeutic goal in patients with af . radiofrequency catheter ablation ( rfca ) for af has been proposed as an effective therapeutic option for af that is resistant to pharmacologic rhythm or rate control , with successful long - term maintenance of sinus rhythm in the absence of treatment with anti - arrhythmic drugs reported in the majority of patients.7 ) however , the recurrence of af after rfca is not uncommon . the recurrence rate of af after rfca has been reported to be between 30 and 40% , depending on the ablation strategy and the type of af.7 - 10 ) some investigators have reported that the left atrial diameter / volume and hypertension are predictors of af recurrence after rfca.11)12 ) recent research has focused increasingly on atrial structural remodeling and electrical dysfunction , which underlie the development of af in different pathologic conditions.13 - 17 ) a particular interest has been generated in the role of renin - angiotensin system ( ras ) blockade in reversing the electrical and structural remodeling of diseased atria . angiotensin - converting enzyme inhibitors ( aceis ) are known to suppress structural and functional remodeling and prevent the induction and promotion of af in chronic rapid atrial pacing dogs.18 ) in several animal models , it has been suggested that angiotension ii type 1 receptor blockers ( arbs ) might be useful for preventing af recurrence after the termination of sustained af by decreasing interstitial fibrosis.19)20 ) however , there is still uncertainty about the role of aceis and arbs for the reduction of af recurrence after rfca in clinical practice . this study was aimed to evaluate the effect of aceis and arbs on the recurrence of af after rfca . we retrospectively evaluated 152 patients ( mean age , 5710 years ; m : f=94 : 58 ) who underwent af ablation due to drug - refractory paroxysmal ( mean age , 5710 years ; m : f=58 : 43 ) or persistent af ( mean age , 5610 years ; m : f=36 : 15 ) . among the 152 patients , 101 had paroxysmal af ( paf ) and 51 had persistent af ( peaf ) . paf was defined as the occurrence of two or more episodes of af during the previous 12 months , typically lasting < 7 days and terminating spontaneously . peaf was defined as the occurrence of af episodes lasting < 7 days , and typically requiring cardioversion for restoration of normal sinus rhythm . the af ablation strategy was 3d mapping ( carto)-guided circumferential ablation , pulmonary vein ostial ablation , and roof line , mitral valve isthmus , and right cavotricuspid isthmus block . , the patients were followed 1 - 2 weeks later , and then visited our hospital every 1 - 3 months during the first year after rfca . whenever the patients visited our clinic , a history was taken and a physical examination was performed . additionally , a 12-lead electrocardiography ( ecg ) and 24-hour ambulatory holter ecg monitoring ( 24 hours holter monitoring ) were obtained . thereafter , we immediately checked a 12-lead ecg and 24 hours holter monitoring if the patients complained of symptoms , such as palpitations that suggest af . twenty - four hours holter monitoring was also performed on asymptomatic patients every 6 months . recurrence was defined if the patients showed af on a 12-lead ecg and/or on 24 hours holter monitoring , or complained of typical episodes of palpitation sat the 3-month follow - up visit after rfca . we compared the recurrence rates between the paf and peaf groups that received aceis or arbs . aceis or arbs were prescribed at least 1 month prior to ablation and for the duration of the follow - up . the statistical package for social sciences ( spss ) for windows , version 15.0 ( chicago , il , usa ) was used for all analyses . the continuous variables are presented as the mean valuesstandard deviations ( sds ) and were compared using paired or unpaired student 's t - tests . the statistical package for social sciences ( spss ) for windows , version 15.0 ( chicago , il , usa ) was used for all analyses . the continuous variables are presented as the mean valuesstandard deviations ( sds ) and were compared using paired or unpaired student 's t - tests . the paf and peaf groups , with or without aceis or arbs , were similar with respect to important baseline clinical characteristics ( table 1 and 2 ) . furthermore , there was no difference in medications , including anti - arrhythmic drugs other than aceis / arbs for the paf and peaffgroups ( table 3 and 4 ) in paf patients , no significant differences existed in the recurrence rates between the group with aceis or arbs and the group without aceis or arbs ( 24.2% vs. 22.9% , p=0.87 ) ( fig . 1 ) . however , in peaf patients , compared with the group not using aceis or arbs , the recurrence rate was significantly decreased in the group using aceis or arbs ( 12.1% vs. 61.1% , p<0.01 ) ( fig . the left atrium dimension ( 44.28.4 mm vs. 44.35.8 mm , respectively , p=0.45 ) and the left ventricle ejection fraction ( 626.5% vs. 61.56.2% , respectively , p=0.28 ) were not significantly different . in multivariate analysis , the use of aceis or arbs was independently associated with recurrence after adjusting for the left atrium dimension and the left ventricle ejection fraction ( or=0.078 , 95% ci=0.02 - 0.35 , p<0.01 ) . the paroxysms of af are consistently initiated by a spontaneous firing focus arising from several sites , including the pulmonary veins,21 - 24 ) the vein of marshall,25 ) the coronary sinus,23)26 ) the crista terminalis,23)26 ) the superior vena cava , and the inferior vena cava . however , electrophysiologic remodeling is commonly observed and is probably an important factor contributing to the persistence of af . in addition to eletrophysiologic remodeling , structural remodeling , such as fibrosis ( at both the subcellular and tissue levels ) is also often present and contributes to the altered tissue substrate that promotes af maintenance.27 ) although there are many anti - arrhythmic drugs available to maintain sinus rhythm and reduce the ventricular rate , there is no drug which can control af effectively . because rfca can effectively treat patients with drug - refractory af , rfca has emerged as a major treatment option for af . however , this procedure is limited by a significant rate of af recurrence and the effect of rfca on patients with peaf is not as effective as on paf . this phenomenon may be caused by structural and electrical remodeling of the atrium during the long period of af . several experimental studies have demonstrated that atrial cells express all components of ras in a pig model of af,28 ) remodeling of the atrium correlated with a high level of angiotensin in atrial tissue , and blockade of ras through aceis or arbs can reverse atrial remodeling.13)18)29 ) nakashima et al.30 ) first demonstrated the role of aceis and arbs in preventing atrial electrical remodeling . they found that in dogs in which the atria were paced at 800 beats / min , candesartan and captopril prevented the atrial effective refractory period from shortening . in the current study , the overall recurrence rate after ablation therapy was 26% ( n=39 ) the recurrence rate was significantly decreased in the peaf group that used aceis or arbs ( 12.1% vs. 61.1% , p<0.01 ) . this result might be caused by the effect of aceis or arbs on alteration of left atrial remodeling and reduction of interstitial fibrosis through ras blockade . however , this difference in the recurrence rate was not observed in paf patients ( 24.2% vs. 22.9% , p=0.87 ) . we presume that the reason for this outcome might be caused by difference of pathophysiologic mechanisms between paf and peaf . that is to say , paf is mainly triggered by electric foci , but electrophysiologic or structural remodeling underlie peaf . therefore , aceis or arbs which can alter remodeling , played an important role in reducing the recurrence rate of peaf , but not paf . aceis or arbs might be effective in preventing af recurrence after catheter ablation in peaf patients . aceis or arbs might be effective in preventing af recurrence after catheter ablation in peaf patients .
background and objectivesit is known that angiotensin converting enzyme inhibitors and angiotensin ii type 1 receptor blockers ( aceis and arbs , respectively ) are effective in preventing atrial fibrillation ( af ) in high - risk patients 
 . however , it is not known whether aceis and arbs are effective in preventing the recurrence of af after catheter ablation.subjects and methodsone hundred fifty - two patients ( mean age , 5710 years ; m : f=94 : 58 ) who underwent catheter ablation due to drug - refractory paroxysmal ( mean age , 5710 years ; m : f=58 : 43 ) or persistent af ( mean age , 5610 years ; m : f=36 : 15 ) were enrolled . 
 we compared the recurrence rates between the groups with and without aceis or arbs use in paroxysmal and persistent af . 
 the mean duration of follow - up was 1814 months.resultsthe overall recurrence rate after ablation therapy was 26% ( n=39 ) . 
 the recurrence rate was significantly decreased in the patients with persistent af with the use of aceis or arbs ( 12.1% vs. 61.1% , p<0.01 ) , but this difference was not observed in the patients with paroxysmal af ( 24.2% vs. 22.9% , p=0.87 ) . in patients with persistent af with and without recurrence , 
 the size of the left atrium ( 44.28.4 mm vs. 44.35.8 mm , respectively , p=0.45 ) and the ejection fraction ( 626.5% vs. 61.56.2% , respectively , p=0.28 ) were not significantly different . 
 in multivariate analysis , the use of aceis or arbs was independently associated with recurrence after adjusting for the size of the left atrium and the ejection fraction { odds ratio ( or)=0.078 , 95% confidence interval ( ci)=0.02 - 0.35 , p<0.01}.conclusionaceis and arbs were shown to be effective in preventing af recurrence after catheter ablation in patients with persistent af .