Dofetilide use is not associated with increased mortality in patients with left ventricular hypertrophy and atrial fibrillation.

BACKGROUND: Left ventricular hypertrophy (LVH) is common in patients with atrial fibrillation (AF), however, many antiarrhythmic drugs (AADs) are contraindicated. US guidelines recommend avoiding pure class III antiarrhythmics such as dofetilide in patients with significant LVH due to concern for an increased risk of death, however, clinical data is lacking. We sought to determine if dofetilide use was associated with increased mortality in patients with LVH. METHODS: Patients ≥18 years of age with AF and LVH ≥ 1.4 cm were included. A group of patients treated with dofetilide and a control group of patients without a history of AAD use were propensity matched. The primary outcome was all-cause mortality at 3 years and secondary outcomes were total number of all-cause hospitalizations and hospitalizations related to AF. RESULTS: There were 359 patients in each of the groups. Baseline variables were well-matched. The primary outcome of all-cause mortality occurred in 7% of patients in the dofetilide group and 12% of patients in the control group (hazard ratio: 0.90, 95% confidence interval: 0.53-1.53). Total all-cause hospitalizations were higher in the control group but hospitalizations for AF were no different. CONCLUSIONS: In a propensity-matched cohort of 718 patients with AF and LVH, dofetilide was not associated with increased mortality at 3 years. Our study adds to prior data demonstrating the safety of dofetilide in this population despite guideline recommendations against its use. Given the limited options for AF management in LVH patients, dofetilide may be reasonable for symptomatic AF management.

Targeted left ventricular lead positioning to the site of latest activation in cardiac resynchronization therapy: a systematic review and meta-analysis.

AIMS: Several studies have evaluated the use of electrically- or imaging-guided left ventricular (LV) lead placement in cardiac resynchronization therapy (CRT) recipients. We aimed to assess evidence for a guided strategy that targets LV lead position to the site of latest LV activation. METHODS AND RESULTS: A systematic review and meta-analysis was performed for randomized controlled trials (RCTs) until March 2023 that evaluated electrically- or imaging-guided LV lead positioning on clinical and echocardiographic outcomes. The primary endpoint was a composite of all-cause mortality and heart failure hospitalization, and secondary endpoints were quality of life, 6-min walk test (6MWT), QRS duration, LV end-systolic volume, and LV ejection fraction. We included eight RCTs that comprised 1323 patients. Six RCTs compared guided strategy (n = 638) to routine (n = 468), and two RCTs compared different guiding strategies head-to-head: electrically- (n = 111) vs. imaging-guided (n = 106). Compared to routine, a guided strategy did not significantly reduce the risk of the primary endpoint after 12-24 (RR 0.83, 95% CI 0.52-1.33) months. A guided strategy was associated with slight improvement in 6MWT distance after 6 months of follow-up of absolute 18 (95% CI 6-30) m between groups, but not in remaining secondary endpoints. None of the secondary endpoints differed between the guided strategies. CONCLUSION: In this study, a CRT implantation strategy that targets the latest LV activation did not improve survival or reduce heart failure hospitalizations.

Incorporation of Serial 12-Lead Electrocardiogram With Machine Learning to Augment the Out-of-Hospital Diagnosis of Non-ST Elevation Acute Coronary Syndrome.

STUDY OBJECTIVE: Ischemic electrocardiogram (ECG) changes are subtle and transient in patients with suspected non-ST-segment elevation (NSTE)-acute coronary syndrome. However, the out-of-hospital ECG is not routinely used during subsequent evaluation at the emergency department. Therefore, we sought to compare the diagnostic performance of out-of-hospital and ED ECG and evaluate the incremental gain of artificial intelligence-augmented ECG analysis. METHODS: This prospective observational cohort study recruited patients with out-of-hospital chest pain. We retrieved out-of-hospital-ECG obtained by paramedics in the field and the first ED ECG obtained by nurses during inhospital evaluation. Two independent and blinded reviewers interpreted ECG dyads in mixed order per practice recommendations. Using 179 morphological ECG features, we trained, cross-validated, and tested a random forest classifier to augment non ST-elevation acute coronary syndrome (NSTE-ACS) diagnosis. RESULTS: Our sample included 2,122 patients (age 59 [16]; 53% women; 44% Black, 13.5% confirmed acute coronary syndrome). The rate of diagnostic ST elevation and ST depression were 5.9% and 16.2% on out-of-hospital-ECG and 6.1% and 12.4% on ED ECG, with ∼40% of changes seen on out-of-hospital-ECG persisting and ∼60% resolving. Using expert interpretation of out-of-hospital-ECG alone gave poor baseline performance with area under the receiver operating characteristic (AUC), sensitivity, and negative predictive values of 0.69, 0.50, and 0.92. Using expert interpretation of serial ECG changes enhanced this performance (AUC 0.80, sensitivity 0.61, and specificity 0.93). Interestingly, augmenting the out-of-hospital-ECG alone with artificial intelligence algorithms boosted its performance (AUC 0.83, sensitivity 0.75, and specificity 0.95), yielding a net reclassification improvement of 29.5% against expert ECG interpretation. CONCLUSION: In this study, 60% of diagnostic ST changes resolved prior to hospital arrival, making the ED ECG suboptimal for the inhospital evaluation of NSTE-ACS. Using serial ECG changes or incorporating artificial intelligence-augmented analyses would allow correctly reclassifying one in 4 patients with suspected NSTE-ACS.

COVID-19 pandemic and initiation of treatment for atrial fibrillation: a nationwide analysis of claims data.

BACKGROUND: The COVID-19 pandemic profoundly disrupted the delivery of medical care. It remains unclear whether individuals diagnosed with new onset disease during the pandemic were less likely to initiate treatments after diagnosis. We sought to evaluate changes in the treatment initiation of patients newly diagnosed with atrial fibrillation (AF) after the onset of the COVID-19 pandemic. METHODS: In this retrospective cohort study, we identified individuals with incident AF from 01/01/2016-09/30/2021 using Optum's de-identified Clinformatics® Data Mart Database. The primary outcome was initiation of oral anticoagulation (OAC) within 30 days of AF diagnosis. Secondary outcomes included initiation of OAC within 180 days of diagnosis, initiation of warfarin, direct oral anticoagulants (DOACs), rhythm control medications and electrical cardioversion within 30 days of diagnosis. We constructed interrupted time series analyses to examine changes in the outcomes following the onset of the pandemic. RESULTS: A total of 573,524 patients (age 73.0 ± 10.9 years) were included in the study. There were no significant changes in the initiation of OAC, DOAC, and rhythm control medications associated with the onset of the pandemic. There was a significant decrease in initiation of electrical cardioversion associated with the onset of the pandemic. The rate of electronic cardioversion within 30 days of diagnosis decreased by 4.9% per 1,000 patients after the onset of the pandemic and decreased by about 35% in April 2020, compared to April 2019, from 5.53% to 3.58%. CONCLUSION: The COVID-19 pandemic did not affect the OAC initiation within 30 days of AF diagnosis but was associated with a decline in the provision of procedures for patients newly diagnosed with AF.

Association between left ventricular lead position and intrinsic QRS morphology with regard to clinical outcome in cardiac resynchronization therapy for heart failure.

BACKGROUND: Left ventricular (LV) lead position may be an important factor for delivering effective cardiac resynchronization therapy (CRT). We therefore aimed to evaluate the effects of LV lead position, stratified by native QRS morphology, regarding the clinical outcome. METHODS: A total of 1295 CRT-implanted patients were retrospectively evaluated. LV lead position was classified as lateral, anterior, inferior, or apical, and was determined using the left and right anterior oblique X-ray views. Kaplan Meier and Cox regression were performed to evaluate the effects on all-cause mortality and heart failure hospitalization, and the potential interaction between LV lead position and native ECG morphologies. RESULTS: A total of 1295 patients were included. Patients were aged 69 ± 7 years, 20% were female, 46% received a CRT-Pacemaker (vs. CRT-Defibrillator), mean LVEF was 25% ± 7%, and median follow-up was 3.3 years [IQR 1.6-5-7 years]. Eight hundred and eighty-two patients (68%) had a lateral LV lead location, 207 (16%) anterior, 155 (12%) apical, and 51 (4%) inferior. Patients with lateral LV lead position had larger QRS reduction (-13 ± 27 ms vs. -3 ± 24 ms, p < .001). Non-lateral lead location was associated with a higher risk for all-cause mortality (HR 1.34 [1.09-1.67], p = .007) and heart failure hospitalization (HR 1.25 [1.03-1.52], p = .03). This association was strongest for patients with native left or right bundle branch block, and not significant for patients with prior paced QRS or nonspecific intraventricular conduction delay. CONCLUSIONS: In patients treated with CRT, non-lateral LV lead positions (including apical, anterior, and inferior positions) were associated with worse clinical outcome and less reduction of QRS duration. This association was strongest for patients with native LBBB or RBBB.

Ventricular pacing and myocardial function in patient with congenital heart block.

INTRODUCTION: Pacing-induced cardiomyopathy (PICM) is a potential complication of chronic right ventricular (RV) pacing, but its characterization in adult patients is often complicated by pre-existing cardiomyopathy. This study investigated the incidence of PICM in patients with congenital heart block (cHB) who have conduction disease from birth without confounding pre-existing cardiac conditions. METHODS AND RESULTS: This retrospective cohort analysis included 42 patients with cHB and baseline left ventricular ejection fraction (LVEF) ≥50%. Kaplan-Meier analysis was used to assess freedom from cardiomyopathy (defined as LVEF <50%) between paced and nonpaced patients. Patients were 26 ± 3 years old at first presentation, 64% were women and baseline LVEF was 60.0 ± 0.2%. Median follow-up from birth was 35 (interquartile range [IQR]: 20-42) years with a median of 6.7 years (IQR: 3.6-9.2) at our institution. Thirty-two patients received pacing at mean age 21 ± 3 years. Patients receiving a pacemaker (PM) were significantly more likely to develop a cardiomyopathy (p = .021) and no patient developed a cardiomyopathy in the absence of a PM. Four patients who developed a new cardiomyopathy were upgraded to biventricular pacing, leading to stabilization or improvement of LVEF. CONCLUSION: In a relatively young and healthy cHB cohort, RV pacing is associated with a higher risk of developing a cardiomyopathy. These data confirm the deleterious effects of RV pacing on myocardial function in patients without pre-existing structural cardiac disease and has clinical implications to the management of patients with cHB.

Management of systemic fungal infections in the presence of a cardiac implantable electronic device: A systematic review.

Evidence to inform the management of systemic fungal infections in the setting of a cardiac implantable electronic devices (CIED), such as a permanent pacemaker or implantable cardioverter-defibrillator, is scant and limited to case reports and series. The available literature suggests high morbidity and mortality. To better characterize the shared experience of these cases and their outcomes, we performed a systematic review. We investigated all published reports of systemic fungal infections-fungemia and fungal vegetative disease-in the context of CIED, drawing from PubMed, EMBASE, and the Cochrane database of systematic reviews, inclusive of patients who received treatment between January 2000 and May 2020. Exclusion criteria included presence of ventricular assist device and concurrent bacteremia, bacterial endocarditis, bacterial vegetative infection, or viremia. Among 6261 screened articles, 48 cases from 41 individual studies were identified. Candida and Aspergillus species were the most commonly isolated fungi. There was significant heterogeneity in antifungal medication selection and duration. CIED extraction-either transvenous or surgical-was associated with increased survival to hospital discharge (92%) and clinical recovery at latest follow-up (81%), compared to cases where CIED extraction was deferred (56% and 40%, respectively). Importantly, there were no prospective data, and the data were limited to individual case reports and one small case series. In summary, CIED extraction is associated with improved fungal clearance and patient survival. Reported antifungal regimens are heterogeneous and nonuniform. Prospective studies are needed to verify these results and define optimal antifungal regimens.

Performance and limitations of automated ECG interpretation statements in patients with suspected acute coronary syndrome.

BACKGROUND: The 12­lead ECG plays an important role in triaging patients with symptomatic coronary artery disease, making automated ECG interpretation statements of "Acute MI" or "Acute Ischemia" crucial, especially during prehospital transport when access to physician interpretation of the ECG is limited. However, it remains unknown how automated interpretation statements correspond to adjudicated clinical outcomes during hospitalization. We sought to evaluate the diagnostic performance of prehospital automated interpretation statements to four well-defined clinical outcomes of interest: confirmed ST- segment elevation myocardial infarction (STEMI); presence of actionable coronary culprit lesions, myocardial necrosis, or any acute coronary syndrome (ACS). METHODS: An observational cohort study that enrolled consecutive patients with non-traumatic chest pain transported via ambulance. Prehospital ECGs were obtained with the Philips MRX monitor from the medical command center and re-processed using manufacturer-specific diagnostic algorithms to denote the likelihood of >>>Acute MI<<< or >>>Acute Ischemia<<<. Two independent reviewers retrospectively adjudicated the study outcomes and disagreements were resolved by a third reviewer. RESULTS: Our study included 2400 patients (age 59 ± 16, 47% females, 41% Black), with 190 (8%) patients with documented automated diagnostic statements of acute MI or acute ischemia. The sensitivity/specificity of the automated algorithm for detecting confirmed STEMI (n = 143, 6%); presence of actionable coronary culprit lesions (n = 258, 11%), myocardial necrosis (n = 291, 12%), or any ACS (n = 378, 16%) were 62.9%/95.6%; 37.2%/95.6%; 38.5%/96.4%; and 30.7%/96.3%, respectively. CONCLUSION: Although being very specific, automated interpretation statements of acute MI/acute ischemia on prehospital ECGs are not satisfactorily sensitive to exclude symptomatic coronary disease. Patients without these automated interpretation statements should be considered further for significant underlying coronary disease based on the clinical context. TRIAL REGISTRATION: ClinicalTrials.gov # NCT04237688.

Novel ECG features and machine learning to optimize culprit lesion detection in patients with suspected acute coronary syndrome.

BACKGROUND: Novel temporal-spatial features of the 12­lead ECG can conceptually optimize culprit lesions' detection beyond that of classical ST amplitude measurements. We sought to develop a data-driven approach for ECG feature selection to build a clinically relevant algorithm for real-time detection of culprit lesion. METHODS: This was a prospective observational cohort study of chest pain patients transported by emergency medical services to three tertiary care hospitals in the US. We obtained raw 10-s, 12­lead ECGs (500 s/s, HeartStart MRx, Philips Healthcare) during prehospital transport and followed patients 30 days after the encounter to adjudicate clinical outcomes. A total of 557 global and lead-specific features of P-QRS-T waveform were harvested from the representative average beats. We used Recursive Feature Elimination and LASSO to identify 35/557, 29/557, and 51/557 most recurrent and important features for LAD, LCX, and RCA culprits, respectively. Using the union of these features, we built a random forest classifier with 10-fold cross-validation to predict the presence or absence of culprit lesions. We compared this model to the performance of a rule-based commercial proprietary software (Philips DXL ECG Algorithm). RESULTS: Our sample included 2400 patients (age 59 ± 16, 47% female, 41% Black, 10.7% culprit lesions). The area under the ROC curves of our random forest classifier was 0.85 ± 0.03 with sensitivity, specificity, and negative predictive value of 71.1%, 84.7%, and 96.1%. This outperformed the accuracy of the automated interpretation software of 37.2%, 95.6%, and 92.7%, respectively, and corresponded to a net reclassification improvement index of 23.6%. Metrics of ST80; Tpeak-Tend; spatial angle between QRS and T vectors; PCA ratio of STT waveform; T axis; and QRS waveform characteristics played a significant role in this incremental gain in performance. CONCLUSIONS: Novel computational features of the 12­lead ECG can be used to build clinically relevant machine learning-based classifiers to detect culprit lesions, which has important clinical implications.

Maternal focal atrial tachycardia during pregnancy: A systematic review.

INTRODUCTION: The presentation and optimal management of maternal focal atrial tachycardia (AT) during pregnancy are unknown. The objective of this study is to conduct a comprehensive summary of the existing evidence. METHODS AND RESULTS: A systematic review of all reported cases of maternal focal AT during pregnancy was performed. The primary search queried PubMed using the MeSH terms "supraventricular tachycardia" and "pregnancy." A stepwise ancillary search included article bibliographies, citations listed by the Google internet search engine, and PubMed using the MeSH terms "atrial tachycardia" and "pregnancy." In total, 28 citations that described 32 patients were retrieved. A case from our institution was added. Detailed information was available for 30 patients. Clinical characteristics at presentation included a mean ± standard deviation of 28.3 ± 5.7 years for maternal age and 24.6 ± 7.7 weeks for gestation age. Suspected tachycardia-induced cardiomyopathy was present in 20 of 30 (67%) patients and left ventricular ejection fraction improved in 15 of 15 (100%) patients with follow-up measurements. Medication failure was common. Focal AT resolved spontaneously after delivery in eight of nine (89%) patients treated with only medications. Automaticity was suggested by discrete electrograms at sites of origin and lack of reported inducibility and termination with programmed stimulation in all patients who underwent electrophysiology studies. There were nine cases of successful catheter ablation with zero fluoroscopy since 2010. CONCLUSIONS: Automaticity is the dominant mechanism for patients with maternal focal AT during pregnancy. Catheter ablation with zero fluoroscopy is an emerging therapy for medically refractory cases.

Severe chronic kidney disease is associated with poor survival after initial CRT-defibrillator tachyarrhythmia therapy.

BACKGROUND: Implantable cardioverter-defibrillator (ICD) recipients who receive appropriate device therapies have limited survival, and survival benefit in chronic kidney disease (CKD) has been questioned. We examined the association between CKD and survival after cardiac resynchronization therapy (CRT)-defibrillator tachyarrhythmia therapies. METHODS: We compared overall survival after appropriate shocks or anti-tachycardia pacing in 439 CRT-defibrillator recipients with left ventricular ejection fraction (LVEF) ≤35%, non-right bundle-branch block QRS pattern, and QRS duration >130 ms according to glomerular filtration rate (GFR) at implant, including 31 patients with GFR ≤30, 164 patients with GFR 31-60, and 244 patients with GFR >60. At least one shock occurred in 302 patients (24 with GFR ≤30, 102 with GFR 31-60, and 176 with GFR >60). Serial echocardiograms were also compared. RESULTS: Patients were followed 64 months (interquartile range [IQR]: 29-94) after implant, including 32 months (IQR: 12-61) after first therapy. Time to first therapy or shock was similar across GFR groups. However, survival after first therapy declined directly with declining GFR (P < .001), with median postshock survival of 90 days for GFR ≤30 (95% confidence of interval [CI]: 0-233), 612 days (95% CI: 365-859) for GFR 31-60, and 1672 days (95% CI: 1396-1948) for GFR >60. Declining GFR category, ischemic heart disease, diabetes, and increasing age were independently associated with increased postshock mortality. Echocardiographic response was similar across GFR groups and was not associated with post-therapy survival. CONCLUSIONS: Survival after appropriate tachyarrhythmia therapies, particularly shocks, is attenuated in patients with GFR ≤30. This raises concern over potential lack of survival benefit conferred by CRT-defibrillators versus CRT-pacemakers in this population.

Documentation of shared decision making around primary prevention defibrillator implantations.

INTRODUCTION: Patients eligible for primary prevention implantable cardioverter-defibrillator (ICD) therapy are faced with a complex decision that needs a clear understanding of the risks and benefits of such an intervention. In this study, our goal was to explore the documentation of primary prevention ICD discussions in the electronic medical records (EMRs) of eligible patients. METHODS: In 1523 patients who met criteria for primary prevention ICD therapy between 2013 and 2015, we reviewed patient charts for ICD-related documentation: "mention" by physicians or "discussion" with patient/family. The attitude of the physician and the patient/family toward ICD therapy during discussions was categorized into negative, neutral, or positive preference. Patients were followed to the end-point of ICD implantation. RESULTS: Over a median follow-up of 442 days, 486 patients (32%) received an ICD. ICD was mentioned in the charts of 1105 (73%) patients, and a discussion with the patient/family about the risks and benefits of ICD was documented in 706 (46%) charts. On multivariable analyses, positive cardiologist (hazard ratio [HR]: 7.9, 95% confidence of intervals [CI]: 1.0-59.7, P < .05), electrophysiologist (HR: 7.7, 95% CI: 1.9-31.7, P < .001), and patient/family (HR: 9.9, 95% CI: 6.2-15.7, P < .001) preferences toward ICD therapy during the first documented ICD discussion were independently associated with ICD implantation. CONCLUSIONS: In a large cohort of patients eligible for primary prevention ICD therapy, a discussion with the patient/family about the risks and benefits of ICD implantation was documented in less than 50% of the charts. More consistent documentation of the shared decision making around ICD therapy is needed.

Identifying the most important ECG predictors of reduced ejection fraction in patients with suspected acute coronary syndrome.

BACKGROUND: Non-invasive screening tools of cardiac function can play a significant role in the initial triage of patients with suspected acute coronary syndrome. Numerous ECG features have been previously linked with cardiac contractility in the general population. We sought to identify ECG features that are most predictive for real-time screening of reduced left ventricular ejection fraction (LVEF) in the acute care setting. METHODS: We performed a secondary analysis of a prospective, observational cohort study of patients evaluated for suspected acute coronary syndrome. We included consecutive patients in whom an echocardiogram was performed during indexed encounter. We evaluated 554 automated 12-lead ECG features in multivariate linear regression for predicting LVEF. We then used regression trees to identify the most important predictive ECG features. RESULTS: Our final sample included 297 patients (aged 63 ± 15, 45% females). The mean LVEF was 57% ± 13 (IQR 50%-65%). In multivariate analysis, depolarization dispersion in the horizontal plane; global repolarization dispersion; and abnormal temporal indices in inferolateral leads were all independent predictors of LVEF (R2 = 0.452, F = 6.679, p < 0.001). Horizontal QRS axis deviation and prolonged ventricular activation time in left ventricular apex were the most important determinants of reduced LVEF, while global QRS duration was of less importance. CONCLUSIONS: Poor R wave progression in precordial leads with dominant QS pattern in V3 is the most predictive feature of reduced LVEF in suspected ACS. This feature constitutes a simple visual marker to aid clinicians in identifying those with impaired cardiac function.

Amiodarone is associated with adverse outcomes in patients with sustained ventricular arrhythmias upgraded to cardiac resynchronization therapy-defibrillators.

INTRODUCTION: Amiodarone reduces recurrent ventricular tachyarrhythmias (VTA) but may worsen cardiovascular outcomes in heart failure (HF) patients. Cardiac resynchronization therapy (CRT) may also be antiarrhythmic. When patients with prior sustained VTA are upgraded to CRT defibrillators (CRT-D) from conventional implantable cardioverter-defibrillators (ICDs), should concomitant amiodarone be continued or is CRT's antiarrhythmic potential sufficient? METHODS AND RESULTS: We identified 67 patients from a prospective CRT registry with spontaneous sustained VTA, New York Heart Association (NYHA) II-IV HF, and left bundle-branch block (LBBB) who were upgraded to CRT defibrillators from conventional ICDs. We compared changes in QRS duration and left ventricular ejection fraction (LVEF) pre- and post-CRT, time to death, transplant or ventricular assist device (VAD), and time to recurrent VTA therapies between 37 patients continuing amiodarone therapy and 30 amiodarone-naïve patients. Amiodarone-treated patients had worse renal function and a higher prevalence of prior VTA storm compared with amiodarone-naïve patients. After CRT, amiodarone-treated patients demonstrated less QRS narrowing (8 vs 20 ms; P = 0.021) and less LVEF improvement (-2.7 vs +5.2%; P = 0.006). Over 29 months, 31 (47%) patients died and 13 (20%) received transplant or VAD. Risk of death, transplant, or VAD was greater in amiodarone-treated than -naïve patients (corrected hazard ratio [HR], 2.14; 95% confidence interval [CI], 1.12-4.11; P = 0.022). Appropriate CRT-D therapies occurred in 37 (55%) patients; amiodarone use was not associated time to first therapy (HR, 1.13; 95% CI, 0.59-2.16; P = 0.72). CONCLUSION: In patients with sustained VTA and LBBB upgraded from conventional ICDs to CRT defibrillators, concomitant amiodarone use is associated with less QRS narrowing, less LVEF improvement, greater risk of death, transplant, or VAD, and similar risk of recurrent VTA.

Non-vitamin K oral anticoagulants versus warfarin for left atrial appendage thrombus resolution in nonvalvular atrial fibrillation or flutter.

BACKGROUND: Non-vitamin K oral anticoagulants (NOACs) have emerged as alternatives to vitamin K antagonists in select situations. For left atrial (LA) appendage thrombus in nonvalvular atrial fibrillation (AF) or flutter, guidelines recommend oral anticoagulation (OAC) for at least 3 weeks prior to reassessment. Data comparing NOACs to warfarin in this scenario are scarce. METHODS: A retrospective study identified subjects with nonvalvular AF or flutter who were: a) noted to have LA thrombus detected on transesophageal echocardiography (TEE), b) previously not receiving long-term OAC; and c) evaluated for resolution of LA thrombus by follow-up TEE between 3 weeks to less than 1 year of the initial TEE. RESULTS: The study included 45 subjects with mean age 63.2 years, 69% male, 78% white race/ethnicity, 42% paroxysmal, and mean CHA2 DS2 -VASc score 3.4 ± 1.7. All LA thrombi were confined to the appendage. OAC received included apixaban (3), dabigatran (13), rivaroxaban (6), and warfarin (23), The median follow-up time to repeat TEE was 67 (interquartile range, 49-96) days. LA appendage thrombus resolution rates were 76% for the entire cohort, 77% for NOACs, and 74% for warfarin. In univariable logistic regression analysis, LA appendage thrombus resolution was similar for NOACs when compared to warfarin (odds ratio, 1.20; 95% confidence interval, 0.31-4.69; P = .79). CONCLUSIONS: In patients nonvalvular AF or flutter who were OAC naïve at the time of diagnosis with LA appendage thrombus, complete resolution was similar between NOACs and warfarin.

Sex-specific clinical outcomes after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Sex differences in clinical outcomes for left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) after cardiac resynchronization therapy (CRT) are not well described. METHODS: A retrospective cohort study at an academic medical center included subjects with LBBB-associated idiopathic NICM who received CRT. Cox regression analyses estimated the hazard ratios (HRs) between sex and clinical outcomes. RESULTS: In 123 total subjects (mean age 62 years, mean initial left ventricular ejection fraction 22.8%, 76% New York Heart Association class III, and 98% CRT-defibrillators), 55 (45%) were men and 68 (55%) were women. The median follow-up time after CRT was 72.4 months. Similar risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate antitachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) was observed between men and women (HR, 1.20; 95% confidence interval [CI] 0.57-2.51; p = 0.63). This persisted in multivariable analyses. Men and women had similar risk for all-cause mortality in univariable analysis, but men had higher risk in the final multivariable model that adjusted for age at diagnosis, QRS duration, and left ventricular end-diastolic dimension index (HR, 4.55; 95% CI, 1.26-16.39; p = 0.02). The estimated 5-year mortality was 9.5% for men and 6.9% for women. CONCLUSIONS: In LBBB-associated idiopathic NICM, men have higher risk for all-cause mortality after CRT when compared to women.

Myocardial recovery after cardiac resynchronization therapy in left bundle branch block-associated idiopathic nonischemic cardiomyopathy: A NEOLITH II substudy.

BACKGROUND: Baseline predictors of myocardial recovery after cardiac resynchronization therapy (CRT) in left bundle branch block (LBBB)-associated idiopathic nonischemic cardiomyopathy (NICM) are unknown. METHODS: A retrospective study included subjects with idiopathic NICM, left ventricular ejection fraction (LVEF) ≤35%, and LBBB. Myocardial recovery was defined as post-CRT LVEF ≥50%. Logistic regression analyses described associations between baseline characteristics and myocardial recovery. Cox regression analyses estimated the hazard ratio (HR) between myocardial recovery status and adverse clinical events. RESULTS: In 105 subjects (mean age 61 years, 44% male, mean initial LVEF 22.6% ± 6.6%, 81% New York Heart Association class III, and 98% CRT-defibrillators), myocardial recovery after CRT was observed in 56 (54%) subjects. Hypertension, heart rate, and serum blood urea nitrogen (BUN) had negative associations with myocardial recovery in univariable analyses. These associations persisted in multivariable analysis: hypertension (odds ratio (OR), 0.40; 95% confidence interval (CI), 0.17-0.95; p = 0.04), heart rate (OR per 10 bpm, 0.69; 95% CI, 0.48-0.997; p = 0.048), and serum BUN (OR per 1 mg/dl, 0.94; 95% CI, 0.88-0.99; p = 0.04). Subjects with post-CRT LVEF ≥50%, when compared to <50%, had lower risk for adverse clinical events (heart failure hospitalization, appropriate implantable cardioverter-defibrillator shock, appropriate anti-tachycardia pacing therapy, ventricular assist device implantation, heart transplantation, and death) over a median follow-up of 75.9 months (HR, 0.38; 95% CI, 0.16-0.88; p = 0.02). CONCLUSION: In LBBB-associated idiopathic NICM, myocardial recovery after CRT was associated with absence of hypertension, lower heart rate, and lower serum BUN. Those with myocardial recovery had fewer adverse clinical events.

Change in myocardial function after resuscitated sudden cardiac arrest and its impact on long-term mortality and defibrillator implantation.

BACKGROUND: The impact of left ventricular ejection fraction (LVEF) changes after sudden cardiac arrest (SCA) on implantable defibrillator (ICD) utilization and long-term survival is not known. We therefore evaluated the influence of LVEF on these parameters in SCA survivors. METHODS: Data were collected on consecutive SCA survivors who had ≥1 echocardiogram after SCA and who survived to hospital discharge (n = 655). The median time from baseline to first follow-up echocardiogram was 162 days. LVEF ≥50% was defined as normal. Patients were classified into 4 groups according to baseline (LVEFb) and follow-up (LVEFf) myocardial function: normal LVEFb and LVEFf (group1, n = 261); reduced LVEFb and normal LVEFf (group 2, n = 104); normal LVEFb but reduced LVEFf (group 3, n = 41); and reduced LVEFb and LVEFf (group 4, n = 249). All-cause mortality and time to ICD implantation were examined in all groups. RESULTS: Over a median follow up of 4.3 years, death occurred in 279 (42%) of patients. Compared with patients in group 1, patients with any reduced LVEF at any time (groups 2-4) had significantly higher mortality, even after adjusting for unbalanced covariates (HR = 1.44, 95.0% CI 1.05-1.95, p = 0.022). ICDs were most commonly implanted in patients with persistently reduced LVEF (group 4: HR = 1.72, 95% CI = 1.26-2.35, p = 0.001). CONCLUSION: We demonstrate that, in survivors of SCA, a reduced LVEF at or after the index event is associated with higher mortality but that patients with persistently reduced LVEF were most likely to receive ICD therapy. These findings have implications on the management of SCA survivors.

Rate and predictors of electrical failure in non-recalled defibrillator leads.

BACKGROUND: Implantable cardioverter defibrillator (ICD) leads are considered as the 'weakest link' in defibrillator systems due to FDA recalls and advisories involving popular lead models from major manufacturers. The rate of electrical failure of ICD leads not implicated in a recall is however not well determined. METHODS: Medical records of patients implanted with ICDs at hospitals of the University of Pittsburgh Medical Center between 2002 and 2014 were analyzed. Leads were classified as having electrically failed if removed or replaced for reasons other than infection or heart transplantation. Patients were followed to endpoint of death or electrical lead failure. RESULTS: 2410 consecutive ICD recipients (mean age 66 ±â€¯13 years, women 22%, single/dual/biventricular-ICD 20%/44%/36%) were included. During a mean follow-up of 3.9 ±â€¯3.3 years, 1272 patients (53%) died, 55 patients (2.3%) had ICD lead electrical failure, and 1052 (44%) patients were alive with functional leads at the time of last follow-up. Patients with failed leads had higher BMI (p = 0.07), better functional status (p = 0.04), higher serum creatinine (p = 0.004), wider QRS complex (p = 0.01), higher number of implanted leads (p = 0.06) and were more likely to have ischemic cardiomyopathy (p = 0.03). After adjusting for these variables in a binary logistic regression model, only a lower BMI, presence of non-ischemic cardiomyopathy, and a better functional status remained independently predictive of electrical failure. CONCLUSIONS: Only 2.3% of non-recalled ICD leads experience electrical failure (annual failure rate of 0.6%). A higher patient functional status, lower BMI, and non-ischemic etiology of cardiomyopathy are independently associated with higher rates of ICD lead failure.

Characterization of pulmonary vein reconnection post Cryoballoon ablation.

BACKGROUND: The Arctic Front Cryoballoon System is a technology in which substrate alterations in patients with atrial fibrillation (AF) recurrence have not been well characterized. In this study, we evaluated sites of pulmonary vein (PV) reconnections and the accuracy of the Achieve™ circular mapping catheter in detecting these reconnections after cryoablation. METHODS: This study included 15 patients undergoing redo AF ablation after a prior single cryoablation procedure. PV reconnection sites were determined by measuring PV signals and high output pacing from 4 vectors of the Achieve catheter. The results were compared with a roving mapping catheter guided by rotational intracardiac echocardiography (ICE) in the left atrium. RESULTS: All patients had PV reconnections (2.1 ±â€¯0.8 veins/patient). The left superior PV was most commonly reconnected (n = 11), whereas the right inferior PV was least likely (n = 3). Both carinas (left: n = 11; right: n = 7) and left atrial appendage ridge (n = 11) were also frequently reconnected. Mapping with the Achieve catheter showed a positive predictive value (PPV) 100% and negative predictive value (NPV) 96% when compared with ICE guided mapping. In 2 patients, right superior PV reconnection was not identified by the Achieve. CONCLUSION: During redo AF ablation after index cryoablation, multiple PVs are usually reconnected, with both carinas and left atrial appendage ridge being common sites of reconnection. The Achieve mapping catheter was able to identify reconnection with high positive and negative predictive values.