Management of cardiogenic shock complicating acute myocardial infarction: A review

Despite advances in percutaneous coronary interventions and their widespread use, mortality in patients presenting with acute myocardial infarction (MI) complicated by cardiogenic shock (CS) has remained very high, and treatment options are limited. Limited evidences exist, supporting many of the routinely used therapies in treating these patients. In the present article, we discuss CS complicating MI in general and an update on the currently available treatment options, including inotropes and vasopressor, coronary revascularization, mechanical circulatory support devices, mechanical complications, and long‐term outcomes.

Estrogen Alters the Synaptic Distribution of Phospho-GluN2B in the Dorsolateral Prefrontal Cortex While Promoting Working Memory in Aged Rhesus Monkeys

Age- and menopause-related deficits in working memory can be partially restored with estradiol replacement in women and female nonhuman primates. Working memory is a cognitive function reliant on persistent firing of dorsolateral prefrontal cortex (dlPFC) neurons that requires the activation of GluN2B-containing glutamate NMDA receptors. We tested the hypothesis that the distribution of phospho-Tyr1472-GluN2B (pGluN2B), a predominant form of GluN2B seen at the synapse, is sensitive to aging or estradiol treatment and coupled to working memory performance. First, ovariectomized young and aged rhesus monkeys (Macaca mulatta) received long-term cyclic vehicle (V) or estradiol (E) treatment and were tested on the delayed response (DR) test of working memory. Then, serial section electron microscopic immunocytochemistry was performed to quantitatively assess the subcellular distribution of pGluN2B. While the densities of pGluN2B immunogold particles in dlPFC dendritic spines were not different across age or treatment groups, the percentage of gold particles located within the synaptic compartment was significantly lower in aged-E monkeys compared to young-E and aged-V monkeys. On the other hand, the percentage of pGluN2B gold particles in the spine cytoplasm was decreased with E treatment in young, but increased with E in aged monkeys. In aged monkeys, DR average accuracy inversely correlated with the percentage of synaptic pGluN2B, while it positively correlated with the percentage of cytoplasmic pGluN2B. Together, E replacement may promote cognitive health in aged monkeys, in part, by decreasing the relative representation of synaptic pGluN2B and potentially protecting the dlPFC from calcium toxicity.

Synaptic distributions of pS214-tau in rhesus monkey prefrontal cortex are associated with spine density, but not with cognitive decline

Female rhesus monkeys and women are subject to age- and menopause-related deficits in working memory, an executive function mediated by the dorsolateral prefrontal cortex (dlPFC). Long-term cyclic administration of 17β-estradiol improves working memory, and restores highly plastic axospinous synapses within layer III dlPFC of aged ovariectomized monkeys. In this study, we tested the hypothesis that synaptic distributions of tau protein phosphorylated at serine 214 (pS214-tau) are altered with age or estradiol treatment, and couple to working memory performance. First, ovariectormized young and aged monkeys received vehicle or estradiol treatment, and were tested on the delayed response (DR) test of working memory. Serial section electron microscopic immunocytochemistry was then performed to quantitatively assess the subcellular synaptic distributions of pS214-tau. Overall, the majority of synapses contained pS214-tau immunogold particles, which were predominantly localized to the cytoplasm of axon terminals. pS214-tau was also abundant within synaptic and cytoplasmic domains of dendritic spines. The density of pS214-tau immunogold within the active zone, cytoplasmic, and plasmalemmal domains of axon terminals, and subjacent to the postsynaptic density within the subsynaptic domains of dendritic spines, were each reduced with age. None of the variables examined were directly linked to cognitive status, but a high density of pS214-tau immunogold particles within presynaptic cytoplasmic and plasmalemmal domains, and within postsynaptic subsynaptic and plasmalemmal domains, accompanied high synapse density. Together, these data support a possible physiological, rather than pathological, role for pS214-tau in the modulation of synaptic morphology in monkey dlPFC.

The Portico transcatheter aortic valve for the treatment of severe aortic stenosis

The Portico TAVI system (Abbott Vascular, Santa Clara, CA, USA) has been specifically designed to mitigate some of the complications associated with first-generation valves. Most of the data generated from randomized studies comparing transcatheter aortic valve implantation with surgery stem from reported experiences with first generation transcatheter heart valve devices. The aim of this review is to describe the repositionable and retrievable Portico system and its implantation technique, coupled with our single-center experience and to provide a review of the clinical results reported so far in the literature.

Effects of estrogen and aging on synaptic morphology and distribution of phosphorylated Tyr1472 NR2B in the female rat hippocampus

Age and estrogens may impact the mobility of N-methyl-D-aspartate receptors (NMDARs) in hippocampal synapses. Here, we used serial section immunogold electron microscopy to examine whether phosphorylated tyrosine 1472 NR2B (pY1472), which is involved in the surface expression of NMDARs, is altered in the dorsal hippocampus of young (3-4 months old) and aged (∼24 months old) ovariectomized rats treated with 17β-estradiol or vehicle for 2 days. The number of gold particles labeling pY1472 was higher in presynaptic and postsynaptic compartments of aged rats with low estradiol (vehicle-treated) compared to other groups. In terminals, pY1472 levels were elevated in aged rats but reduced by estradiol treatment to levels seen in young rats. Conversely, the mitochondria number was lower in aged females but was restored to young levels by estradiol. In the postsynaptic density and dendritic spines, estradiol reduced pY1472 in young and aged rats. As phosphorylation at Y1472 blocks NR2B endocytosis, reduction of pY1472 by estradiol suggests another mechanism through which estrogen enhances synaptic plasticity by altering localization of NMDAR subunits within synapses.

Evolution of Procedural and Clinical Outcomes After Balloon-Expanding Transcatheter Aortic Valve Implantation In Canada (from the Early Canadian Experience and SOURCE XT Registries)

Transcatheter aortic valve implantation (TAVI) has evolved globally, yet its evolution and performance across the Canadian landscape have yet to be formally assessed. Patients captured within the early Canadian TAVI experience with a balloon-expanding valve (n = 339; 2005 to 2009) and those enrolled in the Canadian SOURCE XT registry (n = 415; 2012 to 2015) were systematically compared with respect to baseline clinical, echocardiographic, and procedural characteristics. Valve-related and clinical outcomes were compared across the 2 time periods according to standardized definitions. Notable baseline between-group differences were noted across time, with Society of Thoracic Surgeons Predicted Risk of Mortality score being lower in the SOURCE XT cohort compared with the earlier Canadian cohort (7.4 ± 6.6% vs 9.8 ± 6.4%, p <0.001). The SOURCE XT cohort underwent TAVI through the transfemoral approach more frequently than their earlier Canadian counterparts (75% vs 48%), at the expense of transapical access, with major access site vascular complications (2.7% vs 13%), and ≥mild residual aortic regurgitation (39% vs 69%) being significantly less frequent (p <0.001 for all). At 30-days, there were no significant differences in rates of stroke (1.9% vs 2.4%) or new pacemakers (5.8% vs 5.0%); however, 30-day and 1-year mortality rates were significantly lower in the SOURCE XT cohort (3.6% vs 10.4%; 13.0% vs 24.2%, respectively, p<0.001 for both). In conclusion, TAVIs evolution in Canada with a balloon-expanding valve coincided with more optimized patient selection and increasing use of transfemoral access, which along with increasing operator experience, contributed to improved procedural and longer term clinical outcomes.

Transcatheter Treatment of Bicuspid Aortic Valve Disease: Imaging and Interventional Considerations

Patients with bicuspid aortic valve disease have systematically been excluded from large randomized clinical trials investigating transcatheter aortic valve implantation (TAVI) due to their younger age, lower surgical risk and complex aortic anatomy. The asymmetric nature of the bicuspid valve orifice often accompanied by heavy regional calcification has led to concerns regarding valve positioning and expansion. Bicuspid aortic valve disease patients are at heightened risk of TAVI-related complications including coronary occlusion, aortic dissection and annular rupture, as well as the known risks of progressive aortopathy in these patients. These unique anatomical characteristics pose challenges for TAVI operators. However, with recent and ongoing refinements in implantation technique, improvements in pre-procedural imaging and iterations in device design, TAVI is emerging as a safe and feasible treatment option in this population. Paravalvular aortic regurgitation and high pacemaker rates have been the Achilles Heel for TAVI in bicuspid valve patients, yet newer generation devices are yielding promising results. Further studies are required before TAVI ultimately emerges as a viable option in low and intermediate surgical-risk patients with bicuspid valve disease. This review comprehensively summarizes the epidemiology, pathology and current evidence for TAVI in patients with bicuspid aortic valve disease. We also outline some practical tips for performing TAVI in these patients.

Prosthetic Mitral Surgical Valve in Transcatheter Aortic Valve Replacement Recipients: A Multicenter Analysis

OBJECTIVES

The aim of this study was to determine the prognosis and specific complications of patients with prosthetic mitral valves (PMVs) undergoing transcatheter aortic valve replacement (TAVR).

BACKGROUND

TAVR is performed relatively often in patients with PMVs, but specific risks are not well described.

METHODS

A multicenter analysis was conducted, including patients with severe symptomatic aortic stenosis who underwent TAVR at 10 centers. Patients' clinical characteristics and outcomes were evaluated according to the presence of a PMV.

RESULTS

The mean age of the study population (n = 2,414) was 81 ± 8 years, and 48.8% were men. A total of 91 patients (3.77%) had PMVs. They were more commonly women, younger, and had higher surgical risk. PMVs were implanted a median of 14 years before TAVR, and most patients had mechanical prostheses (73.6%). Eighty-six patients (94.5%) were on long-term vitamin K inhibitor therapy, and bridging antithrombotic therapy was administered in 59 (64.8%). TAVR device embolization occurred in 6.7% (vs. 3.3% in the non-PMV group; p = 0.127), in all instances when distance between the PMV and the aortic annulus was <7 mm. Mortality rates did not show a difference, but the rate of bleeding was higher in patients with PMV (24.2% vs. 16.1%; p = 0.041), even in those treated via the transfemoral approach (22.2% vs. 13.9%; p = 0.048). Indeed, bleeding complications, prior atrial fibrillation, chronic obstructive pulmonary disease, surgical risk, and New York Heart Association functional class were independent predictors of mortality.

CONCLUSIONS

TAVR presents similar mortality irrespective of the presence of a PMV. However, patients with PMVs had higher bleeding risk that was independently associated with higher mortality. Risk for valve embolization was relatively high, but it occurred only in patients with PMV-to-aortic annulus distances <7 mm.

Therapeutic Agents Targeting Cardiometabolic Risk for Preventing and Treating Atherosclerotic Cardiovascular Diseases

Targeting atherogenic lipoprotein levels with statins remains the current cornerstone of atherosclerotic cardiovascular disease (ACVD) management. In patients at high ACVD risk who cannot achieve the desired low-density lipoprotein (LDL) cholesterol target, the addition of compounds such as ezetimibe and proprotein subtilisin/kexin type-9 (PCSK9) inhibitors incrementally lowers cardiovascular risk. New glucose-lowering drugs such as glucacon-like peptide-1 receptor (GLP1R) agonists and sodium-glucose cotransporter-2 (SGLT2) inhibitors were also shown to improve cardiometabolic risk factors and provide cardiovascular benefits in patients with type 2 diabetes. Our objective is to review the role of these agents in the management of patients at high ACVD risk and introduce new and (re)-emerging drugs targeting atherogenic lipoproteins such as LDL (inclisiran, bempedoic acid, etc.), remnant-like particles (fibrates, volanesorsen, and angiopoietin-like protein-3 (ANGPTL3) inhibitors), and lipoprotein(a) (AKCEA-APO[A]L_RX ). The potential role of drugs targeting inflammation (canakinumab, methotrexate, and colchicine) in ACVD risk prevention/management will also be discussed.