Atrial fibrillation and heart failure: A contemporary review of current management approaches

Sex differences in atrial fibrillation ablation outcomes in patients with heart failure

BACKGROUND

There is a lack of data on the impact of sex on the outcomes of patients with heart failure (HF) undergoing atrial fibrillation (AF) ablation. We aimed to analyze the association of sex with outcomes of atrial fibrillation ablation in patients with heart failure.

METHODS

The National Readmissions Database (NRD) was analyzed from 2016 to 2019 to identify patients ≥ 18 years old with heart failure (HF) undergoing AF ablation. The outcomes of interest included peri-procedural complications, in-hospital mortality, resource utilization, and unplanned 1-year readmissions. The final cohort was divided into patients with HFrEF and HFpEF and outcomes were compared between males and females in both cohorts.

RESULTS

A total of 23,277 patients with HF underwent AF ablation between 2016 and 2019, of which 14,480 had HFrEF and 8,797 had HFpEF. Among patients with HFrEF, 61.6% were males and 38.4% were females whereas, among patients with HFpEF, 35.4% were males and 64.6% were females. On a multivariable-adjusted analysis, in patients with HFrEF, there was no difference in the odds of in-hospital mortality, peri-procedural complications, or 1-year HF-related/AF-related/all-cause readmissions between males and females. In patients with HFpEF, females had a higher risk 1-year HF-related readmissions (adjusted hazards ratio: 1.46; 95% CI: 1.13-1.87; p = 0.01), without any difference in the 1-year AF-related/all-cause readmissions, in-hospital mortality, or peri-procedural complications.

CONCLUSION

Our results show that females with HFrEF undergoing AF ablation have similar outcomes whereas females with HFpEF have higher 1-year HF readmissions with no difference in the other outcomes, compared to males.

The SK4 channel allosteric blocker, BA6b9, reduces atrial fibrillation substrate in rats with reduced ejection fraction

Atrial fibrillation (AF), the most common cardiac arrhythmia, is strongly associated with several comorbidities including heart failure (HF). AF in general, and specifically in the context of HF, is progressive in nature and associated with poor clinical outcomes. Current therapies for AF are limited in number and efficacy and do not target the underlying causes of atrial remodeling such as inflammation or fibrosis. We previously identified the calcium-activated SK4 K+ channels, which are preferentially expressed in the atria relative to the ventricles in both rat and human hearts, as attractive druggable target for AF treatment. Here, we examined the ability of BA6b9, a novel allosteric inhibitor of SK4 channels that targets the specific calmodulin-PIP2 binding domain, to alter AF susceptibility and atrial remodeling in a systolic HF rat postmyocardial infarction (post-MI) model. Daily BA6b9 injection (20 mg/kg/day) for 3 weeks starting 1-week post-MI prolonged the atrial effective refractory period, reduced AF induction and duration, and dramatically prevented atrial structural remodeling. In the post-MI left atrium (LA), pronounced upregulation of the SK4 K+ channel was observed, with corresponding increases in collagen deposition, α-SMA levels, and NLRP3 inflammasome expression. Strikingly, BA6b9 treatment reversed these changes while also significantly reducing the lateralization of the atrial connexin Cx43 in the LA of post-MI rats. Our findings indicate that the blockade of SK4 K+ channels using BA6b9 not only favors rhythm control but also remarkably reduces atrial structural remodeling, a property that is highly desirable for novel AF therapies, particularly in patients with comorbid HF.

Catheter ablation versus medical therapy for atrial fibrillation in patients with heart failure with preserved ejection fraction: A systematic review and meta-analysis

BACKGROUND

The benefit of catheter ablation in patients with atrial fibrillation (AF) for patients with heart failure with preserved ejection fraction (HFpEF) remains uncertain.

OBJECTIVE

We performed a systematic review and meta-analysis to compare catheter ablation and medical therapy (antiarrhythmics for rhythm or rate control) in patients with AF and HFpEF.

METHODS

We searched PubMed, Embase, and Cochrane Central Register of Controlled Trials. Outcomes were the composite end points of death or heart failure (HF) hospitalization, all-cause death, cardiovascular death, all-cause rehospitalization, and HF hospitalization. Statistical analysis was performed using the R program (version 4.3.2). Heterogeneity was assessed with I2 statistics.

RESULTS

We included 20,257 patients from 8 studies. Of those, 3 were derived from RCTs, either through post hoc analysis or subgroup analysis, and 5 were observational studies. The median follow-up ranged from 24.6 to 61.2 months. Compared with medical therapy, catheter ablation was associated with a statistically significant lower risk of death or HF hospitalization (hazard ratio [HR] 0.62; 95% confidence interval [CI] 0.47-0.83; P = .001; I2 = 66%), all-cause death (HR 0.68; 95% CI 0.46-0.99; P = .047; I2 = 61%), cardiovascular death (HR 0.42; 95% CI 0.21-0.84; P = .014; I2 = 22%), and HF hospitalization (HR 0.43; 95% CI 0.23-0.82; P = .011; I2 = 87%).

CONCLUSION

In this meta-analysis, catheter ablation was associated with a lower risk of all-cause mortality, cardiovascular death, HF hospitalization, and all-cause rehospitalization in comparison to medical therapy in patients with AF and HFpEF.

Ultrasensitive detection of vital biomolecules based on a multi-purpose BioMEMS for Point of care testing: digoxin measurement as a case study

Rapid and label-free detection of very low concentrations of biomarkers in disease diagnosis or therapeutic drug monitoring is essential to prevent disease progression in Point of Care Testing. For this purpose, we propose a multi-purpose optical Bio-Micro-Electro-Mechanical-System (BioMEMS) sensing platform which can precisely measure very small changes of biomolecules concentrations in plasma-like buffer samples. This is realized by the development of an interferometric detection method on highly sensitive MEMS transducers (cantilevers). This approach facilitates the precise analysis of the obtained results to determine the analyte type and its concentrations. Furthermore, the proposed multi-purpose platform can be used for a wide range of biological assessments in various concentration levels by the use of an appropriate bioreceptor and the control of its coating density on the cantilever surface. In this study, the present system is prepared for the identification of digoxin medication in its therapeutic window for therapeutic drug monitoring as a case study. The experimental results represent the repeatability and stability of the proposed device as well as its capability to detect the analytes in less than eight minutes for all samples. In addition, according to the experiments carried out for very low concentrations of digoxin in plasma-like buffer, the detection limit of LOD = 300 fM and the maximum sensitivity of S = 5.5 × 1012 AU/M are achieved for the implemented biosensor. The present ultrasensitive multi-purpose BioMEMS sensor can be a fully-integrated, cost-effective device to precisely analyze various biomarker concentrations for various biomedical applications.

Early referrals save lives in advanced heart failure

ABSTRACT

Heart failure (HF) is a chronic, progressive medical condition that can quickly cause deterioration of the patient's medical and functional status. Delay of HF diagnosis and improper treatment can lead to catastrophic patient outcomes. This case report describes a 62-year-old with HF with reduced ejection fraction secondary to nonischemic cardiomyopathy, s/p cardiac resynchronization therapy defibrillator in 2020. He presented to the emergency department for worsening shortness of breath and chest pain for 3 days and subsequently had cardiac arrest. The patient eventually underwent a successful implantation of left ventricular assist device as a bridge to transplant. Timely referral yields a better patient outcome. This case study illustrates a clinical pathway that can be used by primary care providers when considering referral of a patient with advanced HF (AHF) to an AHF center for management and possible advanced therapies.

Evaluation of Clinical, Echocardiographic, and Therapeutic Characteristics, and Prognostic Outcomes of Coexisting Heart Failure among Patients with Atrial Fibrillation: The Jordan Atrial Fibrillation (JoFib) Study

BACKGROUND

Atrial fibrillation (AF) is the most commonly encountered cardiac arrhythmia in clinical practice. Heart failure (HF) can occur concurrently with AF.

AIM

We compared different demographic, clinical, and echocardiographic characteristics between patients with AF+HF and patients with AF only. Furthermore, we explored whether concurrent HF independently predicts several outcomes (all-cause mortality, cardiovascular mortality, ischemic stroke/systemic embolism (IS/SE), major bleeding, and clinically relevant non-major bleeding (CRNMB)).

MATERIALS AND METHODS

Comparisons between the AF+HF and the AF-only group were carried out. Multivariable Cox proportional hazard models were constructed for each outcome to assess whether HF was predictive of any of them while controlling for possible confounding factors.

RESULTS

A total of 2020 patients were included in this study: 481 had AF+HF; 1539 had AF only. AF+HF patients were older, more commonly males, and had a higher prevalence of diabetes mellitus, dyslipidemia, coronary artery disease, and chronic kidney disease (p≤0.05). Furthermore, AF+HF patients more commonly had pulmonary hypertension and low ejection fraction (p≤0.001). Finally, HF was independently predictive of all-cause mortality (adjusted HR 2.17, 95% CI (1.66-2.85) and cardiovascular mortality (adjusted HR 2.37, 95% CI (1.68-3.36).

CONCLUSION

Coexisting AF+HF was associated with a more labile and higher-risk population among Jordanian patients. Furthermore, coexisting HF independently predicted higher all-cause mortality and cardiovascular mortality. Efforts should be made to efficiently identify such cases early and treat them aggressively.

Sequencing Quadruple Therapy for Heart Failure with Reduced Ejection Fraction: Does It Really Matter?

The conventional sequence of guideline-directed medical therapy (GDMT) initiation in heart failure with reduced ejection fraction (HFrEF) assumes that the effectiveness and tolerability of GDMT agents mirror their order of discovery, which is not true. In this review, the authors discuss flexible GDMT sequencing that should be permitted in special populations, such as patients with bradycardia, chronic kidney disease, or atrial fibrillation. Moreover, the initiation of certain GDMT medications may enable tolerance of other GDMT medications. Most importantly, the achievement of partial doses of all four pillars of GDMT is better than achievement of target dosing of only a couple.

Validation of E/e' Using the Index-Beat Method as an Estimate of Left Atrial Pressure in Patients with Atrial Fibrillation

INTRODUCTION

Echocardiographic assessment of diastolic function during atrial fibrillation (AF) remains challenging due to the irregular cardiac cycle length. We sought to assess whether the index-beat method, the beat following two preceding cardiac cycles of equal duration, could provide a more reliable measurement of E/e' (mitral E wave/diastolic tissue Doppler velocity) than the conventional averaging of consecutive beats and hence facilitate the noninvasive estimation of elevated left atrial pressure (LAP) in patients with AF.

METHODS

We prospectively studied 35 patients with persistent AF who had preserved left ventricular ejection fraction and underwent radiofrequency ablation. LAP was measured in conjunction with transseptal puncture during catheter ablation. Echocardiography was performed 24 h before ablation and E/e' was determined using the recommended averaging of 10 beats and the index-beat method, with the observers blinded to the clinical details and LAP measurements.

RESULTS

Correlation analysis showed a strong positive correlation between two methods in terms of both septal E/e' (r = 0.841, p < 0.001) and lateral E/e' (r = 0.930, p < 0.001). Bland-Altman analysis also showed a good agreement between the two measurement methods in terms of E/e'. E/e' determined using both conventional averaging and the index-beat method was significantly correlated with LAP (p < 0.05). After Fisher Z transformation, we found that the index-beat septal E/e' had a better correlation with LAP than did the conventional averaging E/e' (r = 0.736 vs. r = 0.392, Zr = -2.110, p = 0.035). Furthermore, the index-beat method took significantly less time to measure E/e' (mean 33.6 s; 95% confidence intervals [CIs]: 32.1 s-36.2 s) than did conventional averaging method (mean 96.2 s; 95% CI: 90.2 s-102.3 s; p < 0.001). Receiver operating characteristic curve analysis revealed that the optimal cut-off for predicting mean LAP >12 mm Hg was 11 (sensitivity 100%; specificity 77.3%) for index-beat septal E/e' and 16 (sensitivity 61.5%; specificity 95.5%) for index-beat lateral E/e'.

CONCLUSIONS

Good correlations were found between E/e' and LAP in patients with AF, particularly with the index-beat method. Moreover, the index-beat method can easily measure E/e' at an accuracy similar to that for the conventional averaging of consecutive beats, which can therefore be applied to assess the diastolic dysfunction and potentially improve the diagnosis of heart failure in patients with AF.

Relative Contribution of Atrial Fibrillation to Outcomes of Patients With Cardiomyopathy Based on Severity of Left Ventricular Dysfunction

In patients with left ventricular (LV) dysfunction, the risk of death or heart failure hospitalizations (HFHs) increases with worsening ejection fraction (EF). Whether the relative contribution of atrial fibrillation (AF) to outcomes is more pronounced in patients with worse EF is not confirmed. The present study aimed to investigate the relative influence of AF on the outcome of cardiomyopathy patients by severity of LV dysfunction. In this observational study, data from 18,003 patients with EF ≤50% seen at a large academic institution between 2011 and 2017 were analyzed. Patients were stratified by EF quartiles (EF<25%, 25%≤EF<35%, 35%≤EF<40%, and EF≥40%, for quartiles 1, 2, 3, and 4, respectively). and followed to the end point of death or HFH. Outcomes of AF versus non-AF patients were compared within each EF quartile. During a median follow-up of 3.35 years, 8,037 patients (45%) died and 7,271 (40%) had at least 1 HFH. Rates of HFH and all-cause mortality increased as EF decreased. The hazard ratios (HRs) of death or HFH for AF versus non-AF patients increased steadily with increasing EF (HR of 1.22, 1.27, 1.45, 1.50 for quartiles 1, 2, 3, and 4, respectively, p = 0.045) driven primarily by the risk of HFH (HR of 1.26, 1.45, 1.59, 1.69 for quartiles 1, 2, 3, and 4, respectively, p = 0.045). In conclusion, in patients with LV dysfunction, the detrimental influence of AF on the risk of HFH is more pronounced in those with more preserved EF. Mitigation strategies for AF with the goal of decreasing HFH may be more impactful in patients with more preserved LV function.

Predicting Heart Failure in Patients with Atrial Fibrillation: A Report from the Prospective COOL-AF Registry

BACKGROUND

This study aimed to determine risk factors and incidence rate and develop a predictive risk model for heart failure for Asian patients with atrial fibrillation (AF).

METHODS

This is a prospective multicenter registry of patients with non-valvular AF in Thailand conducted between 2014 and 2017. The primary outcome was the occurrence of an HF event. A predictive model was developed using a multivariable Cox-proportional model. The predictive model was assessed using C-index, D-statistics, Calibration plot, Brier test, and survival analysis.

RESULTS

There were a total of 3402 patients (average age 67.4 years, 58.2% male) with mean follow-up duration of 25.7 ± 10.6 months. Heart failure occurred in 218 patients during follow-up, representing an incidence rate of 3.03 (2.64-3.46) per 100 person-years. There were ten HF clinical factors in the model. The predictive model developed from these factors had a C-index and D-statistic of 0.756 (95% CI: 0.737-0.775) and 1.503 (95% CI: 1.372-1.634), respectively. The calibration plots showed a good agreement between the predicted and observed model with the calibration slope of 0.838. The internal validation was confirmed using the bootstrap method. The Brier score indicated that the model had a good prediction for HF.

CONCLUSIONS

We provide a validated clinical HF predictive model for patients with AF, with good prediction and discrimination values.

Target heart rate in heart failure with reduced ejection fraction and atrial fibrillation: Goldilocks zone

The rates of atrial fibrillation (AF) and heart failure with reduced ejection fraction (HFrEF) continue to grow with many patients suffering from their combined impact on quality of life and prognosis. A lower heart rate (HR) in HFrEF is associated with reduced morbidity and mortality due to beta-blocker and ivabradine therapy. Postulated mechanisms include reduced neurohumoral activation, increased diastolic filling time and myocardial energy conservation. In contrast, the landmark randomised controlled non-inferiority RACE II trial demonstrated that a lenient rate control strategy (target HR <110 beats per minute [bpm]) was more attainable and safer than a strict rate control strategy (resting HR <80 bpm) in permanent AF. Physiologically, a higher HR is needed to compensate for the lost 'atrial kick' that contributes to the cardiac output by coordinated atrial contractions in normal sinus rhythm. This leaves the not insignificant number of patients with HFrEF and AF in a conundrum over optimal HR control. Retrospective analyses of AF and HR control in landmark HFrEF trials (e.g. CHARM, PARADIGM and ATMOSPHERE) point towards better outcomes with a less stringent target HR. However, this association disappears after adjustment for known prognostic markers in HFrEF, including left ventricular ejection fraction, New York Heart Association class and NT-proBNP levels. There is a clear need for dedicated randomised controlled trials, investigating rate control strategies in this increasingly large subgroup of patients. Regardless of rate control strategy, effective anti-coagulation and guideline-directed medical therapy must not be forgotten in the treatment of patients with HFrEF and AF.

Burden of atrial fibrillation among adults with heart failure in sub-Saharan Africa: a systematic review and meta-analysis

OBJECTIVES

This study aimed to estimate the prevalence of atrial fibrillation (AF) in adults with heart failure (HF) and summarise the all-cause mortality ratio among adult patients with coexisting HF and AF in sub-Saharan Africa (SSA).

SETTING

This was a systematic review and meta-analysis of cross-sectional and cohort studies with primary data on the prevalence and incidence of AF among patients with HF and the all-cause mortality ratio among patients with HF and AF in SSA. We combined text words and MeSH terms to search MEDLINE, PubMed and Global Health Library through Ovid SP, African Journals Online and African Index Medicus from database inception to 10 November 2021. Random-effects meta-analysis was used to estimate pooled prevalence.

PRIMARY OUTCOME MEASURES

The prevalence and incidence of AF among patients with HF, and the all-cause mortality ratio among patients with HF and AF.

RESULTS

Twenty-seven of the 1902 records retrieved from database searches were included in the review, totalling 9987 patients with HF. The pooled prevalence of AF among patients with HF was 15.6% (95% CI 12.0% to 19.6%). At six months, the all-cause mortality was 18.4% (95% CI 13.1% to 23.6%) in a multinational registry and 67.7% (95% CI 51.1% to 74.3%) in one study in Tanzania. The one-year mortality was 48.6% (95% CI 32.5% to 64.7%) in a study in the Democratic Republic of Congo. We did not find any study reporting the incidence of AF in HF.

CONCLUSION

AF is common among patients with HF in SSA, and patients with AF and HF have poor survival. There is an urgent need for large-scale population-based prospective data to reliably estimate the prevalence, incidence and risk of mortality of AF among HF patients in SSA to better understand the burden of AF in patients with HF in the region.

PROSPERO REGISTRATION NUMBER

CRD42018087564.