P-wave alternans rebound following pulmonary vein isolation predicts atrial arrhythmia recurrence.

INTRODUCTION: Numerous P-wave indices have been explored as biomarkers to assess atrial fibrillation (AF) risk and the impact of therapy with variable success. OBJECTIVE: We investigated the utility of P-wave alternans (PWA) to track the effects of pulmonary vein isolation (PVI) and to predict atrial arrhythmia recurrence. METHODS: This medical records study included patients who underwent PVI for AF ablation at our institution, along with 20 control subjects without AF or overt cardiovascular disease. PWA was assessed using novel artificial intelligence-enabled modified moving average (AI-MMA) algorithms. PWA was monitored from the 12-lead ECG at ~1 h before and ~16 h after PVI (n = 45) and at the 4- to 17-week clinically indicated follow-up visit (n = 30). The arrhythmia follow-up period was 955 ± 112 days. RESULTS: PVI acutely reduced PWA by 48%-63% (p < .05) to control ranges in leads II, III, aVF, the leads with the greatest sensitivity in monitoring PWA. Pre-ablation PWA was ~6 µV and decreased to ~3 µV following ablation. Patients who exhibited a rebound in PWA to pre-ablation levels at 4- to 17-week follow-up (p < .01) experienced recurrent atrial arrhythmias, whereas patients whose PWA remained reduced (p = .85) did not, resulting in a significant difference (p < .001) at follow-up. The AUC for PWA's prediction of first recurrence of atrial arrhythmia was 0.81 (p < .01) with 88% sensitivity and 82% specificity. Kaplan-Meier analysis estimated atrial arrhythmia-free survival (p < .01) with an adjusted hazard ratio of 3.4 (95% CI: 1.47-5.24, p < .02). CONCLUSION: A rebound in PWA to pre-ablation levels detected by AI-MMA in the 12-lead ECG at standard clinical follow-up predicts atrial arrhythmia recurrence.

Speech-induced atrial tachycardia: A narrative review of putative mechanisms implicating the autonomic nervous system.

Despite being uncommon, speech-induced atrial tachycardias carry significant morbidity and affect predominantly healthy individuals. Little is known about their mechanism, treatment, and prognosis. In this review, we seek to identify the underlying connections and pathophysiology between speech and arrhythmias while providing an informed approach to evaluation and management.

Anatomic, histologic, and mechanical features of the right atrium: implications for leadless atrial pacemaker implantation.

BACKGROUND: Leadless pacemakers (LPs) may mitigate the risk of lead failure and pocket infection related to conventional transvenous pacemakers. Atrial LPs are currently being investigated. However, the optimal and safest implant site is not known. OBJECTIVES: We aimed to evaluate the right atrial (RA) anatomy and the adjacent structures using complementary analytic models [gross anatomy, cardiac magnetic resonance imaging (MRI), and computer simulation], to identify the optimal safest location to implant an atrial LP human. METHODS AND RESULTS: Wall thickness and anatomic relationships of the RA were studied in 45 formalin-preserved human hearts. In vivo RA anatomy was assessed in 100 cardiac MRI scans. Finally, 3D collision modelling was undertaken assessing for mechanical device interaction. Three potential locations for an atrial LP were identified; the right atrial appendage (RAA) base, apex, and RA lateral wall. The RAA base had a wall thickness of 2.7 ± 1.6 mm, with a low incidence of collision in virtual implants. The anteromedial recess of the RAA apex had a wall thickness of only 1.3 ± 0.4 mm and minimal interaction in the collision modelling. The RA lateral wall thickness was 2.6 ± 0.9 mm but is in close proximity to the phrenic nerve and sinoatrial artery. CONCLUSIONS: Based on anatomical review and 3D modelling, the best compromise for an atrial LP implantation may be the RAA base (low incidence of collision, relatively thick myocardial tissue, and without proximity to relevant epicardial structures); the anteromedial recess of the RAA apex and lateral wall are alternate sites. The mid-RAA, RA/superior vena cava junction, and septum appear to be sub-optimal fixation locations.

Individuals with chronic epilepsy have elevated P-wave heterogeneity comparable to patients with atrial fibrillation.

OBJECTIVE: Identification of epilepsy patients with elevated risk for atrial fibrillation (AF) is critical given the heightened morbidity and premature mortality associated with this arrhythmia. Epilepsy is a worldwide health problem affecting nearly 3.4 million people in the United States alone. The potential for increased risk for AF in patients with epilepsy is not well appreciated, despite recent evidence from a national survey of 1.4 million hospitalizations indicating that AF is the most common arrhythmia in people with epilepsy. METHODS: We analyzed inter-lead heterogeneity of P-wave morphology, a marker reflecting arrhythmogenic nonuniformities of activation/conduction in atrial tissue. The study groups consisted of 96 patients with epilepsy and 44 consecutive patients with AF in sinus rhythm before clinically indicated ablation. Individuals without cardiovascular or neurological conditions (n = 77) were also assessed. We calculated P-wave heterogeneity (PWH) by second central moment analysis of simultaneous beats from leads II, III, and aVR ("atrial dedicated leads") from standard 12-lead electrocardiography (ECG) recordings from admission day to the epilepsy monitoring unit (EMU). RESULTS: Female patients composed 62.5%, 59.6%, and 57.1% of the epilepsy, AF, and control subjects, respectively. The AF cohort was older (66 ± 1.1 years) than the epilepsy group (44 ± 1.8 years, p < .001). The level of PWH was greater in the epilepsy group than in the control group (67 ± 2.6 vs. 57 ± 2.5 µV, p = .046) and reached levels observed in AF patients (67 ± 2.6 vs. 68 ± 4.9 µV, p = .99). In multiple linear regression analysis, PWH levels in individuals with epilepsy were mainly correlated with the PR interval and could be related to sympathetic tone. Epilepsy remained associated with PWH after adjustments for cardiac risk factors, age, and sex. SIGNIFICANCE: Patients with chronic epilepsy have increased PWH comparable to levels observed in patients with AF, while being ~20 years younger, suggesting an acceleration in structural change and/or cardiac electrical instability. These observations are consistent with emerging evidence of an "epileptic heart" condition.

Impact of Preprocedure Imaging for Left Atrial Appendage Occlusion: Insights From the NCDR LAAO Registry.

BACKGROUND: The impact of preprocedure imaging on the safety and effectiveness of left atrial appendage occlusion (LAAO) remains unclear. OBJECTIVES: This study sought to determine the rates of use of preprocedure computed tomography (CT)/cardiac magnetic resonance (CMR) and its association with safety and effectiveness of LAAO procedures. METHODS: The National Cardiovascular Data Registry LAAO Registry was used to evaluate patients who underwent attempted LAAO with the WATCHMAN and WATCHMAN FLX devices between January 1, 2016, and June 30, 2021. Safety and effectiveness of LAAO procedures was compared by use vs nonuse of preprocedural CT/CMR. Outcomes of interest included implantation success (deployment and release of device), device success (device released with peridevice leak <5 mm), and procedure success (device released with peridevice leak <5 mm and no in-hospital major adverse events [MAE]). Multivariable logistic regression was used to assess the relationship between preprocedure imaging and outcomes. RESULTS: Preprocedure CT/CMR was used for 18.2% (n = 20,851) of the 114,384 procedures in this study. CT/CMR use was more common among government and university hospitals and hospitals in the Midwest and South; it was less common among patients with uncontrolled hypertension, with abnormal renal function, and without prior thromboembolism. Overall rates of implantation success, device success, and procedure success were 93.4%, 91.2%, and 89.4%, respectively. Preprocedure CT/CMR was independently associated with an increased likelihood of implantation success (OR: 1.08; 95% CI: 1.00-1.17), device success (OR: 1.10; 95% CI: 1.04-1.16), and procedural success (OR: 1.07; 95% CI: 1.02-1.13). MAE were uncommon (2.3%) and not associated with use of preprocedure CT/CMR (OR: 1.02; 95% CI: 0.92-1.12). CONCLUSIONS: Preprocedure CT/CMR was associated with an increased likelihood of successful LAAO implantation; however, the magnitude of benefit appears small and it was not associated with MAE.

Reduction in atrial and ventricular electrical heterogeneity following pulmonary vein isolation in patients with atrial fibrillation.

BACKGROUND: Pulmonary vein isolation (PVI) modulates the intrinsic cardiac autonomic nervous system and reduces atrial fibrillation (AF) recurrence. METHODS: In this retrospective analysis, we investigated the impact of PVI on ECG interlead P-wave, R-wave, and T-wave heterogeneity (PWH, RWH, TWH) in 45 patients in sinus rhythm undergoing clinically indicated PVI for AF. We measured PWH as a marker of atrial electrical dispersion and AF susceptibility and RWH and TWH as markers of ventricular arrhythmia risk along with standard ECG measures. RESULTS: PVI acutely (16 ± 8.9 h) reduced PWH by 20.7% (from 31 ± 1.9 to 25 ± 1.6 µV, p < 0.001) and TWH by 27% (from 111 ± 7.8 to 81 ± 6.5 µV, p < 0.001). RWH was unchanged after PVI (p = 0.068). In a subgroup of 20 patients with longer follow-up (mean = 47 ± 3.7 days after PVI), PWH remained low (25 ± 1.7 µV, p = 0.01), but TWH partially returned to the pre-ablation level (to 93 ± 10.2, p = 0.16). In three individuals with early recurrence of atrial arrhythmia in the first 3 months after ablation, PWH increased acutely by 8.5%, while in patients without early recurrence, PWH decreased acutely by 22.3% (p = 0.048). PWH was superior to other contemporary P-wave metrics including P-wave axis, dispersion, and duration in predicting early AF recurrence. CONCLUSION: The rapid time course of decreased PWH and TWH after PVI suggests a beneficial influence likely mediated via ablation of the intrinsic cardiac nervous system. Acute responses of PWH and TWH to PVI suggest a favorable dual effect on atrial and ventricular electrical stability and could be used to track individual patients' electrical heterogeneity profile.

Patient Selection, Techniques, and Complication Mitigation for Epicardial Ventricular Tachycardia Ablation.

Percutaneous epicardial ventricular tachycardia ablation can decrease implanted cardioverter defibrillator shocks and hospitalizations; proper patient selection and procedural technique are imperative to maximize the benefit-risk ratio. The best candidates for epicardial ventricular tachycardia will depend on history of prior ablation, type of cardiomyopathy, and specific electrocardiogram and cardiac imaging findings. Complications include hemopericardium, hemoperitoneum, coronary vessel injury, and phrenic nerve injury. Modern epicardial mapping techniques provide new understandings of the 3-dimensional nature of reentrant ventricular tachycardia circuits across cardiomyopathy etiologies. Where epicardial access is not feasible, alternative techniques to reach epicardial ventricular tachycardia sources may be necessary.

Assessing race and ethnicity differences in outcomes based on GDMT and target NT-proBNP in patients with heart failure with reduced ejection fraction: An analysis of the GUIDE-IT study.

BACKGROUND: The GUIDE-IT trial was, a multicenter, randomized, parallel group, unblinded study that randomized patients to having heart failure therapy titrated to achieve an NT-proBNP <1000 pg/mL or to usual clinical care. METHODS AND RESULTS: We performed pre-specified subgroup analysis to look for the race and ethnicity-based differences in clinical outcomes of patients who were able to achieve GDMT or target NT-proBNP concentration of ≤1000 pg/mL at 90 days of follow-up. There were 894 patients enrolled in GUIDE-IT study. Of these, 733 participants had available data on 90-day guideline directed triple therapy and 616 on NT-proBNP. 35% of the patients were Black and 6% were Hispanic. Black patients were younger, had more comorbidities, lower EF, and higher NYHA class compared with non-Black. Adjusting for 90-day NT-proBNP and important baseline covariates, Black patients were at a higher risk than non-Black patients for HF hospitalization [HR, 2.19; 95% CI, 1.51-3.17; p < 0.0001], but at a similar risk for mortality [HR, 0.85.; 95% CI, 0.44-1.66; p = 0.64]. Similar results were seen adjusting for 90-day GDMT [HF hospitalization: Black vs non-Black, HR: 1.97; 1.41-2.77, P < 0.0001; mortality: HR: 0.70; 0.39-1.26, p = 0.23]. There were no significant differences between Hispanic and non-Hispanic patients with respect to heart failure hospitalization, cardiovascular or all-cause mortality. Over the study period, Black and Hispanic patients experienced smaller changes in physical function and quality of life as measured by the Kansas City Cardiomyopathy Questionnaire overall score. CONCLUSION: Compared to non-Black patients, Black patients in GUIDE-IT study had a higher risk of heart failure hospitalization, but a comparable risk of mortality, despite improved use of GDMT and achievement of similar biomarker targets.

Cannabis use disorder among atrial fibrillation admissions, 2008-2018.

BACKGROUND: Despite changes inthe legality of cannabis use and the increasing prevalence of cannabis use disorder (CUD), there is little data investigating the association between CUD and inpatient atrial fibrillation (AF) hospitalizations. METHODS: Using the National Inpatient Sample, we identified Atrial Fibrillation (AF) hospitalizations with and without a codiagnosis of CUD using International Classification of Diseases diagnosis codes and compared demographics, socioeconomics, comorbidities, outcomes, and trends between cohorts. RESULTS: Between 2008 and 2018, we identified 5,155,789 admissions for AF of which 31,768 (0.6%) had a codiagnosis of CUD. The proportion of admissions with a history of CUD increased from 0.3% in 2008 to 1.0% in 2018 (p < .001). Hospital discharges of patients with CUD were significantly younger (53 vs. 72 years, p < .001), had a higher proportion of black race (CUD: 26.6% vs. 8.0%, p < .001), and had a higher proportion of income in the lowest income quartile than without a codiagnosis of CUD (CUD: 40.5% vs. 26.2%, p < .001). CONCLUSIONS: CUD is increasingly prevalent among AF hospitalizations, particularly among young patients. Codiagnosis of CUD in AF hospitalizations is also more common in underserved patients. As a result, it is important for future research to examine and understand the impact of CUD on this population, particularly in the light of changing legislation surrounding the legality of cannabis.

Evaluation of Racial and Ethnic Disparities in Cardiac Transplantation.

Background Racial and ethnic disparities contribute to differences in access and outcomes for patients undergoing heart transplantation. We evaluated contemporary outcomes for heart transplantation stratified by race and ethnicity as well as the new 2018 allocation system. Methods and Results Adult heart recipients from 2011 to 2020 were identified in the United Network for Organ Sharing database and stratified into 3 groups: Black, Hispanic, and White. We analyzed recipient and donor characteristics, and outcomes. Among 32 353 patients (25% Black, 9% Hispanic, 66% White), Black and Hispanic patients were younger, more likely to be women and have diabetes mellitus or renal disease (all, P<0.05). Over the study period, the proportion of Black and Hispanic patients listed for transplant increased: 21.7% to 28.2% (P=0.003) and 7.7% to 9.0% (P=0.002), respectively. Compared with White patients, Black patients were less likely to undergo transplantation (adjusted hazard ratio [aHR], 0.87; CI, 0.84-0.90; P<0.001), but had a higher risk of post-transplant death (aHR, 1.14; CI, 1.04-1.24; P=0.004). There were no differences in transplantation likelihood or post-transplant mortality between Hispanic and White patients. Following the allocation system change, transplantation rates increased for all groups (P<0.05). However, Black patients still had a lower likelihood of transplantation than White patients (aHR, 0.90; CI, 0.79-0.99; P=0.024). Conclusions Although the proportion of Black and Hispanic patients listed for cardiac transplantation have increased, significant disparities remain. Compared with White patients, Black patients were less likely to be transplanted, even with the new allocation system, and had a higher risk of post-transplantation death.

The role of posterior wall isolation in catheter ablation of persistent atrial fibrillation.

The left atrial posterior wall has many embryologic, anatomic, and electrophysiologic characteristics, that are important for the initiation and maintenance of persistent atrial fibrillation. The left atrial posterior wall is a potential target for ablation in patients with persistent atrial fibrillation, a population in whom pulmonary vein isolation alone has resulted in unsatisfactory recurrence rates. Published clinical studies report conflicting results on the safety and efficacy of posterior wall isolation. Emerging technologies including optimized use of radiofrequency ablation, pulse field ablation, and combined endocardial/epicardial ablation may optimize approaches to posterior wall isolation and reduce the risk of injury to nearby structures such as the esophagus. Critical evaluation of future and ongoing clinical studies of posterior wall isolation requires careful scrutiny of many characteristics, including intraprocedural definition of posterior wall isolation, concomitant extrapulmonary vein ablation, and study endpoints.

Effect of Inotropes on Patient-Reported Health Status in End-Stage Heart Failure: A Review of Published Clinical Trials.

BACKGROUND: A growing population of patients with end-stage heart failure (HF) with reduced ejection fraction has limited treatment options to improve their quality and quantity of life. Although positive inotropes have failed to show survival benefit, these agents may enhance patient-reported health status, that is, symptoms, functional status, and health-related quality of life. We sought to review the available clinical trial data on positive inotrope use in patients with end-stage HF and to summarize evidence supporting the use of these agents to improve health status of patients with end-stage HF. METHODS: A literature review of randomized controlled trials examining the use of positive inotropy in HF with reduced ejection fraction was conducted. We searched MEDLINE, SCOPUS, and Web of Science between January 1980 to December 2018 for randomized controlled trials that used as their main outcome measures the effects of inotrope therapy on (1) morbidity/mortality, (2) symptoms, (3) functional status, or (4) health-related quality of life. Inotropes of interest included adrenergic agents, phosphodiesterase inhibitors, calcium sensitizers, myosin activators, and SERCA2a (sarcoplasmic reticulum Ca2+-ATPase) modulators. RESULTS: Twenty-two out of 26 inotrope randomized controlled trials measured the effect of inotropes on at least one patient-reported health status domain. Among the 22 studies with patient-related health status outcomes, 11 (50%) gauged symptom response, 15 (68%) reported functional capacity changes, and 12 (54%) reported health-related quality of life measures. Fourteen (64%) of these trials noted positive outcomes in at least one health status domain measured; 11 (79%) of these positive studies used agents that worked through phosphodiesterase inhibition. CONCLUSIONS: There has been a lack of standardization surrounding measurement of patient-centered outcomes in studies of inotropes for end-stage HF with reduced ejection fraction. The degree to which positive inotropes can improve patient-reported health status and the adverse risk they pose remains unknown.

Repurposing cefuroxime for treatment of COVID-19: a scoping review of in silico studies.

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of Coronavirus disease 19 (COVID-19), is a novel human Coronavirus that is responsible for about 300,000 deaths worldwide. To date, there is no confirmed treatment or vaccine prevention strategy against COVID-19. Due to the urgent need for effective treatment, drug repurposing is regarded as the immediate option. Potential drugs can often be identified via in silico drug screening experiments. Consequently, there has been an explosion of in silico experiments to find drug candidates or investigate anecdotal claims. One drug with several anecdotal accounts of benefit is Cefuroxime. The aim of this study was to identify and summarize in silico evidence for possible activity of Cefuroxime against SARS-CoV-2.To this end, we performed a scoping review of literature of in silico drug repurposing experiments for SARS-CoV-2 using PRISMA-ScR. We searched Medline, Embase, Scopus, Web of Knowledge, and Google Scholar for original studies published between 1st Feb, 2020 and 15th May, 2020 that screened drug libraries, and identified Cefuroxime as a top-ranked potential inhibitor drug against SARS-CoV-2 proteins. Six studies were identified. These studies reported Cefuroxime as a potential inhibitor of 3 key SARS-CoV-2 proteins; main protease, RNA dependent RNA polymerase, and ACE2-Spike complex. We provided a summary of the methodology and findings of the identified studies. Our scoping review identified significant in silico evidence that Cefuroxime may be a potential multi-target inhibitor of SARS-CoV-2. Further in vitro and in vivo studies are required to evaluate the potential of Cefuroxime for COVID-19.Communicated by Ramaswamy H. Sarma.

Clinical implications of differences between real world and clinical trial usage of left ventricular assist devices for end stage heart failure.

IMPORTANCE: Patient outcomes in heart failure clinical trials are generally better than those observed in real-world settings. This may be related to stricter inclusion and exclusion criteria in clinical trials. OBJECTIVE: We study sought to characterize the clinical implications of differences between patients in clinical trials and those in a real-world registry of patients receiving left ventricular assist devices (LVADs). DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study included all patients in INTERMACS (the Interagency Registry for Mechanically Assisted Circulatory Support) who were implanted with an axial flow LVAD from 2010 to 2015 to allow for equivalent comparisons. MAIN OUTCOMES AND MEASURES: Differences in patient characteristics and 2-year rates of adverse outcomes with those reported in the ENDURANCE and MOMENTUM 3 clinical trials. Survival analyses were used to assess the relationships between prespecified patient factors and clinical outcomes. RESULTS: Of the 10,937 LVAD recipients identified in INTERMACS between 2010-2015, 44% met at least 1 clinical trial exclusion criterion. The 2-year incidence of stroke and death amongst LVAD recipients in INTERMACS and the landmark clinical trials differed significantly (P<0.04, both). Nevertheless, patients who would have been excluded from the clinical trials did not have dramatically different 2-year mortality outcomes in INTERMACS [2y survival estimate: 66.4%, 95% CI (64.9-67.9%) versus 71.9%, 95% CI (70.6-73.1%)]. Clinical interventions driving a significantly increased risk of death were relatively rare (<5% of implants) and included mechanical ventilation, ECMO, severe thrombocytopenia, and dialysis. CONCLUSIONS AND RELEVANCE: Most exclusion criteria used in LVAD clinical trials did not afford a substantially greater risk to patients in the real-world setting. In the relatively infrequent cases of end stage renal disease, thrombocytopenia, respiratory failure, and need for ECMO, the risks and benefits of LVAD therapy need careful weighting and further study.

A giant arachnoid cyst: Is it an innocent bystander?

Arachnoid cysts vary in their size and location. Large cysts may cause symptoms requiring surgery. It is important to assess whether patients with arachnoid cysts and neurologic symptoms can benefit from such surgical interventions.

Clinical impact of concomitant tricuspid valve procedures during left ventricular assist device implantation.

BACKGROUND: Tricuspid regurgitation (TR) is common in patients with end-stage heart failure receiving left ventricular assist devices (LVADs), but the benefit of concomitant tricuspid valve procedures (TVPs) remains uncertain. This study examined the impact of TVP at the time of LVAD implantation on clinical outcomes and quality of life (QOL) metrics. METHODS: We included adult patients in the Interagency Registry for Mechanical Circulatory Support database with various degrees of TR who received continuous-flow LVADs from 2008 to 2017. Patients undergoing concomitant TVP were compared with those without the intervention in a stratified analysis. Descriptive analyses, survival analyses, and Andersen‒Gill hazard models were used as appropriate to examine associations with clinical and patient-centered QOL outcomes. RESULTS: Our analysis included 8,263 (53.1%) mild, 4,252 (33.3%) moderate, and 2,100 (13.5%) severe TR cases. TVP rate increased with severity: 8.6% of mild, 18.0% of moderate, and 43.9% of severe cases. TVP was not associated with survival benefit in cases of mild (adjusted hazard ratio [aHR]: 0.97, 95% CI: 0.79-1.19, p = 0.75), moderate (aHR: 1.03, 95% CI: 0.88-1.20, p = 0.72), or severe (aHR: 1.20, 95% CI: 0.98-1.48, p = 0.08) TR. For patients with combined moderate or severe TR, TVP was associated with increased mortality (log-rank p < 0.01, aHR: 1.13, 95% CI: 1.00-1.27, p = 0.04). After adjusting for TR severity, TVP was associated with increased risk of bleeding, arrhythmia, and stroke (p < 0.01 each) and no improvements in QOL (p > 0.05). CONCLUSIONS: TVP at the time of LVAD implantation was not associated with either improved survival or QOL, and there were associations with increased risk of adverse events among patients with moderate and severe TR.