A Novel ECG-Based Deep Learning Algorithm to Predict Cardiomyopathy in Patients With Premature Ventricular Complexes.

BACKGROUND: Premature ventricular complexes (PVCs) are prevalent and, although often benign, they may lead to PVC-induced cardiomyopathy. We created a deep-learning algorithm to predict left ventricular ejection fraction (LVEF) reduction in patients with PVCs from a 12-lead electrocardiogram (ECG). OBJECTIVES: This study aims to assess a deep-learning model to predict cardiomyopathy among patients with PVCs. METHODS: We used electronic medical records from 5 hospitals and identified ECGs from adults with documented PVCs. Internal training and testing were performed at one hospital. External validation was performed with the others. The primary outcome was first diagnosis of LVEF ≤40% within 6 months. The dataset included 383,514 ECGs, of which 14,241 remained for analysis. We analyzed area under the receiver operating curves and explainability plots for representative patients, algorithm prediction, PVC burden, and demographics in a multivariable Cox model to assess independent predictors for cardiomyopathy. RESULTS: Among the 14,241-patient cohort (age 67.6 ± 14.8 years; female 43.8%; White 29.5%, Black 8.6%, Hispanic 6.5%, Asian 2.2%), 22.9% experienced reductions in LVEF to ≤40% within 6 months. The model predicted reductions in LVEF to ≤40% with area under the receiver operating curve of 0.79 (95% CI: 0.77-0.81). The gradient weighted class activation map explainability framework highlighted the sinus rhythm QRS complex-ST segment. In patients who underwent successful PVC ablation there was a post-ablation improvement in LVEF with resolution of cardiomyopathy in most (89%) patients. CONCLUSIONS: Deep-learning on the 12-lead ECG alone can accurately predict new-onset cardiomyopathy in patients with PVCs independent of PVC burden. Model prediction performed well across sex and race, relying on the QRS complex/ST-segment in sinus rhythm, not PVC morphology.

A single-center experience with early adoption of physiologic pacing approaches.

BACKGROUND: Increasing interest in physiological pacing has been countered with challenges such as accurate lead deployment and increasing pacing thresholds with His-bundle pacing (HBP). More recently, left bundle branch area pacing (LBBAP) has emerged as an alternative approach to physiologic pacing. OBJECTIVE: To compare procedural outcomes and pacing parameters at follow-up during initial adoption of HBP and LBBAP at a single center. METHODS: Retrospective review, from September 2016 to January 2020, identified the first 50 patients each who underwent successful HBP or LBBAP. Pacing parameters were then assessed at first follow-up after implantation and after approximately 1 year, evaluating for acceptable pacing parameters defined as sensing R-wave amplitude >5 mV, threshold <2.5 V @ 0.5 ms, and impedance between 400 and 1200 Ω. RESULTS: The HBP group was younger with lower ejection fraction compared to LBBAP (73.2 ± 15.3 vs. 78.2 ± 9.2 years, p = .047; 51.0 ± 15.9% vs. 57.0 ± 13.1%, p = .044). Post-procedural QRS widths were similarly narrow (119.8 ± 21.2 vs. 116.7 ± 15.2 ms; p = .443) in both groups. Significantly fewer patients with HBP met the outcome for acceptable pacing parameters at initial follow-up (56.0% vs. 96.4%, p = .001) and most recent follow-up (60.7% vs. 94.9%, p ≤ .001; at 399 ± 259 vs. 228 ± 124 days, p ≤ .001). More HBP patients required lead revision due to early battery depletion or concern for pacing failure (0% vs. 13.3%, at a mean of 664 days). CONCLUSION: During initial adoption, HBP is associated with a significantly higher frequency of unacceptable pacing parameters, energy consumption, and lead revisions compared with LBBAP.

Prognostic Value of Electrocardiographic QRS Diminution in Patients Hospitalized With COVID-19 or Influenza.

During the clinical care of hospitalized patients with COVID-19, diminished QRS amplitude on the surface electrocardiogram (ECG) was observed to precede clinical decompensation, culminating in death. This prompted investigation into the prognostic utility and specificity of low QRS complex amplitude (LoQRS) in COVID-19. We retrospectively analyzed consecutive adults admitted to a telemetry service with SARS-CoV-2 (n = 140) or influenza (n = 281) infection with a final disposition-death or discharge. LoQRS was defined as a composite of QRS amplitude <5 mm or <10 mm in the limb or precordial leads, respectively, or a ≥50% decrease in QRS amplitude on follow-up ECG during hospitalization. LoQRS was more prevalent in patients with COVID-19 than influenza (24.3% vs 11.7%, p = 0.001), and in patients who died than survived with either COVID-19 (48.1% vs 10.2%, p <0.001) or influenza (38.9% vs 9.9%, p <0.001). LoQRS was independently associated with mortality in patients with COVID-19 when adjusted for baseline clinical variables (odds ratio [OR] 11.5, 95% confidence interval [CI] 3.9 to 33.8, p <0.001), presenting and peak troponin, D-dimer, C-reactive protein, albumin, intubation, and vasopressor requirement (OR 13.8, 95% CI 1.3 to 145.5, p = 0.029). The median time to death in COVID-19 from the first ECG with LoQRS was 52 hours (interquartile range 18 to 130). Dynamic QRS amplitude diminution is a strong independent predictor of death over not only the course of COVID-19 infection, but also influenza infection. In conclusion, this finding may serve as a pragmatic prognostication tool reflecting evolving clinical changes during hospitalization, over a potentially actionable time interval for clinical reassessment.

Gender Differences in the Pursuit of Cardiac Electrophysiology Training in North America.

BACKGROUND: Despite the increase in the number of female physicians across most specialties within cardiology, <10% of clinical cardiac electrophysiology (EP) fellows are women. OBJECTIVES: This study sought to determine the factors that influence fellows-in-training (FITs) to pursue EP as a career choice and whether this differs by gender. METHODS: The authors conducted an online multiple-choice survey through the American College of Cardiology to assess the decision factors that influence FITs in the United States and Canada to pursue cardiovascular subspecialties. RESULTS: A total of 933 (30.5%) FITs completed the survey; 129 anticipated specializing in EP, 259 in interventional cardiology (IC), and 545 in a different field or were unsure. A total of 1 in 7 (14%) FITs indicated an interest in EP. Of this group, more men chose EP than women (84% vs 16%; P < 0.001). The most important factor that influenced FITs to pursue EP was a strong interest in the field. Women were more likely to be influenced by having a female role model (P = 0.001) compared with men. After excluding FITs interested in IC, women who deselected EP were more likely than men to be influenced by greater interest in another field (P = 0.004), radiation concerns (P = 0.001), lack of female role models (P = 0.001), a perceived "old boys' club" culture (P = 0.001) and discrimination/harassment concerns (P = 0.001). CONCLUSIONS: Women are more likely than men to be negatively influenced by many factors when it comes to pursuing EP as a career choice. Addressing those factors will help decrease the gender disparity in the field.

How does the level of pulmonary venous isolation compare between pulsed field ablation and thermal energy ablation (radiofrequency, cryo, or laser)?

AIMS: We studied the extent/area of electrical pulmonary vein isolation (PVI) after either pulsed field ablation (PFA) using a pentaspline catheter or thermal ablation technologies. METHODS AND RESULTS: In a clinical trial (NCT03714178), paroxysmal atrial fibrillation (PAF) patients underwent PVI with a multi-electrode pentaspline PFA catheter using a biphasic waveform, and after 75 days, detailed voltage maps were created during protocol-specified remapping studies. Comparative voltage mapping data were retrospectively collected from consecutive PAF patients who (i) underwent PVI using thermal energy, (ii) underwent reablation for recurrence, and (iii) had durably isolated PVs. The left and right PV antral isolation areas and non-ablated posterior wall were quantified. There were 20 patients with durable PVI in the PFA cohort, and 39 in the thermal ablation cohort [29 radiofrequency ablation (RFA), 6 cryoballoon, and 4 visually guided laser balloon]. Pulsed field ablation patients were younger with shorter follow-up. Left atrial diameter and ventricular systolic function were preserved in both cohorts. There was no significant difference between the PFA and thermal ablation cohorts in either the left- and right-sided PV isolation areas, or the non-ablated posterior wall area. The right superior PV isolation area was smaller with PFA than RFA, but this disappeared after propensity score matching. Notch-like normal voltage areas were seen at the posterior aspect of the carina in the balloon sub-cohort, but not the PFA or RFA cohorts. CONCLUSION: Catheter-based PVI with the pentaspline PFA catheter creates chronic PV antral isolation areas as encompassing as thermal energy ablation.

Atrial Fibrillation in Patients Hospitalized With COVID-19: Incidence, Predictors, Outcomes, and Comparison to Influenza.

OBJECTIVES: The goal of this study is to determine the incidence, predictors, and outcomes of atrial fibrillation (AF) or atrial flutter (AFL) in patients hospitalized with coronavirus disease-2019 (COVID-19). BACKGROUND: COVID-19 results in increased inflammatory markers previously associated with atrial arrhythmias. However, little is known about their incidence or specificity in COVID-19 or their association with outcomes. METHODS: This is a retrospective analysis of 3,970 patients admitted with polymerase chain reaction-positive COVID-19 between February 4 and April 22, 2020, with manual review performed of 1,110. The comparator arm included 1,420 patients with influenza hospitalized between January 1, 2017, and January 1, 2020. RESULTS: Among 3,970 inpatients with COVID-19, the incidence of AF/AFL was 10% (n = 375) and in patients without a history of atrial arrhythmias it was 4% (n = 146). Patients with new-onset AF/AFL were older with increased inflammatory markers including interleukin 6 (93 vs. 68 pg/ml; p < 0.01), and more myocardial injury (troponin-I: 0.2 vs. 0.06 ng/ml; p < 0.01). AF and AFL were associated with increased mortality (46% vs. 26%; p < 0.01). Manual review captured a somewhat higher incidence of AF/AFL (13%, n = 140). Compared to inpatients with COVID-19, patients with influenza (n = 1,420) had similar rates of AF/AFL (12%, n = 163) but lower mortality. The presence of AF/AFL correlated with similarly increased mortality in both COVID-19 (relative risk: 1.77) and influenza (relative risk: 1.78). CONCLUSIONS: AF/AFL occurs in a subset of patients hospitalized with either COVID-19 or influenza and is associated with inflammation and disease severity in both infections. The incidence and associated increase in mortality in both cohorts suggests that AF/AFL is not specific to COVID-19, but is rather a generalized response to the systemic inflammation of severe viral illnesses.

Assessment of Catheter Ablation or Antiarrhythmic Drugs for First-line Therapy of Atrial Fibrillation: A Meta-analysis of Randomized Clinical Trials.

Importance: Early rhythm control of atrial fibrillation (AF) with either antiarrhythmic drugs (AADs) or catheter ablation has been reported to improve cardiovascular outcomes compared with usual care; however, the optimal therapeutic modality to achieve early rhythm control is unclear. Objective: To assess the safety and efficacy of AF ablation as first-line therapy when compared with AADs in patients with paroxysmal AF. Data Sources: PubMed/MEDLINE, Scopus, Google Scholar, and various major scientific conference sessions from January 1, 2000, through November 23, 2020. Study Selection: Randomized clinical trials (RCTs) published in English that had at least 12 months of follow-up and compared clinical outcomes of ablation vs AADs as first-line therapy in adults with AF. The quality of individual studies was assessed using the Cochrane risk of bias tool. Six RCTs met inclusion criteria, including 1212 patients. Data Extraction and Synthesis: Two investigators independently extracted data. Reporting was performed in compliance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analysis) guidelines. Analysis was performed using a random-effects model with the Mantel-Haenszel method, and results are presented as 95% CIs. Main Outcomes and Measures: Main outcomes were safety and efficacy of AF ablation as first-line therapy when compared with AADs. Trials were evaluated as having low risk of selection and attrition biases, high risk of performance bias, and with unclear risk for detection biases due to unblinding and open-label designs. Results: A total of 6 RCTs involving 1212 patients with AF were included (609 were randomized to AF ablation and 603 to drug therapy; mean [SD] age, 56 [11] years). Compared with AADs, catheter ablation use was associated with reductions in recurrent atrial arrhythmia (32.3% vs 53%; risk ratio [RR], 0.62; 95% CI, 0.51-0.74; P < .001; I2 = 40%), with a number needed to treat with ablation to prevent 1 arrhythmia of 5. Use of ablation was also associated with reduced symptomatic atrial arrhythmia (11.8% vs 26.4%; RR, 0.44; 95% CI, 0.27-0.72; P = .001; I2 = 54%) and hospitalization (5.6% vs 18.7%; RR, 0.32; 95% CI, 0.19-0.53; P < .001) with no significant difference in serious adverse events between the groups (4.2% vs 2.8%; RR, 1.52; 95% CI, 0.81-2.85; P = .19). Conclusions and Relevance: In this meta-analysis of randomized clinical trials including first-line therapy of patients with paroxysmal AF, catheter ablation compared with antiarrhythmic drugs was associated with reductions in recurrence of atrial arrhythmias and hospitalizations, with no difference in major adverse events.

Shared Decision Making for Syncope in the Emergency Department: A Randomized Controlled Feasibility Trial.

OBJECTIVES: Significant practice variation is seen in the management of syncope in the emergency department (ED). We sought to evaluate the feasibility of performing a randomized controlled trial of a shared decision making (SDM) tool for low-to-intermediate-risk syncope patients presenting to the ED. METHODS: We performed a randomized controlled trial of adults (≥30 years) with unexplained syncope who presented to an academic ED in the United States. Patients with a serious diagnosis identified in the ED were excluded. Patients were randomized, 1:1, to receive either usual care or a personalized syncope decision aid (SynDA) meant to facilitate SDM. Our primary outcome was feasibility, i.e., ability to enroll 50 patients in 24 months. Secondary outcomes included patient knowledge, involvement (measured with OPTION-5), rating of care, and clinical outcomes at 30 days post-ED visit. RESULTS: After screening 351 patients, we enrolled 50 participants with unexplained syncope from January 2017 to January 2019. The most common reason for exclusion was lack of clinical equipoise to justify SDM (n = 124). Patients in the SynDA arm tended to have greater patient involvement, as shown by higher OPTION-5 scores: 52/100 versus 27/100 (between-group difference = -25.4, 95% confidence interval = -13.5 to -37.3). Both groups had similar levels of clinical knowledge, ratings of care, and serious clinical outcomes at 30 days. CONCLUSIONS: Among ED patients with unexplained syncope, a randomized controlled trial of a shared decision-making tool is feasible. Although this study was not powered to detect differences in clinical outcomes, it demonstrates feasibility, while providing key lessons and effect sizes that could inform the design of future SDM trials.

Does Left Atrial Appendage Closure Reduce Mortality? A Vital Status Analysis of the Randomized PROTECT AF and PREVAIL Clinical Trials.

Compared with warfarin, left atrial appendage closure (LAAC) reduced mortality in an analysis of the PROTECTAF and PREVAIL trials. However, these data were limited by patient drop-out.We sought to estimatethe mortality benefit with LAACusing updated vital status information.In PROTECT AF and PREVAIL, 227 of 1114 randomized subjects failed to complete 5-year follow-up. Centers were manually queried for updated vital status on 76 subjects (33%).During median follow-up 5.0 years (interquartile range 3.8, 5.1), 112 of 732 LAAC subjects (15.3%) and 79 of 382 controls (20.7%) died. The hazard ratio for all-cause mortality with LAAC compared with warfarin was 0.70 (95% CI 0.53-0.94, p=0.017).Subgroup analyses suggested that subjects <75 years and those with higher CHA2DS2-VASc score, history of transient ischemic attack or stroke, and permanent AF derived particular benefit, although interaction terms were not significant.The number needed to treat(NNT) with LAAC to prevent one death over 5 years was 16 (95% CI 10-82). Despite competing mortality risks in this elderly cohort, updated vital status data from PROTECT AF and PREVAIL revealed that LAAC was associated with 30% improved survival compared with warfarin, with an NNT of 16.

Development of a Patient Decision Aid for Syncope in the Emergency Department: the SynDA Tool.

OBJECTIVES: The objective was to develop a patient decision aid (DA) to promote shared decision making (SDM) for stable, alert patients who present to the emergency department (ED) with syncope. METHODS: Using input from patients, clinicians, and experts in the field of syncope, health care design, and SDM, we created a prototype of a paper-based DA to engage patients in the disposition decision (admission vs. discharge) after an unremarkable ED evaluation for syncope. In phase 1, we conducted one-on-one semistructured exploratory interviews with 10 emergency physicians and 10 ED syncope patients. In phase 2, we conducted one-on-one directed interviews with 15 emergency care clinicians, five cardiologists, and 12 ED syncope patients to get detailed feedback on DA content and design. We iteratively modified the aid using feedback from each interviewee until clarity and usability had been optimized. RESULTS: The 11 × 17-inch, paper-based DA, titled SynDA, includes four sections: 1) explanation of syncope, 2) explanation of future risks, 3) personalized 30-day risk estimate, and 4) disposition options. The personalized risk estimate is calculated using a recently published syncope risk-stratification tool. This risk estimate is stated in natural frequency and graphically displayed using a 100-person color-coded pictogram. Patient-oriented questions are included to stimulate dialogue between patient and clinician. At the end of the development process, patient and physician participants expressed satisfaction with the clarity and usability of the DA. CONCLUSIONS: We iteratively developed an evidence-based DA to facilitate SDM for alert syncope patients after an unremarkable ED evaluation. Further testing is required to determine its effects on patient care. This DA has the potential to improve care for syncope patients and promote patient-centered care in emergency medicine.

First robotic endoscopic epicardial isolation of the pulmonary veins with microwave energy in a patient in chronic atrial fibrillation.

The pulmonary veins have been demonstrated to play an important role in generating atrial fibrillation. We report the first successful endoscopic epicardial isolation of the pulmonary veins in a patient with permanent atrial fibrillation, along with a 1-year follow-up. The procedure consisted of making a conduction block around the pulmonary veins with a flexible microwave energy delivery probe. The probe was placed endoscopically on the left atrial epicardium with the aid of robotic instruments.