Rate Control Strategy In Patients Research Articles

Choice of sinus rhythm control strategy in patients with atrial fibrillation: why, when and how? A review

After 20 years of dubious notions of parity between sinus rhythm control and ventricular rate control strategies in patients with atrial fibrillation, there is evidence of the prognostic superiority of the former. The review article presents the results of randomized trials that support early rhythm control in patients with atrial fibrillation, possible pharmacological and non-pharmacological methods of such treatment in real clinical practice.

Abstract 12571: Optimal Rate Control Strategy in Patients With Atrial Fibrillation: A Meta-Analysis of Randomized Trials and Multivariable Adjusted Studies

Introduction: Atrial fibrillation (AF) is associated with an increased risk of impaired quality of life, stroke, and mortality. Despite multiple studies, the optimal target for rate control in AF is not definitively known. Methods: We performed a systematic review and meta-analysis comparing the effects of strict rate control (<80 bpm at rest) with a lenient rate control strategy (<110 bpm at rest) in patients with AF. The outcomes analyzed were all-cause mortality, cardiovascular (CV) death and CV hospitalization. A subgroup analysis was also performed in patients with heart failure (HF). PubMed, Scopus and Cochrane Central were searched for randomized controlled trials or observational studies with multivariable analyses adjusting for confounders. Results: Seven studies were included. All studies were either randomized or reported multivariate adjusted hazard ratios. There were 14,154 (59.6%) patients in the strict rate control strategy and 9,606 (40.4%) in the lenient group. AF was reported as paroxysmal in 1,697 (7.3%) patients. All-cause mortality was not statistically different between a strict vs. lenient heart rate control strategy, although there was a tendency towards improvement in the strict control group (HR 1.10; 95% CI 1.00-1.22; p=0.05; Figure 1A). In patients with AF and HF, there was also no significant difference between groups (HR 1.13; 95% CI 0.99-1.30; p=0.08; Figure 1B). Furthermore, CV death (HR 0.91; 95% CI 0.75-1.11) and CV hospitalization (HR 1.01; 95% CI 0.96-1.06) were also not significantly different between the two strategies. Conclusions: There was no significant difference in all-cause mortality between strict and leninent rate control in patients with AF among randomized trials or multivariable adjusted studies. In a subgroup of patients with HF, there was also no significant difference between the two rate control strategies.

Rhythm Control Better Prevents Dementia than Rate Control Strategies in Patients with Atrial Fibrillation-A Nationwide Cohort Study.

Background: Atrial fibrillation (AF) increases the risk of dementia. Whether the pharmacological rhythm control of AF can reduce the risk of dementia compared to the rate control strategy remains unclear. We hypothesize that the rhythm control strategy is better than the rate control strategy in preventing dementia. Methods: AF patients aged ≥65 years were identified from the Taiwan National Health Insurance Database. Patients receiving anti-arrhythmic drugs at a cumulative defined daily dose (cDDD) of >30 within the first year of enrollment constituted the rhythm control group. Patients who used rate control medications for a cDDD of >30 constituted the rate control group. A multivariate Cox hazards regression model was used to determine the hazard ratio (HR) for dementia. Results: A total of 3382 AF patients (698 in the rhythm control group; 2684 in the rate control group) were analyzed. During a 4.86 ± 3.38 year follow-up period, 414 dementia events occurred. The rhythm control group had a lower rate of dementia than the rate control group (adjust HR: 0.75, p = 0.031). The rhythm control strategy reduced the risk of dementia particularly in those receiving aspirin (p = 0.03). Conclusions: In patients with AF, pharmacological rhythm control was associated with a lower risk of dementia than rate control over a long-term follow-up period, particularly in patients receiving aspirin treatment.

Rhythm control in patients with atrial fibrillation and heart failure: a meta-analysis of randomized controlled trials

Abstract Background Atrial fibrillation (AF) is a common arrhythmia that can promote or worsen heart failure (HF). Limited data exist to guide treatment for patients with AF with HF regarding rate versus rhythm control. Purpose To perform a meta-analysis of randomized controlled trials (RCT) in the determination of the efficacy of rhythm control as compared to rate control among patients with AF and HF. Methods Extensive search of PubMed, Cochrane Library, Ovid, EMBASE, Google scholar, and Medline was done up to October 2020. Studies were limited to RCTs comparing rhythm control in patients with atrial fibrillation and heart failure with rate control. Outcome measures include all-cause mortality and cardiovascular mortality. Statistical analysis was done using Review manager V5.3. Results A total of 9800 patients were included in the pooled analysis of the comparison of rhythm control versus rate control strategy in patients with AF and HF. All pooled analyses were done using random effects model. The pooled risk ratio for all-cause mortality of rate control vs rhythm control did not achieve significance at 1.15, with 95% CI 0.91 to 1.45, and p=0.24. There was statistically significant heterogeneity across the two studies with I2 of 54% and p=0.02 (Figure 1A). The pooled risk ratio for cardiovascular mortality in rate control strategy vs rhythm control is 1.19, with 95% CI 0.94 to 1.50, and p=0.15 (Figure 1B). Eight trials with 9987 participants reported stroke. The pooled risk ratio of stroke in rate control vs rhythm control is 1.11, with 95% CI 0.84 to 1.46, and p=0.47 (Figure 1C). The 95% CI for the pooled risk ratio cross 1.00, indicating an equivocal result. Our results do not indicate statistical heterogeneity across the studies with I2 of 28% and p=0.27. Seven trials with 8311 participants reported bleeding. The pooled risk ratio of hospitalization for bleeding in rate control vs rhythm control is 1.18, with 95% CI 0.81 to 1.73, and p=0.39 (Figure 1D). Thus, we have insufficient evidence to demonstrate whether rate or rhythm control have significantly higher or lower risk for bleeding. Four trials with 8468 participants reported hospitalization rate. The pooled risk ratio of hospitalization in rate control compared to rhythm control is 0.96, with 95% CI 0.86 to 1.07, and p=0.42 (Figure 1E). None of the studies individually showed statistically significant differences but AF–CHF showed benefit of rate control in the first year after enrolment (p=0.001) and a tendency favouring rate control (p=0.06) when the study was analysed in full length except for AF-CHF. Conclusion Among patients with AF and concomitant HF, there is no sufficient evidence between rate and rhythm control strategies in their effects to rates of mortality and major clinical outcomes; therefore, choosing an appropriate therapeutic strategy should consider individual variations such as patient preferences, comorbidities, and treatment cost. Funding Acknowledgement Type of funding sources: None. Forest Plot A–CForest Plot D–E

Benefit of Rhythm Control Over Rate Control in Atrial Fibrillation: Does Timing Matter?

The EAST-AFNET 4 randomized trial (NCT01288352) showed a benefit of a rhythm-control strategy compared with a rate-control strategy in patients with

Rhythm or rate control strategy in CRT recipients with long-standing persistent atrial fibrillation - preliminary results of the PilotCRAfT study

Abstract Funding Acknowledgements Type of funding sources: Public Institution(s). Main funding source(s): National Institute of Cardiology in Warsaw Statutory Grant Background The presence of atrial fibrillation (AF) in cardiac resynchronization therapy (CRT) recipients is common and AF is a marker of poorer CRT response. The negative influence of AF on CRT efficacy is mediated mainly by the drop of the effectively captured biventricular paced beats percentage (BiVp%) which should exceed 95-98% to warrant good CRT response. Sinus rhythm (SR) restoration may improve CRT efficacy which in turn may protect AF recurrence. However, there is lack of randomized studies comparing rhythm and rate control strategies in these patients. Purpose The purpose of the Pilot-CRAfT study (NCT01850277) was to compare the efficacy of rhythm vs rate control strategy in CRT patients with long-standing persistent or permanent atrial fibrillation. Methods The study included patients with CRT and permanent or persistent AF lasting for ≥6 months, resulting in BiVp% <95%, who were randomly assigned to rhythm or rate control strategy. The rhythm control strategy comprised of external electrical cardioversion (EEC). The rate control strategy included pharmacotherapy and atrioventricular node ablation (AVNA) as needed. Both of the study arms received amiodarone. The follow-up lasted 12 months. The primary endpoint was the 12-month BiVp%. The patients underwent ECHO, cardiopulmonary test, quality of live (QoL) and clinical outcomes assessment. Results The study included 43 CRT patients (97,7% males) aged 68,4 (SD: ±8,3) years with mean BiVp% 82,4% ±9,7% at baseline. The mean duration of AF paroxysm was 25 ±19 months. The mean baseline left ventricular ejection fraction (LVEF), left atrium area and maximal oxygen uptake (VO2max) were: 30 ±8%, 33 ±7 cm2, 14 ±5 mL/(kg*min), respectively. The EEC was performed in 19 out of 22 patients assigned to the rhythm control arm. The immediate success rate of EEC was 58%. 42% of the rhythm control arm patients remained in SR after 12 months. In the rate control group 1 person underwent AVNA and in 1 patient spontaneous SR resumption was observed. After 12 months there was significant BiVp% increase in both the rhythm and the rate control arms (98,1 ±2,3 vs 96,3 ±3,9%, respectively. The BiVp% differences between the groups were not significant (P = 0,093). However, in the per protocol analysis, the rhythm control group had greater LVEF after 12 months as opposed to the rate control arm (36,8% vs 29,9% respectively, P = 0,039). The LVEF raised significantly in the rhythm control group (ΔLVEF 5,0 (95%CI: 1,54; 8,46)). No significant differences between the groups in the VO2max, QoL, clinical and safety end-points were noticed. Conclusions Structured follow-up of CRT patients with long-standing persistent or permanent AF leads to significant BiVp% increase exceeding 95%. The rate control strategy did not improve CRT effectivness, irrespective of high BiVp%. However limited in the efficacy, the rhythm control strategy may improve CRT outcome in these patients, resulting in LVEF increase.

Outcomes of heart failure with preserved ejection fraction after radiofrequency catheter ablation for atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Introduction. Recent randomized controlled trials have shown that in heart failure (HF) patients with reduced left ventricle ejection fraction (HFrEF) atrial fibrillation (AF) ablation reduces hospitalization and mortality due to HF compared to medical therapy (MT). However, only few studies have examined outcomes of catheter ablation (CA) for AF in HF patients with preserved left ventricle ejection fraction (HFpEF). Purpose. To compare the effect of catheter ablation on the outcomes of atrial fibrillation with chronic heart failure with preserved ejection fraction. Methods. Our prospective study included the main group (136 patients with the HFpEF who underwent a single procedure of the CA for symptomatic AF) and control group (58 patients with the HFpEF patients with paroxysmal or persistent AF on MT for rhythm and rate control strategy). To be eligible for inclusion for both groups, left ventricular diastolic dysfunction had to be present and/or relevant structural heart disease according to the current guidelines had to be fulfilled within 6 months prior to AF ablation. Outpatient follow-up were performed at 6, 12, 24 months intervals thereafter baseline. Results. At the follow-up the composite primary end point (all-cause death or worsening of HF that led to an unplanned hospitalization) appeared in significantly fewer patients in the CA group than in the MT group (18 (13,2%) patients vs. 16 (27,5%) patients; p =0,005). The secondary analyses showed there was 5 deaths in the CA group and 2 deaths in MT group, with rate of 3,7% and 3,4% respectively that were equal in comparable groups (p = 0,362). The incidences of HF hospitalization and cardiovascular hospitalization were also significantly higher in MT group than in CA group (14 (24,1%) vs. 13 (9,6%), p = 0,005) vs. 21 (15,4%), p = 0,016, respectively). Cardiovascular death and cerebrovascular accident were equal in comparable groups. The Kaplan–Meier curve for primary end-point demonstrated significant higher survival and freedom from hospitalizations due to HF in the CA group compared to MT group (p = 0,005); the freedom from hospitalization for worsening HF and the freedom from the cardiovascular hospitalization were having higher probability in the СA group (p = 0,003 and p= 0,016 ). Conclusion. Comparing catheter ablation with medical therapy for rhythm or rate control strategy in patients with heart failure with preserved left ventricle ejection fraction and atrial fibrillation, we found that catheter ablation was associated with lower rate of deaths and hospitalization due to worsening of heart failure.

Strict Versus Lenient Versus Poor Rate Control Among Patients With Atrial Fibrillation and Heart Failure (from the Get With The Guidelines – Heart Failure Program)

Randomized data suggest lenient rate control (resting heart rate <110 beats/min) is noninferior to strict rate control (resting heart rate <80 beats/min) in patients with atrial fibrillation (AF). However, the optimal rate control strategy in patients with AF and heart failure (HF) remains unknown. Accordingly, we performed an observational analysis using data from the Get With The Guidelines-HF Program linked with Medicare data from July 1, 2011, to September 30, 2014. Of 13,981 patients with AF and HF, 9,100 (65.0%) had strict rate control, 4,617 (33.0%) had lenient rate control, and 264 (1.9%) had poor rate control by resting heart rate on the day of discharge. After multivariable adjustment, compared with strict rate control, lenient rate control was associated with higher adjusted risks of death (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.11 to 1.33, p <0.001), all-cause readmission (HR 1.09, 95% CI 1.03 to 1.15, p <0.002), death or all-cause readmission (HR 1.11, 95% CI 1.05 to 1.18, p <0.001), but not cardiovascular readmission (HR1.08, 95% CI 1.00 to 1.16, p = 0.051) at 90 days. Associations were comparable in patients with poor rate control and with heart rate modeled as a continuous variable. The presence or absence of reduced ejection fraction did not impact the magnitude of most observed associations. In conclusion, in patients with HF and AF, 2 of 3 patients had a heart rate that met strict-control goals at discharge. Heart rates >80 beats/min were associated with adverse outcomes irrespective of left ventricular ejection fraction.

Comparative occurrence of ischemic stroke with the rhythm versus rate control strategy in a national prospective cohort of atrial fibrillation.

Background/AimsComparative occurrence of ischemic stroke for rhythm versus rate control strategy in patients with non-valvular atrial fibrillation (NVAF) is still inconclusive. The purpose of this study was to investigate whether the rhythm control strategy is associated with a lower risk of ischemic stroke compared to the rate control strategy in NVAF patients.MethodsThe CODE-AF registry prospectively enrolled 6,280 consecutive patients who were treated for NVAF at 10 tertiary referral centers in South Korea. Of these, 2,513 NVAF patients (age, 67 ± 10 years; male, 61.8%) were clinically followed up for over 1-year and divided into rate and rhythm control groups.ResultsThose treated with the rhythm control strategy were younger and had less proportions of underlying disease compared to those treated with the rate control strategy. After the propensity matching analysis, those treated with the rhythm control strategy had similar baseline characteristics including the CHA2DS2-VASC score compared to those treated with the rate control strategy. The rate of oral anticoagulation, all bleeding, and hospitalization were also similarly between the two groups. The incidence rate of ischemic stroke in the rhythm control group was significantly lower than in the rate control group (0.7 vs. 6.9 per 1,000 person-years, p = 0.011).ConclusionsThe rhythm control strategy demonstrated a beneficial effect to lower the risk of ischemic stroke during a 1-year follow-up compared to the rate control strategy.

Rhythm control better prevents stroke and mortality than rate control strategies in patients with atrial fibrillation - A nationwide cohort study

BackgroundAtrial fibrillation (AF) increases the risk of stroke and mortality. However, rhythm control strategy did not reduce cardiovascular risks in short-term studies. We hypothesize that rhythm control better prevents stroke and mortality than rate control in AF patients over a long-term period. MethodsAF patients aged ≥18 years were identified from Taiwan National Insurance Database. Patients using anti-arrhythmia drugs to control rhythm at a >30 defined daily dose (DDD) were defined as the rhythm control group. Patients who used rate control medications for >30 DDDs constituted the rate control group. Multivariate Cox hazards regression model was used to evaluate the hazard ratio (HR) for major adverse cardiovascular events (MACE), including ischemic/hemorrhagic stroke and mortality. ResultsA total of 11,968 AF patients were enrolled, and 2850 of them (654 in rhythm control group; 2196 in rate control group) were analyzed. During a 6.3 ± 3.7 year's follow-up, a total of 1101 MACE occurred. Compared to rate control group, rhythm control group displayed a lower rate of ischemic stroke (adjusted HR: 0.65, p = 0.002) and mortality (adjusted HR: 0.81, p = 0.009). The rhythm control group showed a lower incidence of MACE than that of the rate control group (adjusted HR: 0.82, p = 0.009). The reduction of stroke (p = 0.004), mortality (p = 0.006), and MACE (p = 0.007) risk was observed particularly in rhythm control patients with a CHA2DS2-VASc score of ≥3. ConclusionsIn patients with AF, rhythm control better prevents MACE risk than rate control over a long-term period, particularly in those at high risk (CHA2DS2-VASc score ≥3) for stroke.

Abstract 214: Strict versus Lenient versus Poor Rate Control Among Patients With Atrial Fibrillation and Heart Failure: Findings From the Get With the Guidelines - Heart Failure Program

Background: Randomized data suggest that lenient rate control (resting heart rate &lt;110 bpm) is noninferior to strict rate control (resting heart rate &lt;80 bpm) in patients with atrial fibrillation (AF). However, the optimal rate control strategy in patients with AF and heart failure (HF) remains unknown. Methods: Using data from the Get With The Guidelines-HF Program linked with Medicare data from July 1, 2011 to September 30, 2014, we identified patients with HF and AF and evaluated the association of heart rate at discharge with subsequent outcomes and the differential association by ejection fraction. Results: Of 13 981 patients with AF, 9 100 (65.0%) had strict rate control, 4 617 (33.0%) had lenient rate control, and 264 (1.9%) had poor rate control by resting heart rate on the day of discharge. After multivariable adjustment inclusive of medical therapy, compared with strict rate control, lenient rate control was associated with higher adjusted risks of all-cause death (HR 1.21, 95% CI 1.11-1.33, p&lt;0.001), all-cause readmission (HR 1.09, 95% CI 1.03-1.15, p&lt;0.002), all-cause death or all-cause readmission (HR 1.11, 95% CI 1.05-1.18, p&lt;0.001), but not cardiovascular readmission (HR1.08, 95% CI 1.00-1.16, p=0.051) at 90 days. Associations were largely comparable among patients with poor rate control and with heart rate modeled as a continuous variable (Table). The presence or absence of reduced ejection fraction did not impact the magnitude of most observed associations. Conclusions: Among patients with HF and AF, 2 out of 3 patients had a heart rate that met strict-control heart rate goals at discharge. Heart rates above 80 bpm at discharge were associated with adverse outcomes irrespective of left ventricular ejection fraction.

The effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter: A systematic review with meta-analysis and Trial Sequential Analysis.

BackgroundAtrial fibrillation and atrial flutter may be managed by either a rhythm control strategy or a rate control strategy but the evidence on the clinical effects of these two intervention strategies is unclear. Our objective was to assess the beneficial and harmful effects of rhythm control strategies versus rate control strategies for atrial fibrillation and atrial flutter.MethodsWe searched CENTRAL, MEDLINE, Embase, LILACS, Web of Science, BIOSIS, Google Scholar, clinicaltrials.gov, TRIP, EU-CTR, Chi-CTR, and ICTRP for eligible trials comparing any rhythm control strategy with any rate control strategy in patients with atrial fibrillation or atrial flutter published before November 2016. Our primary outcomes were all-cause mortality, serious adverse events, and quality of life. Our secondary outcomes were stroke and ejection fraction. We performed both random-effects and fixed-effect meta-analysis and chose the most conservative result as our primary result. We used Trial Sequential Analysis (TSA) to control for random errors. Statistical heterogeneity was assessed by visual inspection of forest plots and by calculating inconsistency (I2) for traditional meta-analyses and diversity (D2) for TSA. Sensitivity analyses and subgroup analyses were conducted to explore the reasons for substantial statistical heterogeneity. We assessed the risk of publication bias in meta-analyses consisting of 10 trials or more with tests for funnel plot asymmetry. We used GRADE to assess the quality of the body of evidence.Results25 randomized clinical trials (n = 9354 participants) were included, all of which were at high risk of bias. Meta-analysis showed that rhythm control strategies versus rate control strategies significantly increased the risk of a serious adverse event (risk ratio (RR), 1.10; 95% confidence interval (CI), 1.02 to 1.18; P = 0.02; I2 = 12% (95% CI 0.00 to 0.32); 21 trials), but TSA did not confirm this result (TSA-adjusted CI 0.99 to 1.22). The increased risk of a serious adverse event did not seem to be caused by any single component of the composite outcome. Meta-analysis showed that rhythm control strategies versus rate control strategies were associated with better SF-36 physical component score (mean difference (MD), 6.93 points; 95% CI, 2.25 to 11.61; P = 0.004; I2 = 95% (95% CI 0.94 to 0.96); 8 trials) and ejection fraction (MD, 4.20%; 95% CI, 0.54 to 7.87; P = 0.02; I2 = 79% (95% CI 0.69 to 0.85); 7 trials), but TSA did not confirm these results. Both meta-analysis and TSA showed no significant differences on all-cause mortality, SF-36 mental component score, Minnesota Living with Heart Failure Questionnaire, and stroke.ConclusionsRhythm control strategies compared with rate control strategies seem to significantly increase the risk of a serious adverse event in patients with atrial fibrillation. Based on current evidence, it seems that most patients with atrial fibrillation should be treated with a rate control strategy unless there are specific reasons (e.g., patients with unbearable symptoms due to atrial fibrillation or patients who are hemodynamically unstable due to atrial fibrillation) justifying a rhythm control strategy. More randomized trials at low risk of bias and low risk of random errors are needed.Trial registrationPROSPERO CRD42016051433

Characterization of rate and regularity of ventricular response during atrial tachyarrhythmias. Insight on atrial and nodal determinants

Objective: Ventricular rate and regularity affect hemodynamic stability and are targets of rate control therapy in patients with atrial flutter (AFL) and atrial fibrillation (AF). Nevertheless, the characteristics and determinants of ventricular response during these atrial arrhythmias are poorly understood. This work aims to investigate the effects of changes in atrial activity and atrioventricular (AV) conduction patterns on ventricular response in patients with atrial tachyarrhythmias by a combined quantitative analysis of atrial and ventricular time series. Approach: Time series were determined in patients during 24 episodes of AFL and 13 episodes of AF. Ventricular response was characterized in terms of mean ventricular interval, time-domain variability parameters, and entropy-based irregularity measures (quadratic entropy rate, QSE, and coefficient of sample entropy, COSEn). Atrial activity was characterized in terms of mean atrial rate and variability. AV conduction was analyzed by AV synchrogram method, quantifying the stability of AV coupling and the average AV conduction ratio. The dependence of ventricular features on atrial/AV determinants was investigated by correlation analysis. Main results: The analysis showed ventricular response to display a wide spectrum of variability and irregularity features at changing atrial and AV properties. The ventricular interval was significantly correlated with the AV conduction ratio (Spearman correlation coefficient ρ = −0.76, p < 0.005), while it did not correlate with atrial rate. The variability and irregularity of ventricular response were influenced by both atrial and AV parameters. QSE and COSEn significantly increased at shorter atrial cycle lengths (ρ = −0.67 and −0.71, p < 0.005), at higher atrial variability (ρ = 0.80 and 0.77, p < 0.005), at reduced AV coupling (ρ = −0.91, p < 0.005) and at smaller AV conduction ratios (ρ = −0.65 and −0.52, p < 0.005). Significance: The identification of the determinants of ventricular rate and regularity may have significant implications in the development of efficacious rate control strategies in patients with atrial tachyarrhythmias.

Treatment Failure With Rhythm and Rate Control Strategies in Patients With Atrial Fibrillation and Congestive Heart Failure: An AF-CHF Substudy.

Rate and rhythm control strategies for atrial fibrillation (AF) are not always effective or well tolerated in patients with congestive heart failure (CHF). We assessed reasons for treatment failure, associated characteristics, and effects on survival. A total of 1,376 patients enrolled in the AF-CHF trial were followed for 37 ± 19 months, 206 (15.0%) of whom failed initial therapy leading to crossover. Rhythm control was abandoned more frequently than rate control (21.0% vs. 9.1%, P < 0.0001). Crossovers from rhythm to rate control were driven by inefficacy, whereas worsening heart failure was the most common reason to crossover from rate to rhythm control. In multivariate analyses, failure of rhythm control was associated with female sex, higher serum creatinine, functional class III or IV symptoms, lack of digoxin, and oral anticoagulation. Factors independently associated with failure of rate control were paroxysmal (vs. persistent) AF, statin therapy, and presence of an implantable cardioverter-defibrillator. Crossovers were not associated with cardiovascular mortality (hazard ratio [HR] 1.11 from rhythm to rate control; 95% confidence interval [95% CI, 0.73-1.73]; P = 0.6069; HR 1.29 from rate to rhythm control; 95% CI, 0.73-2.25; P = 0.3793) or all-cause mortality (HR 1.16 from rhythm to rate control, 95% CI [0.79-1.72], P = 0.4444; HR 1.15 from rate to rhythm control, 95% [0.69, 1.91], P = 0.5873). Rhythm control is abandoned more frequently than rate control in patients with AF and CHF. The most common reasons for treatment failure are inefficacy for rhythm control and worsening heart failure for rate control. Changing strategies does not impact survival.

A Randomized Controlled Trial of Catheter Ablation Versus Medical Treatment of Atrial Fibrillation in Heart Failure (The CAMTAF Trial)

Restoring sinus rhythm in patients with heart failure (HF) and atrial fibrillation (AF) may improve left ventricular (LV) function and HF symptoms. We sought to compare the effect of a catheter ablation strategy with that of a medical rate control strategy in patients with persistent AF and HF. Patients with persistent AF, symptomatic HF, and LV ejection fraction <50% were randomized to catheter ablation or medical rate control. The primary end-point was the difference between groups in LV ejection fraction at 6 months. Baseline LV ejection fraction was 32±8% in the ablation group and 34±12% in the medical group. Twenty-six patients underwent catheter ablation, and 24 patients were rate controlled. Freedom from AF was achieved in 21/26 (81%) at 6 months off antiarrhythmic drugs. LV ejection fraction at 6 months in the ablation group was 40±12% compared with 31±13% in the rate control group (P=0.015). Ablation was associated with better peak oxygen consumption (22±6 versus 18±6 mL/kg per minute; P=0.014) and Minnesota living with HF questionnaire score (24±22 versus 47±22; P=0.001) compared with rate control. Catheter ablation is effective in restoring sinus rhythm in selected patients with persistent AF and HF, and can improve LV function, functional capacity, and HF symptoms compared with rate control. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique identifier: NCT01411371.

Atrial Fibrillation in Heart Failure

Management of atrial tachyarrhythmias, especially atrial fibrillation (AF), in patients with congestive heart failure (CHF) remains a major challenge. It is widely recognized that CHF promotes AF and that AF worsens CHF. An individual with either condition who develops the other has higher morbidity and poorer prognosis. The prevalence of AF and CHF is expected to increase as the population ages. Therefore, it remains just as likely as it was more than a decade ago that the emerging epidemic of AF and CHF will continue to be both a challenge and an opportunity. Article p 93 Current antiarrhythmic drugs (AADs) for AF prevention in patients with CHF remain unsatisfactory, with limited efficacy and considerable potential for adverse effects. Preliminary results from a large trial examining whether a rhythm-control strategy is superior to a rate-control strategy in patients with AF and CHF do not suggest a benefit in cardiovascular mortality rate, CHF, or stroke by attempting to maintain sinus rhythm with current AAD therapy (primarily amiodarone).1 Newer nonpharmacological therapies, including pulmonary vein (PV) isolation and cardiac resynchronization therapy, are generating considerable interest; however, their rates of efficacy in patients with AF and CHF have not been established definitively. Thus, continued progress toward an enhanced understanding of upstream mechanisms that promote AF and contractile dysfunction in CHF and development of innovative therapeutic approaches based on fundamental, mechanistic insights is of paramount importance. In this context, the study by Yeh et al2 in this issue of Circulation: Arrhythmia and Electrophysiology provides important new insights into the role of atrial calcium dysregulation in promoting atrial arrhythmias and contractile dysfunction in the CHF substrate. This report comes from the Nattel laboratory, which has been a major driving force in improving our understanding of arrhythmogenic mechanisms in a variety of AF substrates, including CHF. …

Ablation of chronic atrial fibrillation

Although several studies suggested equivalent outcome for pharmacologic rhythm and rate-control strategies in patients with atrial fibrillation (AF), substudies demonstrated that patients in sinus rhythm had lower mortality, but use of antiarrhythmic drugs significantly increased mortality.1 Therefore, restoration and maintenance of sinus rhythm without using antiarrhythmic drugs should lead to greater benefit for patients with chronic AF. Catheter ablation targeting the pulmonary veins (PVs) has evolved over the past decade and has become the treatment of choice for drug-resistant paroxysmal AF.

Stroke Prevention in Atrial Fibrillation

Atrial fibrillation is a common arrhythmia associated with increased risk for embolic stroke. Restoration of sinus rhythm in patients with atrial fibrillation is a logical strategy to prevent the cardiovascular and thromboembolic complications of this dysrhythmia. The most common strategy for restoration of sinus rhythm is pharmacological antiarrhythmic therapy with or without electrical cardioversion. Five randomized clinical trials compared rhythm to rate-control strategies in patients with atrial fibrillation. These trials examined mortality, thromboembolic complications, exercise tolerance, quality of life, hospital admissions and drug-related adverse reactions. Mortality ranged from 2.9% to 23.8% among the trial subjects randomized to rhythm control versus 1.0% to 21.3% in the rate control subjects. The risk of thromboemboli was greater: 2.9% to 7.9% in the rhythm-control subjects compared with 0% to 5.5% in the rate control subjects. Hospital admissions and drug-related adverse events were increased in the rhythm-control subjects. Stroke and systemic emboli occurred more often in the rhythm-control subjects many of whom had been withdrawn from anticoagulation. Rhythm-control offered no advantage compared with rate control for patients with atrial fibrillation at increased risk for stroke. One explanation for this finding is that those patients thought to have been successfully converted to sinus rhythm in fact had asymptomatic paroxysmal episodes of atrial fibrillation increasing their risk of stroke because they were unprotected by anticoagulation. Pharmacological attempts to restore atrial fibrillation to sinus rhythm do not improve mortality or reduce thromboembolic events. All patients with atrial fibrillation at increased risk for stroke should be continued on long-term anticoagulation even if they appear to have been successfully restored to sinus rhythm.

Antiarrhythmic drug therapy for atrial fibrillation: Are the guidelines guiding clinical practice?

The AFFIRM study showed no clear survival advantage for a rhythm versus rate control strategy in patients with atrial fibrillation (AF). However, rhythm control with antiarrhythmic drugs (AADs) is appropriate in a large number of patients with AF. The American College of Cardiology/ American Heart Association/European Society of Cardiology AF management guidelines include a safety-based algorithm for selection of AAD therapy. Class 1C agents are recommended as first-line therapy in patients without or with minimal structural heart disease. However, market research and clinical study data indicate a growing use of class III agents (mainly amiodarone) despite long-term safety and tolerability concerns, suggesting that clinical practice does not adhere to current guidelines.

Management of Atrial Fibrillation in Patients With Congestive Heart Failure

An increase in the prevalence of both atrial fibrillation and congestive heart failure is occurring in part because of the demographic shift toward an aging population. These two clinical entities often coexist in the same patient, resulting in the worsening of symptoms and prognosis, rendering their management even more challenging. A large clinical trial is currently examining whether a rhythm-control strategy is superior to a rate-control strategy in patients with congestive heart failure. New nonpharmacologic therapies such as pulmonary vein isolation are undergoing clinical investigation and may also alter the management of these patients. At present, therapy for atrial fibrillation in patients with congestive heart failure should aim first at controlling heart rate to provide symptomatic relief; then sinus rhythm should be restored if symptoms persist or if congestive heart failure worsens. For a more definitive approach in managing these patients, the authors await further clinical trial data.