Prevalence and Prognostic Implication of Atrial Fibrillation in Heart Failure Subtypes: Systematic Review and Meta-Analysis.

BACKGROUND: Atrial fibrillation (AF) and heart failure (HF) portends a poor outcome. The HF universal definition has incorporated Heart Failure with mildly reduced Ejection Fraction (HFmrEF). We sought to evaluate the relationship between AF and different HF subtypes, with emphasis on HFmrEF. METHODS: PubMed and Embase databases were searched up to July 2022. Studies that classified HF with EF≥50% as Heart Failure with Preserved Ejection Fraction (HFpEF); EF 40%-49% as HFmrEF; and EF <40% as Heart Failure with Reduced Ejection Fraction (HFrEF) were included. RESULTS: Fifty (50) eligible studies, with 126,720 acute HF and 109,683 chronic HF patients, were included. Ten percent (10%) and 12% of patients constituted HFmrEF subtype in patients with acute and chronic HF, respectively. The AF prevalence was 38% (95%CI [33, 44], I2=96.9%) in HFmrEF, as compared to 43% (95%CI [39, 47], I2=97.9%) in HFpEF, and 32% (95%CI [29, 35], I2=98.6%) in HFrEF in acute HF patients. Meta-regression showed HFmrEF shared age as a determinant for AF prevalence with HFrEF and HFpEF. Similar AF prevalence also was observed in chronic HF. Compared to sinus rhythm, AF was associated with an increased risk of all-cause mortality in all HF subtypes: HFmrEF (n=6; HR 1.28, 95%CI [1.08, 1.51], I2=71%), HFpEF (n=10; HR 1.14, 95%CI [1.06, 1.23], I2=55%) and HFrEF (n=9; HR 1.11, 95%CI [1.02, 1.21], I2=78%). CONCLUSION: The prevalence of AF was intermediate for HFmrEF in between HFpEF and HFrEF, with determinants shared with either HF subtype. The co-existence of AF and HF predicts an increased all-cause mortality across all categories of HF. (PROSPERO registry: CRD42021189411).

Should We Check It? Assessing Interrogation of Cardiac Implantable Electronic Devices in the Emergency Department-The CHECK-ED Study: Implications for Service Planning and Care Delivery.

BACKGROUND: Requests from the emergency department (ED) for cardiac implantable electronic device (CIED) checks constitute a large workload for cardiac electrophysiology services. We sought to determine the yield of, and clinical characteristics associated with, clinically relevant (remarkable) issues from ED CIED checks. METHODS: Consecutive CIED checks from our ED over a 12-month period were studied. A remarkable issue (RI) was defined as arrhythmia relating to the presentation or device/lead issue requiring reprogramming or intervention. The association between the presenting complaint and an RI was assessed using regression analysis. Multivariable regression model was used to identify pre-specified patient-level characteristics that were predictive of a RI. RESULTS: A RI was found in 28% (n=98) of 354 ED CIED checks for 306 patients (76±16 yrs, 59% male). Most patients had no RI (n=224, 73%). One third of checks occurred after-hours and these had a higher yield of RIs than those during routine clinic hours (35% vs 23%, p=0.018). Presenting with a perceived ICD shock was predictive of a RI (odds ratio [OR] 6.0, 95% CI=1.8-20.0). Syncope/presyncope was five-fold less likely to be predictive of a RI (OR 0.19, 95% CI=0.13-0.28) despite being the most common indication for CIED check (51%, n=180 checks). Only history of AF was predictive of RI while advancing age was predictive of not finding a RI. CONCLUSION: Almost three-quarters of ED CIED checks did not yield any RI. Patient-reported ICD shock and history of AF were predictive of RI, while syncope/presyncope was not. New models of care especially during after-hours, may help to reduce the burden on cardiac electrophysiology services and health care costs.

Associations between adipokines and atrial fibrillation: A systematic review and meta-analysis.

AIMS: Although overweight and obesity are associated with increased risk of atrial fibrillation (AF), the underlying mechanisms are not well characterised. Recent data suggest that this link may be partly due to abnormal adipose tissue-derived cytokines or adipokines. However, this relationship is not well clarified. To evaluate the association between adipokines and AF in a systematic review and meta-analysis. DATA SYNTHESIS: PubMed, Embase, and Web of Science Core Collection were searched from inception through 1st March 2021. Studies were included if they reported any adipokine and AF, with their quality assessed using the Newcastle-Ottawa scale. Data were independently abstracted, with unadjusted and multivariable adjusted estimates pooled in a random-effects meta-analysis. Data are presented for overall prevalent or incident AF and AF subtypes (paroxysmal, persistent, or non-paroxysmal AF). A total of 34 studies, with 31,479 patients, were included. The following adipokines were significantly associated with AF in the pooled univariate data - apelin (risk ratio for prevalent AF: 0.05 [0.00-0.50], p = 0.01; recurrent AF: 0.21 [0.11-0.42], p < 0.01) and resistin (incident AF: 2.05 [1.02-4.1], p = 0.04; prevalent AF: 2.62 [1.78-3.85], p < 0.01). Pooled analysis of multivariable adjusted effect size estimates showed adiponectin as the sole independent predictor of AF incidence (1.14 [1.02-1.27], p = 0.02). Moreover, adiponectin was associated with non-paroxysmal AF (persistent AF: 1.45 [1.08-1.94, p = 0.01; non-paroxysmal versus paroxysmal AF: 3.14 [1.87-5.27, p < 0.01). CONCLUSIONS: Adipokines, principally adiponectin, apelin, and resistin, are associated with the risk of atrial fibrillation. However, the association is not seen after multivariate adjustment, likely reflecting the lack of statistical power. Future research should investigate these relationships in larger prospective cohorts and how they can refine AF monitoring strategies. PROSPERO ID: CRD42020208879.

Predictive role of atrial fibrillation in cognitive decline: a systematic review and meta-analysis of 2.8 million individuals.

AIMS: To systematic review and meta-analyse the association and mechanistic links between atrial fibrillation (AF) and cognitive impairment. METHODS AND RESULTS: PubMed, EMBASE, and Cochrane Library were searched up to 27 March 2021 and yielded 4534 citations. After exclusions, 61 were analysed; 15 and 6 studies reported on the association of AF and cognitive impairment in the general population and post-stroke cohorts, respectively. Thirty-six studies reported on the neuro-pathological changes in patients with AF; of those, 13 reported on silent cerebral infarction (SCI) and 11 reported on cerebral microbleeds (CMB). Atrial fibrillation was associated with 39% increased risk of cognitive impairment in the general population [n = 15: 2 822 974 patients; hazard ratio = 1.39; 95% confidence interval (CI) 1.25-1.53, I2 = 90.3%; follow-up 3.8-25 years]. In the post-stroke cohort, AF was associated with a 2.70-fold increased risk of cognitive impairment [adjusted odds ratio (OR) 2.70; 95% CI 1.66-3.74, I2 = 0.0%; follow-up 0.25-3.78 years]. Atrial fibrillation was associated with cerebral small vessel disease, such as white matter hyperintensities and CMB (n = 8: 3698 patients; OR = 1.38; 95% CI 1.11-1.73, I2 = 0.0%), SCI (n = 13: 6188 patients; OR = 2.11; 95% CI 1.58-2.64, I2 = 0%), and decreased cerebral perfusion and cerebral volume even in the absence of clinical stroke. CONCLUSION: Atrial fibrillation is associated with increased risk of cognitive impairment. The association with cerebral small vessel disease and cerebral atrophy secondary to cardioembolism and cerebral hypoperfusion may suggest a plausible link in the absence of clinical stroke. PROSPERO CRD42018109185.

BMI and atrial fibrillation recurrence post catheter ablation: A dose-response meta-analysis.

INTRODUCTION: The evidence on the association between obesity and atrial fibrillation (AF) recurrence was equivocal. We aimed to evaluate the dose-response relationship between body mass index (BMI) and AF recurrence and adverse events. METHODS: A systematic literature search was conducted using PubMed, Europe PMC, EBSCO, ProQuest and Cochrane Library. Obesity was defined as BMI ≥28 kg/m2 . The primary outcome was AF recurrence, and the secondary outcome was adverse events. Adverse events were defined as procedure-related complications and cardio-cerebrovascular events. RESULTS: There were a total of 52,771 patients from 20 studies. Obesity was associated with higher AF recurrence (Odds ratio [OR] 1.30 [95% confidence interval [CI] 1.16-1.47], P < .001; I2 : 72.7%) and similar rate of adverse events (OR 1.21 [95% CI 0.87-1.67], P = .264; I2 : 23.9%). Meta-regression showed that the association varies by age (coefficient: -0.03, P = .024). Meta-analysis of highest versus lowest BMI showed that the highest group had higher AF recurrence (OR 1.37 [95% CI 1.18-1.58], P < .001; I2 : 64.9%) and adverse events (OR 2.02 [95% CI 1.08-3.76], P = .028; I2 : 49.5%). The linear association analysis for AF recurrence was not significant (P = .544). The dose-response relationship for BMI and AF recurrence was nonlinear (pnonlinearity  < 0.001), the curve became steeper at 30-35 kg/m2 . For adverse events, an increase of 1% for every 1 kg/m2 increase in BMI (OR 1.01 [95% CI 1.00-1.02], P = .001), the relationship was nonlinear (pnonlinearity  = 0.001). CONCLUSION: Obesity was associated with higher AF recurrence in patients undergoing catheter ablation. High BMI might be associated with a higher risk for adverse events. PROSPERO ID: CRD42020198787.

Magnetic resonance imaging in non-conditional pacemakers and implantable cardioverter-defibrillators: a systematic review and meta-analysis.

AIMS: There is growing evidence that magnetic resonance imaging (MRI) scanning in patients with non-conditional cardiac implantable electronic devices (CIEDs) can be performed safely. Here, we aim to assess the safety of MRI in patients with non-conditional CIEDs. METHODS AND RESULTS: English scientific literature was searched using PubMed/Embase/CINAHL with keywords of 'magnetic resonance imaging', 'pacemaker', 'implantable defibrillator', and 'cardiac resynchronization therapy'. Studies assessing outcomes of adverse events or significant changes in CIED parameters after MRI scanning in patients with non-conditional CIEDs were included. References were excluded if the MRI conditionality of the CIEDs was undisclosed; number of patients enrolled was <10; or studies were case reports/series. About 35 cohort studies with a total of 5625 patients and 7196 MRI scans (0.5-3 T) in non-conditional CIEDs were included. The overall incidence of lead failure, electrical reset, arrhythmia, inappropriate pacing and symptoms related to pocket heating, or torque ranged between 0% and 1.43%. Increase in pacing lead threshold >0.5 V and impedance >50Ω was seen in 1.1% [95% confidence interval (CI) 0.7-1.8%] and 4.8% (95% CI 3.3-6.4%) respectively. The incidence of reduction in P- and R-wave sensing by >50% was 1.5% (95% CI 0.6-2.9%) and 0.4% (95% CI 0.06-1.1%), respectively. Battery voltage reduction of >0.04 V was reported in 2.2% (95% CI 0.2-6.1%). CONCLUSION: This meta-analysis affirms the safety of MR imaging in non-conditional CIEDs with no death or implantable cardioverter-defibrillator shocks and extremely low incidence of lead or device-related complications.

Complex interaction of obesity, intentional weight loss and heart failure: a systematic review and meta-analysis.

OBJECTIVE: The aim of the meta-analysis was to determine the association of obesity and heart failure (HF) and the cardiac impact of intentional weight loss following bariatric surgery on cardiac structure and myocardial function in obese subjects. METHODS: MEDLINE, Embase and Web of Science were searched up to 3 April 2018. Studies reporting association and prognostic impact of obesity in HF and the impact of intentional weight loss following bariatric surgery on cardiac structure and myocardial function in obesity were included in the meta-analysis. RESULTS: 4959 citations were reviewed. After exclusions, 29 studies were analysed. A 'J curve' relationship was observed between body mass index (BMI) and risk of HF with maximum risk in the morbidly obese (1.73 (95% CI 1.30 to 2.31), p<0.001, n=11). Although 'obesity paradox' was observed for all-cause mortality, the overweight group was associated with lower cardiovascular (CV) mortality (OR=0.86 (95% CI 0.79 to 0.94), n=11) with no significant differences across other BMI groups. Intentional weight loss induced by bariatric surgery in obese patients (n=9) without established HF, atrial fibrillation or known coronary artery disease, was associated with a reduction in left ventricular mass index (p<0.0001), improvement in left ventricular diastolic function (p≤0.0001) and a reduction in left atrial size (p=0.02). CONCLUSIONS: Despite the increased risk of HF with obesity, an 'obesity paradox' is observed for all-cause mortality. However, the nadir for CV mortality is observed in the overweight group. Importantly, intentional weight loss was associated with improvement in indices of cardiac structure and myocardial function in obese patients. TRIAL REGISTRATION NUMBER: APP 74412.

Feasibility, Safety, and Efficacy of Posterior Wall Isolation During Atrial Fibrillation Ablation: A Systematic Review and Meta-Analysis.

BACKGROUND: The posterior left atrium is an arrhythmogenic substrate that contributes to the initiation and maintenance of atrial fibrillation (AF); however, the feasibility, safety, and efficacy of posterior wall isolation (PWI) as an AF ablation strategy has not been widely reported. METHODS: We undertook a systematic review and meta-analysis of studies performing PWI to assess (1) acute procedural success including the ability to achieve PWI and the number of procedure-related complications, (2) Long-term, clinical success including rates of arrhythmia recurrence and posterior wall reconnection, and (3) The efficacy of PWI compared with pulmonary vein isolation on preventing arrhythmia recurrence. MEDLINE, EMBASE, and Web of Science databases were searched in May 2018 to retrieve relevant studies. Results were pooled using a random effects model. RESULTS: Seventeen studies (13 box isolation, 3 single ring isolation, and 1 debulking ablation) comprising 1643 patients (31.3% paroxysmal AF, left atrial diameter 41±3.1 mm) were included in the final analysis. In studies focusing specifically on PWI, the acute procedural success rate for achieving PWI was 94.1% (95% CI, 87.2%-99.3%). Single-procedure 12-month freedom from atrial arrhythmia was 65.3% (95% CI, 57.7%-73.9%) overall and 61.9% (54.2%-70.8%) for persistent AF. Randomized control trials comparing PWI to pulmonary vein isolation (3 studies, 444 patients) yielded conflicting results and could not confirm an incremental benefit to PWI. Fifteen major complications (0.1%), including 2 atrio-esophageal fistulas, were reported. CONCLUSIONS: PWI as an end point of AF ablation can be achieved in a large proportion of cases with good rates of 12-month freedom from atrial arrhythmia. Although the procedure-related complication rate is low, it did not eliminate the risk of atrio-esophageal fistula. Registration: URL: http://www.crd.york.ac.uk/prospero. PROSPERO registration number: CRD42018107212.

Implication of ventricular pacing burden and atrial pacing therapies on the progression of atrial fibrillation: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Atrial fibrillation (AF) is common after pacemaker implantation. However, the impact of pacemaker algorithms in AF prevention is not well understood. OBJECTIVE: The purpose of this study was to evaluate the role of pacing algorithms in preventing AF progression. METHODS: A systematic search of articles using the PubMed and Embase databases resulted in a total of 754 references. After exclusions, 21 randomized controlled trials (8336 patients) were analyzed, comprising studies reporting ventricular pacing percentage (VP%) (AAI vs DDD, n = 1; reducing ventricular pacing [RedVP] algorithms, n = 2); and atrial pacing therapies (atrial preference pacing [APP], n = 14; atrial antitachycardia pacing [aATP]+APP, n = 3; RedVP+APP+aATP, n = 1). RESULTS: Low VP% (<10%) lead to a nonsignificant reduction in the progression of AF (hazard ratio [HR] 0.80; 95% confidence interval [CI] 0.57-1.13; P = .21; I2 = 67%) compared to high VP% (>10%). APP algorithm reduced premature atrial complexes (PAC) burden (mean difference [MD] -1117.74; 95% CI -1852.36 to -383.11; P = .003; I2 = 67%) but did not decrease AF burden (MD 8.20; 95% CI -5.39 to 21.80; P = .24; I2 = 17%) or AF episodes (MD 0.00; 95% CI -0.24 to 0.25; P = .98; I2 = 0%). Similarly, aATP+APP programming showed no significant difference in AF progression (odds ratio 0.65; 95% CI 0.36-1.14; P = .13; I2 = 61%). No serious adverse events related to algorithm were reported. CONCLUSION: This meta-analysis of randomized controlled trials demonstrated that algorithms to reduce VP% can be considered safe. Low burden VP% did not significantly suppress AF progression. The atrial pacing therapy algorithms could suppress PAC burden but did not prevent AF progression.

Predicted longevity of contemporary cardiac implantable electronic devices: A call for industry-wide "standardized" reporting.

BACKGROUND: Battery longevity is an important factor that may influence the selection of cardiac implantable electronic devices (CIEDs). However, there remains a lack of industry-wide standardized reporting of predicted CIED longevity to facilitate informed decision-making for implanting physicians and payers. OBJECTIVE: The purpose of this study was to compare the predicted longevity of current generation CIEDs using best-matched CIEDs settings to assess differences between brands and models. METHODS: Data were extracted for current model pacemakers, implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy-defibrillators (CRT-Ds) from product manuals and, where absent, by communication with the manufacturers. Pacemaker longevity estimations were based on standardized pacing outputs (2.5V, 0.40-ms pulse width, 500-Ω impedance) and pacing loads of 50% or 100% at 60 bpm. ICD and CRT-D longevity were estimated at 0% pacing and 15% atrial plus 100% biventricular pacing, with essential capacitor reforms and zero clinical shocks. RESULTS: Mean maximum predicted longevity of single- and dual-chamber pacemakers was 12.0 ± 2.1 and 9.8 ± 1.9 years, respectively. Use of advanced features such as remote monitoring, prearrhythmia electrogram storage, and rate response can result in ∼1.4 years of reduction in longevity. Mean maximum predicted longevity of ICDs and CRT-Ds was 12.4 ± 3.0 and 8.8 ± 2.1 years, respectively. Of note, there were significant variations in predicted CIED longevity according to device manufacturers, with up to 44%, 42%, and 44% difference for pacemakers, ICDs, and CRT-Ds, respectively. CONCLUSION: Contemporary CIEDs demonstrate highly variable predicted longevity according to device manufacturers. This may impact on health care costs and long-term clinical outcomes.

Outcomes of persistent and long-standing persistent atrial fibrillation ablation: a systematic review and meta-analysis.

Aims: Several techniques have been utilized for the ablation of persistent (P) and long-standing persistent (LsP) atrial fibrillation (AF); however, the best approach of substrate ablation remains poorly defined. This study aims to examine the impact of ablation approach on outcomes associated with P or LsP AF ablation by conducting a meta-analysis and regression on contemporary literature. Methods and results: A systematic literature review was conducted up to 29 July 2015 for scientific literature reporting on outcomes associated with P or LsP AF ablation. One hundred and thirteen studies reported outcomes in a total of 18 657 patients undergoing various ablation approaches for the treatment of P-LsP AF between 2001 and 2015. The point efficacy estimate of a single-AF ablation procedure without the use of anti-arrhythmic drugs was 43% (95% CI; 39-47%). Multiple procedures and/or the use of anti-arrhythmic drugs increase success to 69% (95% CI; 66-71%). Meta-regression revealed that ablation technique (P < 0.001) and left atrial size (P = 0.02) were predictive of single procedure, drug-free success. The addition of extra-pulmonary substrate approaches was associated with declining efficacy when compared to a pulmonary vein ablation alone. Conclusion: The efficacy of a single-AF ablation procedure for P or LsP AF is 43%; however, can be increased to 69% with the use of multiple procedures and/or anti-arrhythmic drugs. Current literature supports the finding that pulmonary vein antrum ablation/isolation is at least equivalently efficacious to other contemporary P-LsP ablation strategies.

Premature Trigger of ERI in Medtronic EnRhythm Devices.

BACKGROUND: Medical technology has made significant advances over the last few decades with smaller and more dynamic pacemakers. However, technical failures leading to premature replacement is a cause of concern. We present a series of Medtronic EnRhythm devices that reached premature elective replacement indicator (ERI). METHODS: The database of Centre of Heart Rhythm Disorders was searched for EnRhythm device implantation from 2006 to 2011. Battery depletion <8.5 years was considered premature considering the projected average longevity to be 8.5-10.5 years. An unexpected premature ERI was defined when it was reached within 3 months of last normal check. Device follow-up was conducted every 3 months after advisory. RESULTS: A total of 88 EnRhythm pacemakers were implanted. Over a median follow-up of 6.2 years (range: 0.3-9.2), 39 (44.3%) EnRhythm devices reached premature ERI. In 11 (28%), ERI was not recognized and patients were being investigated for other causes of unsteadiness or dyspnea prior to device check. Notably, three (7%) patients had premature ERI < 3.5 years. Ten (25.6%) had sudden and unexpected premature ERI. While asynchronous pacing was observed, there were no cases of absence of pacing. CONCLUSIONS: The rate of premature ERI for EnRhythm devices was 44.3%, significantly higher than reported by the manufacturer. Of concern, a sizeable proportion occurred unexpectedly, warranting more frequent reviews and empirical replacement in some patients. With the experience of the EnRhythm, appropriate monitoring strategies are recommended for future advisories.

Feasibility and safety of Reveal LINQ insertion in a sterile procedure room versus electrophysiology laboratory.

BACKGROUND: Insertable cardiac monitors (ICMs) are increasingly utilized for diagnosis of unexplained syncope and arrhythmia monitoring. The Reveal LINQ is a novel miniaturized ICM with improved algorithms. The feasibility and safety of insertion outside the traditional electrophysiology laboratory is unknown. Here we compare outcomes of Reveal LINQ insertion in different environments. METHODS: We report on a prospective, single-centre, non-randomized, observational experience of consecutive Reveal LINQ implantation in the electrophysiology laboratory or a procedure room between October 2013 and October 2015. RESULTS: Of 178 consecutive patients who underwent LINQ device insertion, 80 were implanted in the electrophysiology laboratory and 98 in a procedure room. There were no significant differences in baseline patient characteristics. All implants were performed in the recommended manufacturer method with the exception of 1 which required suture closure. Only a minority received peri-procedural antibiotics with a greater number in the electrophysiology laboratory group (11 [14%] versus 1 [1%], p=0.007). Overall, there were 3 (1.7%) complications with no significant difference between the electrophysiology laboratory and the procedure room groups (2 [3%] versus 1 [1%], p=0.45). There was 1 superficial infection in the procedure room group and 1 superficial infection with device extrusion and 1 traumatic extrusion in the electrophysiology laboratory group. Procedure room implantation subjectively improved laboratory efficiency and patient flow. CONCLUSION: Reveal LINQ insertion can be safely performed outside of the cardiac laboratory provided a sterile technique is followed by the operator using manufacturer recommendations for insertion. These findings have significant resource implications for hospitals undertaking such procedures.