Outcomes of cardiac resynchronization therapy in patients with versus those without atrial fibrillation: a systematic review and meta-analysis. Heart Rhythm. 2011;8:1088-1094. [PMID: 21338711 DOI: 10.1016/j.hrthm.2011.02.014]

Electrical therapies in heart failure: Evolving technologies and indications

Device therapy for heart failure has rapidly evolved over 2 decades. The knowledge of indications, assessment lead and device technology has expanded to include CRT, leadless pacing and conduction system pacing such as His bundle and left bundle branch area pacing. But there is still a lack of evidence for these new technologies as well as for common indications such as atrial fibrillation and upgrading from a previous device. The role of personalized medicine will become increasingly important when selecting candidates for CRT, primary preventive ICD ablation procedures and emerging new devices such as cardiac contractility modulation (CCM). Rapidity of therapy is associated with outcome which will be a challenge. If properly implemented devices and drugs will have a large positive affect of HF outcomes.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines

AIM

The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation.

METHODS

A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate.

STRUCTURE

Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.

Predictors of Higher Frequency of Atrial Fibrillation in Patients with Cardiac Resynchronization Therapy

Background and Objectives: Cardiac resynchronization therapy (CRT) is one of the effective therapeutic options in the treatment of systolic heart failure (HF) with persistent symptoms. This prospective study was designed to determine whether CRT with biventricular pacing would reduce the risk of development of atrial fibrillation (AF) and to identify predictors for AF occurrence. Materials and Methods: The study population consisted of 126 patients, with a mean age of 63.8 ± 9.1 years, who were eligible for CRT with biventricular pacing. Inclusion criteria were left ventricular ejection fraction (LVEF) ≤ 35%, QRS duration ≥ 130 msec, and persistent HF symptoms of New York Heart Association (NYHA) II or III, despite optimal drug therapy. Patients were followed for a period of 24 months and were evaluated through clinical, electrocardiographic, and echocardiographic examination at baseline (prior to CRT implantation), as well as at 6 and 24 months post-implantation. At the end of follow-up, patients were divided into clinical responders and non-responders based on the following criteria: decrease in NYHA class ≥ I, increase in LVEF ≥ 10%, and reduction in QRS duration ≥ 20 msec. Results: At follow-up, CRT was associated with a significant increase in LVEF (20.6 ± 6.9% pre-implantation, 32.9 ± 9.3% 24 months after implantation; p < 0.001), reduction in left ventricular end-diastolic and end-systolic diameters, and decrease in QRS duration (167.6 ± 14.3 msec pre-implantation, 131.7 ± 11.7 msec 24 months after implantation; p < 0.001), while left atrial (LA) diameter was slightly increased (p = 0.070). The frequency of AF occurrence increased after two years of follow-up (52.4% to 56.9%, p < 0.001). Significant predictors of AF occurrence in our study population were response to CRT-AF more frequent in non-responders (B = 8.134; p < 0.001), LA diameter-AF more frequent with larger LA diameter (B = 0.813; p < 0.001), and coronary sinus (CS) lead position-AF more frequent with posterolateral in comparison with lateral CS lead position (B = 5.159; p = 0.005). Conclusions: The results of our study provide new data on AF predictors in patients with HF subjected to CRT. There remains a permanent need for new predictors, which might help in patient selection and improvement in response rate.

Transition mechanisms from atrial flutter to atrial fibrillation during anti-tachycardia pacing therapy

BACKGROUND

Atrial anti-tachycardia pacing (aATP) has been shown to be effective for the termination of atrial tachyarrhythmias, but its success rate is still not high enough.

OBJECTIVE

The main objective of this study was to investigate the mechanisms of atrial flutter (AFL) termination by aATP and the transition from AFL to atrial fibrillation (AF) during aATP.

METHODS

We developed a multi-scale model of the human atrium based on magnetic resonance images and examined the atrial electrophysiology of AFL during aATP with a ramp protocol.

RESULTS

In successful cases of aATP, paced excitation entered the excitable gap and collided with the leading edge of the reentrant wave front. Furthermore, the excitation propagating in the opposite direction collided with the trailing edge of the reentrant wave to terminate AFL. The second collision was made possible by the distribution of the wave propagation velocity in the atria. The detailed analysis revealed that the slowing of propagation velocity occurred at the exit of the sub-Eustachian isthmus, probably due to source-sink mismatch. During the transition from AFL to AF, the excitation collided with the refractory zone of the preceding wave and broke into multiple wave fronts to induce AF. A similar observation was made for the transition from AF to sinus rhythm. In both cases, the complex anatomy of the atria played an essential role.

CONCLUSION

The complex anatomy of atria plays an essential role in the maintenance of stable AFL and its termination by aATP, which were revealed by the realistic three-dimensional simulation model.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

Cardiac resynchronization therapy in patients with a prior history of atrial fibrillation: Insights from four major clinical trials

AIMS

To investigate the association of cardiac resynchronization therapy (CRT) on outcomes among participants with and without a history of atrial fibrillation (AF).

METHODS

Individual-patient-data from four randomized trials investigating CRT-Defibrillators (COMPANION, MADIT-CRT, REVERSE) or CRT-Pacemakers (COMPANION, MIRACLE) were analyzed. Outcomes were time to a composite of heart failure hospitalization or all-cause mortality or to all-cause mortality alone. The association of CRT on outcomes for patients with and without a history of AF was assessed using a Bayesian-Weibull survival regression model adjusting for baseline characteristics.

RESULTS

Of 3964 patients included, 586 (14.8%) had a history of AF; 2245 (66%) were randomized to CRT. Overall, CRT reduced the risk of the primary composite endpoint (hazard ratio [HR]: 0.69, 95% credible interval [CI]: 0.56-0.81). The effect was similar (posterior probability of no interaction = 0.26) in patients with (HR: 0.78, 95% CI: 0.55-1.10) and without a history of AF (HR: 0.67, 95% CI: 0.55-0.80). In these four trials, CRT did not reduce mortality overall (HR: 0.82, 95% CI: 0.66-1.01) without evidence of interaction (posterior probability of no interaction = 0.14) for patients with (HR: 1.09, 95% CI: 0.70-1.74) or without a history of AF (HR: 0.70, 95% CI: 0.60-0.97).

CONCLUSION

The association of CRT on the composite endpoint or mortality was not statistically different for patients with or without a history of AF, but this could reflect inadequate power. Our results call for trials to confirm the benefit of CRT recipients with a history of AF.

2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure

Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.

The role of conduction system pacing in patients with atrial fibrillation

Conduction system pacing (CSP) has emerged as a promising novel delivery method for Cardiac Resynchronisation Therapy (CRT), providing an alternative to conventional biventricular epicardial (BiV) pacing in indicated patients. Despite increasing popularity and widespread uptake, CSP has rarely been specifically examined in patients with atrial fibrillation (AF), a cohort which forms a significant proportion of the heart failure (HF) population. In this review, we first examine the mechanistic evidence for the importance of sinus rhythm (SR) in CSP by allowing adjustment of atrioventricular delays (AVD) to achieve the optimal electrical response, and thus, whether the efficacy of CSP may be significantly attenuated compared to conventional BiV pacing in the presence of AF. We next evaluate the largest clinical body of evidence in this field, related to patients receiving CSP following atrioventricular nodal ablation (AVNA) for AF. Finally, we discuss how future research may be designed to address the vital question of how effective CSP in AF patients is, and the potential hurdles we may face in delivering such studies.

Rate or Rhythm Control in CRT (RHYTHMIC): Study rationale and protocol

Background

Atrial fibrillation (AF) has several detrimental effects on heart failure patients treated with cardiac resynchronization therapy (CRT). These include suboptimal biventricular pacing and the loss of atrioventricular (AV) synchrony. AV node ablation improves biventricular pacing and clinical outcomes in large observational studies. However, restoration of sinus rhythm with AF ablation may have additional benefits.

Objectives

To compare the effects of AV node ablation and AF ablation on echocardiographic and symptomatic outcomes in patients with CRT and suboptimal biventricular pacing.

Methods

RHYTHMIC is a multicenter prospective randomized controlled trial. Seventy patients will be recruited and randomized to each ablation strategy in a 1:1 ratio. Key inclusion criteria include a previous CRT implant (with atrial lead) for dyssynchronous heart failure, and biventricular pacing <95% secondary to AF. Patients with permanent AF will be excluded.

Results

Patients will undergo baseline assessment including transthoracic echocardiography (TTE), device check, blood tests, electrocardiogram (ECG), 6-minute walk test, and symptom questionnaire. They will then undergo either AV node ablation or AF ablation according to their allocated group. Follow-up will occur at 1 week (TTE and ECG) and at 6 months (repeat of baseline investigations). The primary endpoint will be change in left ventricular ejection fraction on TTE.

Conclusion

This is the first randomized controlled trial comparing AV node ablation and AF ablation in patients with CRT. We anticipate it will provide valuable insight into the management of this frequently encountered clinical scenario in a challenging patient cohort.

Cardiac resynchronization therapy in the presence of total atrioventricular block reduces long-lasting atrial fibrillation episodes

Background

There is an ongoing debate on how cardiac resynchronization therapy (CRT) in the presence of total AV block affects atrial fibrillation (AF) episodes and symptoms in patients with AF.

Methods

Seventy-five patients with symptomatic, drug and ablation refractory AF received, irrespective of their left ventricular ejection fraction (EF), either a CRT device and underwent subsequent atrioventricular node (AVN) ablation or already had a total AV block and underwent CRT upgrade. Long-lasting AF episodes (>48 h), left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVEDD), left atrial diameter (LAD), NTproBNP levels, EHRA score, and NYHA class had been monitored on the follow-up.

Results

The number of patients experiencing long-lasting AF episodes (>48 h) and symptoms decreased significantly within 24 months after CRT implantation in the presence of total AV block (p < .001) from 57 (76%) to 25 (33.3%). Mean LAD decreased from 52 mm (IQR 48.0-56.0) to 48 mm (IQR 42.0-52.0, p < .001) and LVEDD from 54 mm (IQR 49.0-58.0) to 51 mm (IQR 46.5-54.0, p < .001).

Conclusion

A combination of total AVN block and biventricular pacing markedly reduces long-lasting AF episodes, symptoms, left atrial diameter, and left ventricular end-diastolic diameter.

Atrial fibrillation-induced tachycardiomyopathy and heart failure: an underappreciated and elusive condition

Many patients with persistent, chronic, or frequently recurring paroxysmal atrial fibrillation (AF) may develop a tachycardiomyopathy (TCM) with left ventricular (LV) dysfunction and heart failure (HF), which is reversible upon restoration and maintenance of sinus rhythm, when feasible, or via better and tighter ventricular rate (VR) control. Mechanisms involved in producing this leading cause of TCM (AF-TCM) include loss of atrial contraction, irregular heart rate, fast VR, neurohumoral activation, and structural myocardial changes. The most important of all mechanisms relates to optimal VR control, which seems to be an elusive target. Uncontrolled AF may also worsen preexisting LV dysfunction and exacerbate HF symptoms. Data, albeit less robust, also point to deleterious effects of slow VRs on LV function. Thus, a J-shaped relationship between VR and clinical outcome has been suggested, with the optimal VR control hovering at ~ 65 bpm, ranging between 60 and 80 bpm; VRs above and below this range may confer higher morbidity and mortality rates. A convergence of recent guidelines is noted towards a stricter rather than a more lenient VR control with target heart rate < 80 bpm at rest and < 110 bpm during moderate exercise which seems to prevent TCM or improve LV function and exercise capacity and relieve TCM-related symptoms and signs. Of course, restoring and maintaining sinus rhythm is always a most desirable target, when feasible, either with drugs or more likely with ablation. All these issues are herein reviewed, current guidelines are discussed and relevant data are tabulated and pictorially illustrated.

Multi-lead pacing for cardiac resynchronization therapy in heart failure: a meta-analysis of randomized controlled trials

Aims

Multi-lead pacing is a potential therapy to improve response to cardiac resynchronization therapy (CRT) by providing rapid activation of the myocardium from multiple sites. Here, we perform a meta-analysis of randomized controlled trials to assess the efficacy of multi-lead pacing.

Methods and results

A literature search was performed which identified 251 unique records. After screening, 6 studies were found to meet inclusion criteria, with 415 patients included in the meta-analysis. Four studies performed multi-lead pacing with two left ventricular (LV) leads and one right ventricular (RV) lead. One study used two RV leads and one LV lead, and one study used both configurations. There was no difference between multi-lead pacing and conventional CRT in LV end-systolic volume [mean difference (MD) -0.54 mL, P = 0.93] or LV ejection fraction (MD 1.42%, P = 0.40). There was a borderline significant improvement in Minnesota Living With Heart Failure Questionnaire score for multi-lead pacing vs. conventional CRT (MD -4.46, P = 0.05), but the difference was not significant when only patients receiving LV-only multi-lead pacing were included (MD -3.59, P = 0.25). There was also no difference between groups for 6-min walk test (MD 15.06 m, P = 0.38) or New York Heart Association class at follow-up [odds ratio (OR) 1.49, P = 0.24]. There was no difference in mortality between groups (OR 1.11, P = 0.77).

Conclusion

This meta-analysis does not support the use of multi-lead pacing for CRT delivery. However, significant variation between studies was noted, and therefore a benefit for multi-lead pacing in select patients cannot be excluded, and further investigation may be warranted.

Pacemaker and Atrioventricular Junction Ablation in Patients With Atrial Fibrillation—A Systematic Review of Systematic Review and Meta-Analysis

Background

Cardiac resynchronization therapy (CRT) could be considered for heart failure (HF) patients with atrial fibrillation (AF) unless a potent ventricular capture strategy is conducted. However, the benefit of a pacemaker (PM; as part of CRT) in patients with AF and whether atrioventricular junction (or nodal) ablation (AVAB) can improve the prognosis of these patients compared with those treated medically to support ventricular capture are unclear.

Methods and Results

Systematic reviews and meta-analyses investigating the roles of PMs and AVAB in patients with AF were obtained in a search of the PubMed, Embase, and Medline databases and then analyzed with respect to the following outcomes: mortality, left ventricular ejection fraction, and clinical findings including the New York Heart Association class, 6-min walk distance (6MWD), quality of life as assessed in a specific questionnaire, and response to CRT. The quality of the included reviews was assessed using the Assessing the Methodological Quality of Systematic Reviews 2 tool, which includes 16 items. This study was finally based on 13 systematic reviews or meta-analyses. The results showed that patients with AF have higher all-cause mortality rates compared with patients with sinus rhythm and that AVAB can reduce all-cause mortality in patients with AF. Although the functional improvement was better in sinus rhythm than in patients with AF, in the latter, AVAB increased the 6MWD and reduced the CRT nonresponse rate in patients with AF.

Conclusion

Atrial fibrillation is associated with a higher all-cause mortality rate in patients with CRT implantation. AVAB, by increasing the 6MWD and survival, can improve the prognosis of these patients.

Junctional AV ablation in patients with atrial fibrillation undergoing cardiac resynchronization therapy (JAVA-CRT): results of a multicenter randomized clinical trial pilot program

Introduction

Cardiac resynchronization therapy (CRT) improves outcomes in sinus rhythm, but the data in atrial fibrillation (AF) is limited. Atrio-ventricular junctional ablation (AVJA) has been proposed as a remedy. The objective was to test if AVJA results in LV end-systolic volume (ESV) reduction ≥ 15% from baseline to 6 months.

Methods

The trial was a prospective multicenter randomized trial in 26 patients with permanent AF who were randomized 1:1 to CRT-D with or without AVJA.

Results

LVESV improved similarly by at least 15% in 5/10 (50%) in the CRT-D-only arm and in 6/12 (50%) in the AVJA + CRT-D arm (OR = 1.00 [0.14, 7.21], p = 1.00). In the CRT-D-only arm, the median 6-month improvement in LVEF was 9.2%, not different from the AVJA + CRT-D arm, 8.2%. When both groups were combined, a significant increase in LVEF was observed (25.4% at baseline vs 36.2% at 6 months, p = 0.002). NYHA class from baseline to 6 months for all patients combined improved 1 class in 15 of 24 (62.5%), whereas 9 remained in the same class and 0 degraded to a worse class.

Conclusion

In patients with permanent AF, reduced LVEF, and broad QRS who were eligible for CRT, there was insufficient evidence that AVJA improved echocardiographic or clinical outcomes; the results should be interpreted in light of a smaller than planned sample size. CRT, however, seemed to be effective in the combined study cohort overall, suggesting that CRT can be reasonably deployed in patients with AF.

Trial registration

ClinicalTrials.gov Identifier: NCT02946853.

Device treatment of heart failure

Background: The incidence of heart failure (HF) is rapidly increasing, introducing a significant burden and challenges in clinical practice. Non-pharmacological cardiac device therapy has been established as an essential component of optimal HF management, particularly for the prevention of sudden cardiac death and the improvement of HF symptoms, left ventricular (LV) systolic function, quality of life, and eventually survival.Current Concepts: Cardiac resynchronization therapy (CRT) can correct atrioventricular or inter/intraventricular dyssynchrony, thereby improving LV systolic function. Recently, the concept of CRT is being expanded, including His bundle (HB), HB-optimized LV, left bundle branch (LBB), and LBB optimized LV pacing CRTs. Newly introduced CRT approaches by stimulating the cardiac conduction system are expected to correct dyssynchrony better and consequently exhibit better CRT outcomes than the conventional biventricular pacing CRT. The current versions of implantable cardioverter-defibrillators (ICDs) or CRT devices can continuously monitor multiple biosignals. CRT/ICD can calculate a single index by combining these multiple bio-signal data for early detection of HF aggravation. Recently, subcutaneous and transvenous ICDs showed comparable safety and efficacy in HF patients. In drug-refractory HF patients without LV dyssynchrony, cardiac contractility modulation therapy provides some promising results.Discussion and Conclusion: Recent technological advancements have improved the efficacy and safety of cardiac device therapy. Therefore, cardiac device therapy should be used more actively to manage HF patients better.

Atrial fibrillation in cardiac resynchronization therapy

Patients with atrial fibrillation (AF) were largely excluded from the major clinical trials of cardiac resynchronization therapy (CRT), despite the presence of AF in up to 40% of patients receiving CRT in clinical practice. AF appears to attenuate the response to CRT, by the combination of a reduction in biventricular pacing and the loss of atrioventricular synchrony. In addition, remodeling secondary to CRT may influence the progression of AF. Management options for patients with AF and CRT include rate control, with drugs or atrioventricular node ablation, or rhythm control, with electrical cardioversion and antiarrhythmic therapy, or AF catheter ablation. The evidence for these therapies in patients with CRT is largely limited to observational studies or inferred from randomized studies in the general heart failure population. In this review, we explore the complex interaction between AF, heart failure, and CRT and discuss the evidence for the treatment options in this difficult patient cohort.

Contemporary ICD Use in Patients with Heart Failure

Despite constant breakthroughs in heart failure (HF) therapy, the population of HF patients resume to grow and is linked to increased mortality and morbidity. Ventricular arrhythmias (VA) are one of the leading causes of mortality in HF subjects. Implantable cardioverter-defibrillators (ICDs) are currently the gold standard in treatment, preventing arrhythmic sudden cardiac death (SCD) episodes. However, the death rates related to HF remain elevated, as not all HF subjects benefit equally. Cardiac resynchronization therapy (CRT) has emerged as a novel approach for HF patients. These devices have been thoroughly investigated in major randomized controlled studies but continue to be underutilized in various countries. This review discusses the use of ICD in HF populations on top of treatments.

Managing Atrial Fibrillation in Patients With Heart Failure and Reduced Ejection Fraction: A Scientific Statement From the American Heart Association

Atrial fibrillation and heart failure with reduced ejection fraction are increasing in prevalence worldwide. Atrial fibrillation can precipitate and can be a consequence of heart failure with reduced ejection fraction and cardiomyopathy. Atrial fibrillation and heart failure, when present together, are associated with worse outcomes. Together, these 2 conditions increase the risk of stroke, requiring oral anticoagulation in many or left atrial appendage closure in some. Medical management for rate and rhythm control of atrial fibrillation in heart failure remain hampered by variable success, intolerance, and adverse effects. In multiple randomized clinical trials in recent years, catheter ablation for atrial fibrillation in patients with heart failure and reduced ejection fraction has shown superiority in improving survival, quality of life, and ventricular function and reducing heart failure hospitalizations compared with antiarrhythmic drugs and rate control therapies. This has resulted in a paradigm shift in management toward nonpharmacological rhythm control of atrial fibrillation in heart failure with reduced ejection fraction. The primary objective of this American Heart Association scientific statement is to review the available evidence on the epidemiology and pathophysiology of atrial fibrillation in relation to heart failure and to provide guidance on the latest advances in pharmacological and nonpharmacological management of atrial fibrillation in patients with heart failure and reduced ejection fraction. The writing committee's consensus on the implications for clinical practice, gaps in knowledge, and directions for future research are highlighted.

Brady-arrhythmias in patients with atrial fibrillation and heart failure of reduced ejection fraction: is his-bundle pacing superior to biventricular pacing？

OBJECTIVE

To investigate the efficacy and safety of His-bundle pacing (HBP) compared with the traditional biventricular pacing (BVP) on patients with brady-arrhythmias, who suffer from permanent atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF).

METHODS

All patients with brady-arrhythmias, permanent AF and HFrEF were continuously enrolled from January 2017 to July 2019 and followed up for at least 12 months. The differences in QRS duration (QRSd), New York Heart Association (NYHA) classification, left ventricular ejection fraction (LVEF), tricuspid regurgitation grade, mitral regurgitation grade, left ventricular end-diastolic diameter (LVEDD), and left atrial size were compared.

RESULTS

A total of 52 patients were enrolled: 37 patients were with HBP and 15 patients with BVP. There was no electrode dislodged, perforation, infection or thrombosis during the follow-up of 18.12 ± 4.45 months. The success rate for HBP implantation was 88.10%. The capture threshold of his-bundle and the threshold of the left ventricular lead remained stable during follow-up. LVEF increased to higher than 50% in 11 patients with HBP (29.73%). The NYHA classification (both p < .001), LVEF (both p < .001) and LVEDD improved significantly during the follow-up in both groups. NYHA (p = .030), LVEF (p = .013), and LVEDD (p = .003) improved in patients with HBP compared with BVP.

CONCLUSION

HBP was safe and more effective in improving the cardiac function and remodeling in patients with brady-arrhythmias, permanent AF and HFrEF compared with BVP.

Atrial fibrillation in patients with systolic heart failure: pathophysiology mechanisms and management

Heart failure (HF) and atrial fibrillation (AF) demonstrate a constantly increasing prevalence during the 21^st century worldwide, as a result of the aging population and the successful interventions of the clinical practice in the deterioration of adverse cardiovascular outcomes. HF and AF share common risk factors and pathophysiological mechanisms, creating the base of a constant interrelation. AF impairs systolic and diastolic function, resulting in the increasing incidence of HF, whereas the structural and neurohormonal changes in HF with preserved or reduced ejection fraction increase the possibility of the AF development. The temporal relationship of the development of either condition affects the diagnostic algorithms, the prognosis and the ideal therapeutic strategy that leads to euvolaemia, management of non-cardiovascular comorbidities, control of heart rate or restoration of sinus rate, ventricular synchronization, prevention of sudden death, stroke, embolism, or major bleeding and maintenance of a sustainable quality of life. The indicated treatment for the concomitant HF and AF includes rate or/and rhythm control as well as thromboembolism prophylaxis, while the progress in the understanding of their pathophysiological interdependence and the introduction of the genetic profiling, create new paths in the diagnosis, the prognosis and the prevention of these diseases.

Cardiac Resynchronization Therapy in Patients with Heart Failure: What is New?

Cardiac resynchronization therapy (CRT) is an established treatment of patients with medically refractory, mild-to-severe systolic heart failure (HF), impaired left ventricular function, and wide QRS complex. The pathologic activation sequence observed in patients with abnormal QRS duration and morphology results in a dyssynchronous ventricular activation and contraction leading to cardiac remodeling, worsening systolic and diastolic function, and progressive HF. In this article, the authors aim to explore the current CRT literature, focusing their attentions on the promising innovation in this field.

The Benefit of Atrioventricular Junction Ablation for Permanent Atrial Fibrillation and Heart Failure Patients Receiving Cardiac Resynchronization Therapy: An Updated Systematic Review and Meta-analysis

BACKGROUND

Atrial fibrillation (AF) is correlated with a poor biventricular pacing and inadequate response to cardiac resynchronization therapy (CRT). Biventricular pacing improvement can be achieved by conducting the atrioventricular junction ablation (AVJA). We aimed to investigate the benefit of AVJA for permanent AF and heart failure with reduced ejection fraction (HFrEF) patients receiving CRT.

METHODS

In August 2020, a systematic review and meta-analysis study comparing CRT plus AVJA versus CRT for permanent AF and HFrEF patients was conducted. Relevant articles were identified through the electronic scientific database such as ClinicalTrials.gov, ProQuest, ScienceDirect, PubMed, and Cochrane. The pooled risk ratio (RR) and pooled mean difference (MD) were estimated.

RESULTS

A total of 3199 patients from 14 cohort studies were involved in this study. Additional AVJA reduced cardiovascular mortality (RR = 0.75, 95% confidence interval [CI] = 0.61 to 0.93, P < 0.01) in permanent AF and HFrEF patients receiving CRT. Biventricular pacing rate was higher in CRT plus AVJA group (MD = 8.65%, 95% CI = 5.62 to 11.67, P < 0.01) than in CRT alone group. The reverse remodeling characterized by the reduction of left ventricular end-diastolic diameter (LVEDD) was greater in the CRT plus AVJA group (MD = -2.11 mm, 95% CI = -3.79 to -0.42, P = 0.01).

CONCLUSION

In permanent AF and HFrEF patients receiving CRT, AVJA effectively increased the biventricular pacing rate. Adequate biventricular pacing rate provided a better response to the CRT marked by the greater ventricular reverse remodeling and survival from cardiovascular mortality.

Why is the clinical response to cardiac resynchronization better in LBBB patients?

Aims

The improved clinical response in patients with left bundle branch block (LBBB) over LBBB‐free patients treated with cardiac resynchronization therapy with a defibrillator (CRT‐D) is commonly attributed to an LBBB abnormality. We aimed to find an alternative explanation.

Methods and results

We analysed an immediate effect of selecting the LBBB group of patients in a cohort of 63 non‐ischaemic cardiomyopathy (non‐ICM) and 83 ischaemic cardiomyopathy (ICM) patients treated with CRT‐D; 75% of non‐ICM and 51% of ICM patients had an LBBB abnormality on the electrocardiogram, with a significant difference (P = 0.0032 by χ²). As a result of this difference, the proportion of non‐ICM patients increased from 43% in the primary cohort to 53% in LBBB selection and decreased to 28% in non‐LBBB group. By nonparametric survival analysis, the hazard ratio in non‐ICM patients in the LBBB selection decreased from 0.48 (P = 0.0488) to 0.36 (P = 0.0251) and increased in the non‐LBBB group to 0.75 (P = 0.6496). Any comparison of LBBB and non‐LBBB groups must compare sets with a significantly altered proportion of patients of different aetiologies. Most publications on LBBB patients are erroneous because they compare LBBB with non‐LBBB groups, not taking into account that the groups have been substantially changed by the selection process.

Conclusions

The declared outcome of the LBBB groups reflects inevitably the survival outcome of their non‐ICM patients and not the intended outcome of patients with LBBB. CRT‐D in patients with different aetiologies of cardiomyopathy calls for separate evaluation.

Efficacy and Safety of Exercise Rehabilitation for Heart Failure Patients With Cardiac Resynchronization Therapy: A Systematic Review and Meta-Analysis

Background: Many heart failure (HF) patients admitted to cardiac rehabilitation (CR) centers have a cardiac resynchronization therapy (CRT) device. However, information about the efficacy and safety of exercise rehabilitation in HF patients with a CRT device is scant. We assessed the effects of exercise rehabilitation in HF patients with a CRT device. Methods and Results: The PubMed, EMBASE, Cochrane Central Register of Controlled Trials, CINAHL, PsycInfo, China Biology Medicine, Wanfang, and China National Knowledge Infrastructure databases were searched comprehensively to identify randomized controlled trials (RCTs) published between January 1, 1990 and July 1, 2019 on exercise rehabilitation in HF patients with CRT devices. We identified seven studies published from 2006 to 2019, including 661 patients with an intervention duration of 8 to 24 weeks. Three studies reported all-cause mortality and serious adverse events, and no significant difference was found between exercise rehabilitation patients and controls at the longest available follow-up (both P > 0.05; both I 2 = 0%). Exercise rehabilitation patients exhibited a higher exercise capacity (peak oxygen uptake: random-effect WMD = 2.02 ml/kg/min, 95% CI 0.62 to 3.41, P = 0.005, I 2 = 67.4%; exercise duration: fixed-effect WMD = 102.34s, 95% CI 67.06 to 137.62, P < 0.001, I 2 = 25%) after intervention, despite the significant heterogeneity of studies. Left ventricular ejection fraction (LVEF) was significantly improved in exercise rehabilitation patients compared to that in controls (fixed-effect WMD = 3.89%, 95% CI 1.50 to 6.28; P = 0.001; I 2 = 48.0%). Due to differences in health-related quality of life (HRQOL) assessment methods, we only pooled data that reported Minnesota Living with Heart Failure Questionnaire scores. Exercise rehabilitation patients exhibited a better HRQOL than controls (fixed-effect WMD = -5.34, 95% CI -10.12 to -0.56; P = 0.028; I 2 = 0%). Conclusions: Exercise rehabilitation may restore exercise capacity and cardiac function in HF patients with a CRT device. Furthermore, exercise training was associated with better HRQOL on follow-up.

Prevalence and prognostic significance of device-detected subclinical atrial fibrillation in patients with heart failure and reduced ejection fraction

BACKGROUND

Cardiac implanted electronic devices (CIEDs) can detect short durations of previously unrecognised atrial fibrillation (AF). The prognostic significance of device-detected subclinical AF, in the context of contemporary heart failure (HF) therapy, is unclear.

METHODS

Amongst patients enrolled in the Remote Monitoring in HF with implanted devices (REM-HF) trial, three categories were defined based on total AF duration in the first year of follow-up: no AF, subclinical AF (≥6 min to ≤24 h), and AF >24 h. All-cause mortality, stroke, and cardiovascular hospitalisation were assessed.

RESULTS

1561 patients (94.6%) had rhythm data: 71 (4.6%) had subclinical AF (median of 4 episodes, total duration 3.1 h) and 279 (17.9%) had AF >24 h. During 2.8 ± 0.8 years' follow-up, 39 (2.5%) patients had a stroke. Stroke rate was highest amongst patients with subclinical AF (2.0 per 100-person years) versus no AF or AF >24 h (0.8 and 1.0 per 100-person years, respectively). In the overall cohort, AF >24 h was not an independent predictor of stroke. However, amongst patients with no history of AF (n = 932), new-onset subclinical AF conferred a three-fold higher stroke risk (adjusted HR 3.35, 95%CI 1.15-9.77, p = 0.027). AF >24 h was associated with more frequent emergency cardiovascular hospitalisation (adjusted HR 1.46, 95%CI 1.19-1.79, p < 0.0005). Neither AF classification was associated with mortality.

CONCLUSIONS

In patients with HF and a CIED, subclinical AF was infrequent but, as a new finding, was associated with an increased risk of stroke. Anticoagulation remains an important consideration in this population, particularly when the clinical profile indicates a high stroke risk.

Probability of sinus rhythm conversion and maintenance in cardiac resynchronization therapy patients with atrial fibrillation during 5-year follow-up

INTRODUCTION

There is a high prevalence of atrial fibrillation (AF) in patients with heart failure presented for cardiac resynchronization therapy (CRT). It remains unclear whether an atrial lead should be implanted in these patients. We, therefore, analyzed outcomes and course of rhythm in AF patients undergoing CRT implantation during long-term follow-up.

METHODS AND RESULTS

Between 2004 and 2018, 328 consecutive patients with a history of AF receiving CRT implantation were included in this study. 132 patients had preoperatively paroxysmal AF (px-AF), while 70 and 126 patients had persistent AF (ps-AF) and long-standing persistent AF (lp-AF), respectively. The outcome data were collected in our institutional database and analyzed retrospectively. Two hundred and seventy-seven patients received an atrial lead at the time of implantation, nine during follow-up. No major lead implantation-associated complications were observed. In patients with px-AF, sinus rhythm (SR) was present in 78.8% at admission, 95.5% (p < .001) at discharge, and 85.7% (p = .965) after 5 years. In ps-AF patients SR was present in 28.6%, 91.4% (p < .001) and 69.7% (p < .001), while all lp-AF patients showed AF at admission and had SR rate of 50.8% (p < .001) at discharge and 44.1% after 5 years (p < .001).

CONCLUSION

We observed a high rate of conversion and long-term persistence of SR in AF patients undergoing CRT implantation. Due to the low rate of lead implantation-associated complications and the high successful SR conversion rates, we recommend the implantation of an atrial lead in CRT patients with AF.

Nonpharmacological Treatment of Atrial Fibrillation: What Is the Role of Device Therapy?

Atrial fibrillation is the most common arrhythmia in the adult population, and its incidence and prevalence are still rising. Cardiac devices are widely used in clinical practice in the management of various rhythm disturbances and heart failure treatment. Many patients who receive a pacemaker, implantable cardioverter-defibrillator, or cardiac resynchronization therapy also experience atrial fibrillation in the course of their life. Therefore, this review aims to describe the role of these devices in the treatment and prevention of atrial fibrillation in the device recipients. In addition, all these implantable devices also serve as permanent ECG (electrocardiogram) monitors, thus providing important information about the presence and characteristics of atrial fibrillation that may or may not be detected by the patient but can modify our therapeutical approach with regard to the stroke prevention.

Mortality and Heart Failure After Upgrade to Cardiac Resynchronization Therapy

Background

Cardiac resynchronization therapy (CRT) is effective in treating advanced heart failure (HF), but data describing benefits and long-term outcomes for upgrades from a preexisting device are limited. This study sought to compare long-term outcomes in de novo CRT implants with those eligible for CRT with a prior device.

Methods

This is a retrospective cohort study using data from a provincial registry (2002-2015). Patients were included if they had mild-moderate HF, left ventricular ejection fraction ≤ 35%, and QRS duration ≥ 130 ms. Patients were classified as de novo CRT or upgraded to CRT from a prior device. Outcomes were mortality and composite mortality and HF hospitalization.

Results

There were 342 patients included in the study. In a multivariate model, patients in the upgraded cohort (n = 233) had a higher 5-year mortality rate (adjusted hazard ratio, 2.86; 95% confidence interval, 1.59-5.15; P = 0.0005) compared with the de novo cohort (n = 109) and higher composite mortality and HF hospitalization (adjusted hazard ratio, 2.60; 95% confidence interval, 1.54-4.37; P = 0.0003).

Conclusions

Implantation of de novo CRTs was associated with lower mortality and HF hospitalization compared with upgraded CRTs from preexisting devices. It is unknown whether these differences are due to the timing of CRT implementation or other clinical factors. Further work in this area may be helpful to determine how to improve outcomes for these patients.

Prognostication of Poor Survival After Cardiac Resynchronization Therapy

Background and Objectives: Cardiac resynchronization therapy (CRT) is a successful treatment option for appropriately selected patients. However, one–third of recipients do not experience any positive outcome or their condition even declines. We aimed to assess preimplantation factors associated with worse survival after the CRT. Materials and Methods: This was a retrospective unicenter trial. The study cohort included 183 consecutive CRT-treated patients. Baseline demographic, clinical, electrocardiographic, and echocardiographic characteristics were analyzed. Results: After the median follow-up of 15.6 months (9.3–26.3), 20 patients had died (11%). In multivariate Cox regression analysis, ischemic origin of heart failure (HF) was a significant predictor of poor survival (adjusted hazard ratio (aHR) 15.235, 95% confidence interval (CI) (1.999–116.1), p = 0.009). In univariate Cox regression, tricuspid annular plane systolic excursion (TAPSE) <15.5 mm (sensitivity 0.824, specificity 0.526; HR 5.019, 95% CI (1.436–17.539), p = 0.012), post-implantation prescribed antiplatelet agents (HR 2.569, 95% CI (1.060–6.226), p = 0.037), statins (HR 2.983, 95% CI (1.146–7.764), p = 0.025), and nitrates (HR 3.694, 95% CI (1.342–10.171), p = 0.011) appeared to be related with adverse outcome. Conclusions: ischemic etiology of HF is a significant factor associated with worse survival after the CRT. Decreased TAPSE is also related to poor survival.

[Resynchronization Therapy for Chronic Heart Failure: Diagnostic and Therapeutic Approaches]

Chronic heart failure (CHF) remains one of the most important problems of modern cardiology. One of the effective treatment methods is resynchronization therapy (RT). The article presents an analysis of literature data on the effectiveness of RT in improving the quality of life, reducing the number of hospitalizations and mortality in patients with heart failure with severe left ventricular systolic dysfunction and expanding QRS complex, and also discusses key methods for optimizing RT.

Comparison of current German and European practice in cardiac resynchronization therapy: lessons from the ESC/EHRA/HFA CRT Survey II

INTRODUCTION

The European CRT Survey II was introduced to offer insights into CRT implantation practice in Europe. We compared the national data from the participating German centres with that of the other European countries with regard to differences in patient selection, implant results, and initial properties.

METHODS AND RESULTS

11,088 patients were enrolled in 288 centres from 42 countries between 2015 and 2017. Of these, 675 (6.1%) were included in 17 centres in Germany. Patients from Germany were older, had more comorbidities and more symptoms of heart failure (HF) than patients from other European countries. There were no differences with regard to HF aetiology and guideline-directed medical treatment was overall well implemented. There was a high use of CRT in patients with atrial fibrillation, even higher in German patients. CRT was most often applied due to HF with wide QRS complex (class I recommendation) but with relatively higher frequency in Germany due to HF with primary indication for an implantable cardioverter-defibrillator (class IIb) or a pacemaker with expected pacing dependency (class I). The overall implant success rate was high with some differences in the implant procedure. The use of remote monitoring was lower in Germany.

CONCLUSION

This analysis from the European CRT Survey II overall shows good guideline adherence, high implantation success and a low rate of complications in daily practice. There are some regional differences in baseline characteristics, CRT indication, and procedural aspects. The use of remote monitoring in Germany lags behind other European countries.

Focused Update of 2016 Korean Society of Heart Failure Guidelines for the Management of Chronic Heart Failure

The incidence of heart failure (HF) is increasing in South Korea and devising the optimal care plan is crucial to promote appropriate and effective treatment of HF. To this end, the first Korean guideline for management of chronic HF was published in 2016 by the HF research group under the Korean Society of Cardiology (KSC). After this publication, considerable data have been accumulated and a new guideline for the management of HF was published in Europe, and an update regarding pharmacological therapy was published in the United States, which made it warrant to update the Korean guideline. Under this premise, The Clinical Practice Guidelines Committee under the Korean Society of Heart Failure (KSHF) founded in 2018 decided to publish a focused update management guideline for chronic HF and selected 15 topics that need an update regarding the diagnosis, definition, diagnostic algorithm, monitoring, novel biomarkers, drug therapy related to non-vitamin K antagonist oral anticoagulants and angiotensin receptor neprilysin inhibitors, and with respect to comorbidities changes in the guidelines of relevant institutions, such as new guidelines for the management of hypertension, a procedure used to treat severe aortic stenosis, information on sodium glucose co-transporter-2 inhibitor, and that about sleep apnea. Among nonpharmacological therapies, changes to the recommendations for implantable cardioverter defibrillator, cardiac resynchronization therapy, and cardiac rehabilitation were updated. Subsequent and continuous updates based on additional clinical research findings, with continual supervision by the KSHF will be needed.

Devices in Heart Failure Patients-Who Benefits From ICD and CRT?

Despite advances in heart failure treatment, this condition remains a relevant medical issue and is associated with a high morbidity and mortality. The cause of death in patients suffering from heart failure is not only a result of hemodynamic failure, but can also be due to ventricular arrhythmias. Implantable cardioverter defibrillators (ICDs) are these days the only tool to significantly reduce arrhythmic sudden death; but not all patients benefit to the same extend. In addition, cardiac resynchronization therapy (CRT) is another tool which is used in patients suffering from heart fialure. Even though both devices have been investigated in large randomized trials, both ICD and CRT remain underutilized in many countries. This brief review focuses on various aspects in this regard including a short overview on upcoming device novelties in the near future.

Atrial fibrillation incidence and impact of biventricular pacing on long-term outcome in patients with heart failure treated with cardiac resynchronization therapy

Background

In patients with cardiac resynchronization therapy (CRT), atrial fibrillation (AF) is associated with an unfavorable outcome and may cause loss of biventricular pacing (BivP). An effective delivery of BivP of more than 98% of all ventricular beats has been shown to be a major determinant of CRT-success.

Methods

At a Swedish tertiary referral center, data was retrospectively obtained from patient registers, medical records and preoperative electrocardiograms. Data regarding AF and BivP during the first year of follow-up was assessed from CRT-device interrogations. No intra-cardiac electrograms were studied. Kaplan-Meier curves and Cox-regression analyses adjusted for age, etiology of heart failure, left ventricular ejection fraction, left bundle branch block and NYHA class were performed to assess the impact of AF and BivP on the risk of death or heart transplantation (HTx) at 10-years of follow-up.

Results

Preoperative AF-history was found in 54% of the 379 included patients and was associated with, but did not independently predict death or HTx. The one-year incidence of new device-detected AF was 22% but not associated with poorer prognosis. At one-year, AF-history and BivP≤98%, was associated with a higher risk of death or HTx compared to patients without AF (HR 1.9, 95%CI 1.2–3.0, p = 0.005) whereas AF and BivP> 98% was not (HR 1.4, 95%CI 0.9–2.3, p = 0.14).

Conclusions

In CRT-recipients, AF-history is common and associated with poor outcome. AF-history does not independently predict mortality and is probably only a marker of a more severe underlying disease. BivP≤98% during first-year of CRT-treatment independently predicts poor outcome thus further supporting the use of 98% threshold of BivP, which should be attained to maximize the benefits of CRT.

A Post hoc analysis on rhythm and high intensity interval training in cardiac resynchronization therapy

Objectives. Evaluate the effects of a 6-month High Intensity Interval Training (HIIT) program on (1) functional capacity and health-related quality of life, (2) multiple blood biomarkers, (3) echocardiographic parameters, and (4) exercise performance, in patients in cardiac resynchronization therapy (CRT) stratified by the presence of atrial fibrillation (AF), targeting the following questions: (1) Does CRT provide similar benefits in patients in AF and sinus rhythm (SR)?; and (2) Does HIIT provides similar benefits in patients in AF and SR? Design. Estimates were available at baseline and 6 months after CRT implantation in 37 patients with heart failure. Patients were randomized after CRT to a 24-week HIIT group or to a usual care group (CON). In this sub-analysis, HIIT (AF = 7; SR = 11) and CON (AF = 9; SR = 10) were stratified by the presence of AF. Results. Patients in AF benefitted to a lesser degree from CRT in functional status than patients in SR (23.8-46.0%). However, HIIT induced superior improvements in patients in AF compared to CON (23.9-61.0%). Decreases in TNF-α (8.5-42.9%), BNP (15.3-34.6%) and left ventricular mass (9.6-26.2%) were only observed in patients in SR, whereas increases in peak oxygen uptake were only observed in patients in AF (19.5-23.2%). HIIT improved exercise capacity (8.8-59.4%) in patients in SR. Conclusions. Patients in AF or SR undergoing CRT demonstrated distinct benefits from device implantation and from HIIT as an adjunctive therapeutic strategy. This suggests that both mainstay and adjunctive therapeutics may need to be managed differently in patients in AF and SR.

Change in indication for cardiac resynchronization therapy?

Cardiac resynchronization therapy (CRT) has rapidly evolved as a standard therapy for heart failure (HF) patients with ventricular conduction delay. Although in early trials, only patients with sinus rhythm and advanced stages of HF have been candidates for CRT, more recent data have expanded the indications to patients with mild-to-moderate HF and atrial fibrillation and patients in need of antibradycardia pacing with reduced left ventricular function. On the other hand, it is now well recognized that patients with a wide QRS (>150 ms) and left bundle branch block morphology benefit most from CRT, whereas in patients with a more narrow QRS complex (<130 ms) CRT may actually be harmful despite the evidence of ventricular dyssynchrony by echocardiography. There is no prospective randomized study showing mortality benefit from a combined CRT defibrillating device over a CRT pacer alone. This is especially important because recent data indicate that older patients with non-ischaemic cardiomyopathy may not benefit from the implantable cardioverter-defibrillator as much as previously thought. Thus, the decision for a CRT pacer versus CRT defibrillating should be tailored to the therapeutic goal (improvement in prognosis versus symptomatic relief), patient age, underlying cardiac disease and comorbidities. This article gives an overview over the current indications for CRT according to published literature and the European guidelines for pacing and HF.

Does Left Ventricular Systolic Function Matter? Treating Atrial Fibrillation in HFrEF Versus HFpEF

Atrial fibrillation (AF) and heart failure (HF) pose international health care challenges that contribute significantly to hospitalizations, morbidity, mortality, and significant health care costs. Both AF and HF contribute to the development of each other and both are associated with a worsened prognosis when they occur together. Assessment of systolic function via transthoracic echocardiography is essential in the investigation of the AF patient. Clinical and echocardiographic assessment may classify AF patients with HF into HF with reduced ejection fraction (HF-rEF) and HF with preserved ejection fraction (HF-pEF). Such classification can assist in numerous important management decisions in AF.

Outcomes of cardiac resynchronisation therapy in patients with heart failure with atrial fibrillation: a systematic review and meta-analysis of observational studies

Background

Cardiac resynchronisation therapy (CRT) is beneficial in selected patients with heart failure (HF) in normal sinus rhythm (NSR). We sought to evaluate the impact of CRT with or without atrioventricular junction (AVJ) ablation in patients with HF with concomitant atrial fibrillation (AF).

Methods and results

Literature was searched (inception through 30 August 2017) for observational studies that reported outcomes in patients with HF with CRT and AF that reported all-cause and cardiovascular mortality. Thirty-one studies with 83, 571 patients were included. CRT did not decrease mortality compared with internal cardioverter defibrillator or medical therapy alone in patients with HF and AF with indications for CRT (OR: 0.851, 95% CI 0.616 to 1.176, p=0.328, I2=86.954). CRT-AF patients had significantly higher all-cause and cardiovascular mortality than CRT-NSR patients ([OR: 1.472, 95% CI 1.301 to 1.664, p=0.000] and [OR: 1.857, 95% CI 1.350 to 2.554, p=0.000] respectively). Change in left ventricular ejection fraction was not different between CRT patients with and without AF (p=0.705). AVJ ablation, however, improved all-cause mortality in CRT-AF patients when compared with CRT-AF patients without AVJ ablation (OR: 0.485, 95% CI 0.247 to 0.952, p=0.035). With AVJ ablation, there was no difference in all-cause mortality in CRT-AF patients compared with CRT-NSR patients (OR: 1.245, 95% CI 0.914 to 1.696, p=0.165).

Conclusion

The results of our meta-analysis suggest that AF was associated with decreased CRT benefits in patients with HF. CRT, however, benefits patients with AF with AVJ ablation.

Contemporary Treatment of Heart Failure

Heart failure (HF) affects 2.4% of the adult population in the United States and is associated with high health care costs. Medical and device therapy delay disease progression and improve survival in HF with reduced ejection fraction. Stage D HF is characterized by significant functional limitation, frequent HF hospitalization for decompensation, intolerance of medical therapy, use of inotropes, and high diuretic requirement. Advanced therapies with left ventricular assist devices and cardiac transplantation reduce mortality and improve quality of life, and early referral to specialized centers is imperative for patient selection and success with these therapies.

Role of Atrioventricular Junctional Ablation and Cardiac Resynchronization Therapy in Patients with Chronic Atrial Fibrillation

There remains a great deal of uncertainty whether general application of cardiac resynchronization therapy (CRT) to patients with atrial fibrillation (AF) provides any benefit assuming all other eligibility criteria are met. Preliminary observations suggest that performing atrioventricular junction ablation can improve the results of CRT in patients with AF by rendering the patient pacemaker dependent. Ongoing randomized clinical trials may provide more definitive answers in the future.