Temporal and geographical trends in women operators of electrophysiology procedures in the United States.

BACKGROUND: Cardiac electrophysiology (EP) has few women physicians. OBJECTIVE: The purpose of this study was to determine temporal and geographical trends in the proportion of women EP operators in the United States. METHODS: We extracted data from the Medicare Provider Utilization and Payment Database from 2013 to 2019 using procedure codes for atrial fibrillation (AF) ablation, supraventricular tachycardia/atrial flutter (SVT/AFL) ablation, and cardiac device implantation. The Medicare Provider Utilization and Payment Database excludes operators who perform ≤10 procedures annually for a given individual procedure code. The proportion of women operators was compared across the 7-year period. RESULTS: On average annually between 2013 and 2019, 5% (n = 187) of the 3524 EP operators were women. Procedure-specific analyses demonstrated a similarly low proportion of women EP operators across each procedure type. Despite a 137% increase in the total number of AF ablationists over the 7-year period, the proportion of women remained unchanged (P = .3966). The number of SVT/AFL ablationists and device operators remained constant over time as did the proportion of women operators (P = .9709 and .3583, respectively). In 2019, 10 states (20%) had no women EP operators who performed >10 of any given EP procedure annually, 20 states (39%) had no women who performed >10 of either AF or SVT/AFL ablation procedures annually, and 10 states (20%) had no women device operators who performed >10 of any given type of device implantation annually. CONCLUSION: Women EP operators remain underrepresented, and the proportion of women is stagnant even in areas of major clinical growth such as AF ablation. One-fifth of states had no women operators who performed >10 of any given EP procedure annually.

New-Onset Atrial Fibrillation in Patients Hospitalized With COVID-19: Results From the American Heart Association COVID-19 Cardiovascular Registry.

BACKGROUND: New-onset atrial fibrillation (AF) in patients hospitalized with COVID-19 has been reported and associated with poor clinical outcomes. We aimed to understand the incidence of and outcomes associated with new-onset AF in a diverse and representative US cohort of patients hospitalized with COVID-19. METHODS: We used data from the American Heart Association COVID-19 Cardiovascular Disease Registry. Patients were stratified by the presence versus absence of new-onset AF. The primary and secondary outcomes were in-hospital mortality and major adverse cardiovascular events (MACE; cardiovascular death, myocardial infarction, stroke, cardiogenic shock, and heart failure). The association of new-onset AF and the primary and secondary outcomes was evaluated using Cox proportional-hazards models for the primary time to event analyses. RESULTS: Of the first 30 999 patients from 120 institutions across the United States hospitalized with COVID-19, 27 851 had no history of AF. One thousand five hundred seventeen (5.4%) developed new-onset AF during their index hospitalization. New-onset AF was associated with higher rates of death (45.2% versus 11.9%) and MACE (23.8% versus 6.5%). The unadjusted hazard ratio for mortality was 1.99 (95% CI, 1.81-2.18) and for MACE was 2.23 (95% CI, 1.98-2.53) for patients with versus without new-onset AF. After adjusting for demographics, clinical comorbidities, and severity of disease, the associations with death (hazard ratio, 1.10 [95% CI, 0.99-1.23]) fully attenuated and MACE (hazard ratio, 1.31 [95% CI, 1.14-1.50]) partially attenuated. CONCLUSIONS: New-onset AF was common (5.4%) among patients hospitalized with COVID-19. Almost half of patients with new-onset AF died during their index hospitalization. After multivariable adjustment for comorbidities and disease severity, new-onset AF was not statistically significantly associated with death, suggesting that new-onset AF in these patients may primarily be a marker of other adverse clinical factors rather than an independent driver of mortality. Causality between the MACE composites and AF needs to be further evaluated.

Response to cardiac resynchronisation therapy in men and women: a secondary analysis of the SMART-AV randomised controlled trial.

OBJECTIVES: There is a controversy about whether both sexes' response to cardiac resynchronisation therapy (CRT) is similar. We aimed to assess a causal effect of sex on CRT response. DESIGN: Secondary analysis of a randomised controlled trial (RCT) data. Doubly robust augmented-inverse-probability-weighted (AIPW) estimation of sex effect on CRT response. SETTING: The SmartDelay Determined Atrioventricular (AV) Optimisation (SMART-AV) RCT. PARTICIPANTS: The SMART-AV RCT enrolled New York Heart Association class III-IV patients with heart failure (HF) with left ventricular ejection fraction (LVEF) ≤35% despite optimal medical therapy and QRS duration ≥120 ms, in sinus rhythm. After exclusion of those with missing outcome or covariates, 741 participants (age 66±11 years; 33% female; 78% white; LVEF 28%±9%; 58% ischaemic cardiomyopathy; 75% left bundle branch block; left ventricular end-systolic volume index (LVESVI) 65±30 mL/m2) were included. INTERVENTIONS: Implanted CRT defibrillator with randomly assigned AV delay as either (1) fixed at 120 ms, or (2) echocardiography-determined, or (3) SmartDelay algorithm-programmed. OUTCOME: A composite of freedom from death and HF hospitalisation and a >15% reduction in LVESVI at 6 month post-CRT was the endpoint. RESULTS: The primary endpoint was met by 337 patients (45.5%); 134 were women (55.6% response) and 203 were men (40.6% response); p<0.0001. After conditioning for 33 covariates that included baseline demographic, clinical, ECG, echocardiographic and biomarker characteristics, known predictors of CRT response, logistic regression showed a higher probability for composite CRT response for women versus men (OR 1.79; 95% CI 1.08 to 2.98; p<0.0001), whereas AIPW estimation showed no difference in CRT response (average treatment effect 0.88; 95% CI 0.41 to 1.89; p=0.739). After removing colliders from the model, both logistic regression (OR 1.00; 95% CI 0.69 to 1.44) and AIPW (ATE 1.06; 95% CI 0.96 to 1.16) reported similar results. CONCLUSIONS: Both sexes' response to CRT is similar. Sex differences in HF substrate, treatment and comorbidities explain sex disparities in CRT outcomes. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier; NCT00677014.

Thick Heart, Wide QRS, Broad Differential.

Routine electrocardiogram in a middle-aged man with left ventricular hypertrophy showed sinus rhythm, a short PR interval, and delta wave, confirming ventricular pre-excitation. Pre-excitation was fixed after a premature atrial complex and in atrial fibrillation, features diagnostic of a fasciculo-ventricular pathway. Genetic testing confirmed a diagnosis of hypertrophic cardiomyopathy. (Level of Difficulty: Intermediate.).

Using Machine-Learning for Prediction of the Response to Cardiac Resynchronization Therapy: The SMART-AV Study.

OBJECTIVES: This study aimed to apply machine learning (ML) to develop a prediction model for short-term cardiac resynchronization therapy (CRT) response to identifying CRT candidates for early multidisciplinary CRT heart failure (HF) care. BACKGROUND: Multidisciplinary optimization of cardiac resynchronization therapy (CRT) delivery can improve long-term CRT outcomes but requires substantial staff resources. METHODS: Participants from the SMART-AV (SmartDelay-Determined AV Optimization: Comparison of AV Optimization Methods Used in Cardiac Resynchronization Therapy [CRT]) trial (n = 741; age: 66 ± 11 years; 33% female; 100% New York Heart Association HF functional class III-IV; 100% ejection fraction ≤35%) were randomly split into training/testing (80%; n = 593) and validation (20%; n = 148) samples. Baseline clinical, electrocardiographic, echocardiographic, and biomarker characteristics, and left ventricular (LV) lead position (43 variables) were included in 8 ML models (random forests, convolutional neural network, lasso, adaptive lasso, plugin lasso, elastic net, ridge, and logistic regression). A composite of freedom from death and HF hospitalization and a >15% reduction in LV end-systolic volume index at 6 months after CRT was the end point. RESULTS: The primary end point was met by 337 patients (45.5%). The adaptive lasso model was the most more accurate (area under the receiver operating characteristic curve: 0.759; 95% CI: 0.678-0.840), well calibrated, and parsimonious (19 predictors; nearly half potentially modifiable). Participants in the 5th quintile compared with those in the 1st quintile of the prediction model had 14-fold higher odds of composite CRT response (odds ratio: 14.0; 95% CI: 8.0-14.4). The model predicted CRT response with 70% accuracy, 70% sensitivity, and 70% specificity, and should be further validated in prospective studies. CONCLUSIONS: ML predicts short-term CRT response and thus may help with CRT procedure and early post-CRT care planning. (SmartDelay-Determined AV Optimization: A Comparison of AV Optimization Methods Used in Cardiac Resynchronization Therapy [CRT] [SMART-AV]; NCT00677014).

Competing risks in patients with primary prevention implantable cardioverter-defibrillators: Global Electrical Heterogeneity and Clinical Outcomes study.

BACKGROUND: Global electrical heterogeneity (GEH) is associated with sudden cardiac death in the general population. Its utility in patients with systolic heart failure who are candidates for primary prevention (PP) implantable cardioverter-defibrillators (ICDs) is unclear. OBJECTIVE: The purpose of this study was to investigate whether GEH is associated with sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies in patients with heart failure and PP ICDs. METHODS: We conducted a multicenter retrospective cohort study. GEH was measured by spatial ventricular gradient (SVG) direction (azimuth and elevation) and magnitude, QRS-T angle, and sum absolute QRST integral on preimplant 12-lead electrocardiograms. Survival analysis using cause-specific hazard functions compared the strength of associations with 2 competing outcomes: sustained ventricular tachycardia/ventricular fibrillation leading to appropriate ICD therapies and all-cause death without appropriate ICD therapies. RESULTS: We analyzed 2668 patients (mean age 63 ± 12 years; 624 (23%) female; 78% white; 43% nonischemic cardiomyopathy; left ventricular ejection fraction 28% ± 11% from 6 academic medical centers). After adjustment for demographic, clinical, device, and traditional electrocardiographic characteristics, SVG elevation (hazard ratio [HR] per 1SD 1.14; 95% confidence interval [CI] 1.04-1.25; P = .004), SVG azimuth (HR per 1SD 1.12; 95% CI 1.01-1.24; P = .039), SVG magnitude (HR per 1SD 0.75; 95% CI 0.66-0.85; P < .0001), and QRS-T angle (HR per 1SD 1.21; 95% CI 1.08-1.36; P = .001) were associated with appropriate ICD therapies. Sum absolute QRST integral had different associations in infarct-related cardiomyopathy (HR 1.29; 95% CI 1.04-1.60) and nonischemic cardiomyopathy (HR 0.78; 95% CI 0.62-0.96) (Pinteraction = .022). CONCLUSION: In patients with PP ICDs, GEH is independently associated with appropriate ICD therapies. The SVG vector points in distinctly different directions in patients with 2 competing outcomes.

Appropriate and inappropriate shocks in hypertrophic cardiomyopathy patients with subcutaneous implantable cardioverter-defibrillators: An international multicenter study.

BACKGROUND: Subcutaneous implantable cardioverter-defibrillators (S-ICDs) are attractive for preventing sudden cardiac death in hypertrophic cardiomyopathy (HCM) as they mitigate risks of transvenous leads in young patients. However, S-ICDs may be associated with increased inappropriate shock (IAS) in HCM patients. OBJECTIVE: The purpose of this study was to assess the incidence and predictors of appropriate shock and IAS in a contemporary HCM S-ICD cohort. METHODS: We collected electrocardiographic and clinical data from HCM patients who underwent S-ICD implantation at 4 centers. Etiologies of all S-ICD shocks were adjudicated. We used Firth penalized logistic regression to derive adjusted odds ratios (aORs) for predictors of IAS. RESULTS: Eighty-eight HCM patients received S-ICDs (81 for primary and 7 for secondary prevention) with a mean follow-up of 2.7 years. Five patients (5.7%) had 9 IAS episodes (3.8 IAS per 100 patient-years) most often because of sinus tachycardia and/or T-wave oversensing. Independent predictors of IAS were higher 12-lead electrocardiographic R-wave amplitude (aOR 2.55 per 1 mV; 95% confidence interval 1.15-6.38) and abnormal T-wave inversions (aOR 0.16; 95% confidence interval 0.02-0.97). There were 2 appropriate shocks in 7 secondary prevention patients and none in 81 primary prevention patients, despite 96% meeting Enhanced American College of Cardiology/American Heart Association criteria and the mean European HCM Risk-SCD score predicting 5.7% 5-year risk. No patients had sudden death or untreated sustained ventricular arrhythmias. CONCLUSION: In this multicenter HCM S-ICD study, IAS were rare and appropriate shocks confined to secondary prevention patients. The R-wave amplitude increased IAS risk, whereas T-wave inversions were protective. HCM primary prevention implantable cardioverter-defibrillator guidelines overestimated the risk of appropriate shocks in our cohort.