Cardiac blood vessels and irreversible electroporation: findings from pulsed field ablation.

The clinical use of irreversible electroporation in invasive cardiac laboratories, termed pulsed field ablation (PFA), is gaining early enthusiasm among electrophysiologists for the management of both atrial and ventricular arrhythmogenic substrates. Though electroporation is regularly employed in other branches of science and medicine, concerns regarding the acute and permanent vascular effects of PFA remain. This comprehensive review aims to summarize the preclinical and adult clinical data published to date on PFA's effects on pulmonary veins and coronary arteries. These data will be contrasted with the incidences of iatrogenic pulmonary vein stenosis and coronary artery injury secondary to thermal cardiac ablation modalities, namely radiofrequency energy, laser energy, and liquid nitrogen-based cryoablation.

Outcomes in patients implanted with a Watchman device in relation to choice of anticoagulation and indication for implant.

BACKGROUND: Patients with atrial fibrillation are increasingly prescribed a direct oral anticoagulant (DOAC) over warfarin and seek to avoid anticoagulation even without a history of major bleeding. This study explores the outcomes of patients implanted with a Watchman device in relation to anticoagulation choice (warfarin versus DOAC) in the post-procedure period and a history of bleeding. METHODS: Patients implanted with a Watchman device at a single center were retrospectively analyzed. Characteristics including anticoagulation in the first 45 days and history of major bleed were assessed and efficacy (thromboembolism) and safety (bleeding) outcomes compared by Kaplan-Meier analysis. RESULTS: Two hundred nine patients were implanted (57% male, age 74.6 ± 7.8 years) and followed for 23.5 ± 7.1 months. In the first half of patients, 98% were prescribed warfarin, which dropped to 51% in the second half (p < 0.0001). A history of major bleed was present in 80.8% of the first half of patients and decreased to 60% in the second half (p = 0.001). There were 16 safety and 4 efficacy events. There was no difference in safety outcomes according to history of major bleeding or anticoagulant choice in the first 45 days. There was no difference in efficacy outcomes over the duration of follow-up according to anticoagulation choice in the first 45 days. CONCLUSIONS: Patients implanted with a Watchman device were increasingly over time prescribed a DOAC and implanted without a history of major bleeding. Bleeding and thromboembolic events were infrequent and related neither to choice of anticoagulant nor to prior major bleeding.

The emerging role of cardiac contractility modulation in heart failure treatment.

PURPOSE OF REVIEW: Heart failure often progresses despite optimal medical and device therapies, and advanced mechanical circulatory support has limited availability and substantial associated morbidity. Cardiac contractility modulation (CCM) provides nonexcitatory stimulation to ventricular myocardium which increases cardiac contractility without increasing oxygen demand. This review describes the emerging role of CCM in heart failure treatment. RECENT FINDINGS: The FIX-HF-5C2 study demonstrated similar safety and efficacy profile of the two-lead Optimizer device in comparison with the prior three-lead system, thereby decreasing procedural complexity and minimizing endocardial hardware. The FIX-HF-5C trial underscored the benefit of CCM in patients with mild-moderate left ventricular dysfunction (ejection fraction, 25-45%) with New York Heart Association (NYHA) Class III symptoms. The summarized randomized trial data show consistent improvements in peak VO2, 6-min walk distance, and NYHA functional class with CCM. Future trials are planned to determine the role of CCM in heart failure patients with preserved ejection fraction, obligate ventricular pacing, and atrial arrhythmias. SUMMARY: Nonexcitatory extracellular electric potentials can facilitate inotropic improvements in the failing heart. The mechanism of CCM does not increase myocardial oxygen consumption and has been shown to mitigate heart failure symptoms, decrease hospitalizations, and work in synergy with guideline-directed therapy for heart failure.

Non-Concordance between Patient and Clinician Estimates of Prognosis in Advanced Heart Failure.

IMPORTANCE: Despite efforts to enhance serious illness communication, patients with advanced heart failure (HF) lack prognostic understanding. OBJECTIVES: To determine rate of concordance between HF patients' estimation of their prognosis and their physician's estimate of the patient's prognosis, and to compare patient characteristics associated with concordance. DESIGN: Cross-sectional analysis of a cluster randomized controlled trial with 24-month follow-up and analysis completed on 09/01/2020. Patients were enrolled in inpatient and outpatient settings between September 2011 to February 2016 and data collection continued until the last quarter of 2017. SETTING: Six teaching hospitals in the U.S. PARTICIPANTS: Patients with advanced HF and implantable cardioverter defibrillators (ICDs) at high risk of death. Of 537 patients in the parent study, 407 had complete data for this analysis. INTERVENTION: A multi-component communication intervention on conversations between HF clinicians and their patients regarding ICD deactivation and advance care planning. MAIN OUTCOME(S) AND MEASURE(S): Patient self-report of prognosis and physician response to the "surprise question" of 12-month prognosis. Patient-physician prognostic concordance (PPPC) measured in percentage agreement and kappa. Bivariate analyses of characteristics of patients with and without PPPC. RESULTS: Among 407 patients (mean age 62.1 years, 29.5% female, 42.4% non-white), 300 (73.7%) dyads had non-PPPC; of which 252 (84.0%) reported a prognosis >1 year when their physician estimated <1 year. Only 107 (26.3%) had PPPC with prognosis of ≤ 1 year (n=20 patients) or > 1 year (n=87 patients); (Κ = -0.20, p = 1.0). Of those with physician estimated prognosis of < 1 year, non-PPPC was more likely among patients with lower symptom burden- number and severity (both p ≤.001), without completed advance directive (p=.001). Among those with physician prognosis estimate > 1 year, no patient characteristic was associated with PPPC or non-PPPC. CONCLUSIONS AND RELEVANCE: Non-PPPC between HF patients and their physicians is high. HF patients are more optimistic than clinicians in estimating life expectancy. These data demonstrate there are opportunities to improve the quality of prognosis disclosure between patients with advanced HF and their physicians. Interventions to improve PPPC might include serious illness communication training.

Prevention and Early Recognition of Complications During Catheter Ablation by Intracardiac Echocardiography.

The effective diagnosis and management of procedural complications remains an important challenge for electrophysiology operators. Intracardiac echocardiography provides a real-time imaging modality with spectral and color Doppler capabilities that integrates directly with electroanatomic mapping systems. It provides detailed characterization of anatomic variants, which allows the operator to optimize the ablation strategy to the individual thereby avoiding the inherent risk of excessive or ineffective lesions. Complications, such as intracardiac thrombus or pericardial effusion, can be detected and managed before the onset of clinical symptoms. Intracardiac echocardiography facilitates the diagnosis and management of intraoperative hypotension.

Progression of infarct-mediated arrhythmogenesis in a rodent model of heart failure.

Heart failure (HF) post-myocardial infarction (MI) presents with increased vulnerability to monomorphic ventricular tachycardia (mmVT). To appropriately evaluate new therapies for infarct-mediated reentrant arrhythmia in the preclinical setting, chronologic characterization of the preclinical animal model pathophysiology is critical. This study aimed to evaluate the rigor and reproducibility of mmVT incidence in a rodent model of HF. We hypothesize a progressive increase in the incidence of mmVT as the duration of HF increases. Adult male Sprague-Dawley rats underwent permanent left coronary artery ligation or SHAM surgery and were maintained for either 6 or 10 wk. At end point, SHAM and HF rats underwent echocardiographic and invasive hemodynamic evaluation. Finally, rats underwent electrophysiologic (EP) assessment to assess susceptibility to mmVT and define ventricular effective refractory period (ERP). In 6-wk HF rats (n = 20), left ventricular (LV) ejection fraction (EF) decreased (P < 0.05) and LV end-diastolic pressure (EDP) increased (P < 0.05) compared with SHAM (n = 10). Ten-week HF (n = 12) revealed maintenance of LVEF and LVEDP (P > 0.05), (P > 0.05). Electrophysiology studies revealed an increase in incidence of mmVT between SHAM and 6-wk HF (P = 0.0016) and ERP prolongation (P = 0.0186). The incidence of mmVT and ventricular ERP did not differ between 6- and 10-wk HF (P = 1.0000), (P = 0.9831). Findings from this rodent model of HF suggest that once the ischemia-mediated infarct stabilizes, proarrhythmic deterioration ceases. Within the 6- and 10-wk period post-MI, no echocardiographic, invasive hemodynamic, or electrophysiologic changes were observed, suggesting stable HF. This is the necessary context for the evaluation of experimental therapies in rodent HF.NEW & NOTEWORTHY Rodent model of ischemic cardiomyopathy exhibits a plateau of inducible monomorphic ventricular tachycardia incidence between 6 and 10 wk postinfarction.

Modulating the Infarcted Ventricle's Refractoriness with an Epicardial Biomaterial.

Patients diagnosed with heart failure with reduced ejection fraction (HFrEF) are at increased risk of monomorphic ventricular tachycardia (VT) and ventricular fibrillation. The presence of myocardial fibrosis provides both anatomical and functional barriers that promote arrhythmias in these patients. Propagation of VT in a reentrant circuit depends on the presence of excitable myocardium and the refractoriness of the circuit. We hypothesize that myocardial refractoriness can be modulated surgically in a model of HFrEF, leading to decreased susceptibility to VT.Male Sprague-Dawley rats were infarcted via permanent left coronary artery ligation. At 3 weeks post-infarction, engineered grafts composed of human dermal fibroblasts cultured into a polyglactin-910 biomaterial were implanted onto the epicardium to cover the area of infarction. Three weeks post-graft treatment, all rats underwent a terminal electrophysiologic study to compare monophasic action potential electroanatomic maps and susceptibility to inducible monomorphic VT.HFrEF rats (n=29) demonstrated a longer (p=0.0191) ventricular effective refractory period (ERP) and a greater (p=0.0394) VT inducibility compared with sham (n=7). HFrEF rats treated with the graft (n=12) exhibited no change in capture threshold (p=0.3220), but had a longer ventricular ERP (p=0.0029) compared with HFrEF. No statistically significant change in VT incidence was found between HFrEF rats treated with the graft and untreated HFrEF rats (p=0.0834).Surgical deployment of a fibroblast-containing biomaterial in a rodent ischemic cardiomyopathy model prolonged ventricular ERP as measured by programmed electrical stimulation. This hypothesis-generating study warrants additional studies to further characterize the antiarrhythmic or proarrhythmic effects of this novel surgical therapy.

Prognostic Awareness and Goals of Care Discussions Among Patients With Advanced Heart Failure.

BACKGROUND: Prognostic awareness (PA)-the understanding of limited life expectancy-is critical for effective goals of care discussions (GOCD) in which patients discuss their goals and values in the context of their illness. Yet little is known about PA and GOCD in patients with advanced heart failure (HF). This study aims to determine the prevalence of PA among patients with advanced HF and patient characteristics associated with PA and GOCD. METHODS: We assessed the prevalence of self-reported PA and GOCD using data from a multisite communication intervention trial among patients with advanced HF with an implantable cardiac defibrillator at high risk of death. RESULTS: Of 377 patients (mean age 62 years, 30% female, 42% nonwhite), 78% had PA. Increasing age was a negative predictor of PA (odds ratio, 0.95 [95% CI, 0.92-0.97]; P<0.01). No other patient characteristics were associated with PA. Of those with PA, 26% had a GOCD. Higher comorbidities and prior advance directives were associated with GOCD but were of only borderline statistical significance in a fully adjusted model. Symptom severity (odds ratio, 1.77 [95% CI, 1.19-2.64]; P=0.005) remained a robust and statistically significant positive predictor of having a GOCD in the fully adjusted model. CONCLUSIONS: In a sample of patients with advanced HF, the frequency of PA was high, but fewer patients with PA discussed their end-of-life care preferences with their physician. Improved efforts are needed to ensure all patients with advanced HF have an opportunity to have GOCD with their doctors. Clinicians may need to target older patients with HF and continue to focus on those with signs of worsening illness (higher symptoms). Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01459744.

Evaluation of a Novel Educational Intervention to Improve Conversations About Implantable Cardioverter-Defibrillators Management in Patients with Advanced Heart Failure.

Background: Implantable cardioverter-defibrillators (ICDs) reduce the incidence of sudden cardiac death for high-risk patients with heart failure (HF), but shocks from these devices can also cause pain and anxiety at the end of life. Although professional society recommendations encourage proactive discussions about ICD deactivation, clinicians lack training in conducting these conversations, and they occur infrequently. Methods: As part of a six-center randomized controlled trial, we evaluated the educational component of a multicomponent intervention shown to increase conversations about ICD deactivation by clinicians who care for a subset of patients with advanced HF. This consisted of a 90-minute training workshop designed to improve the quality and frequency of conversations about ICD management. To characterize its utility as an isolated intervention, we compared HF clinicians' pre- and postworkshop scores (on a 5-point Likert scale) assessing self-reported confidence and skills in specific practices of advance care planning, ICD deactivation discussions, and empathic communication. Results: Forty intervention-group HF clinicians completed both pre- and postworkshop surveys. Preworkshop scores showed high baseline levels of confidence (4.36, standard deviation [SD] = 0.70) and skill (4.08, SD = 0.72), whereas comparisons of pre- and postworkshop scores showed nonsignificant decreases in confidence (-1.16, p = 0.252) and skill (-0.20, p = 0.843) after the training session. Conclusions: Our findings showed no significant changes in self-assessment ratings immediately after the educational intervention. However, our data did demonstrate that HF clinicians had high baseline self-perceptions of their skills in advance care planning conversations and appear to be well-primed for further professional development to improve communication in the setting of advanced HF.

Improving Communication in Heart Failure Patient Care.

BACKGROUND: Although implantable cardioverter-defibrillators (ICDs) reduce sudden death, these patients die of heart failure (HF) or other diseases. To prevent shocks at the end of life, clinicians should discuss deactivating the defibrillation function. OBJECTIVES: The purpose of this study was to determine if a clinician-centered teaching intervention and automatic reminders increased ICD deactivation discussions and increased device deactivation. METHODS: In this 6-center, single-blinded, cluster-randomized, controlled trial, primary outcomes were proportion of patients: 1) having ICD deactivation discussions; and 2) having the shocking function deactivated. Secondary outcomes included goals of care conversations and advance directive completion. RESULTS: A total of 525 subjects were included with advanced HF who had an ICD: 301 intervention and 224 control. At baseline, 52% (n = 272) were not candidates for advanced therapies (i.e., cardiac transplant or mechanical circulatory support). There were no differences in discussions (41 [14%] vs. 26 [12%]) or deactivation (33 [11%] vs. 26 [12%]). In pre-specified subgroup analyses of patients who were not candidates for advanced therapies, the intervention increased deactivation discussions (32 [25%] vs. 16 [11%]; odds ratio: 2.90; p = 0.003). Overall, 99 patients died; there were no differences in conversations or deactivations among decedents. SECONDARY OUTCOMES: Among all participants, there was an increase in goals of care conversations (47% intervention vs. 38% control; odds ratio: 1.53; p = 0.04). There were no differences in completion of advance directives. CONCLUSIONS: The intervention increased conversations about ICD deactivation and goals of care. HF clinicians were able to apply new communication techniques based on patients' severity of illness. (An Intervention to Improve Implantable Cardioverter-Defibrillator Deactivation Conversations [WISDOM]; NCT01459744).

Monophasic action potential amplitude for substrate mapping.

Although radiofrequency ablation has revolutionized the management of tachyarrhythmias, the rate of arrhythmia recurrence is a large drawback. Successful substrate identification is paramount to abolishing arrhythmia, and bipolar voltage electrogram's narrow field of view can be further reduced for increased sensitivity. In this report, we perform cardiac mapping with monophasic action potential (MAP) amplitude. We hypothesize that MAP amplitude (MAPA) will provide more accurate infarct sizes than other mapping modalities via increased sensitivity to distinguish healthy myocardium from scar tissue. Using the left coronary artery ligation Sprague-Dawley rat model of ischemic heart failure, we investigate the accuracy of in vivo ventricular epicardial maps derived from MAPA, MAP duration to 90% repolarization (MAPD90), unipolar voltage amplitude (UVA), and bipolar voltage amplitude (BVA) compared with gold standard histopathological measurement of infarct size. Numerical analysis reveals discrimination of healthy myocardium versus scar tissue using MAPD90 (P = 0.0158) and UVA (P < 0.001, n = 21). MAPA and BVA decreased between healthy and border tissue (P = 0.0218 and 0.0015, respectively) and border and scar tissue (P = 0.0037 and 0.0094, respectively). Contrary to our hypothesis, BVA mapping performed most accurately regarding quantifying infarct size. MAPA mapping may have high spatial resolution for myocardial tissue characterization but was quantitatively less accurate than other mapping methods at determining infarct size. BVA mapping's superior utility has been reinforced, supporting its use in translational research and clinical electrophysiology laboratories. MAPA may hold potential value for precisely distinguishing healthy myocardium, border zone, and scar tissue in diseases of disseminated fibrosis such as atrial fibrillation.NEW & NOTEWORTHY Monophasic action potential mapping in a clinically relevant model of heart failure with potential implications for atrial fibrillation management.

aVR ST Segment Elevation: Acute STEMI or Not? Incidence of an Acute Coronary Occlusion.

BACKGROUND: Identification of ST elevation myocardial infarction (STEMI) is critical because early reperfusion can save myocardium and increase survival. ST elevation (STE) in lead augmented vector right (aVR), coexistent with multilead ST depression, was endorsed as a sign of acute occlusion of the left main or proximal left anterior descending coronary artery in the 2013 STEMI guidelines. We investigated the incidence of an acutely occluded coronary in patients presenting with STE-aVR with multilead ST depression. METHODS: STEMI activations between January 2014 and April 2018 at the University of Arizona Medical Center were identified. All electrocardiograms (ECGs) and coronary angiograms were blindly analyzed by experienced cardiologists. Among 847 STEMI activations, 99 patients (12%) were identified with STE-aVR with multilead ST depression. RESULTS: Emergent angiography was performed in 80% (79/99) of patients. Thirty-six patients (36%) presented with cardiac arrest, and 78% (28/36) underwent emergent angiography. Coronary occlusion, thought to be culprit, was identified in only 8 patients (10%), and none of those lesions were left main or left anterior descending occlusions. A total of 47 patients (59%) were found to have severe coronary disease, but most had intact distal flow. Thirty-two patients (40%) had mild to moderate or no significant disease. However, STE-aVR with multilead ST depression was associated with 31% in-hospital mortality compared with only 6.2% in a subgroup of 190 patients with STEMI without STE-aVR (p<0.00001). CONCLUSIONS: STE-aVR with multilead ST depression was associated with acutely thrombotic coronary occlusion in only 10% of patients. Routine STEMI activation in STE-aVR for emergent revascularization is not warranted, although urgent, rather than emergent, catheterization appears to be important.