Impact of Defibrillator Electrode Placement on Outcome of Electrical Cardioversion of Atrial Fibrillation: A Pilot Observational Study.

BACKGROUND: Anterior-posterior electrode placement is preferred in electrical cardioversion of atrial fibrillation. However, the optimal anterior-posterior electrode position in relation to the heart is not studied. METHODS AND RESULTS: We performed a prospective observational study on patients presenting for cardioversion of atrial fibrillation. Electrodes were placed in the anterior-posterior position and shock was delivered in a step-up approach (100 J→200 J→360 J). Fluoroscopic images were obtained, and distances were measured from points A, midanterior electrode; and B, midposterior electrode, to midpoint of the cardiac silhouette. Patients requiring one 100 J shock for cardioversion success (group I) were compared with those requiring >1 shock/100 J (group II). Logistic regression was used to determine the impact of electrode distance on low energy (100 J) cardioversion success. Computed tomography scans from this cohort were analyzed for anatomic landmark correlation to the cardiac silhouette. Of the 87 patients included, 54 (62%) comprised group I and 33 (38%) group II. Group I had significantly lower distances from the mid-cardiac silhouette to points A (5.0±2.4 versus 7.4±3.3 cm; P<0.001) and B (7.3±3.0 versus 10.0±3.8 cm; P=0.002) compared with group II. On multivariate analysis, higher distances from the mid-cardiac silhouette to point A (odds ratio, 1.33 [95% CI, 1.07-1.70]; P=0.01) and B (odds rsatio, 1.24 [95% CI, 1.05-1.50]; P=0.01) were independent predictors of low energy (100 J) cardioversion failure. Based on review of computed tomography scans, we suggest that the xiphoid process may be an easy landmark to guide proximity to the myocardium. CONCLUSIONS: In anterior-posterior electrode placement, closer proximity to the cardiac silhouette predicts successful 100 J cardioversion irrespective of clinical factors.

Catheter ablation versus medical therapy in atrial fibrillation: an umbrella review of meta-analyses of randomized clinical trials.

This umbrella review synthesizes data from 17 meta-analyses investigating the comparative outcomes of catheter ablation (CA) and medical treatment (MT) for atrial fibrillation (AF). Outcomes assessed were mortality, risk of hospitalization, AF recurrence, cardiovascular events, pulmonary vein stenosis, major bleeding, and changes in left ventricular ejection fraction (LVEF) and MLHFQ score. The findings indicate that CA significantly reduces overall mortality and cardiovascular hospitalization with high strength of evidence. The risk of AF recurrence was notably lower with CA, with moderate strength of evidence. Two associations reported an increased risk of pulmonary vein stenosis and major bleeding with CA, supported by high strength of evidence. Improved LVEF and a positive change in MLHFQ were also associated with CA. Among patients with AF and heart failure, CA appears superior to MT for reducing mortality, improving LVEF, and reducing cardiovascular rehospitalizations. In nonspecific populations, CA reduced mortality and improved LVEF but had higher complication rates. Our findings suggest that CA might offer significant benefits in managing AF, particularly in patients with heart failure. However, the risk of complications, including pulmonary vein stenosis and major bleeding, is notable. Further research in understudied populations may help refine these conclusions.

Characterizing advanced heart failure risk and hemodynamic phenotypes using interpretable machine learning.

BACKGROUND: Although previous risk models exist for advanced heart failure with reduced ejection fraction (HFrEF), few integrate invasive hemodynamics or support missing data. This study developed and validated a heart failure (HF) hemodynamic risk and phenotyping score for HFrEF, using Machine Learning (ML). METHODS: Prior to modeling, patients in training and validation HF cohorts were assigned to 1 of 5 risk categories based on the composite endpoint of death, left ventricular assist device (LVAD) implantation or transplantation (DeLvTx), and rehospitalization in 6 months of follow-up using unsupervised clustering. The goal of our novel interpretable ML modeling approach, which is robust to missing data, was to predict this risk category (1, 2, 3, 4, or 5) using either invasive hemodynamics alone or a rich and inclusive feature set that included noninvasive hemodynamics (all features). The models were trained using the ESCAPE trial and validated using 4 advanced HF patient cohorts collected from previous trials, then compared with traditional ML models. Prediction accuracy for each of these 5 categories was determined separately for each risk category to generate 5 areas under the curve (AUCs, or C-statistics) for belonging to risk category 1, 2, 3, 4, or 5, respectively. RESULTS: Across all outcomes, our models performed well for predicting the risk category for each patient. Accuracies of 5 separate models predicting a patient's risk category ranged from 0.896 +/- 0.074 to 0.969 +/- 0.081 for the invasive hemodynamics feature set and 0.858 +/- 0.067 to 0.997 +/- 0.070 for the all features feature set. CONCLUSION: Novel interpretable ML models predicted risk categories with a high degree of accuracy. This approach offers a new paradigm for risk stratification that differs from prediction of a binary outcome. Prospective clinical evaluation of this approach is indicated to determine utility for selecting the best treatment approach for patients based on risk and prognosis.

Atrial fibrillation considerations in the fourth trimester (postpartum period).

Postpartum atrial fibrillation is an uncommon but increasingly prevalent tachyarrhythmia that merits special management considerations with regards to the safety and efficacy of anticoagulation, rate and rhythm control as well as drug exposure to infants throughout breastfeeding. In this state-of-the-art review, we examine the demographics of postpartum atrial fibrillation with its associated risk factors, describe the safety of commonly used atrial fibrillation therapies, and discuss important considerations for women considering subsequent pregnancies.

Echocardiographic derived pulmonary artery wedge pressure is associated with mortality, heart hospitalizations, and functional capacity in chronic systolic heart failure: insights from the HF-ACTION trial.

BACKGROUND: Heart Failure (HF) is associated with increased morbidity and mortality. Identification of patients at risk for adverse events could lead to improved outcomes. Few studies address the association of echocardiographic-derived PAWP with exercise capacity, readmissions, and mortality in HF. METHODS: HF-ACTION enrolled 2331 outpatients with HF with reduced ejection fraction (HFrEF) who were randomized to aerobic exercise training versus usual care. All patients underwent baseline echocardiography. Echocardiographic-derived PAWP (ePAWP) was assessed using the Nagueh formula. We evaluated the relationship between ePAWP to clinical outcomes. RESULTS: Among the 2331 patients in the HF-ACTION trial, 2125 patients consented and completed follow-up with available data. 807 of these patients had complete echocardiographic data that allowed the calculation of ePAWP. Of this cohort, mean age (SD) was 58 years (12.7), and 255 (31.6%) were female. The median ePAWP was 14.06 mmHg. ePAWP was significantly associated with cardiovascular death or HF hospitalization (Hazard ratio [HR] 1.02, coefficient 0.016, CI 1.002-1.030, p = 0.022) and all-cause death or HF hospitalization (HR 1.01, coefficient 0.010, CI 1.001-1.020, p = 0.04). Increased ePAWP was also associated with decreased exercise capacity leading to lower peak VO2 (p = < 0.001), high Ve/VCO2 slope (p = < 0.001), lower exercise duration (p = < 0.001), oxygen uptake efficiency (p = < 0.001), and shorter 6-MWT distance (p = < 0.001). CONCLUSIONS: Among HFrEF patients, echocardiographic-derived PAWP was associated with increased mortality, reduced functional capacity and heart failure hospitalization. ePAWP may be a viable noninvasive marker to risk stratify HFrEF patients.

Change in Systemic Arterial Pulsatility Index (SAPi) during Heart Failure Hospitalization is Associated with Improved Outcomes.

Study Objective: To identify Change in Systemic Arterial Pulsatitlity index (ΔSAPi) as a novel hemodynamic marker associated with outcomes in heart failure (HF). Design: The ESCAPE trial was a randomized controlled trial. Setting: The ESCAPE trial was conducted at 26 sites. Participants: 134 patients were analyzed (mean age 56.8 ± 13.4 years, 29% female). Interventions: We evaluated the change in SAPi, ([systemic pulse pressure/pulmonary artery wedge pressure) obtained at baseline and at the final hemodynamic measurement in the ESCAPE trial. Main Outcome Measures: Change in SAPi, (ΔSAPi), was analyzed for the primary outcomes of death, heart transplant, left ventricular assist device (DTxLVAD) or hospitalization, (DTxLVADHF) and secondary outcome of DTxLVAD using Cox proportional hazards regression. Results: Median change in SAPi was 0.81 (IQR 0.20-1.68). ΔSAPi in uppermost quartile was associated with reductions in DTxLVADHF (HR 0.55 [95% CI 0.32, 0.93]). ΔSAPi in the uppermost and lowermost quartiles combined was similarly associated with significant reductions in DTxLVADHF (HR 0.62 [95% CI 0.41, 0.94]). ΔSAPi higher than 1.17 was associated with improved DTxLVADHF. ΔSAPi was also associated with troponin levels at discharge (regression coefficient p = 0.001) and trended with 6-minute walk at discharge (Spearman correlation r = 0.179, p = 0.058). Conclusion: ΔSAPi was strongly associated with improved HF clinical profile and adverse outcomes. These findings support further exploration of Δ SAPi in the risk stratification of HF.

Cardiac Magnetic Resonance, Electromechanical Activation, Kidney Function, and Natriuretic Peptides in Cardiac Resynchronization Therapy Upgrades.

As the mechanism for worse prognosis after cardiac resynchronization therapy (CRT) upgrades in heart failure patients with RVP dependence (RVP-HF) has clinical implications for patient selection and CRT implementation approaches, this study's objective was to evaluate prognostic implications of cardiac magnetic resonance (CMR) findings and clinical factors in 102 HF patients (23.5% female, median age 66.5 years old, median follow-up 4.8 years) with and without RVP dependence undergoing upgrade and de novo CRT implants. Compared with other CRT groups, RVP-HF patients had decreased survival (p = 0.02), more anterior late-activated LV pacing sites (p = 0.002) by CMR, more atrial fibrillation (p = 0.0006), and higher creatinine (0.002). CMR activation timing at the LV pacing site predicted post-CRT LV functional improvement (p < 0.05), and mechanical activation onset < 34 ms by CMR at the LVP site was associated with decreased post-CRT survival in a model with higher pre-CRT creatinine and B-type natriuretic peptide (AUC 0.89; p < 0.0001); however, only the higher pre-CRT creatinine partially mediated (37%) the decreased survival in RVP-HF patients. In conclusion, RVP-HF had a distinct CMR phenotype, which has important implications for the selection of LV pacing sites in CRT upgrades, and only chronic kidney disease mediated the decreased survival after CRT in RVP-HF.

Mortality Outcomes in Patients With Cardiac Implantable Electronic Devices Before and After Transcatheter Aortic Valve Replacement.

Transcatheter aortic valve replacement (TAVR) carries a risk of high-grade AV block requiring cardiac implantable electronic device (CIED) implantation, which has been associated with a higher mortality rate. However, the outcomes of TAVR in patients with preexisting CIEDs are not well understood. We conducted a retrospective analysis of consecutive patients who underwent TAVR from December 2014 to December 2019 at our institution. Patients were categorized into 3 groups: preexisting CIED pre-TAVR (group 1), CIED implanted within 30 days after TAVR (group 2), and no CIED implanted (group 3). Cox proportional hazard was conducted to determine the primary end point of all-cause mortality. A total of 366 patients were included, of whom 93 (25.4%), 51 (13.9%), and 222 (60.7%) comprised group 1, 2, and 3, respectively. The median follow-up time was 2.3 years. The all-cause mortality rate was higher in group 1 than group 2 (hazard ratio [HR] 2.60, 95% confidence interval [CI] 1.09 to 6.18, p = 0.03) and group 3 (HR 1.96, 95% CI 1.24 to 3.08, p = 0.004). On the multivariate analysis, there was no statistically significant difference in mortality among the groups (group 1 vs group 2: HR 1.95, 95% CI 0.70 to 5.44, p = 0.20 and group 1 vs group 3: HR 1.27, 95% CI 0.66 to 2.43, p = 0.47). Preoperative hemoglobin ≤12 g/100 ml was an independent predictor of all-cause mortality (HR 1.75, 95% CI 1.10 to 2.80, p = 0.02). Group 1 had a higher 1 year congestive heart failure readmission rate (29%) than group 2 (17.6%) and group 3 (8.1%; p <0.0001). In conclusion, there was no difference in the adjusted long-term survival based on the CIED grouping. However, patients with preexisting CIEDs had higher all-cause mortality and 1-year congestive heart failure readmission rates owing to their higher co-morbidity burden, irrespective of their Society of Thoracic Surgeons score. This can be taken into account for preoperative risk stratification.

Current landscape in US schools for bystander CPR training and AED requirements.

BACKGROUND: Out-of-hospital cardiac arrest is a public health crisis affecting about 356,000 adults and 23,000 children annually in the US with 90% fatality. Early bystander CPR and AED application improve survival. Less than 3% of the US population is CPR trained annually. Since 20% of the US population is at school daily, these represent ideal places to target CPR training. Having standardized state school CPR and AED laws will help with training. METHODS: We performed a systemic search of the state-specific laws for school AED and CPR requirements within the US. We used PubMed and Google search using keywords: school CPR mandates, US laws for CPR in schools, US state laws for AED implementation, and gaps in US school CPR and AED. We searched for mandates for schools in other countries for comparison. RESULTS: The state laws for CPR training for high school graduation and AED requirements in US. schools are highly variable, and funding for AEDs is inadequate, especially in schools in lower socio-economic zip codes. Recent AED legislative efforts focus mainly on athletic areas and don't adequately address school size, number of buildings, non-athletic areas, and engagement of student-led advocacy efforts. CONCLUSION: To improve OHCA survival, we identified potential solutions to consolidate efforts and overcome the barriers-standardize state laws, involve student bodies, increase funding, and allocate appropriate resources. The CPR/AED education needs to start earlier in schools and be part of the standard curriculum rather than implemented as a stopgap check-box mandate.

PV Isolation Using a Spherical Array PFA Catheter: Preclinical Assessment and Comparison to Radiofrequency Ablation.

BACKGROUND: A multielectrode spherical array catheter capable of single-shot mapping and ablation has been introduced. OBJECTIVES: This study sought to compare the efficacy and safety of circumferential, linear, and focal ablation using either microsecond pulsed field (PF) and radiofrequency (RF) ablation in preclinical model. METHODS: Under general anesthesia, a 122 gold-plated multielectrode array was introduced into the left atrium. Twenty-nine canines underwent isolation of two pulmonary veins (PVs), with linear and focal left atrial ablation with both RF (n = 12) and PF (n = 17). PF was also delivered within the superior vena cava and atop the esophagus in three swine. Animals were sacrificed acutely (immediately for RF [6 of 12] and 3 days for PF [6 of 17]) and the remaining (n = 17) at 14 to 30 days. Detailed necropsy and histopathology were performed. RESULTS: All PVs were acutely (58 of 58) and durably (34 of 34) isolated and exhibited wide confluent lesions. Lesions were transmural for 97% to 100% of sections with depths of 2.5 to 3.4 mm and 2.5 to 3.5 mm in the acute and chronic cohorts, respectively. Linear and focal lesions displayed transmurality rates of 85% to 100% with depths of 3.5 millimeters to 4.2 millimeters in the acute cohort. In the chronic cohorts, linear lesions created with RF, PF+RF, and PF had no significant differences in depth (3.5 ± 1.8 mm, 4.0 ± 1.4 mm, and 3.9 ± 0.9 mm) or transmurality (83.3%, 100%, and 80%). Current of injury was seen on local unipolar electrogram immediately after PF and RF, and this occurred to a wider extent with PF. PF but not RF elicited bradycardia from ganglionated plexi stimulation. There were no instances of phrenic palsy, venous stenosis, esophageal damage, or thromboembolism. CONCLUSIONS: Circumferential, linear, and focal mapping and ablation can be achieved with this novel catheter using both PF and RF, with excellent efficacy and safety.

Positional obstructive sleep apnea in patients with atrial fibrillation.

PURPOSE: Obstructive sleep apnea (OSA) is a common, potentially modifiable condition implicated in the pathogenesis of atrial fibrillation (AF). The presence and severity of OSA is largely sleep position-dependent, yet there is high variability in positional dependence among patients with OSA. We investigated the prevalence of positional OSA (POSA) and examined associated factors in patients with AF. METHODS: We recruited an equal number of patients with and without AF who underwent diagnostic polysomnography. Patients included had ≥ 120 min of total sleep time with 30 min of sleep in both supine and lateral positions. POSA was defined as an overall apnea hypopnea index (AHI) ≥ 5/h, supine AHI (sAHI) ≥ 5/h, and sAHI greater than twice the non-supine AHI. POSA prevalence was compared in patients with and without AF adjusting for age, sex, OSA severity, and heart failure. RESULTS: A total of patients (male: 56%, mean age 62 years) were included. POSA prevalence was similar between the two groups (46% vs. 39%; p = 0.33). Obesity and severe OSA (AHI ≥ 30/h) were associated with low likelihood of POSA (OR [CI] of 0.17 [0.09-0.32] and 0.28 [0.12-0.62]). In patients with AF, male sex was associated with a higher likelihood of POSA (OR [CI] of 3.16 [1.06-10.4]). CONCLUSION: POSA is common, affecting more than half of patients with AF, but the prevalence was similar in those without AF. Obesity and more severe OSA are associated with lower odds of POSA. Positional therapy should be considered in patients with mild OSA and POSA.

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.

Racial disparities in ventricular tachycardia in young adults: analysis of national trends.

BACKGROUND: In the last two decades, risk factors, prevalence, and mortality due to coronary artery disease in young adults are on the rise. We sought to assess the prevalence, trends, and economic burden of ventricular tachycardia (VT) hospitalizations in young adults (< 45 years), further stratified by race and gender. METHODS: The Nationwide Inpatient Sample was explored for hospitalizations with VT in patients (< 45 years) between 2005 and 2018 and divided among 3 groups of the quadrennial period using validated International Classification of Diseases (ICD) 9th and 10th revision Clinical Modification (CM) codes. The Pearson chi-square test and Wilcoxon rank-sum were used for categorical and continuous variables, respectively. We assessed the temporal trends of mortality in VT hospitalizations and trends of VT hospitalization stratified by age, sex, and race by using Joinpoint regression analysis. The primary outcome was in-hospital mortality trends. Secondary outcomes were trends of hospital stay in days, cost of care in US dollars, cardiac arrest, and discharge disposition. RESULTS: Out of 5,156,326 patients admitted with VT between 2005 and 2018, 309,636 were young adults. Among them, 102,433 were admitted between 2005 and 2009 (mean age 36.1 ± 6.99; 61% male, 58.5% White), 109,591 between 2010 and 2014 (mean age 35.5 ± 7.16; 59% male, 54.2% White), and 97,495 between 2015 and 2018 (mean age 35.4 ± 7.00; 60% male, 52.3% White) (p < 0.07). In the young adults with VT, all-cause mortality was 7.37% from 2005 to 2009, 7.85% from 2010 to 2014 (6.5% relative increase from 2005 to 2009), and 8.98% from 2015 to 2018 (relative increase of 14.4% from 2010 to 2014) (p < 0.0001). Similarly, risk of cardiac arrest was on the rise (6.15% from 2005 to 2009 to 7.77% in 2010-2014 and 9.97% in 2015-2018). Inflation-adjusted cost increased over the years [$12,177 in 2005-2009; $13,249 in 2010-2014; $15,807 in 2015-2018; p < 0.0001)]. CONCLUSIONS: VT hospitalizations and related all-cause mortality, and healthcare utilization costs in young adults are on the rise in the study period. Hospitalization burden related to VT and poor outcomes were more notable for Black adults. Further studies are required for targeted screening and preventative measures in young adults.

Coronary perfusion pressure is associated with adverse outcomes in advanced heart failure.

BACKGROUND: Myocardial perfusion is an important determinant of cardiac function. We hypothesized that low coronary perfusion pressure (CPP) would be associated with adverse outcomes in heart failure. Myocardial perfusion impacts the contractile efficiency thus a low CPP would signal low myocardial perfusion in the face of increased cardiac demand as a result of volume overload. METHODS: We analyzed patients with complete hemodynamic data in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness trial using Cox Proportional Hazards regression for the primary outcome of the composite risk of death, heart transplantation, or left ventricular assist device [(LVAD). DT × LVAD] and the secondary outcome of the composite risk of DT × LVAD and heart failure hospitalization (DT × LVADHF). CPP was calculated as the difference between diastolic blood pressure and pulmonary artery wedge pressure. Heart failure categories (ischemic vs non-ischemic) were also stratified based on CPP strata. RESULTS: The 158 patients (56.7 ± 13.6 years, 28.5% female) studied had a median CPP of 40 mmHg (IQR 35-52 mmHg). During 6 months of follow-up, 35 (22.2%) had the composite primary outcome and 109 (69.0%) had the composite secondary outcome. When these outcomes were then stratified based on the median, CPP was associated with these outcomes. Increasing CPP was associated with lower risk of both the primary outcome of DT × LVAD (HR 0.96, 95% CI 0.94-0.99 p = .002) and as well as the secondary outcome of DT × LVADHF (p = .0008) There was significant interaction between CPP and ischemic etiology (p = .04). CONCLUSION: A low coronary artery perfusion pressure below (median) 40mmHg in patients with advanced heart failure undergoing invasive hemodynamic monitoring with a pulmonary artery catheter was associated with adverse outcomes. CPP could useful in guiding risk stratification of advanced heart failure patients and timely evaluation of advanced heart failure therapies.