Management of Ventricular Arrhythmias in Patients With Advanced Heart Failure

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

One-year mortality and causes of death after stereotactic radiation therapy for refractory ventricular arrhythmias: A systematic review and pooled analysis

Patients treated with cardiac stereotactic body radiation therapy (radioablation) for refractory ventricular arrhythmias are patients with advanced structural heart disease and significant comorbidities. However, data regarding 1-year mortality after the procedure are scarce. This systematic review and pooled analysis aimed at determining 1-year mortality after cardiac radioablation for refractory ventricular arrhythmias and investigating leading causes of death in this population. MEDLINE/EMBASE databases were searched up to January 2023 for studies including patients undergoing cardiac radioablation for the treatment of refractory ventricular arrhythmias. Quality of included trials was assessed using the NIH Tool for Case Series Studies (PROSPERO CRD42022379713). A total of 1,151 references were retrieved and evaluated for relevance. Data were extracted from 16 studies, with a total of 157 patients undergoing cardiac radioablation for refractory ventricular arrhythmias. Pooled 1-year mortality was 32 % (95 %CI: 23-41), with almost half of the deaths occurring within three months after treatment. Among the 157 patients, 46 died within the year following cardiac radioablation. Worsening heart failure appeared to be the leading cause of death (52 %), although non-cardiac mortality remained substantial (41 %) in this population. Age≥70yo was associated with a significantly higher 12-month all-cause mortality (p<0.022). Neither target volume size nor radiotherapy device appeared to be associated with 1-year mortality (p = 0.465 and p = 0.199, respectively). About one-third of patients undergoing cardiac stereotactic body radiation therapy for refractory ventricular arrhythmias die within the first year after the procedure. Worsening heart failure appears to be the leading cause of death in this population.

Prognostic value of ventricular arrhythmia in early post-infarction left ventricular dysfunction: the French nationwide WICD-MI study

BACKGROUND AND AIMS

Prophylactic implantable cardioverter-defibrillators (ICDs) are not recommended until left ventricular ejection fraction (LVEF) has been reassessed 40 to 90 days after an acute myocardial infarction. In the current therapeutic era, the prognosis of sustained ventricular arrhythmias (VAs) occurring during this early post-infarction phase (i.e. within 3 months of hospital discharge) has not yet been specifically evaluated in post-myocardial infarction patients with impaired LVEF. Such was the aim of this retrospective study.

METHODS

Data analysis was based on a nationwide registry of 1032 consecutive patients with LVEF ≤ 35% after acute myocardial infarction who were implanted with an ICD after being prescribed a wearable cardioverter-defibrillator (WCD) for a period of 3 months upon discharge from hospital after the index infarction.

RESULTS

ICDs were implanted either because a sustained VA occurred while on WCD (VA+/WCD, n = 72) or because LVEF remained ≤35% at the end of the early post-infarction phase (VA-/WCD, n = 960). The median follow-up was 30.9 months. Sustained VAs occurred within 1 year after ICD implantation in 22.2% and 3.5% of VA+/WCD and VA-/WCD patients, respectively (P < .0001). The adjusted multivariable analysis showed that sustained VAs while on WCD independently predicted recurrence of sustained VAs at 1 year (adjusted hazard ratio [HR] 6.91; 95% confidence interval [CI] 3.73-12.81; P < .0001) and at the end of follow-up (adjusted HR 3.86; 95% CI 2.37-6.30; P < .0001) as well as 1-year mortality (adjusted HR 2.86; 95% CI 1.28-6.39; P = .012).

CONCLUSIONS

In patients with LVEF ≤ 35%, sustained VA during the early post-infarction phase is predictive of recurrent sustained VAs and 1-year mortality.

Management of patients with heart failure and chronic kidney disease

Chronic kidney disease (CKD) and heart failure are often co-existing conditions due to a shared pathophysiological process involving neurohormonal activation and hemodynamic maladaptation. A wide range of pharmaceutical and interventional tools are available to patients with CKD, consisting of traditional ones with decades of experience and newer emerging therapies that are rapidly reshaping the landscape of medical care for this population. Management of patients with heart failure and CKD requires a stepwise approach based on renal function and the clinical phenotype of heart failure. This is often challenging due to altered drug pharmacokinetics interactions with various degrees of kidney function and frequent adverse effects from the therapy that lead to poor patient tolerance. Despite a great body of clinical evidence and guidelines that have offered various treatment options for patients with heart failure and CKD, respectively, patients with CKD are still underrepresented in heart failure clinical trials, especially for those with advanced CKD and end-stage renal disease (ESRD). Future studies are needed to better understand the generalizability of these therapeutic options among heart failures with different stages of CKD.

The Year in Electrophysiology: Selected Highlights From 2023

This special article is a continuation of an annual series for the Journal of Cardiothoracic and Vascular Anesthesia, highlighting the latest developments in the field of electrophysiology, particularly concerning cardiac anesthesiologists. The selected topics in the specialty for 2023 include consensus statements on left atrial appendage closure, outcomes in patients with atrial fibrillation and heart failure after ablation, further developments in the field of pulse field ablation, alternate defibrillation strategies for refractory ventricular fibrillation, updates on conduction system pacing, new devices such as the Aurora EV system and AVEIR leadless pacemaker system, artificial intelligence and its use in electrocardiogram-based diagnosis and latest evidence regarding the impact of anesthetic techniques on patient outcomes undergoing electrophysiology procedures.

Impact of Catheter Ablation of Electrical Storm on Survival: A Propensity Score-Matched Analysis

BACKGROUND

Electrical storm (ES) is a life-threatening condition, associated with substantial early and subacute mortality. Catheter ablation (CA) is a well-established therapy for ES. However, data regarding the impact of CA on the short-term and midterm survival of patients admitted for ES remain unclear.

OBJECTIVES

This multicenter study aimed to investigate the impact of CA of ES on survival outcomes, while accounting for key patient characteristics associated with treatment selection.

METHODS

A propensity score-matching (PSM) analysis was performed on 780 consecutive patients admitted for ES in 4 tertiary centers. PSM (1:1) based on the main characteristics associated with the use of CA or medical therapy alone was performed, resulting in 2 groups of 288 patients.

RESULTS

After PSM, patients who underwent CA (n = 288) and those treated with medical therapy alone (n = 288) did not present any significant differences in the main demographic characteristics, ES presentation, and management. Compared with medical therapy alone, CA was associated with a significantly lower rate of ES recurrence at 1 year (5% vs 26%; P < 0.001). Similarly, CA was associated with a higher 1-year (91% vs 81%; P < 0.001) and 3-year (78% vs 71%; P = 0.017) survival after discharge. In subgroup analyses, effect of ablation therapy remained consistent in patients older than 70 years of age (HR: 0.39; 95% CI: 0.24-0.66), with substantial efficacy in patients with a LVEF <35% (HR: 0.39; 95% CI: 0.27-0.59).

CONCLUSIONS

In propensity-matched analyses, this large study shows that CA-based management of patients admitted for ES is associated with a reduction in mortality compared with medical treatment, particularly in patients with a low ejection fraction.

Percutaneous mechanical support in catheter ablation of ventricular arrhythmias: hype or hope?

Catheter ablation (CA) has become an established treatment strategy for managing recurrent ventricular tachycardias (VTs) in patients with structural heart disease. In recent years, percutaneous mechanical circulatory support (PMCS) devices have been increasingly used intra-operatively to improve the ablation outcome. One indication would be rescue therapy for patients who develop haemodynamic deterioration during the ablation. However, more efforts are focused on identifying subjects who are at high risk of such deterioration and could benefit from the pre-emptive use of the PMCS. The third reason to use PMCS could be the inability to identify diffuse substrate, especially in non-ischaemic cardiomyopathy. This paper reviews available experiences using various types of PMCS in different clinical scenarios. Although PMCS allows mapping during VT, it does not significantly influence acute outcomes and not convincingly long-term outcomes. On the contrary, the complication rate appears to be higher in PMCS cohorts. Our data suggest that even in patients with severe left ventricular dysfunction, the substrate modification can be performed without the need for general anaesthesia and risk of haemodynamic decompensation. In end-stage heart failure associated with the electrical storm, implantation of a left ventricular assist device (or PMCS with a transition to the left ventricular assist device) might be the preferred strategy before CA. In high-risk patients who are not potential candidates for these treatment options, radiotherapy could be considered as a bail-out treatment of recurrent VTs. These approaches should be studied in prospective trials.

USP38 exacerbates pressure overload-induced left ventricular electrical remodeling

BACKGROUND

Ubiquitin-specific protease 38 (USP38), belonging to the USP family, is recognized for its role in controlling protein degradation and diverse biological processes. Ventricular arrhythmias (VAs) following heart failure (HF) are closely linked to ventricular electrical remodeling, yet the specific mechanisms underlying VAs in HF remain inadequately explored. In this study, we examined the impact of USP38 on VAs in pressure overload-induced HF.

METHODS

Cardiac-specific USP38 knockout mice, cardiac-specific USP38 transgenic mice and their matched control littermates developed HF induced by aortic banding (AB) surgery. After subjecting the mice to AB surgery for a duration of four weeks, comprehensive investigations were conducted, including pathological analysis and electrophysiological assessments, along with molecular analyses.

RESULTS

We observed increased USP38 expression in the left ventricle of mice with HF. Electrocardiogram showed that the USP38 knockout shortened the QRS interval and QTc, while USP38 overexpression prolonged these parameters. USP38 knockout decreased the susceptibility of VAs by shortening action potential duration (APD) and prolonging effective refractory period (ERP). In addition, USP38 knockout increased ion channel and Cx43 expression in ventricle. On the contrary, the increased susceptibility of VAs and the decreased expression of ventricular ion channels and Cx43 were observed with USP38 overexpression. In both in vivo and in vitro experiments, USP38 knockout inhibited TBK1/AKT/CAMKII signaling, whereas USP38 overexpression activated this pathway.

CONCLUSION

Our data indicates that USP38 increases susceptibility to VAs after HF through TBK1/AKT/CAMKII signaling pathway, Consequently, USP38 may emerge as a promising therapeutic target for managing VAs following HF.

Predictors of mortality and burden of arrhythmias in endstage heart failure

BACKGROUND

Heart failure (HF) is a significant cause of morbidity and mortality in the United States, contributing to approximately 1 in 8 deaths. Individuals with end-stage HF (eHF) experience debilitating symptoms leading to poor quality of life (QoL).

METHODS

We used the ICD-10 code for eHF (I5084) from the National Inpatient Sample (NIS) (2016-2020) to identify all patients with eHF. We used a multivariable logistic regression model to adjust for confounders and estimate the mortality probability in each arrhythmia cohort. Our primary outcome was in-hospital mortality risk in each group. A p-value of 0.05 was deemed significant.

RESULTS

There were 22,703 hospitalizations with eHF (mean age 67 years ±16). Men represented 66.5 % (15,091) of the population. In this cohort, 59 % (13,018) were Caucasians, 27.2 % (6,017) were Blacks, 8.7 % (1,924) were Hispanics, and 2.9 % (505) were Asians. Of these individuals, 50.4 % (11,434) had atrial fibrillation (AFIB). The majority of the arrhythmia subgroups had independent associations with mortality, with adjusted odds ratio (aOR) for VFIB 5.8 (4.6-7.1), AFIB 4.3 (3.9-4.5), SVT 1.9 (1.6-2.4), and VT 1.2 (1.1-1.4), p < 0.0001, each.

CONCLUSION

This analysis revealed that approximately half of the hospitalized population with end-stage heart failure are burdened with atrial fibrillation. Ventricular and atrial fibrillation, supraventricular tachycardia, and ventricular tachycardia each carried an independent mortality risk, with ventricular fibrillation having the highest risk.

Thirty-day readmission after catheter ablation for ventricular tachycardia: associated factors and outcomes

BACKGROUND

Patients with ventricular tachycardia (VT) who require VT ablation are at high risk for readmission. This study aimed to identify the causes and outcomes of 30-day readmission after VT ablation and to analyze the predictors of recurrent VT that required rehospitalization.

METHODS

Using the Nationwide Readmission Database, our study included patients aged ≥ 18 years who underwent VT catheter ablation between 2017 and 2020. Based on the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), we identified the causes of 30-day readmission by organ systems and analyzed their outcomes. Additional analysis was performed to determine the independent predictors of 30-day readmission for recurrent VT.

RESULTS

Of the 4228 patients who underwent VT ablation, 14.2% were readmitted within 30 days of the procedure. The most common cause of readmission was cardiac events (73.6%). Among the cardiac-related readmissions, recurrent VT (47.7%) and congestive heart failure (CHF) (12.9%) were the most common etiologies. Among the readmissions, patients readmitted for CHF had the highest rate of readmission mortality (9.2%). Of the patients readmitted within 30 days of the procedure, 278 patients (6.8%) were readmitted for recurrent VT. Via multivariable analysis, CHF (OR: 1.97; 95% CI: 1.12-3.47; P = 0.02) and non-elective index admissions (OR: 1.63; 95% CI: 1.04-2.55; P = 0.03) were identified as the independent predictors predictive of 30-day readmissions for recurrent VT.

CONCLUSIONS

Recurrent VT was the most common cause of readmission after the VT ablation procedure, and CHF and non-elective index admissions were the significant predictors of these early readmissions. Readmission due to CHF had the highest mortality rate during readmission.

Anesthetic Management for Ventricular Tachycardia Ablation: A National Anesthesia Clinical Outcomes Registry Analysis

OBJECTIVES

The authors analyzed anesthetic management trends during ventricular tachycardia (VT) ablation, hypothesizing that (1) monitored anesthesia care (MAC) is more commonly used than general anesthesia (GA); (2) MAC uses significantly increased after release of the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias; and (3) anesthetic approach varies based on patient and hospital characteristics.

DESIGN

Retrospective study.

SETTING

National Anesthesia Clinical Outcomes Registry data.

PARTICIPANTS

Patients 18 years or older who underwent elective VT ablation between 2013 and 2021.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Covariates were selected a priori within multivariate models, and interrupted time-series analysis was performed. Of the 15,505 patients who underwent VT ablation between 2013 and 2021, 9,790 (63.1%) received GA. After the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias supported avoidance of GA in idiopathic VT, no statistically significant increase in MAC was evident (immediate change in intercept post-consensus statement release adjusted odds ratio 1.41, p = 0.1629; change in slope post-consensus statement release adjusted odds ratio 1.06 per quarter, p = 0.1591). Multivariate analysis demonstrated that sex, American Society of Anesthesiologists physical status, age, and geographic location were statistically significantly associated with the anesthetic approach.

CONCLUSIONS

GA has remained the primary anesthetic type for VT ablation despite the 2019 Expert Consensus Statement on Catheter Ablation of Ventricular Arrhythmias suggested its avoidance in idiopathic VT. Achieving widespread clinical practice change is an ongoing challenge in medicine, emphasizing the importance of developing effective implementation strategies to facilitate awareness of guideline release and subsequent adherence to and adoption of recommendations.

Guiding ablation strategies for ventricular tachycardia in patients with structural heart disease by analyzing links and conversion patterns of traceable abnormal late potential zone

BACKGROUND

Substrate-based ablation can treat uninducible or hemodynamically instability scar-related ventricular tachycardia (VT). However, whether a correlation exists between the critical VT isthmus and late activation zone (LAZ) during sinus rhythm (SR) is unknown.

OBJECTIVE

To demonstrate the structural and functional properties of abnormal substrates and analyze the link between the VT circuit and abnormal activity during SR.

METHODS

Thirty-six patients with scar-related VT (age, 50.0 ± 13.7 years and 86.1% men) who underwent VT ablation were reviewed. The automatic rhythmia ultrahigh resolution mapping system was used for electroanatomic substrate mapping. The clinical characteristics and mapping findings, particularly the LAZ characteristics during SR and VT, were analyzed. To determine the association between the LAZ during the SR and VT circuits, the LAZ was defined as five activation patterns: entrance, exit, core, blind alley, and conduction barrier.

RESULTS

Forty-five VTs were induced in 36 patients, 91.1% of which were monomorphic. The LAZ of all patients was mapped during the SR and VT circuits, and the consistency of the anatomical locations of the LAZ and VT circuits was analyzed. Using the ultrahigh resolution mapping system, interconversion patterns, including the bridge, T, puzzle, maze, and multilayer types, were identified. VT ablation enabled precise ablation of abnormal late potential conduction channels.

CONCLUSION

Five interconversion patterns of the LAZ during the SR and VT circuits were summarized. These findings may help formulate more precise substrate-based ablation strategies for scar-related VT and shorter procedure times.

Non-revascularized chronic total occlusions impact on substrate and post-ablation results in drug-refractory electrical storm

Background and aims

There is limited data concerning the effect of non-revascularized chronic total occlusions (NR-CTOs) after VT ablation. This study sought to evaluate the impact of NR-CTOs after ablation for electrical storm (ES).

Methods

Post-hoc retrospective analysis of data regarding 64 consecutive post-myocardial infarction patients (out of which 12 patients with NR-CTOs and 52 without NR-CTOs) undergoing substrate ablation for ES with an available median follow-up of 37.53 (7.25-64.65) months. Ablation result was assessed by inducibility of sustained monomorphic VT (SMVT) during final programmed ventricular stimulation (PVS). The primary endpoints were all-cause mortality and VT/VF recurrences after ablation, respectively, stratified by the presence of NR-CTOs. The secondary endpoint was to assess the predictive effect of NR-CTOs on all-cause mortality and VT/VF recurrences in relation to other relevant prognostic factors.

Results

At baseline, the presence of NR-CTOs was associated with higher bipolar BZ-to-total scar ratio (72.4% ± 17.9% vs. 52% ± 37.7%, p = 0.022) and more failure to eliminate the clinical VT (25% (3) vs. 0% (0), p < 0.001). During follow-up, overall all-cause mortality and recurrences were more frequent in the NR-CTO subgroup (75% (9) vs. 19.2% (10), log rank p = 0.003 and 58.3% vs. 23.1% (12), log rank p = 0.042 respectively). After adjusting for end-procedural residual SMVT inducibility, NR-CTOs predicted death during follow-up (HR 3.380, p = 0.009) however not recurrence (HR 1.986, p = 0.154).

Conclusions

NR-CTO patients treated by RFCA for drug-refractory ES demonstrated a higher ratio of BZ-to-total-scar area. In this analysis, NR-CTO was associated with worse acute procedural results and may as well impact long-term outcomes which should be further assessed in larger patient populations.

Invasive Phenoprofiling of Acute-Myocardial-Infarction-Related Cardiogenic Shock

BACKGROUND

Studies had previously identified three cardiogenic shock (CS) phenotypes (cardiac-only, cardiorenal, and cardiometabolic). Therefore, we aimed to understand better the hemodynamic profiles of these phenotypes in acute myocardial infarction-CS (AMI-CS) using pulmonary artery catheter (PAC) data to better understand the AMI-CS heterogeneity.

METHODS

We analyzed the PAC data of 309 patients with AMI-CS. The patients were classified by SCAI shock stage, congestion profile, and phenotype. In addition, 24 h hemodynamic PAC data were obtained.

RESULTS

We identified three AMI-CS phenotypes: cardiac-only (43.7%), cardiorenal (32.0%), and cardiometabolic (24.3%). The cardiometabolic phenotype had the highest mortality rate (70.7%), followed by the cardiorenal (52.5%) and cardiac-only (33.3%) phenotypes, with significant differences (p < 0.001). Right atrial pressure (p = 0.001) and pulmonary capillary wedge pressure (p = 0.01) were higher in the cardiometabolic and cardiorenal phenotypes. Cardiac output, index, power, power index, and cardiac power index normalized by right atrial pressure and left-ventricular stroke work index were lower in the cardiorenal and cardiometabolic than in the cardiac-only phenotypes. We found a hazard ratio (HR) of 2.1 for the cardiorenal and 3.3 for cardiometabolic versus the cardiac-only phenotypes (p < 0.001). Also, multi-organ failure, acute kidney injury, and ventricular tachycardia/fibrillation had a significant HR. Multivariate analysis revealed that CS phenotypes retained significance (p < 0.001) when adjusted for the Society for Cardiovascular Angiography & Interventions score (p = 0.011) and ∆congestion (p = 0.028). These scores independently predicted mortality.

CONCLUSIONS

Accurate patient prognosis and treatment strategies are crucial, and phenotyping in AMI-CS can aid in this effort. PAC profiling can provide valuable prognostic information and help design new trials involving AMI-CS.

Fighting Cardiac Thromboembolism during Transcatheter Procedures: An Update on the Use of Cerebral Protection Devices in Cath Labs and EP Labs

Intraprocedural stroke is a well-documented and feared potential risk of cardiovascular transcatheter procedures (TPs). Moreover, subclinical neurological events or covert central nervous system infarctions are concerns related to the development of dementia, future stroke, cognitive decline, and increased risk of mortality. Cerebral protection devices (CPDs) were developed to mitigate the risk of cardioembolic embolism during TPs. They are mechanical barriers designed to cover the ostium of the supra-aortic branches in the aortic arch, but newer devices are able to protect the descending aorta. CPDs have been mainly designed and tested to provide cerebral protection during transcatheter aortic valve replacement (TAVR), but their use in both Catheterization and Electrophysiology laboratories is rapidly increasing. CPDs have allowed us to perform procedures that were previously contraindicated due to high thromboembolic risk, such as in cases of intracardiac thrombosis identified at preprocedural assessment. However, several concerns related to their employment have to be defined. The selection of patients at high risk of thromboembolism is still a subjective choice of each center. The aim of this review is to update the evidence on the use of CPDs in either Cath labs or EP labs, providing an overview of their structural characteristics. Future perspectives focusing on their possible future employment are also discussed.

Cardiomyocyte-Targeting Peptide to Deliver Amiodarone

BACKGROUND

Amiodarone is underutilized due to significant off-target toxicities. We hypothesized that targeted delivery to the heart would lead to the lowering of the dose by utilizing a cardiomyocyte-targeting peptide (CTP), a cell-penetrating peptide identified by our prior phage display work.

METHODS

CTP was synthesized thiolated at the N-terminus, conjugated to amiodarone via Schiff base chemistry, HPLC purified, and confirmed with MALDI/TOF. The stability of the conjugate was assessed using serial HPLCs. Guinea pigs (GP) were injected intraperitoneally daily with vehicle (7 days), amiodarone (7 days; 80 mg/kg), CTP-amiodarone (5 days; 26.3 mg/kg), or CTP (5 days; 17.8 mg/kg), after which the GPs were euthanized, and the hearts were excised and perfused on a Langendorff apparatus with Tyrode's solution and blebbistatin (5 µM) to minimize the contractions. Voltage (RH237) and Ca2+-indicator dye (Rhod-2/AM) were injected, and fluorescence from the epicardium split and was captured by two cameras at 570-595 nm for the cytosolic Ca2+ and 610-750 nm wavelengths for the voltage. Subsequently, the hearts were paced at 250 ms with programmed stimulation to measure the changes in the conduction velocities (CV), action potential duration (APD), and Ca2+ transient durations at 90% recovery (CaTD90). mRNA was extracted from all hearts, and RNA sequencing was performed with results compared to the control hearts.

RESULTS

The CTP-amiodarone remained stable for up to 21 days at 37 °C. At ~1/15th of the dose of amiodarone, the CTP-amiodarone decreased the CV in hearts significantly compared to the control GPs (0.92 ± 0.05 vs. 1.00 ± 0.03 ms, p = 0.0007), equivalent to amiodarone alone (0.87 ± 0.08 ms, p = 0.0003). Amiodarone increased the APD (192 ± 5 ms vs. 175 ± 8 ms for vehicle, p = 0.0025), while CTP-amiodarone decreased it significantly (157 ± 16 ms, p = 0.0136), similar to CTP alone (155 ± 13 ms, p = 0.0039). Both amiodarone and CTP-amiodarone significantly decreased the calcium transients compared to the controls. CTP-amiodarone and CTP decreased the CaTD90 to an extent greater than amiodarone alone (p < 0.001). RNA-seq showed that CTP alone increased the expression of DHPR and SERCA2a, while it decreased the expression of the proinflammatory genes, NF-kappa B, TNF-α, IL-1β, and IL-6.

CONCLUSIONS

Our data suggest that CTP can deliver amiodarone to cardiomyocytes at ~1/15th the total molar dose of the amiodarone needed to produce a comparable slowing of CVs. The ability of CTP to decrease the AP durations and CaTD90 may be related to its increase in the expression of Ca-handling genes, which merits further study.

Multidisciplinary Critical Care Management of Electrical Storm: JACC State-of-the-Art Review

Electrical storm (ES) reflects life-threatening cardiac electrical instability with 3 or more ventricular arrhythmia episodes within 24 hours. Identification of underlying arrhythmogenic cardiac substrate and reversible triggers is essential, as is interrogation and programming of an implantable cardioverter-defibrillator, if present. Medical management includes antiarrhythmic drugs, beta-adrenergic blockade, sedation, and hemodynamic support. The initial intensity of these interventions should be matched to the severity of ES using a stepped-care algorithm involving escalating treatments for higher-risk presentations or recurrent ventricular arrhythmias. Many patients with ES are considered for catheter ablation, which may require the use of temporary mechanical circulatory support. Outcomes after ES are poor, including frequent ES recurrences and deaths caused by progressive heart failure and other cardiac causes. A multidisciplinary collaborative approach to the management of ES is crucial, and evaluation for heart transplantation or palliative care is often appropriate, even for patients who survive the initial episode.

Prognostic impact of implantable cardioverter defibrillators and associated adverse events in patients with continuous flow left ventricular assist devices

Objectives

Implantation of implantable cardioverter defibrillators (ICD) reduces the risk of all-cause mortality in symptomatic heart failure (HF) patients with severe left ventricular (LV) dysfunction. Nevertheless, the prognostic impact of ICD therapy in continuous flow left ventricular assist device (LVAD) recipients remains controversial.

Methods

162 consecutive HF patients, who underwent LVAD implantation at our institution between 2010 and 2019, were categorized according to the presence (n = 94, ICD-group) or absence (n = 68, Control-group) of ICDs. Apart from clinical baseline and follow-up parameters, adverse events (AEs) related to ICD therapy and overall survival rates were retrospectively analyzed.

Results

Out of 162 consecutive LVAD recipients 79 patients (48.8%) were preoperatively categorized as Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) profile ≤2. The prevalence of severe HF symptoms and preoperative use of short-term circulatory support devices (54.4% vs. 13.8%, p < 0.001) was higher within the Control-group, although baseline severity of LV and RV dysfunction was similar. Apart from an increased prevalence of perioperative right heart failure (RHF) within the Control-group (45.6% vs. 17.0%; p < 0.001), procedural characteristics and perioperative outcome were similar. Overall-survival during a median follow-up of 14 (3.0-36.5) months was similar within both groups (p = 0.46). During the first 2 years after LVAD implantation 53 ICD-related AEs occurred within the ICD-group. Thereof, lead-dysfunction occurred in 19 patients and unplanned ICD-reintervention in 11 patients. Furthermore, in 18 patients appropriate shocks without loss of consciousness occurred, whereas inappropriate shocks occurred in 5 patients.

Conclusion

ICD therapy in LVAD recipients was not associated with a survival benefit or reduced morbidity after LVAD implantation. Conservative ICD-programming seems to be justified to avoid ICD-related complications and "awake shocks" after LVAD implantation.

Cardiomyocyte Targeting Peptide to Deliver Amiodarone

Background

Amiodarone is underutilized due to significant off-target toxicities. We hypothesized that targeted delivery to the heart would lead to lowering of dose by utilizing a cardiomyocyte targeting peptide (CTP), a cell penetrating peptide identified by our prior phage display work.

Methods

CTP was synthesized thiolated at the N-terminus, conjugated to amiodarone via Schiff base chemistry, HPLC purified and confirmed with MALDI/TOF. Stability of the conjugate was assessed using serial HPLCs. Guinea pigs (GP) were injected intraperitoneally daily with vehicle (7 days), amiodarone (7 days; 80mg/Kg), CTP-amiodarone (5 days;26.3mg/Kg), or CTP (5 days; 17.8mg/Kg), after which GPs were euthanized, hearts excised, perfused on a Langendorff apparatus with Tyrode's solution and blebbistatin (5μM) to minimize contractions. Voltage (RH237) and Ca 2+ -indicator dye (Rhod-2/AM) were injected, fluorescence from the epicardium split and focused on two cameras capturing at 570-595nm for cytosolic Ca 2+ and 610-750nm wavelengths for voltage. Subsequently, hearts were paced at 250ms with programmed stimulation to measure changes in conduction velocities (CV), action potential duration (APD) and Ca 2+ transient durations at 90% recovery (CaTD 90 ). mRNA was extracted from all hearts and RNA sequencing performed with results compared to control hearts.

Results

CTP-amiodarone remained stable for up to 21 days at 37°C. At ∼1/15 th of the dose of amiodarone, CTP-amiodarone decreased CV in hearts significantly compared to control GPs (0.92±0.05 vs. 1.00±0.03m/s, p=0.0007), equivalent to amiodarone alone (0.87±0.08ms, p=0.0003). Amiodarone increased APD (192±5ms vs. 175±8ms for vehicle, p=0.0025), while CTP-amiodarone decreased it significantly (157±16ms, p=0.0136) similar to CTP alone (155±13ms, p=0.0039). Both amiodarone and CTP-amiodarone significantly decreased calcium transients compared to controls. CTP-amiodarone and CTP decreased CaTD 90 to an extent greater than amiodarone alone (p<0.001). RNA-seq showed that CTP alone increased the expression of DHPR and SERCA2a, while decreasing expression of proinflammatory genes NF-kappa B, TNF-α, IL-1β, and IL-6.

Conclusions

Our data suggests that CTP can deliver amiodarone to cardiomyocytes at ∼1/15 th the total molar dose of amiodarone needed to produce comparable slowing of CVs. The ability of CTP to decrease AP durations and CaTD 90 may be related to its increase in expression of Ca-handling genes, and merits further study.

Association between blood urea nitrogen to creatinine ratio and neurologically favourable outcomes in out-of-hospital cardiac arrest in adults: A multicentre cohort study

BACKGROUND

We aimed to investigate the association between blood urea nitrogen to creatinine ratio (BCR) and survival with favourable neurological outcomes in patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This prospective, multicentre, observational study conducted in Osaka, Japan enrolled consecutive OHCA patients transported to 16 participating institutions from 2012 through 2019. We included adult patients with non-traumatic OHCA who achieved a return of spontaneous circulation and whose blood urea nitrogen and creatinine levels on hospital arrival were available. Based on BCR values, they were divided into: 'low BCR' (BCR <10), 'normal BCR' (10 ≤ BCR < 20), 'high BCR' (20 ≤ BCR < 30), and 'very high BCR' (BCR ≥ 30). We evaluated the association between BCR values and neurologically favourable outcomes, defined as cerebral performance category score of 1 or 2 at one month after OHCA.

RESULTS

Among 4415 eligible patients, the 'normal BCR' group had the highest favourable neurological outcome [19.4 % (461/2372)], followed by 'high BCR' [12.5 % (141/1127)], 'low BCR' [11.2 % (50/445)], and 'very high BCR' groups [6.6 % (31/471)]. In the multivariable analysis, adjusted odds ratios for 'low BCR', 'high BCR', and 'very high BCR' compared with 'normal BCR' for favourable neurological outcomes were 0.58 [95 % confidence interval (CI 0.37-0.91)], 0.70 (95 % CI 0.49-0.99), and 0.40 (95 % CI 0.21-0.76), respectively. Cubic spline analysis indicated that the association between BCR and favourable neurological outcomes was non-linear (p for non-linearity = 0.003). In subgroup analysis, there was an interaction between the aetiology of arrest and BCR in neurological outcome (p for interaction <0.001); favourable neurological outcome of cardiogenic OHCA patients was lower when the BCR was higher or lower, but not in non-cardiogenic OHCA patients.

CONCLUSIONS

Both higher and lower BCR were associated with poor neurological outcomes compared to normal BCR, especially in cardiogenic OHCA patients.

Role of Connexin 43 phosphorylation on Serine-368 by PKC in cardiac function and disease

Intercellular communication mediated by gap junction channels and hemichannels composed of Connexin 43 (Cx43) is vital for the propagation of electrical impulses through cardiomyocytes. The carboxyl terminal tail of Cx43 undergoes various post-translational modifications including phosphorylation of its Serine-368 (S368) residue. Protein Kinase C isozymes directly phosphorylate S368 to alter Cx43 function and stability through inducing conformational changes affecting channel permeability or promoting internalization and degradation to reduce intercellular communication between cardiomyocytes. Recent studies have implicated this PKC/Cx43-pS368 circuit in several cardiac-associated diseases. In this review, we describe the molecular and cellular basis of PKC-mediated Cx43 phosphorylation and discuss the implications of Cx43 S368 phosphorylation in the context of various cardiac diseases, such as cardiomyopathy, as well as the therapeutic potential of targeting this pathway.

An artificial intelligence-enabled ECG algorithm for identifying ventricular premature contraction during sinus rhythm

Background

Ventricular premature complex (VPC) is a common arrhythmia in clinical practice. VPC could trigger ventricular tachycardia/fibrillation or VPC-induced cardiomyopathy in susceptible patients. Existing screening methods require prolonged monitoring and are limited by cost and low yield when the frequency of VPC is low. Twelve-lead electrocardiogram (ECG) is low cost and widely used. We aimed to identify patients with VPC during normal sinus rhythm (NSR) using artificial intelligence (AI) and machine learning-based ECG reading.

Methods

We developed AI-enabled ECG algorithm using a convolutional neural network (CNN) to detect the ECG signature of VPC presented during NSR using standard 12-lead ECGs. A total of 2515 ECG records from 398 patients with VPC were collected. Among them, only ECG records of NSR without VPC (1617 ECG records) were parsed.

Results

A total of 753 normal ECG records from 387 patients under NSR were used for comparison. Both image and time-series datasets were parsed for the training process by the CNN models. The computer architectures were optimized to select the best model for the training process. Both the single-input image model (InceptionV3, accuracy: 0.895, 95% confidence interval [CI] 0.683–0.937) and multi-input time-series model (ResNet50V2, accuracy: 0.880, 95% CI 0.646–0.943) yielded satisfactory results for VPC prediction, both of which were better than the single-input time-series model (ResNet50V2, accuracy: 0.840, 95% CI 0.629–0.952).

Conclusions

AI-enabled ECG acquired during NSR permits rapid identification at point of care of individuals with VPC and has the potential to predict VPC episodes automatically rather than traditional long-time monitoring.

Monomorphic VT Non-Inducibility after Electrical Storm Ablation Reduces Mortality and Recurrences

Background: Electrical storm (ES) is defined by clustering episodes of ventricular tachycardia (VT) and is associated with severe long-term outcomes. We sought to evaluate the prognostic impact of radiofrequency catheter ablation (RFCA) in ES as assessed by aggressive programmed ventricular stimulation (PVS). Methods: Single-center retrospective longitudinal study with 82 consecutive ES patients referred for RFCA with a median follow-up (IQR 25−75%) of 45.43 months (15−69.86). All-cause mortality and VT recurrences were assessed in relation to RFCA outcomes defined by 4-extrastimuli PVS: Class 1—no ventricular arrhythmia; Class 2—no sustained monomorphic VTs (mVT) inducible, but non-sustained mVTs, polymorphic VTs, or VF inducible; Class 3—clinical VT non-inducible, other sustained mVTs inducible; and Class 4—clinical VT inducible. Results: Class 1, Class 2, Class 3, and Class 4 were achieved in 56.1%, 13.4%, 23.2%, and 7.4% of cases, respectively. The combined outcome of Class 1 + Class 2 (no sustained monomorphic VT inducible) led to improved survival (log-rank p < 0.001) and reduced VT recurrence (log-rank p < 0.001). Residual monomorphic VT inducibility (HR 6.262 (95% CI: 2.165−18.108, p = 0.001), NYHA IV heart failure symptoms (HR 20.519 (95% CI: 1.623−259.345), p = 0.02)), and age (HR 1.009 (95% CI: 1.041−1.160), p = 0.001)) independently predicted death during follow-up. LVEF was not predictive of death (HR 1.003 (95% CI: 0.946−1.063) or recurrences (HR 0.988 (95% CI: 0.955−1.021)). Conclusions: Non-inducibility for sustained mVTs after aggressive PVS post-RFCA leads to improved survival in ES, independently of LVEF.

Left Ventricular End-Diastolic Dimension and Clinical Outcomes After Centrifugal Flow Left Ventricular Assist Device Implantation

The impact of preoperative end-diastolic left ventricular dimension (preLVEDD) on long-term outcomes with centrifugal continuous-flow left ventricular assist device (CF-LVAD) is not well established. Accordingly, we performed an analysis of the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) registry to study this relationship. All patients with centrifugal CF-LVAD in the INTERMACS registry from June 2006 to December 2017 were screened. The final study group consisted of 3,304 patients. After a median follow-up of 9.0 months (interquartile range [IQR], 4.2-18.8 months), 2,596 (79%) patients were alive. After adjusting for significant covariates, increased preLVEDD was associated with lower mortality (hazard ratio [HR], 0.91; 95% confidence interval [CI], 0.84-0.98; p = 0.01), stroke (HR, 0.85; 95% CI, 0.77-0.93; p < 0.001), and gastrointestinal bleeding (HR, 0.88; 95% CI, 0.80-0.97; p = 0.01), although there were more arrhythmias (HR, 1.14; 95% CI, 1.05-1.24; p = 0.003). Our study suggests that preLVEDD is an independent predictor of mortality and adverse events in patients treated with centrifugal CF-LVAD. preLVEDD should be considered an important preimplant variable for risk stratification when considering a CF-LVAD.

Association between implantable cardioverter-defibrillator and survival in patients awaiting heart transplantation: A meta-analysis and systematic review

Background

Patients with end-stage heart failure are at high risk for sudden cardiac death. However, implantable cardioverter-defibrillator (ICD) is not routinely implanted given the high competing risk of pump failure. A unique population worth separate consideration are patients with end-stage heart failure awaiting heart transplantation, as prolonged survival improves the chances of receiving transplant.

Objective

To compare clinical outcomes of heart failure patients with and without an ICD awaiting heart transplant.

Methods

We performed an extensive literature search and systematic review of studies that compared end-stage heart failure patients with and without an ICD awaiting heart transplantation. We separately assessed the rates of total mortality, sudden cardiac death, nonsudden cardiac death, and heart transplantation. Risk ratio (RR) and 95% confidence intervals were measured using the Mantel-Haenszel method. The random effects model was used owing to heterogeneity across study cohorts.

Results

Ten studies with a total of 36,112 patients were included. A total of 62.5% of patients had an ICD implanted. Patients with an ICD had decreased total mortality (RR 0.60, 95% CI 0.51–0.71, P < .00001) and sudden cardiac death (RR 0.27, 95% CI 0.11–0.66, P = .004) and increased rates of heart transplantation (RR 1.09, 95% CI 1.05–1.14, P < .0001). There was no difference in prevalence of nonsudden cardiac death (RR 0.68, 95% CI 0.44–1.04, P = .07).

Conclusion

ICD implantation is associated with improved outcomes in patients awaiting heart transplant, characterized by decreased total mortality and sudden cardiac death as well as higher rates of heart transplantation.

Management of ventricular arrhythmias in heart failure: Current perspectives

Congestive heart failure (HF) is a progressive affliction defined as the inability of the heart to sufficiently maintain blood flow. Ventricular arrhythmias (VAs) are common in patients with HF, and conversely, advanced HF promotes the risk of VAs. Management of VA in HF requires a systematic, multimodality approach that comprises optimization of medical therapy and use of implantable cardioverter-defibrillator and/or device combined with cardiac resynchronization therapy. Catheter ablation is one of the most important strategies with the potential to abolish or decrease the number of recurrences of VA in this population. It can be a curative strategy in arrhythmia-induced cardiomyopathy and may even save lives in cases of an electrical storm. Additionally, modulation of the autonomic nervous system and stereotactic radiotherapy have been introduced as novel methods to control refractory VAs. In patients with end-stage HF and refractory VAs, an institution of the mechanical circulatory support device and cardiac transplant may be considered. This review aims to provide an overview of current evidence regarding management strategies of VAs in HF with an emphasis on interventional treatment.

Ventricular Arrhythmias in Seniors with Heart Failure: Present Dilemmas and Therapeutic Considerations: A Systematic Review

BACKGROUND

Heart Failure (HF) is a global public health problem, which affects over 23 million people worldwide. The prevalence of HF is higher among seniors in the USA and other developed countries. Ventricular Arrhythmias (VAs) account for 50% of deaths among patients with HF. We aim to elucidate the factors associated with VAs among seniors with HF, as well as therapies that may improve the outcomes.

METHODS

PubMed, Web of Science, Scopus, Cochrane Library databases, Science Direct, and Google Scholar were searched using specific keywords. The reference lists of relevant articles were searched for additional studies related to HF and VAs among seniors as well as associated outcomes.

RESULTS

The prevalence of VAs increases with worsening HF. A 24-hour Holter electrocardiogram may be useful in risk stratifying patients for device therapy if they do not meet the criterion of low ventricular ejection fraction. Implantable Cardiac Defibrillators (ICDs) are superior to anti-arrhythmic drugs in reducing mortality in patients with HF. Guideline-Directed Medical Therapy (GDMT) together with device therapy may be required to reduce symptoms. In general, the proportion of seniors on GDMT is low. A combination of ICDs and cardiac resynchronization therapy may improve outcomes in selected patients.

CONCLUSION

Seniors with HF and VAs have high mortality even with the use of device therapy and GDMT. The holistic effect of device therapy on outcomes among seniors with HF is equivocal. More studies focused on seniors with advanced HF as well as therapeutic options are, therefore, required.

Ventricular Arrhythmias Among Patients With Advanced Heart Failure: A Population-Based Study

Background The epidemiology of ventricular arrhythmias (VAs) in patients with advanced heart failure (HF) is not well defined. Methods and Results Residents of Olmsted County, Minnesota, with advanced HF from 2007 to 2017 were identified using the 2018 European Society of Cardiology criteria. Billing codes were used to capture VAs; severe VAs requiring emergency care were defined as events associated with emergency department visits or hospitalizations. The cumulative incidence of VAs postadvanced HF was estimated with the Kaplan-Meier method. Multivariable Cox analyses were used to determine the following: (1) Predictors of severe VAs postadvanced HF; and (2) Impact of severe VAs on mortality. Of 936 patients with advanced HF, 261 (27.9%) had a history of VA. The 1-year cumulative incidence of severe VAs postadvanced HF was 5.4%. Prior VAs (hazard ratio [HR] 2.22 [95% CI, 1.26-3.89], P=0.006) and left ventricular ejection fraction <40% (HR, 3.79 [95% CI, 1.72-8.39], P<0.001) were independently associated with increased severe VA risk postadvanced HF. New-onset severe VAs were associated with increased mortality (HR, 4.41 [95% CI, 2.80-6.94]; P<0.001), whereas severe VAs in patients with prior VAs had no significant association with mortality risk (HR, 1.08 [95% CI, 0.65-1.78]; P=0.77). Severe VAs were associated with increased mortality in patients without implantable cardioverter defibrillators (HR, 4.89 [95% CI, 2.89-8.26]; P<0.001), but not in patients with implantable cardioverter defibrillators (HR, 1.42 [95% CI, 0.92-2.19]; P=0.11). Conclusions Patients with left ventricular ejection fraction <40% and prior VAs have increased risk of severe VA postadvanced HF. New-onset severe VAs or severe VAs without implantable cardioverter defibrillators postadvanced HF are associated with increased mortality.

Mexiletine and False Positive Urine Drug Screen for Amphetamine: A Case Review

Advanced heart failure patients commonly suffer from ventricular arrhythmias which can be managed by antiarrhythmic drugs like mexiletine. These ventricular arrhythmias can be complicated by illicit drug use which alter outcomes and can potentially impact the patient-physician relationship through countertransference. However, mexiletine can lead to false positive urine drug screen testing for amphetamine, and these false-positive urine drug screen test results can affect the decision-making process. Health care providers should be aware of this fact and should either use confirmatory testing or look for confounding compounds in patients who deny using illicit substances and have a positive urine drug screen. Our patient is 64 years old who arrived at the emergency department after experiencing a shock by his intracardiac defibrillator. The patient tested positive for amphetamine on his urine drug screen and was later ruled out by confirmatory quantitative testing.

Primary Graft Dysfunction after Heart Transplantation - Unravelling the Enigma

Primary graft dysfunction (PGD) remains the main cause of early mortality following heart transplantation despite several advances in donor preservation techniques and therapeutic strategies for PGD. With that aim of establishing the aetiopathogenesis of PGD and the preferred management strategies, the new consensus definition has paved the way for multiple contemporaneous studies to be undertaken and accurately compared. This review aims to provide a broad-based understanding of the pathophysiology, clinical presentation and management of PGD.

Catheter ablation for atrial fibrillation in left ventricular assist device: A case report

INTRODUCTION

Mechanical circulatory support such as the left ventricular assist device (LVAD) has become widely implemented in the treatment of end-stage heart failure, whether as bridge-to-transplant or as destination therapy. The hemodynamic effects of arrhythmia on LVADs and its management are significant in determining the long-term outcome of these patients. Both atrial arrhythmia and ventricular arrhythmia are commonly seen after implantation of the device. There are no strict guidelines, however, on the need for intensive management of arrhythmias in LVAD. In this case report, we present a patient with new onset atrial fibrillation after LVAD implantation which leads to acute decompensating heart failure. The patient was treated with catheter ablation. The intervention demonstrated positive outcomes for this patient.

PATIENT CONCERNS

The patient was a Korean male, who presented with dyspnea, fatigue and generalized edema after persistent atrial fibrillation precipitated by implantation of the left ventricular assist device.

DIAGNOSIS

The patient was diagnosed with acute decompensating heart failure that was aggravated by recurrent atrial arrhythmia.

INTERVENTION

We attempted to relieve symptoms of right ventricular dysfunction by method of strict rhythm control in this patient. The patient underwent radiofrequency catheter ablation for recurrent atrial fibrillation.

OUTCOME

The patient showed improved clinical symptoms, BNP levels, and echocardiogram parameters immediately after the procedure as well as during long term outpatient follow up.

CONCLUSION

In this case report, we present the first successful case in Korea of atrial fibrillation in LVAD treated with catheter ablation. This case suggests setting catheter ablation as a routine first-line treatment for atrial arrhythmia in LVAD patients, especially when the arrhythmia predisposes the patient at risk for decompensating heart failure.

Excessive O-GlcNAcylation Causes Heart Failure and Sudden Death

BACKGROUND

Heart failure is a leading cause of death worldwide and is associated with the rising prevalence of obesity, hypertension, and diabetes. O-GlcNAcylation (the attachment of O-linked β-N-acetylglucosamine [O-GlcNAc] moieties to cytoplasmic, nuclear, and mitochondrial proteins) is a posttranslational modification of intracellular proteins and serves as a metabolic rheostat for cellular stress. Total levels of O-GlcNAcylation are determined by nutrient and metabolic flux, in addition to the net activity of 2 enzymes: O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA). Failing myocardium is marked by increased O-GlcNAcylation, but whether excessive O-GlcNAcylation contributes to cardiomyopathy and heart failure is unknown.

METHODS

We developed 2 new transgenic mouse models with myocardial overexpression of OGT and OGA to control O-GlcNAcylation independent of pathologic stress.

RESULTS

We found that OGT transgenic hearts showed increased O-GlcNAcylation and developed severe dilated cardiomyopathy, ventricular arrhythmias, and premature death. In contrast, OGA transgenic hearts had lower O-GlcNAcylation but identical cardiac function to wild-type littermate controls. OGA transgenic hearts were resistant to pathologic stress induced by pressure overload with attenuated myocardial O-GlcNAcylation levels after stress and decreased pathologic hypertrophy compared with wild-type controls. Interbreeding OGT with OGA transgenic mice rescued cardiomyopathy and premature death, despite persistent elevation of myocardial OGT. Transcriptomic and functional studies revealed disrupted mitochondrial energetics with impairment of complex I activity in hearts from OGT transgenic mice. Complex I activity was rescued by OGA transgenic interbreeding, suggesting an important role for mitochondrial complex I in O-GlcNAc-mediated cardiac pathology.

CONCLUSIONS

Our data provide evidence that excessive O-GlcNAcylation causes cardiomyopathy, at least in part, attributable to defective energetics. Enhanced OGA activity is well tolerated and attenuation of O-GlcNAcylation is beneficial against pressure overload-induced pathologic remodeling and heart failure. These findings suggest that attenuation of excessive O-GlcNAcylation may represent a novel therapeutic approach for cardiomyopathy.

Hospitalization for Heart Failure and Subsequent Ventricular Tachyarrhythmias in Patients With Left Ventricular Dysfunction

OBJECTIVES

This study aimed to evaluate the risk of sustained life-threatening ventricular tachyarrhythmias (VTAs) after hospitalization for heart failure (HHF).

BACKGROUND

HHF is common among patients with an implantable cardioverter-defibrillator (ICD).

METHODS

We analyzed all 5,511 ICD patients enrolled in the landmark MADIT and RAID trials. Multivariate Cox regression was used to evaluate the association of in-trial HHF occurrence with the risk of subsequent VTA and the composite end point of VTA or cardiac death.

RESULTS

Mean age was 64 ± 11 years, 23% were women, 62% were ischemic, and 40% had cardiac resynchronization therapy with defibrillators. The 3-year cumulative rate of VTA subsequent to HHF was significantly higher than the corresponding rate without HHF (44% vs. 24%, respectively; p < 0.001). After multivariable adjustment, time-dependent HHF was shown to be associated with a 79% increased risk for VTA and a 2.9-fold increased risk for VTA/cardiac death (p < 0.001 for both). In-trial development of atrial tachyarrhythmia (ATA) was also identified as an independent risk factor for the VTA and VTA/cardiac death end points (hazard ratios [HRs]: 1.59 and 1.43, respectively; p ≤ 0.001 for both) but did not affect the association of HHF with VTA. Subgroup analysis demonstrated that the association of HHF with the risk of subsequent VTA was maintained among risk subsets categorized by age, sex, history of ATA, and implantation indication, but was significantly more pronounced among patients with nonischemic versus ischemic cardiomyopathy (HRs: 2.54 and 1.43, respectively; p value for interaction: 0.017).

CONCLUSIONS

HHF is a powerful risk factor for subsequent VTA in patients implanted with an ICD. These data may be used for improved risk stratification in this population.

Cardiac Sympathetic Denervation for Refractory Ventricular Arrhythmia in Continuous-Flow Left Ventricular Assist Device

Cardiac sympathetic denervation has been shown to reduce sustained ventricular arrhythmias and implantable cardioverter-defibrillator shocks by inhibiting sympathetic outflow to the heart. We describe the first case to our knowledge of cardiac sympathetic denervation in the left ventricular assist device population. (Level of Difficulty: Advanced.)

Bilateral Cardiac Sympathectomy and Extrapericardial Coil Implantation for the Management of Electrical Storm

We present a novel multidisciplinary approach for the treatment of electrical storm combining bilateral cardiac sympathectomy, extrapericardial coil insertion, and implantable cardioverter defibrillator upgrade in a patient with nonischemic cardiomyopathy and ventricular arrhythmias refractory to conventional therapies. (Level of Difficulty: Advanced.)

Increased Rate of Pump Thrombosis and Cardioembolic Events Following Ventricular Tachycardia Ablation in Patients Supported With Left Ventricular Assist Devices

Ventricular arrhythmias are common following left ventricular assist device implantation (LVAD), and the effects of ventricular tachycardia (VT) ablation on thrombosis and embolic events are unknown. We aimed to assess LVAD thrombosis, stroke, and embolic event rates after VT ablation. Left ventricular assist device implantation patients from two academic centers who underwent endocardial VT ablation between 2009 and 2016 were compared to a control group with VT who were not ablated and followed for one year. The primary composite outcome was confirmed or suspected LVAD thrombosis, stroke, or other embolic event. Survival analysis was conducted with Kaplan-Meier curves, log-rank tests, and Cox regression. Forty-three LVAD patients underwent VT ablation, and 73 LVAD patients had VT but were not ablated. Patients who were ablated were more likely have VT prior to LVAD (p = 0.04), monomorphic VT (p < 0.01), and to be on antiarrhythmics (p < 0.01). Fifty-eight percent of the patients in the ablation group experienced the primary composite outcome (11% had confirmed device thrombosis [DT], 41% suspected DT, 39% had a stroke or embolic event) compared to 30% in the control group (12% with confirmed DT, 11% with suspected DT, 14% with stroke or embolic event) (p = 0.002). In multivariable regression, ablation was an independent predictor of the primary composite outcome (hazard ratios, 2.24; 95% confidence interval, 1.09-4.61; p = 0.03). Patients with LVADs referred for endocardial VT ablation had elevated rates of DT and embolic events.

Protocatechualdehyde protects oxygen-glucose deprivation/reoxygenation-induced myocardial injury via inhibiting PERK/ATF6α/IRE1α pathway

Endoplasmic reticulum (ER) stress has been considered as a promising strategy in developing novel therapeutic agents for cardiovascular diseases through inhibiting cardiomyocyte apoptosis. Protocatechualdehyde (PCA) is a natural phenolic compound from medicinal plant Salvia miltiorrhiza with cardiomyocyte protection. However, the potential mechanism of PCA on cardiovascular ischemic injury is largely unexplored. Here, we found that PCA exerted markedly anti-apoptotic effect in oxygen-glucose deprivation/reoxygenation (OGD/R)-induced H9c2 cells (Rat embryonic ventricular H9c2 cardiomyocytes), which was detected by 3-(4, 5-dimethyl thiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT), lactate dehydrogenase (LDH), Hoechst 33258 and acridine orange/ethidium bromide (AO/EB) assays. PCA also obviously protected cardiomyocytes in myocardial fibrosis model of mice, which was determined by hematoxylin-eosin (HE) staining and TdT-mediated dUTP Nick-End Labeling (TUNEL) staining. Transcriptomics coupled with bioinformatics analysis revealed a complex pharmacological signaling network especially for PCA-mediated ER stress on cardiomyocytes. Further mechanism study suggested that PCA suppressed ER stress via inhibiting protein kinase R-like ER kinase (PERK), inositol-requiring enzyme1α (IRE1α), and transcription factor 6α (ATF6α) signaling pathway through Western blot, DIOC6 and ER-Tracker Red staining, leading to a protective effect against ER stress-mediated cardiomyocyte apoptosis. Taken together, our observations suggest that PCA is a major component from Salvia miltiorrhiza against cardiovascular ischemic injury by suppressing ER stress-associated PERK, IRE1α and ATF6α signaling pathways.

Psychological stress in heart failure: a potentially actionable disease modifier

Psychological stress is common in patients with heart failure, due in part to the complexities of effective disease self-management and progressively worsening functional limitations, including frequent symptom exacerbations and hospitalizations. Emerging evidence suggests that heart failure patients who experience higher levels of stress may have a more burdensome disease course, with diminished quality of life and increased risk for adverse events, and that multiple behavioral and pathophysiological pathways are involved. Furthermore, the reduced quality of life associated with heart failure can serve as a life stressor for many patients. The purpose of this review is to summarize the current state of the science concerning psychological stress in patients with heart failure and to discuss potential pathways responsible for the observed effects. Key knowledge gaps are also outlined, including the need to understand patterns of exposure to various heart failure-related and daily life stressors and their associated effects on heart failure symptoms and pathophysiology, to identify patient subgroups at increased risk for stress exposure and disease-related consequences, and the effect of stress specifically for patients who have heart failure with preserved ejection fraction. Stress is a potentially modifiable factor, and addressing these gaps and advancing the science of stress in heart failure is likely to yield important insights about actionable pathways for improving patient quality of life and outcomes.

Primary Prevention Implantable Cardiac Defibrillators: A Townsville District Perspective

Background: Despite major advances in treating patients with severe heart failure, deciding who should receive an implantable cardiac defibrillator (ICD) remains challenging.

Objective: To study the risk factors and mortality in patients after receiving an ICD (January 2008–December 2015) in a regional hospital in Australia.

Methods: Eighty-two primary prevention patients received an ICD for ischemic cardiomyopathy (ICM, n = 41) and non-ischemic cardiomyopathy (NICM, n = 40) with 4.8-yrs follow-up. One patient had mixed ICM/NICM indications. Ventricular arrhythmias were assessed using intracardiac electrograms. Statistical analysis compared the total population and ICM and NICM groups using Kaplan-Meier for survival, Cox regression for mortality predictors, and binary logistic regression for predictors of ventricular arrhythmias (p < 0.05).

Results: Major risk factors were hypercholesterolemia (70.7%), hypertension (47.6%), and obesity (41.5%). Severe obstructive sleep apnea (OSA) was found exclusively in NICM patients (23.7%, p = 0.001). Mortality was 30.5% after 4.8-yrs. The majority of patients (n=67) had no sustained ventricular arrhythmias yet 28% received therapy (n = 23), 18.51% were appropriate (n = 15), and 13.9% inappropriate (n = 11). Patients receiving ≥2 incidences of inappropriate shocks were 18-times more likely to die (p = 0.013). Three sudden cardiac deaths (SCD) (3.7%) were prevented by the ICD.

Conclusion: Patients implanted with an ICD in Townsville had 30.5% all-cause mortality after 4.8-yrs. Only 28% of patients received ICD therapy and 13.9% were inappropriate. OSA may have contributed to the fourfold increase in inappropriate therapy in NICM patients. Our study raises important efficacy, ethical and healthcare cost questions about who should receive an ICD, and possible regional and urban center disparities.

Periprocedural Acute Kidney Injury in Patients With Structural Heart Disease Undergoing Catheter Ablation of VT

OBJECTIVES

This study sought to examine the impact of periprocedural acute kidney injury (AKI) in scar-related ventricular tachycardia (VT) patients undergoing radiofrequency catheter ablation (RFCA) on short- and long-term outcomes.

BACKGROUND

The clinical significance of periprocedural AKI in patients with scar-related VT undergoing RFCA has not been previously investigated.

METHODS

This study included 317 consecutive patients with scar-related VT undergoing RFCA (age: 64 ± 13 years, mean left ventricular ejection fraction: 33 ± 13%, 55% ischemic cardiomyopathy). Periprocedural AKI was defined as an absolute increase in creatinine of ≥0.3 mg/dl over 48 h or an increase of >1.5× the baseline values within 1 week post-procedure.

RESULTS

Periprocedural AKI occurred in 31 patients (10%). Independent predictors of AKI included chronic kidney disease (odds ratio [OR]: 3.43; 95% confidence interval [CI]: 1.48 to 7.96; p = 0.004), atrial fibrillation (OR: 2.42; 95% CI: 1.01 to 5.78; p = 0.047), and peri-procedural acute hemodynamic decompensation (OR: 3.98; 95% CI: 1.17 to 13.52; p = 0.003). After a median follow-up of 39 months (interquartile range: 6 to 65 months), 95 patients (30%) died. Periprocedural AKI was associated with increased risk of early mortality (within 30 days; hazard ratio [HR]: 9.91; 95% CI: 2.87 to 34.22; p < 0.001) and late mortality (within 1 year) (HR: 4.57; 95% CI: 2.08 to 10.05; p < 0.001). After multivariable adjustment, AKI remained independently associated with increased risk of early and late mortality (HR: 4.49; 95% CI: 1.1 to 18.36; p = 0.04, and HR: 3.28; 95% CI: 1.43 to 7.49; p = 0.005, respectively).

CONCLUSIONS

Periprocedural AKI occurs in 10% of patients undergoing RFCA of scar-related VT and is strongly associated with increased risk of early and late post-procedural mortality.

Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip®

Background

Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR.

Methods

We retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction (LVEF), functional mitral regurgitation (FMR) grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up.

Results

Ninety-three patients (68.2±10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-month follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0±17.8 vs. 2.7±13.5, P=0.002), sustained VT or ventricular fibrillation (0.9±2.5 vs. 0.5±2.9, P=0.012) and ICD antitachycardia therapies (2.5±12.0 vs. 0.9±5.0, P=0.033) were observed.

Conclusions

PMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort.

Transseptal use of high-density grid catheter for VT mapping and retrograde hemodynamic support with Impella pump in presence of Mitraclips

PURPOSE

We sought to establish the technical feasibility of VT-mapping with high-density catheters in patients with Mitraclips, requiring a hemodynamic support.

METHODS

A 73-year-old man with ischemic cardiomyopathy and reduced left ventricular ejection fraction (LVEF ~ 20%) was presented due to syncope and adequate shock of his ICD. Due to severe mitral valve regurgitation (MR), two Mitraclips were implanted earlier. The decision for catheter ablation was made in line with current guidelines. Given the increased PAAINESD score, the use of hemodynamic support was required. To employ an Impella pump via the retrograde transaortic approach, LV-mapping and VT-ablation were necessary to be performed via the transseptal approach, which was challenging due to the presence of Mitraclips. The MV passage with the steerable sheath was guided by a quadripolar catheter and 3D transoesophageal echo (TEE). After the 12F steerable sheath had passed the MV, the quadripolar catheter was exchanged by a high-density (HD) Grid® catheter. Hereafter, the Impella pump was placed retrogradely in the LV, and voltage-mapping of the LV and ablation was performed.

RESULTS

At the end of the procedure, the Impella pump could be removed in stable hemodynamic conditions. The follow-up after 3, 6, and 12 months showed no new VT episodes.

CONCLUSIONS

This case demonstrates the feasibility of the transseptal approach of VT mapping used HD Grid catheter and retrograde hemodynamic support with Impella Pump for VT treatment in patients after Mitraclips implantation. To avoid a damage of the MV and Mitraclips, 3D-TEE is advisable.

Safety of bioelectrical impedance analysis in advanced heart failure patients

BACKGROUND

Cardiac cachexia and frailty are major complications of advanced heart failure (AHF). Bioelectrical impedance analysis (BIA) may provide valuable information regarding fluid balance, muscle mass and prognosis. The main concerns regarding the use of BIA in AHF patients remain arrhythmias and electromagnetic interferences with cardiac implantable electronic devices (CIEDs). Reliable data regarding patients on continuous-flow ventricular assist device (cf-VAD) remain scarce. The aim of this study is to evaluate the safety of BIA in AHF patients on pro-arrhythmogenic therapy with an implanted CIED and/or with a cf-VAD.

METHODS

We prospectively performed 217 BIA measurements in 143 AHF patients at risk of severe arrhythmias due to inotropic support/a history of ventricular arrhythmias and/or treated with CIED, including 104 patients with an ICD, CRT or pacemaker and 95 patients with a cf-VAD. All patients were under continuous Electrocardiogram (ECG) monitoring and clinical surveillance for 24 hours.

RESULTS

No adverse events were observed during the 217 BIA measurements: No rhythm disturbances were documented in the telemetric monitoring during or within 30 minutes after the measurement. CIEDs showed no malfunction, regardless of the location measured or the device manufacturer. In particular, no inappropriate shocks were observed. No alarms, flow disturbances, or malfunctions of the cf-VAD occurred during or after the measurements.

CONCLUSION

We consider BIA a safe measurement with major clinical relevance in our cohort of AHF patients, despite an increased arrhythmic potential on inotropic support or the presence of implanted electronic devices (ICD, CRT, pacemaker and cf-VAD).

Ventricular Fibrillation 7 Years After Left Ventricular Assist Device Implantation

Patient: Male, 74-year-old

Final Diagnosis: Ventricular fibrillation

Symptoms: Altered mental status • slurred speech • somnolence

Medication:—

Clinical Procedure: Left ventricular assist device placement

Specialty: Cardiology • Critical Care Medicine • General and Internal Medicine