Does early detection of atrial fibrillation reduce the risk of thromboembolic events? Rationale and design of the Heartline study.

BACKGROUND: The impact of using direct-to-consumer wearable devices as a means to timely detect atrial fibrillation (AF) and to improve clinical outcomes is unknown. METHODS: Heartline is a pragmatic, randomized, and decentralized application-based trial of US participants aged ≥65 years. Two randomized cohorts include adults with possession of an iPhone and without a history of AF and those with a diagnosis of AF taking a direct oral anticoagulant (DOAC) for ≥30 days. Participants within each cohort are randomized (3:1) to either a core digital engagement program (CDEP) via iPhone application (Heartline application) and an Apple Watch (Apple Watch Group) or CDEP alone (iPhone-only Group). The Apple Watch Group has the watch irregular rhythm notification (IRN) feature enabled and access to the ECG application on the Apple Watch. If an IRN notification is issued for suspected AF then the study application instructs participants in the Apple Watch Group to seek medical care. All participants were "watch-naïve" at time of enrollment and have an option to either buy or loan an Apple Watch as part of this study. The primary end point is time from randomization to clinical diagnosis of AF, with confirmation by health care claims. Key secondary endpoint are claims-based incidence of a 6-component composite cardiovascular/systemic embolism/mortality event, DOAC medication use and adherence, costs/health resource utilization, and frequency of hospitalizations for bleeding. All study assessments, including patient-reported outcomes, are conducted through the study application. The target study enrollment is approximately 28,000 participants in total; at time of manuscript submission, a total of 26,485 participants have been enrolled into the study. CONCLUSION: The Heartline Study will assess if an Apple Watch with the IRN and ECG application, along with application-facilitated digital health engagement modules, improves time to AF diagnosis and cardiovascular outcomes in a real-world environment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04276441.

Network meta-analysis and systematic review comparing efficacy and safety between very high power short duration, high power short duration, and conventional radiofrequency ablation of atrial fibrillation.

BACKGROUND: High-power short-duration (HPSD) atrial fibrillation (AF) ablation with a power of 40-50 W was proved to be safe and effective. Very high-power short-duration (vHPSD) AF ablation is a novel method using >50 W to obtain more durable AF ablation. This study aimed to evaluate the efficacy and safety of vHPSD ablation compared with HPSD ablation and conventional power ablation. METHODS: A literature search for studies that reported AF ablation outcomes, including short-term freedom from atrial arrhythmia, first-pass isolation (FPI) rate, procedure time, and major complications, was conducted utilizing MEDLINE, EMBASE, and Cochrane databases. All relevant studies were included in this analysis. A random-effects model of network meta-analysis and surface under cumulative ranking curve (SUCRA) were used to rank the treatment for all outcomes. RESULTS: A total of 29 studies with 9721 patients were included in the analysis. According to the SUCRA analysis, HPSD ablation had the highest probability of maintaining sinus rhythm. Point estimation showed an odds ratio of 1.5 (95% confidence interval [CI]: 1.2-1.9) between HPSD ablation and conventional power ablation and an odds ratio of 1.3 (95% CI: 0.78-2.2) between vHPSD ablation and conventional power ablation. While the odds ratio of FPI between HPSD ablation and conventional power ablation was 3.6 (95% CI: 1.5-8.9), the odds ratio between vHPSD ablation and conventional power ablation was 2.2 (95% CI: 0.61-8.6). The procedure times of vHPSD and HPSD ablations were comparable and, therefore, shorter than that of conventional power ablation. Major complications were low in all techniques. CONCLUSION: vHPSD ablation did not yield higher efficacy than HPSD ablation and conventional power ablation. With the safety concern, vHPSD ablation outcomes were comparable with those of other techniques.

Same-day discharge following catheter ablation and venous closure with VASCADE MVP: A postmarket registry.

INTRODUCTION: Early and safe ambulation can facilitate same-day discharge (SDD) following catheter ablation, which can reduce resource utilization and healthcare costs and improve patient satisfaction. This study evaluated procedure success and safety of the VASCADE MVP venous vascular closure system in patients with atrial fibrillation (AF). METHODS: The AMBULATE SDD Registry is a two-stage series of postmarket studies in patients with paroxysmal or persistent AF undergoing catheter ablation followed by femoral venous access-site closure with VASCADE MVP. Efficacy endpoints included SDD success, defined as the proportion of patients discharged the same day who did not require next-day hospital intervention for procedure/access site-related complications, and access site sustained success within 15 days of the procedure. RESULTS: Overall, 354 patients were included in the pooled study population, 151 (42.7%) treated for paroxysmal AF and 203 (57.3%) for persistent AF. SDD was achieved in 323 patients (91.2%) and, of these, 320 (99.1%) did not require subsequent hospital intervention based on all study performance outcomes. Nearly all patients (350 of 354; 98.9%) achieved total study success, with no subsequent hospital intervention required. No major access-site complications were recorded. Patients who had SDD were more likely to report procedure satisfaction than patients who stayed overnight. CONCLUSION: In this study, 99.7% of patients achieving SDD required no additional hospital intervention for access site-related complications during follow-up. SDD appears feasible and safe for eligible patients after catheter ablation for paroxysmal or persistent AF in which the VASCADE MVP is used for venous access-site closure.

Academic cardiac electrophysiologists' perspectives on sleep apnea care.

PURPOSE: Obstructive sleep apnea syndrome (OSAS) is an important, modifiable risk factor in the pathophysiology of arrhythmias including atrial fibrillation (AF). The purpose of the study was to evaluate cardiac electrophysiologists' (EPs) perception of OSAS. METHODS: We designed a 27-item online Likert scale-based survey instrument entailing several domains: (1) relevance of OSAS in EP practice, (2) OSAS screening and diagnosis, (3) perception on treatments for OSAS, (4) opinion on the OSAS care model. The survey was distributed to 89 academic EP programs in the USA and Canada. While the survey instrument questions refer to the term sleep apnea (SA), our discussion of the diagnosis, management, and research on the sleep disorder is more accurately described with the term OSAS. RESULTS: A total of 105 cardiac electrophysiologists from 49 institutions responded over a 9-month period. The majority of respondents agreed that sleep apnea (SA) is a major concern in their practice (94%). However, 42% reported insufficient education on SA during training. Many (58%) agreed that they would be comfortable managing SA themselves with proper training and education and 66% agreed cardiac electrophysiologists should become more involved in management. Half of EPs (53%) were not satisfied with the sleep specialist referral process. Additionally, a majority (86%) agreed that trained advanced practice providers should be able to assess and manage SA. Time constraints, lack of knowledge, and the referral process are identified as major barriers to EPs becoming more involved in SA care. CONCLUSIONS: We found that OSAS is widely recognized as a major concern for EP. However, incorporation of OSAS care in training and routine practice lags. Barriers to increased involvement include time constraints and education. This study can serve as an impetus for innovation in the cardiology OSAS care model.

Comparative risk of dementia among patients with atrial fibrillation treated with catheter ablation versus anti-arrhythmic drugs.

Atrial fibrillation (AF) is associated with an increased risk of dementia. Emerging evidence suggests AF suppression is associated with reduced risk of dementia, but the optimal strategy to achieve this is unknown. We sought to compare the risk of dementia in patients with AF who underwent catheter ablation (CA) versus anti-arrhythmic drug (AAD) treatment. METHODS AND RESULTS: Using the 2000 to 2021 Optum Clinformatics database, patients with AF who underwent CA versus AAD treatment (≥1 prescription fill for ≥2 different AADs) were identified and propensity score matched overall and within sex subgroups. A cause-specific hazard model was performed to assess dementia overall and in sex-specific subgroups. After matching, there were 19,088 patients per group. CA was associated with a 41% lower risk of dementia compared with AAD alone (1.9% vs 3.3%; hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.52-0.67, log-rank P < .0001). When examined by sex, dementia risk reduction associated with CA versus AAD use alone was observed among both males (HR 0.55, 95% CI 0.46-0.66) and females (HR 0.60, 95% CI 0.50-0.72). Though not studied as a primary outcome, patients treated with CA were also observed to have 49% lower associated risk of mortality compared with AAD only (HR 0.51 95% CI 0.46-0.55, P < .0001). CONCLUSIONS: Among patients treated for AF, CA was associated with significantly lower risk of dementia and death compared with AADs only. These reductions in risk associated with CA versus AAD were seen in both males and females.

Bimodal distribution of atrial fibrillation burden in 3 distinct cohorts: What is 'paroxysmal' atrial fibrillation?

BACKGROUND: Burden of atrial fibrillation (AF), as a continuous measure, is an emerging alternative classification often assumed to increase linearly with progression of disease. Yet there are no descriptions of AF burden distributions across populations. METHODS: We examined patterns of AF burden (% time in AF) across 3 different cohorts: outpatients with AF undergoing Holter monitoring in a national registry (ORBIT-AF II), routine outpatients undergoing Holter monitoring in a tertiary healthcare system (UHealth), and patients >= 65 years with cardiac implantable electronic devices (Merlin.netTM linked to Medicare). RESULTS: We included 2,058 ORBIT-AF II patients, 4,537 UHealth patients, and 39,710 from Merlin.net. Mean age ranged from 56 to 77 years, sex ranged from 40% to 61% male, and mean CHA2DS2-VASc scores ranged from 2.2 to 4.9. Across all cohorts, AF burden demonstrated skewed frequency towards the extremes, with the vast majority of patients having either very low or very high AF burden. This bimodal distribution was consistent across cohorts, across clinically-documented AF types (paroxysmal v persistent), patients with or without a known AF diagnosis, and among patients with different types of cardiac implantable electronic devices. CONCLUSIONS: Across 3 broad, diverse cohorts with continuous monitoring, distribution of AF burden was consistently skewed towards the extremes without an even, linear distribution or progression. As AF burden is increasingly recognized as a descriptor and potential risk-stratifier, these findings have important implications for future research and patient care.

Association between economic and arrhythmic burden of paroxysmal atrial fibrillation in patients with cardiac implanted electronic devices.

BACKGROUND: As the prevalence of atrial fibrillation (AF) increases, a greater understanding of the costs associated with AF care is required. While individuals with greater arrhythmic burden may interact with the health system more frequently, the relationship between AF burden and costs remains undefined. METHODS: In a longitudinal patient cohort with paroxysmal AF and newly implanted cardiovascular implantable electronic devices (CIED) (2010-2016), we linked CIED remote-monitoring data with Medicare claims to assess the association between the 30-day averaged device-detected daily percentage of time in AF ("AF burden") and healthcare costs. RESULTS: Among 39,345 patients, the mean age was 77.1 ± 8.7 years, 60.7% were male, and the mean CHA2DS2-VASc score was 4.9 ± 1.3. The mean total 1-year costs were $18,668 ± 29,173, driven by hospitalization costs where two-thirds of admissions were due to heart failure. Increasing AF burden was associated with increasing costs: $17,860 ± 28,525 for 0% daily AF burden; $18,840 ± 29,104 for 0-5% daily AF burden; and $20,968 ± 31,228 for 5-98% daily AF burden. There was a linear relationship between AF burden expressed as a continuous variable and 1-year costs (adjusted cost rate ratio 1.031 per 10% daily duration in AF, 95% confidence interval 1.023-1.038; P < .001). CONCLUSIONS: Among older patients with paroxysmal AF and CIEDs, increasing AF burden is associated with higher healthcare costs. As the observational study design is unable to determine causal relationships, prospective study is required to explore the intriguing hypothesis that targeted AF strategies, including comorbidity management, that reduce AF burden may also reduce the high annual costs associated with AF.

Long-term outcomes in patients treated with flecainide for atrial fibrillation with stable coronary artery disease.

BACKGROUND: Class 1C antiarrhythmic drugs (AAD) have been associated with harm in patients treated for ventricular arrhythmias with a prior myocardial infarction. Consensus guidelines have advocated that these drugs not be used in patients with stable coronary artery disease (CAD). However, long-term data are lacking to know if unique risks exist when these drugs are used for atrial fibrillation (AF) in patients with CAD without a prior myocardial infarction. METHODS: In 24,315 patients treated with the initiation of AADs, two populations were evaluated: (1) propensity-matched AF patients with CAD were created based upon AAD class (flecainide, n = 1,114, vs class-3 AAD, n = 1,114) and (2) AF patients who had undergone a percutaneous coronary intervention or coronary artery bypass graft (flecainide, n = 150, and class-3 AAD, n = 1,453). Outcomes at 3 years for mortality, heart failure (HF) hospitalization, ventricular tachycardia (VT), and MACE were compared between the groups. RESULTS: At 3 years, mortality (9.1% vs 19.3%, P < .0001), HF hospitalization (12.5% vs 18.3%, P < .0001), MACE (22.9% vs 36.6%, P < .0001), and VT (5.8% vs 8.5%, P = .02) rates were significantly lower in the flecainide group for population 1. In population 2, adverse event rates were also lower, although not significantly, in the flecainide compared to the class-3 AAD group for mortality (20.9% vs 25.8%, P = .26), HF hospitalization (24.5% vs 26.1%, P = .73), VT (10.9% vs 14.7%, P = .28) and MACE (44.5% vs 49.5%, P = .32). CONCLUSIONS: Flecainide in select patients with stable CAD for AF has a favorable safety profile compared to class-3 AADs. These data suggest the need for prospective trials of flecainide in AF patients with CAD to determine if the current guideline-recommended exclusion is warranted.

Short-term natural course of esophageal thermal injury after ablation for atrial fibrillation.

INTRODUCTION: Esophageal injury is rare but potentially a devastating complication of atrial fibrillation (AF) ablation. The goal here was to provide insight into the short-term natural history of esophageal thermal injury (ETI) after radiofrequency catheter ablation (RFCA) for AFby esophagogastroduodenoscopy (EGD). METHODS: We screened patients who underwent RFCA for AF and EGD based on esophageal late gadolinium enhancement (LGE) in postablation magnetic resonance imaging. Patients with ETI diagnosed with EGD were included. We defined severity of ETI according to Kansas City classification: type 1: erythema; type 2: ulcers (2a: superficial; 2b deep); type 3 perforation (3a: perforation; 3b: perforation with atrioesophageal fistula [AEF]). Repeated EGD was performed within 1-14 days after the last EGD if recommended and possible until any certain healing signs (visible reduction in size without deepening of ETI or complete resolution) were observed. RESULTS: ETI was observed in 62 of 378 patients who underwent EGD after RFCA. Out of these 62 patients with ETI, 21% (13) were type 1, 50% (31) were type 2a and 29% (18) were type 2b at the initial EGD. All esophageal lesions, but one type 2b lesion that developed into an AEF, showed signs of healing in repeated EGD studies within 14 days after the procedure. The one type 2b lesion developing into an AEF showed an increase in size and ulcer deepening in repeat EGD 8 days after the procedure. CONCLUSION: We found that all ETI which did not progress to AEF presented healing signs within 14 days after the procedure and that worsening ETI might be an early signal for developing esophageal perforation.

Patient-reported outcomes and costs associated with vascular closure and same-day discharge following atrial fibrillation ablation.

BACKGROUND: We aimed to measure patient-reported outcomes (PROs) and costs associated with same-day discharge (SDD) for atrial fibrillation (AF) ablation and vascular closure device implantation in clinical practice. METHODS: PROs were prospectively measured in 50 AF ablation patients, comparing complete vascular device closure (n = 25) versus manual compression hemostasis (n = 25). Health-system costs for SDD patients receiving vascular device closure were compared to matched controls with one-night stays who did not receive any closure device. RESULTS: Prospectively enrolled patients receiving vascular device closure for AF ablation had a mean age of 65 years, 17% were female, with a mean CHA2 DS2 -VASc score of 3. The mean number of venous sheaths was higher among patients receiving vascular device closure (3.8 vs. 3.1, p < 0.001), and there was one case of rebleeding in a patient receiving a vascular closure device (no other complications). Same-day discharge rates (76% vs. 8.3%, p < 0.001), patient satisfaction with bedrest time (8.5 vs. 6, p = 0.004) and with pain (8 vs. 5.1, p = 0.009) were significantly better among patients receiving vascular closure. In matched analyses of health-system costs, patients with vascular closure had mean age 66, 32% were female, and the mean CHA2 DS2 -VASc score was 2 (p = NS vs. controls). SDD with vascular closure was associated with the significantly lower facility, pharmacy, and disposable costs, but higher implant costs. Overall costs for ablation were not significantly different (mean difference 1.10%, 95% confidence interval [CI] -3.03 to 5.42). CONCLUSIONS: Vascular closure for AF ablation improves patient experience in routine care. The use of vascular closure and SDD after AF ablation reduces several components of healthcare system costs, without an overall increase.

Quantifying the Impact of Atrial Fibrillation on Heart Failure-Related Patient-Reported Outcomes in the Utah mEVAL Program.

BACKGROUND: Atrial fibrillation (AF) frequently complicates heart failure (HF), and each is associated with lower overall health-related quality of life. We aimed to quantify the incremental burden of AF on the health-related quality of life of patients with HF in clinical practice. METHODS AND RESULTS: We used data from the Utah mEVAL program to analyze patient-reported outcomes (PROs) among patients with HF with and without AF. The primary outcome was the HF-specific Kansas City Cardiomyopathy Questionnaire, with generic PROs as secondary outcomes. Among 1707 patients with HF, 36% had AF (n = 616). Those with HF and AF were older (mean age 69 years vs 58 years, P < .001), more likely to have prior stroke (29% vs 17%, P < .001) and ischemic cardiomyopathy (28% vs 23%, P = .01), but had similar ejection fractions (mean 44% each, P = .6). After adjustment, and compared with HF alone, HF with AF was associated with worse Kansas City Cardiomyopathy Questionnaire scores (adjusted mean difference -3.45, 95% confidence interval [CI] -6.24 to -0.65), and worse Patient-Reported Outcomes Measurement Information System physical function scores (adjusted mean difference -1.63, 95% CI -2.59 to -0.67). The difference in visual analog scale general health was borderline (adjusted mean difference -2.01, 95% CI -4.51 to 0.49), and Patient-Reported Outcomes Measurement Information System depression scores were similar (adjusted mean difference 0.54, 95% CI -0.48 to 1.57). CONCLUSIONS: AF complicates nearly one-third of HF cases, and patients with HF and AF are substantially older and sicker. After adjustment, AF was independently associated with worse disease-specific and overall health-related quality of life than HF alone. Whether maintaining sinus rhythm can improve the HF-related health status of patients with HF in clinical practice should be explored further.

Influence of atrial fibrillation type on outcomes of ablation vs. drug therapy: results from CABANA.

AIMS: Influence of atrial fibrillation (AF) type on outcomes seen with catheter ablation vs. drug therapy is incompletely understood. This study assesses the impact of AF type on treatment outcomes in the Catheter Ablation vs. Antiarrhythmic Drug Therapy for Atrial Fibrillation Trial (CABANA). METHODS AND RESULTS: CABANA randomized 2204 patients ≥65 years old or <65 with at least one risk factor for stroke to catheter ablation or drug therapy. Of these, 946 (42.9%) had paroxysmal AF (PAF), 1042 (47.3%) had persistent AF (PersAF), and 215 (9.8%) had long-standing persistent AF (LSPAF) at baseline. The primary endpoint was a composite of death, disabling stroke, serious bleeding, or cardiac arrest. Symptoms were measured with the Mayo AF-Specific Symptom Inventory (MAFSI), and quality of life was measured with the Atrial Fibrillation Effect on Quality of Life (AFEQT). Comparisons are reported by intention to treat. Compared with drug therapy alone, catheter ablation produced a 19% relative risk reduction in the primary endpoint for PAF {adjusted hazard ratio [aHR]: 0.81 [95% confidence interval (CI): 0.50, 1.30]}, and a 17% relative reduction for PersAF (aHR: 0.83, 95% CI: 0.56, 1.22). For LSPAF, the ablation relative effect was a 7% reduction (aHR: 0.93, 95% CI: 0.36, 2.44). Ablation was more effective than drug therapy at reducing first AF recurrence in all AF types: by 51% for PAF (aHR: 0.49, 95% CI: 0.39, 0.62), by 47% for PersAF (aHR: 0.53, 95% CI: 0.43,0.65), and by 36% for LSPAF (aHR 0.64, 95% CI 0.41,1.00). Ablation was associated with greater improvement in symptoms, with the mean difference between groups in the MAFSI frequency score favouring ablation over 5 years of follow-up in all subgroups: PAF had a clinically significant -1.9-point difference (95% CI: -1.2 to -2.6); PersAF a -0.9 difference (95% CI: -0.2 to -1.6); LSPAF a clinically significant difference of -1.6 points (95% CI: -0.1 to -3.1). Ablation was also associated with greater improvement in quality of life in all subgroups, with the AFEQT overall score in PAF patients showing a clinically significant 5.3-point improvement (95% CI: 3.3 to 7.3) over drug therapy alone over 5 years of follow-up, PersAF a 1.7-point difference (95% CI: 0.0 to 3.7), and LSPAF a 3.1-point difference (95% CI: -1.6 to 7.8). CONCLUSION: Prognostic treatment effects of catheter ablation compared with drug therapy on the primary and major secondary clinical endpoints did not differ consequentially by AF subtype. With regard to decreases in AF recurrence and improving quality of life, ablation was more effective than drug therapy in all three AF type subgroups. CLINICALTRIALS.GOV IDENTIFIER: NCT00911508.

Atrial Fibrillation and Dementia.

Atrial fibrillation is associated with multiple adverse comorbidities, including the development of dementia in patients with and without a history of stroke. Mechanistic models have been proposed to explain the association of AF and dementia. Alterations of brain perfusion from embolic events, bleeding, and rhythm-related hypoperfusion underlie many of these models. Multiple mediators such as oxidative injury, inflammatory and autoimmune mechanisms, and genetic predisposition also interplay in the disease association. There are potential therapeutic opportunities to reduce dementia risk, including early and effective use of anticoagulation and strategies to improve brain perfusion through rhythm and rate control approaches. Prospective trials are needed to evaluate these therapeutic opportunities that carefully measure cognitive function and dementia incidence.

Zero fluoroscopy approach versus fluoroscopy approach for cardiac arrhythmia ablations: A systematic review and meta-analysis.

BACKGROUND: Radiofrequency catheter ablation for cardiac arrhythmias has traditionally been guided by fluoroscopy. Fluoroscopy exposes the patient, operator, and staff to ionizing radiation which has no safe dose void of stochastic and deterministic biologic risks. Zero fluoroscopy (ZF) approaches for catheter ablation have been advocated to eliminate these risks. We conducted a meta-analysis comparing acute procedure success, recurrence-free survival, complications, and procedure times between the approaches. METHODS: We conducted a literature search from inception through December 2020 in the databases of EMBASE and MEDLINE. We included randomized controlled trials and cohorts that compared the outcomes of interest in ZF and conventional/low fluoroscopy (CF/LF) approaches. The outcomes sought were acute procedure success, recurrence-free survival, complications, and procedure times. Effect estimates were combined, using the random-effects, generic inverse variance method of DerSimonian and Laird. RESULTS: Sixteen studies from 2013 to 2020, including 6052 patients (2219 ZF, 3833 CF/LF) were included. There were no significant differences in acute procedure success rate (odds ratio [OR]: 1.10, 95% confidence interval [CI]: 0.75-1.59), recurrence-free survival (OR: 1.08, 95% CI: 0.78-1.49), periprocedural complication rate (OR: 0.72, 95% CI: 0.45-1.16), or total procedure time (weighted mean difference 2.32 min, 95% CI: -2.85-7.50) between ZF and CF/LF approaches, respectively. Overall, only 1.26% of patients crossed over from ZF to CF/LF arm. CONCLUSIONS: Periprocedural and postprocedural outcomes with a ZF approach compared favorably with traditional fluoroscopic guidance without increasing procedural times. As comfort with ZF grows, coupled with evolving mapping technologies, this method has potential to become the standard approach for catheter ablation.

Catheter ablation of ventricular tachycardia in patients with prior cardiac surgery: An analysis from the International VT Ablation Center Collaborative Group.

INTRODUCTION: Patients with prior cardiac surgery may represent a subgroup of patients with ventricular tachycardia (VT) that may be more difficult to control with catheter ablation. METHODS: We evaluated 1901 patients with ischemic and nonischemic cardiomyopathy who underwent VT ablation at 12 centers. Clinical characteristics and VT radiofrequency ablation procedural outcomes were assessed and compared between those with and without prior cardiac surgery. Kaplan-Meier analysis was used to estimate freedom from recurrent VT and survival. RESULTS: There were 578 subjects (30.4%) with prior cardiac surgery identified in the cohort. Those with prior cardiac surgery were older (66.4 ± 11.0 years vs. 60.5 ± 13.9 years, p < .01), with lower left ventricular ejection fraction (30.2 ± 11.5% vs. 34.8 ± 13.6%, p < .01) and more ischemic heart disease (82.5% vs. 39.3%, p < .01) but less likely to undergo epicardial mapping or ablation (9.0% vs. 38.1%, p<.01) compared to those without prior surgery. When epicardial mapping was performed, a significantly greater proportion required surgical intervention for access (19/52 [36.5%] vs. 14/504 [2.8%]; p < .01). Procedural complications, including epicardial access-related complications, were lower (5.7% vs. 7.0%, p < .01) in patients with versus without prior cardiac surgery. VT-free survival (75.1% vs. 74.1%, p = .805) and survival (86.5% vs. 87.9%, p = .397) were not different between those with and without prior heart surgery, regardless of etiology of cardiomyopathy. VT recurrence was associated with increased mortality in patients with and without prior cardiac surgery. CONCLUSION: Despite different clinical characteristics and fewer epicardial procedures, the safety and efficacy of VT ablation in patients with prior cardiac surgery is similar to others in this cohort. The incremental yield of epicardial mapping in predominant ischemic cardiomyopathy population prior heart surgery may be low but appears safe in experienced centers.

Meta-analysis comparing outcomes of catheter ablation for ventricular arrhythmia in ischemic versus nonischemic cardiomyopathy.

BACKGROUND: Catheter ablation is an effective treatment for ventricular arrhythmia (VA) in ischemic cardiomyopathy (ICM). However, results in non-ICM (NICM) patients are not satisfactory, and studies comparing differences between NICM and ICM are limited. We conducted a meta-analysis of procedural characteristics and long-term outcomes of catheter ablation for VA, comparing results between ICM and NICM. METHODS: Studies in the PubMed, EMBASE, and Cochrane databases were systematically reviewed. Four studies reporting comparison of catheter ablation of VA between ICM and NICM were examined. The Newcastle-Ottawa Scale was used to appraise study quality. A random-effects model with inverse variance method was used for comparisons. RESULTS: Epicardial approach was significantly more undertaken for the NICM group than in the ICM group (odds ratio [OR]: 0.13; 95% confidence interval [CI]: 0.09-0.18; P < .00001). Mean ablation time (P = .54), fluoroscopy time (P = .55), and procedural time (P = .18) did not differ significantly between the ICM and NICM groups. Procedural failure rates (OR: 0.46; 95% CI: 0.24-0.89; P = .02) and VA recurrence rates (risk ratio [RR]: 0.68; 95% CI: 0.46-1.01; P = .06) were significantly higher in the NICM group than in the ICM group. However, all-cause mortality (RR: 1.37; 95% CI: 0.75-2.49; P = .31) did not differ significantly between groups. CONCLUSIONS: Procedural failure and VA recurrence rates were significantly higher in the NICM group, despite significantly more frequent epicardial access. These highlight the limitations of catheter ablation for VA in NICM, given our current knowledge.

Smart Wearables for Cardiac Monitoring-Real-World Use beyond Atrial Fibrillation.

The possibilities and implementation of wearable cardiac monitoring beyond atrial fibrillation are increasing continuously. This review focuses on the real-world use and evolution of these devices for other arrhythmias, cardiovascular diseases and some of their risk factors beyond atrial fibrillation. The management of nonatrial fibrillation arrhythmias represents a broad field of wearable technologies in cardiology using Holter, event recorder, electrocardiogram (ECG) patches, wristbands and textiles. Implementation in other patient cohorts, such as ST-elevation myocardial infarction (STEMI), heart failure or sleep apnea, is feasible and expanding. In addition to appropriate accuracy, clinical studies must address the validation of clinical pathways including the appropriate device and clinical decisions resulting from the surrogate assessed.

Feasibility of combining serial smartphone single-lead electrocardiograms for the diagnosis of ST-elevation myocardial infarction.

BACKGROUND: The rate-limiting step in STEMI diagnosis often is the availability of a 12-lead electrocardiogram (ECG) and its interpretation. The potential may exist to speed the availability of 12-lead ECG information by using commonly available mobile technologies. We sought to test whether combining serial smartphone single-lead ECGs to create a virtual 12-lead ECG can accurately diagnose STEMI. METHODS: Consenting patients presenting with symptoms consistent with a possible STEMI had contemporaneous standard 12-lead and smartphone '12-lead equivalent' ECG (produced by electronically combining serial single-lead ECGs) recordings obtained. Matched ECGs were evaluated qualitatively and quantitatively by a panel of blinded readers and classified as STEMI/STEMI equivalent (LBBB), Not-STEMI, or uninterpretable. Interpretable ECG pairs were graded as showing good, fair, or poor correlation. RESULTS: Two hundred four subjects (age = 60 years, males = 57%, STEMI activation = 45%) were enrolled from 5 international sites. Smartphone ECG quality was graded as good in 151 (74.0%), fair in 32 (15.7%), poor in 8 (3.9%), and uninterpretable in 13 (6.4%). A STEMI/STEMI equivalent diagnosis was identified by standard 12-lead ECG in 57/204 (27.9%) recordings. For all interpretable pairs of smartphone ECGs compared with standard ECGs (n = 190), the sensitivity, specificity, and positive and negative predictive values for STEMI/STEMI equivalent by smartphone were 0.89, 0.84, 0.70 and 0.95, respectively. CONCLUSIONS: A '12-lead equivalent' ECG obtained from multiple serial single-lead ECGs from a smartphone can identify STEMI with good correlation to a standard 12-lead ECG. This technology holds promise to improve outcomes in STEMI by enhancing the reach and speed of diagnosis and thereby early treatment.