Early Ventricular Arrhythmias After Left Ventricular Assist Device Implantation.

BACKGROUND: Although sustained ventricular arrhythmias (VAs) are a common complication after durable left ventricular assist device (LVAD) implantation, the incidence, risk factors, and prognostic implications of postoperative early VAs (EVAs) in contemporary patients with LVAD are poorly understood. METHODS AND RESULTS: A single-center retrospective analysis was performed of patients who underwent LVAD implantation from October 1, 2006, to October 1, 2022. EVA was defined as an episode of sustained VA identified ≤30 days after LVAD implantation. A total of 789 patients underwent LVAD implantation (mean age 62.9 ± 0. years 5, HeartMate 3 41.4%, destination therapy 43.3%). EVAs occurred in 100 patients (12.7%). A history of end-stage renal disease (odds ratio [OR] 5.6, 95% confidence interval [CI] 1.45-21.70), preoperative electrical storm (OR 2.82, 95% CI 1.11-7.16), and appropriate implantable cardiac defibrillator therapy before implantation (OR 2.8, 95% CI 1.26-6.19) are independently associated with EVAs. EVA was associated with decreased 30-day survival (hazard ratio 3.02, 95% CI 1.1-8.3, P = .032). There was no difference in transplant-free survival time between patients with and without EVAs (hazard ratio 0.82, 95% CI 0.5-1.4, P = .454). CONCLUSIONS: EVAs are common after durable LVAD implantation and are associated with an increased risk of 30-day mortality.

Review of Pathophysiology of Cardiogenic Shock and Escalation of Mechanical Circulatory Support Devices.

PURPOSE OF REVIEW: Cardiogenic shock (CS) is a complex clinical entity that continues to carry a high risk of mortality. The landscape of CS management has changed with the advent of several temporary mechanical circulatory support (MCS) devices designed to provide hemodynamic support. It remains challenging to understand the role of different temporary MCS devices in patients with CS, as many of these patients are critically ill, requiring complex care with multiple MCS device options. Each temporary MCS device can provide different types and levels of hemodynamic support. It is important to understand the risk/benefit profile of each one of them for appropriate device selection in patients with CS. RECENT FINDINGS: MCS may be beneficial in CS patients through augmentation of cardiac output with subsequent improvement of systemic perfusion. Selecting the optimal MCS device depends on several variables including the underlying etiology of CS, clinical strategy of MCS use (bridge to recovery, bridge to transplant or durable MCS, or abridge to decision), amount of hemodynamic support needed, associated respiratory failure, and institutional preference. Furthermore, it is even more challenging to determine the appropriate time to escalate from one MCS device to another or combine different MCS devices. In this review, we discuss the current available data published in the literature on the management of CS and propose a standardized approach for escalation of MCS devices in patients with CS. Shock teams can play an important role to help in hemodynamic-guided management and algorithm-based step-by-step approach in early initiation and escalation of temporary MCS devices at different stages of CS. It is important to define the etiology of CS, and stage of shock and recognize univentricular vs biventricular shock for appropriate device selection and escalation of therapy.

Frequency-specific medial septal nucleus deep brain stimulation improves spatial memory in MK-801-treated male rats.

BACKGROUND: Few treatments exist for the cognitive symptoms of schizophrenia. Pharmacological agents resulting in glutamate N-methyl-d-aspartate (NMDA) receptor hypofunction, such as MK-801, mimic many of these symptoms and disrupt neural activity. Recent evidence suggests that deep brain stimulation (DBS) of the medial septal nucleus (MSN) can modulate medial prefrontal cortex (mPFC) and hippocampal activity and improve spatial memory. OBJECTIVE: Here, we examine the effects of acute MK-801 administration on oscillatory activity within the septohippocampal circuit and behavior. We also evaluate the potential for MSN stimulation to improve cognitive behavioral measures following MK-801 administration. METHODS: 59 Sprague Dawley male rats received either acute intraperitoneal (IP) saline vehicle injections or MK-801 (0.1 mg/kg). Theta (5-12 Hz), low gamma (30-50 Hz) and high frequency oscillatory (HFO) power were analyzed in the mPFC, MSN, thalamus and hippocampus. Rats underwent MSN theta (7.7 Hz), gamma (100 Hz) or no stimulation during behavioral tasks (Novel object recognition (NOR), elevated plus maze, Barnes maze (BM)). RESULTS: Injection of MK-801 resulted in frequency-specific changes in oscillatory activity, decreasing theta while increasing HFO power. Theta, but not gamma, stimulation enhanced the anxiolytic effects of MK-801 on the elevated plus maze. While MK-801 treated rats exhibited spatial memory deficits on the Barnes maze, those that also received MSN theta, but not gamma, stimulation found the escape hole sooner. CONCLUSIONS: These findings demonstrate that acute MK-801 administration leads to altered neural activity in the septohippocampal circuit and impaired spatial memory. Further, these findings suggest that MSN theta-frequency stimulation improves specific spatial memory deficits and may be a possible treatment for cognitive impairments caused by NMDA hypofunction.

Right Ventricular Ejection Fraction and Beta-Blocker Effect in Heart Failure With Reduced Ejection Fraction.

BACKGROUND: A low right ventricular ejection fraction (RVEF) is a marker of poor outcomes in patients with heart failure with reduced ejection fraction (HFrEF). Beta-blockers improve outcomes in HFrEF, but whether this effect is modified by RVEF is unknown. METHODS AND RESULTS: Of the 2798 patients in Beta-Blocker Evaluation of Survival Trial (BEST), 2008 had data on baseline RVEF (mean 35%, median 34%). Patients were categorized into an RVEF of less than 35% (n = 1012) and an RVEF of 35% or greater (n = 996). We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) within each RVEF subgroup and formally tested for interactions between bucindolol and RVEF. The effect of bucindolol on all-cause mortality in 2008 patients with baseline RVEF (HR 0.88, 95% CI 0.75-1.02) is consistent with that in 2798 patients in the main trial (HR 0.90, 95% CI 0.78-1.02). Bucindolol use was associated with a lower risk of all-cause mortality in patients with an RVEF of 35% or greater (HR 0.70, 95% CI 0.55-0.89), but not in those with an RVEF of less than 35% (HR 1.02, 95% CI 0.83-1.24, P for interaction = .022). Similar variations were observed for cardiovascular mortality (P for interaction = .009) and sudden cardiac death (P for interaction = .018), but not for pump failure death (P for interaction = .371) or HF hospitalization (P for interaction = .251). CONCLUSIONS: The effect of bucindolol on mortality in patients with HFrEF was modified by the baseline RVEF. If these hypothesis-generating findings can be replicated using approved beta-blockers in contemporary patients with HFrEF, then RVEF may help to risk stratify patients with HFrEF for optimization of beta-blocker therapy.

In-Hospital Weight Loss and Outcomes in Patients With Heart Failure.

BACKGROUND: Acute decompensation of heart failure (HF) is often marked by fluid retention, and weight loss is a marker of successful diuresis. We examined the relationship between in-hospital weight loss and post-discharge outcomes in patients with HF. METHODS: We conducted a propensity score-matched study of 8830 patients hospitalized for decompensated HF in the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry, in which 4415 patients in the weight-loss group and 4415 patients in the no-weight-loss group were balanced on 75 baseline characteristics. We defined weight loss as an admission-to-discharge weight loss of 1-30 kilograms, and we defined no weight loss as a weight gain or loss of < 1 kilogram. Hazard ratios (HRs) and 95% confidence intervals (CIs) for outcomes associated with weight loss were estimated. RESULTS: Patients had a mean age of 78 years, 57% were women, and 11% were African American. The median weight loss in the weight-loss group was 3.6 (interquartile range, 2.0-6.0) kilograms. HRs and 95% CIs for 30-day all-cause mortality, all-cause readmission and HF readmission associated with weight loss were 0.75 (0.63-0.90), 0.90 (0.83-0.99) and 0.83 (0.72-0.96), respectively. Respective 60-day HRs (95% CIs) were 0.80 (0.70-0.92), 0.91 (0.85-0.98) and 0.88 (0.79-0.98). These associations were attenuated and lost significance during 6 months of follow-up. CONCLUSIONS: Among older patients hospitalized for decompensated HF, in-hospital weight loss was associated with a lower risk of mortality and hospital readmission. These findings suggest that in-hospital weight loss, a marker of successful diuresis and decongestion, is also a marker of improved clinical outcomes.

Beta-blockers and Ambulatory Inotropic Therapy.

BACKGROUND: Continuous infusion of ambulatory inotropic therapy (AIT) is increasingly used in patients with end-stage heart failure (HF). There is a paucity of data concerning the concomitant use of beta-blockers (BB) in these patients. METHODS: We retrospectively reviewed all patients discharged from our institution on AIT. The cohort was stratified into 2 groups based on BB use. The 2 groups were compared for differences in hospitalizations due to HF, ventricular arrhythmias and ICD therapies (shock or antitachycardia pacing). RESULTS: Between 2010 and 2017, 349 patients were discharged on AIT (95% on milrinone); 74% were males with a mean age of 61 ± 14 years. BB were used in 195 (56%) patients, whereas 154 (44%) did not receive these medications. Patients in the BB group had longer duration of AIT support compared to those in the non-BB group (141 [1-2114] vs 68 [1-690] days). After adjusting for differences in baseline characteristics and indication for AIT, patients in the BB group had significantly lower rates of hospitalizations due to HF (hazard ratio [HR] 0.61 (0.43-0.86); P = 0.005), ventricular arrhythmias (HR 0.34 [0.15-0.74]; P = 0.007) and ICD therapies (HR 0.24 [0.07-0.79]; P = 0.02). CONCLUSION: In patients with end-stage HF on AIT, the use of BB with inotropes was associated with fewer hospitalizations due to HF and fewer ventricular arrhythmias.

Outcomes in patients with smaller body surface area after HeartMate 3 left ventricular assist device implantation.

BACKGROUND: Due to anatomic and physiologic concerns, prior generations of the left ventricular assist devices (LVAD) have frequently been denied to patients with small body size. However, outcomes in patients with small body surface area (BSA) following HeartMate 3 (HM3) LVAD implantation remain relatively unknown. METHODS: A cohort of 220 patients implanted at a single center was divided into two groups: BSA ≤1.8 m2 (small BSA, n = 37) and BSA >1.8 m2 (large BSA, n = 183). We investigated baseline characteristics and clinical outcomes including survival and incidence of adverse events. RESULTS: Small BSA patients were older (60 vs. 57 years), more likely female (60% vs. 20%), had a lower body mass index (24 vs. 32 kg/m2 ), lower incidence of diabetes (32% vs. 51%), history of stroke (5% vs. 19%), and left ventricular thrombus (0% vs. 11%). They had smaller left ventricular end diastolic diameter (64.8 vs. 69.3 mm). Pump speed and pump flows at discharge were lower in the small BSA group. Survival at 1 year and 2 years was 86% versus 87% and 86% versus 79% for small versus large BSA groups (p = 0.408), respectively. The rates of adverse events were similar between groups and there were no cases of confirmed pump thrombosis. The incidence of readmissions for low flow alarms was higher in the small BSA group (0.55 vs. 0.24 EPPY). CONCLUSIONS: These findings demonstrate comparable outcomes in patients with small body size and suggest that this parameter should not be an exclusion criterion on patients who are otherwise candidates for HM3 LVAD implantation.

Ventricular fibrillation in a left ventricular assist device patient: Can the echocardiogram be misleading?

Sustained ventricular tachycardia and ventricular fibrillation (VF) are life-threatening arrhythmias which remain highly prevalent in patients with advanced heart failure. These ventricular arrhythmias may impair the support provided by continuous-flow left ventricular assist devices (CF-LVADs) and lead to frequent hospitalizations, antiarrhythmic medication use, external defibrillations, and need for heart transplantation. We report a case in which a patient with a CF-LVAD and an implantable cardioverter defibrillator at end of life presented with asymptomatic low-flow alarms and was found to have VF of unknown duration. Unique in our case was the presence of apparent organized contractility and rhythmic opening of the mitral valve on echocardiogram despite VF on electrocardiogram.

Edge-to-edge mitral repair for iatrogenic chordal rupture related to Impella 5.0.

Iatrogenic chordal rupture with severe mitral regurgitation is a rare but serious complication associated with the use of Impella device. We present a case of a 47-year-old man with ischemic cardiomyopathy who required insertion of an Impella 5.0 device. During Impella support, he developed acute pulmonary edema secondary to newly diagnosed posterior mitral valve chordal rupture and subsequent severe mitral regurgitation. He underwent implantation of a durable left ventricular assist device with concomitant edge-to-edge mitral valve repair through the apex.

Neuro-protection and neuro-regeneration of the optic nerve: recent advances and future directions.

PURPOSE OF REVIEW: Optic neuropathies refer to a collection of diseases in which retinal ganglion cells (RGCs), the specialized neuron of the retina whose axons make up the optic nerve, are selectively damaged. Blindness secondary to optic neuropathies is irreversible as RGCs do not have the capacity for self-renewal and have a limited capacity for self-repair. Numerous strategies are being developed to either prevent further RGC degeneration or replace the cells that have degenerated. In this review, we aim to discuss known limitations to regeneration in central nervous system (CNS), followed by a discussion of previous, current, and future strategies for optic nerve neuroprotection as well as approaches for neuro-regeneration, with an emphasis on developments in the past two years. RECENT FINDINGS: Neuro-regeneration in the CNS is limited by both intrinsic and extrinsic factors. Environmental barriers to axon regeneration can be divided into two major categories: failure to clear myelin and formation of glial scar. Although inflammatory scars block axon growth past the site of injury, inflammation also provides important signals that activate reparative and regenerative pathways in RGCs. Neuroprotection with neurotrophins as monotherapy is not effective at preventing RGC degeneration likely secondary to rapid clearance of growth factors. Novel approaches involve exploiting different technologies to provide sustained delivery of neurotrophins. Other approaches include application of anti-apoptosis molecules and anti-axon retraction molecules. Although stem cells are becoming a viable option for generating RGCs for cell-replacement-based strategies, there are still many critical barriers to overcome before they can be used in clinical practice. Adjuvant treatments, such as application of electrical fields, scaffolds, and magnetic field stimulation, may be useful in helping transplanted RGCs extend axons in the proper orientation and assist with new synapse formation. SUMMARY: Different optic neuropathies will benefit from neuro-protective versus neuro-regenerative approaches. Developing clinically effective treatments for optic nerve disease will require a collaborative approach that not only employs neurotrophic factors but also incorporates signals that promote axonogenesis, direct axon growth towards intended targets, and promote appropriate synaptogenesis.