Cognitive impairment and treatment strategy for atrial fibrillation in older adults: The SAGE-AF study.

BACKGROUND: Cognitive impairment is strongly associated with atrial fibrillation (AF). Rate and rhythm control are the two treatment strategies for AF and the effect of treatment strategy on risk of cognitive decline and frailty is not well established. We sought to determine how treatment strategy affects geriatric-centered outcomes. METHODS: The Systematic Assessment of Geriatric Elements-AF (SAGE-AF) was a prospective, observational, cohort study. Older adults with AF were prospectively enrolled between 2016 and 2018 and followed longitudinally for 2 years. In a non-randomized fashion, participants were grouped by rate or rhythm control treatment strategy based on clinical treatment at enrollment. Baseline characteristics were compared. Longitudinal binary mixed models were used to compare treatment strategy with respect to change in cognitive function and frailty status. Cognitive function and frailty status were assessed with the Montreal Cognitive Assessment Battery and Fried frailty phenotype tools. RESULTS: 972 participants (mean age = 75, SD = 6.8; 49% female, 87% non-Hispanic white) completed baseline examination and 2-year follow-up. 408 (42%) were treated with rate control and 564 (58%) with rhythm control. The patient characteristics of the two groups were different at baseline. Participants in the rate control group were older, more likely to have persistent AF, prior stroke, be treated with warfarin and have baseline cognitive impairment. After adjusting for baseline differences, participants treated with rate control were 1.5 times more likely to be cognitively impaired over 2 years (adjusted OR: 1.47, 95% CI:1.12, 1.98) and had a greater decline in cognitive function (adjusted estimate: -0.59 (0.23), p < 0.01) in comparison to rhythm control. Frailty did not vary between the treatment strategies. CONCLUSIONS: Among those who had 2-year follow-up in non-randomized observational cohort, the decision to rate control AF in older adults was associated with increased odds of decline in cognitive function but not frailty.

Retrieval of Embolized WATCHMAN® Flex Atrial Appendage Occlusion Device.

This case report documents the management of a 66-year old man with atrial fibrillation with recent placement of a WATCHMAN® Flex atrial appendage occlusion device. The patient presented with renal failure, abdominal pain, and difficulty walking 2 months after placement. The WATCHMAN® Flex device was found to have embolized to his abdominal aorta at the level of the renal arteries with associated thrombus. Extensive workup revealed reduced left ventricular cardiac function and decreased renal function, both of which were felt to be potentially reversible with device removal. The patient then underwent retrieval of the device and all associated thrombus via an open retroperitoneal approach. This case demonstrates a potential consequence of implanting devices such as an atrial appendage occlusion device and describes a technique for removal.

Incidence and prognostic significance of newly-diagnosed atrial fibrillation among older U.S. veterans hospitalized with COVID-19.

Most prior studies on the prognostic significance of newly-diagnosed atrial fibrillation (AF) in COVID-19 did not differentiate newly-diagnosed AF from pre-existing AF. To determine the association between newly-diagnosed AF and in-hospital and 30-day mortality among regular users of Veterans Health Administration using data linked to Medicare. We identified Veterans aged ≥ 65 years who were hospitalized for ≥ 24 h with COVID-19 from 06/01/2020 to 1/31/2022 and had ≥ 2 primary care visits within 24 months prior to the index hospitalization. We performed multivariable logistic regression analyses to estimate adjusted risks, risk differences (RD), and odds ratios (OR) for the association between newly-diagnosed AF and the mortality outcomes adjusting for patient demographics, baseline comorbidities, and presence of acute organ dysfunction on admission. Of 23,299 patients in the study cohort, 5.3% had newly-diagnosed AF, and 29.2% had pre-existing AF. In newly-diagnosed AF adjusted in-hospital and 30-day mortality were 16.5% and 22.7%, respectively. Newly-diagnosed AF was associated with increased mortality compared to pre-existing AF (in-hospital: OR 2.02, 95% confidence interval [CI] 1.72-2.37; RD 7.58%, 95% CI 5.54-9.62) (30-day: OR 1.86; 95% CI 1.60-2.16; RD 9.04%, 95% CI 6.61-11.5) or no AF (in-hospital: OR 2.24, 95% CI 1.93-2.60; RD 8.40%, 95% CI 6.44-10.4) (30-day: 2.07, 95% CI 1.80-2.37; RD 10.2%, 95% CI 7.89-12.6). There was a smaller association between pre-existing AF and the mortality outcomes. Newly-diagnosed AF is an important prognostic marker for patients hospitalized with COVID-19. Whether prevention or treatment of AF improves clinical outcomes in these patients remains unknown.

Prognostic Importance of Atrial Fibrillation and Anticoagulation in Alcoholic Versus Dilated Cardiomyopathy.

AIMS: Limited data exist to describe the prognostic impact of atrial fibrillation (AF) and oral anticoagulation on patients with alcoholic cardiomyopathy (ACM) compared with dilated cardiomyopathy (DCM) and were investigated in this study. METHODS: Using Danish nationwide registries, a cohort analysis was conducted to assess the prognostic differences for patients with a first diagnosis of ACM versus DCM with and without AF 1994-2018 (followed until end 2019). Our study also assessed differences in mortality following initiation of anticoagulation in both populations. RESULTS: Totally, 1237 patients with ACM (33% with AF) and 17,211 individuals with DCM (33% with AF) were included. Those with ACM were more often men (89 versus 71%) and younger than patients with DCM (mean age 56 versus 64 years). Cumulative 5-year mortality was greater among patients with ACM, compared with DCM, regardless of AF (ACM with AF 49% [95% CI: 44-54%], ACM without AF 48% [45-53%], DCM with AF 41% [39-42%], DCM without AF 30% [29-31%], P < 0.0001). The prognosis associated with AF was statistically significantly different in people with ACM and DCM (adjusted hazards ratio 0.85 [95% CI: 0.74-0.98] versus 1.04 [1.00-1.09] in ACM and DCM, P < 0.0001). The mortality associated with oral anticoagulation was similar in ACM and DCM (hazards ratio 0.81 [0.61-1.07] versus 0.87 [0.80-0.94], P = 0.49). CONCLUSIONS: Patients with ACM had a worse prognosis when compared with patients with DCM, but this did not appear to be driven by AF. Patients with ACM were observed to have similar associated risk benefits of oral anticoagulation as DCM.

Meta-Analysis of Randomized Clinical Trials Comparing the Impact of Implantable Loop Recorder Versus Usual Care After Ischemic Stroke for Detection of Atrial Fibrillation and Stroke Risk.

Implantable loop recorder (ILR) is recommended to detect subclinical atrial fibrillation (AF) after cryptogenic stroke; however, the clinical outcomes of this practice is unclear. We conducted a systematic review and meta-analysis of randomized controlled trials to evaluate 12-month AF detection, change in oral anticoagulation (OAC), and recurrent stroke in ILR versus usual care after ischemic stroke. We searched Medline, Embase, Web of Science, Cochrane Library for randomized controlled trials comparing ILR with usual care after any ischemic stroke. Primary outcomes were cumulative AF detection and recurrent stroke (ischemic or hemorrhagic) or transient ischemic attack over 12 months. Secondary outcome was OAC initiation. Meta-analysis was performed with Mantel-Haenszel pooled odds ratios (ORs) and random effects models. Of 200 identified articles, 3 trials were included (1,233 participants). Cryptogenic stroke and underlying AF included cryptogenic stroke only, stroke of known cause and underlying-AF included small or large vessel stroke only, and post embolic rhythm detection with implantable vs external monitoring included all ischemic strokes. The 12-month AF detection was 13% in the ILR group and 2.4% in controls. ILR was more likely to detect AF compared with usual care (OR 5.8, 95% confidence interval 3.2 to 10.2). Stroke or transient ischemic attack occurred in 7% with ILR and 9% with usual care (OR 0.8, 95% confidence interval 0.5 to 1.2). In patients with detected AF, 97% and 100% were started on OAC in cryptogenic stroke and underlying AF and post embolic rhythm detection with implantable vs external monitoring, respectively, compared with 68% in stroke of known cause and underlying-AF. In conclusion, ILR was superior to usual care in AF detection, but the relative low incidence of AF and the nondifferential risk of stroke between the ILR and usual care arms may suggest that most patients do not benefit from ILR implantation. Further studies are warranted to understand if patient selection can be improved to increase the diagnostic yield of ILR.

Long-term risk of heart failure and mortality following mitral valve surgery in patients with and without right ventricular pacemaker.

OBJECTIVES: Patients undergoing mitral valve surgery are at risk of developing postoperative conduction blocks and have a high incidence of heart failure (HF). Mitral valve surgery often results in reduced left ventricular systolic ejection fraction following surgery and the imposition of dyssynchrony with right ventricular (RV) pacing may further compromise stroke volume. Our aim was to investigate the risks of HF and mortality in patients with vs without RV pacemaker placement (PPM) after mitral valve surgery. METHODS: Using Danish nationwide databases, we identified all patients undergoing mitral valve repair or replacement surgery between 1997 and 2017, who were free from HF at baseline. The association of PPM implanted within 30 days following surgery with long-term risks of HF and mortality was investigated by multivariable Cox regression models. RESULTS: Of 4072 patients (33% female), 248 (6%) had a PPM implanted at 30-day postsurgery. Patients with PPM were older (68 vs 63 years), had a higher prevalence of concomitant aortic valve surgery (15% vs 11%), ischemic heart disease (13% vs 8%), and atrial fibrillation (19% vs 12%), compared with patients without PPM. Over a median follow-up of 5 years, 68 (27%) vs 825 (22%) patients with vs without PPM developed HF and 74 (30%) vs 1018 (27%) died. In multivariable-adjusted models, the hazard ratios associated with PPM were 1.00 (0.78-1.30), P = .93 for HF, and .96 (0.76-1.21), P = .72 for mortality. CONCLUSIONS: Postoperative implantation of a permanent RV pacemaker does not alter the long-term risks of HF and mortality following mitral valve surgery.

High impedance alert with safety switching: An unreported hazard of hybrid pacing systems.

Several Boston Scientific pacemaker models have a known issue with intermittent oversensing of the minute ventilation sensor when paired with non-Boston Scientific leads. Several of our patients with these hybrid systems have had transient out of range impedances and oversensing after safety switching which we suspected may be related. A retrospective analysis of 395 patients who had pacemakers implanted between 2015-2017 found that transient out of range impedances with safety switching was present in 9% of Boston Scientific pacemakers paired with Abbott or Medtronic leads compared with 0% in other device-lead combinations (P = 0.0089). We postulate that the root cause of the minute ventilation oversensing and transient high impedance issue is the same, a header-lead interaction from low-level incompatibility. Recognizing this issue is critical to prevent unnecessary lead revisions or extractions as it can be prevented with a simple reprogramming of lead pace/sense configuration.

Mechanisms and management of inappropriate therapy in subcutaneous implantable cardioverter defibrillators.

Subcutaneous implantable cardioverter defibrillators (S-ICDs) provide reliable defibrillation and have enhanced supraventricular tachycardia discrimination and fewer infection rates compared with traditional transvenous systems. However, inappropriate shocks remain a frequent problem. Herein, we review the various mechanisms of these inappropriate therapies, some of which are unique to S-ICDs, and propose an algorithm for preventing recurrences. Proper screening of preimplants is essential to help minimize inappropriate therapies, but patients with hypertrophic cardiomyopathy, Brugada syndrome, and arrhythmogenic right ventricular cardiomyopathy are at particular risk and may require additional measures.

Racial Differences in Response to Tilt-Table Testing in Patients Refered.

BACKGROUND: Syncope is a common problem in the general population and results in significant societal and patient costs. Several small studies have demonstrated differences in orthostatic response, and possibly tolerance, between blacks and whites. Based on these observations, we retrospectively reviewed results from our tilt table database to identify potential differences in response to tilt-table testing with regards to race, between black and white patients. METHODS: The reports of 446 tilt-table tests performed on adults, older than 18 years of age, at Boston Medical Center, an urban, tertiary-care, academic hospital, were reviewed. Clinical variables were retrieved from the procedure report. Occurrence of syncope was noted and hemodynamic classification was recorded as neurocardiogenic response, with subcategories of mixed, vasodepressor, or cardio-inhibitory. RESULTS: Of records reviewed, 360 patients (80.7%) identified as white and 86 patients as black (19.3%). There was a significantly lower observed frequency of syncope with a neurocardiogenic response in black vs. white patients (45.5% vs. 60.3%, p=0.015). In addition, significantly fewer black patients demonstrated a mixed neuro-cardiogenic response as compared to white patients (7.0% vs. 15.8%, p=0.038) or cardio-inhibitory response (0% vs. 5.3%, p=0.032). There was no difference in frequency of vasodepressor response in black vs. white patients (39.2 vs.38.4%, p=1.000). CONCLUSIONS: We observed a statistically-significant lower incidence of neurocardiogenic syncope among black patients compared to white patients referred for tilt-table testing for evaluation of syncope.

Nonreentrant supraventricular tachycardia misdiagnosed as inappropriate sinus tachycardia.

We report a case of a woman with incessant palpitations initially misdiagnosed as inappropriate sinus tachycardia that proved refractory to ß-blockers. At the time of electrophysiologic testing, a sustained narrow-complex tachycardia with a 1:2 atrioventricular relationship was repeatedly initiated by a posterior fascicle depolarization induced by means of a timed ventricular extrastimulus. The tachycardia was repeatedly terminated with a timed atrial extrastimulus, which excluded junctional bigeminy and confirmed the diagnosis of nonreentrant supraventricular tachycardia. Catheter ablation of the slow pathway eliminated dual-pathway conduction and tachycardia.

Pharmacotherapy for atrial arrhythmias: present and future.

Atrial fibrillation (AF) is the most commonly encountered arrhythmia in clinical practice. It is associated with significant morbidity, including palpitations, exercise intolerance, congestive heart failure, and increased risk of embolic stroke. Mortality is increased twofold in patients with AF. Management of AF with antiarrhythmic drugs traditionally has been hindered by lack of efficacy, poor tolerance of side effects, drug-associated toxicity, and proarrhythmic potential. Improved understanding of atrial electrical and structural remodeling as well as advances in rational drug design have led to new agents that may be superior to their predecessors. New agents that target atrium-specific ion channels limit the potential for ventricular arrhythmias, and less toxic derivatives such as dronedarone may be more tolerable. Drugs with entirely novel mechanisms, such as the gap junction modulator rotigaptide, have shown efficacy in ventricular arrhythmias and have potential for atrial arrhythmias as well. This review discusses recent advances in pharmacotherapy for treatment of atrial arrhythmias.

Influence of drive cycle length on initiation of ventricular fibrillation during implantable cardioverter defibrillator threshold testing.

BACKGROUND: Programmed electrical stimulation of the heart as a method to induce tachyarrhythmias has been described since the 1960s. To date, no study has examined optimal drive cycle length in the induction of ventricular fibrillation (VF) during defibrillation threshold testing after implantable cardioverter-defibrillator placement. We hypothesized that longer drive cycle length, by means of the longer action potential duration, would promote intramyocardial phase 2 reentry and facilitate induction of VF. METHODS: Fifty consecutive implants were randomized in a prospective crossover format for this study. The group consisted of 40 men and 10 women, with each patient receiving either a 400 or 600 ms initial drive train prior to 1.2 J internal shock on the T wave with a goal to induce ventricular fibrillation. The timing of the T wave shock was determined by measuring the interval from the beginning of the QRS to the apex of the T wave in lead II. Successful inductions were defibrillated via the cardioverter defibrillator. Patients were then crossed over and the protocol repeated. RESULTS: Twenty of 23 (87%) patients were successfully induced into VF in the initial 400 ms drive train arm whereas 22 of 27 (81%) were successfully induced in the 600 ms arm. Thus, a total of 44 (88%) patients were successfully induced at 400 ms, 41 (82%) patients were successfully induced at 600 ms, and 2 (4%) patients were not inducible at either cycle length, but were inducible with 50 Hz ventricular stimulation. However, no significant difference was noted between the two groups. CONCLUSION: No investigation to date has questioned whether a relationship exists between drive cycle length and initiation of ventricular fibrillation. Our study addresses this question, though negative for difference between 400 and 600 ms drive trains. Further research into optimal strategies for inducing ventricular fibrillation will minimize patient sedation time and discomfort while undergoing defibrillator threshold testing.

Sudden cardiac death and the role of device therapy in dilated cardiomyopathy.

Both nonischemic and ischemic dilated cardiomyopathy are associated with an increased risk of sudden cardiac death, most commonly as a result of ventricular tachyarrhythmias. The pathophysiology of sudden death is complex and results from the interplay of scarred myocardium with physiologic and environmental triggers. Clinical trials completed within the past decade have clarified the role of implantable defibrillators in prolonging survival and have expanded the indications for the use of these devices in patients with heart failure. This article examines the pathophysiology of sudden cardiac death and reviews the clinical trials that have defined the role of device therapy in current practice.