Synthesis and reactivity of a heteroleptic magnesium hydride on a dearomatized picolyl-based NNN-chelator.

Heteroleptic magnesium hydrides are important for their stoichiometric and catalytic reduction chemistry. Their primary nucleophilic site is typically the hydride, while the ancillary ligands commonly used are mostly spectators. Chemically non-innocent ligands in comparison are rarely applied on MgH as their reactivity can be complex. Milstein et al. have recently reported Mg-mediated alkyne hydrogenation by using their metal-ligand cooperation (MLC) concept on a dearomatized picolyl-based PNP pincer that is non-innocent with a nucleophilic nature. A '(PNP)MgH' is noted as the active catalyst in hydrogenation but without structural validation. Inspired by the same, we report herein a novel NNN-chelator (MesL) with a dearomatized picolyl moiety and its well-defined MgH. Having two prominent nucleophilic sites, the present MgH shows metal-ligand competition while reacting with certain electrophiles. It also distinguishes nonpolar alkynes and polar carbonyls by cleanly inserting itself into the former but not the latter. The nucleophilicities of the two sites are also probed by DFT methods and compared with Milstein's (PNP)MgH. Although the present system shows no MLC-type H2 activation, the addition of a CS2 molecule in that way is realized.

In patients with NSTE-ACS and previous CABG, routine invasive vs. conservative management does not improve outcomes.

SOURCE CITATION: Kelham M, Vyas R, Ramaseshan R, et al. Non-ST-elevation acute coronary syndromes with previous coronary artery bypass grafting: a meta-analysis of invasive vs. conservative management. Eur Heart J. 2024;45:2380-2391. 38805681.

(CAAC)CuCl: A Competent Precatalyst for Carbonyl and Ester Hydrosilylation.

Cu-catalyzed carbonyl hydrosilylation involves a ligated "[(L)CuH]" as the active catalyst, where the ligand L has a crucial role toward the stability, stereoselectivity, and enhancement of the hydridicity. Strongly σ-donating N-heterocyclic carbenes (NHCs), their ring-expanded form, and an abnormal NHC as ligands have yielded robust and efficient Cu catalysts. However, cyclic(alkyl)(amino)carbenes (CAACs), despite being stronger σ-donors than NHCs and already having a salient Cu(I) chemistry, are yet to be reported as a similar ligand platform for this purpose. We establish here the familiar [(Me2CAAC)CuCl] as a powerful precatalyst in this regard. Additionally, it also catalyzes the more challenging ester hydrosilylation, which is a rare feat for a Cu catalyst. Apart from the stronger σ-donating ability, the more steric "openness" of CAACs than bulky NHCs also seems to be advantageous. To corroborate, three new (CAAC)CuCl complexes [(ArCH2,MeCAAC)CuCl] (Ar = Ph, 1-naphthyl, and 1-prenyl) are devised, where the effective steric around the copper is practically unaltered from the case of [(Me2CAAC)CuCl]. All three are equally active in carbonyl and ester hydrosilylation as [(Me2CAAC)CuCl]. Computation suggests the carbonyl insertion into a "(CAAC)Cu-H" as the rate-limiting step. To elucidate the involvement of a "(CAAC)CuH", "(PhCH2,MeCAAC)CuH" is generated in situ and is trapped as its BH3 adduct (PhCH2,MeCAAC)CuBH4.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery. METHODS: A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. STRUCTURE: Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines.

AIM: The "2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM Guideline for Perioperative Cardiovascular Management for Noncardiac Surgery" provides recommendations to guide clinicians in the perioperative cardiovascular evaluation and management of adult patients undergoing noncardiac surgery. METHODS: A comprehensive literature search was conducted from August 2022 to March 2023 to identify clinical studies, reviews, and other evidence conducted on human subjects that were published in English from MEDLINE (through PubMed), EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. STRUCTURE: Recommendations from the "2014 ACC/AHA Guideline on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery" have been updated with new evidence consolidated to guide clinicians; clinicians should be advised this guideline supersedes the previously published 2014 guideline. In addition, evidence-based management strategies, including pharmacological therapies, perioperative monitoring, and devices, for cardiovascular disease and associated medical conditions, have been developed.

Pericardial Decompression Syndrome: A Comprehensive Review of a Controversial Entity.

Pericardial decompression syndrome is an ambiguous clinical entity which has generated controversy regarding its existence. Following pericardial decompression, patients experienced clinical deterioration ranging in complications from pulmonary edema to death that could not be attributed to any other distinct clinical pathology. Multiple theories have suggested the pathophysiology behind pericardial decompression syndrome is related to preload-afterload mismatch following pericardial decompression, coronary microvascular ischemia, and stress from high adrenergic state. Our review aims to describe this syndrome by analyzing demographics, etiology of pericardial effusion, method of drainage, volume of pericardial fluid removed, time to decompensation, and clinical outcomes. A systematic review of MEDLINE/PubMed and Google Scholar literature databases were queried for case reports, case series, review articles, and abstracts published in English journals between 1983 and December 2022. Each author's interpretation of echocardiographic and/or pulmonary arterial catheterization data provided in the case reports was used to characterize ventricular dysfunction. Based on our inclusion criteria, 72 cases of pericardial decompression syndrome were included in our review. Our results showed that phenotypic heterogeneity was present based on echocardiographic findings of right/left or biventricular failure with similar proportions in each type of ventricular dysfunction. Time to decompensation was similar between immediate, subacute, and acute cases with presentation varying between hypoxic respiratory failure and shock. This review article highlights theories behind the pathophysiology, clinical outcomes, and therapeutic options in this high mortality condition.

Heteroleptic Magnesium n-Butyl on a Chemically Non-innocent 2-Anilidomethylpyridine Ligand Leading to Diverse Magnesium Hydrides.

Molecular magnesium hydrides and hydride-rich clusters are of significant interest for applications ranging from catalysis and small molecule activation to hydrogen storage. Here, we investigate the 2-anilidomethylpyridine framework NNL as an ancillary support for magnesium organometallics with a special emphasis on hydrides. The proligand NNLH (N-[2,6-bis(1-methylethyl)phenyl]-α,6-diphenyl-2-pyridinemethanamine) gives [(NNL)Mg(nBu)(thf)] (1) by nbutane elimination from Mg(nBu)2(thf)n. A stronger donor such as DMAP replaces the THF from 1 to give [(NNL)Mg(nBu)(dmap)] (2). Both are air-sensitive, and 1 is adventitiously oxidized into [(NNL)Mg(µ-OnBu)]2 (32). The homoleptic [(NNL)2Mg] (8) is made from 1 and a second equiv of NNLH. 1's terminal nBu group is selectively protonated by HN(SiMe3)2 to give [(NNL)MgHMDS] (4; HMDS = N(SiMe3)2), whereas Ph3SiOH partially protonates the backbone anilide as well to give a mixture of [(NNL)Mg(OSiPh3)(thf)] (5) and free NNLH. Like HN(SiMe3)2, aprotic MeOTf also reacts by selectively abstracting the nBu group from 1 to give [(NNL)Mg(µ:κ2-O,O'-OTf)(thf)]2 (62). Interestingly, screening the common synthetic routes for magnesium hydrides leads to diverse outcomes upon varying the Mg precursors and hydride sources. 1 and PhSiH3 give the hydride cluster [{(NNL)2Mg2(µ-H)}2(µ-H)4Mg] (7), whereas 2 and PhSiH3 give the molecular complex [(NNLde)Mg(dmap)2] (9) with a dearomatized pyridyl backbone. 1 and HBpin (pinacolborane) give a product mixture, from which a different hydride cluster [(NNL)2Mg2(µ-H)}2(µ:κ2-O,O'-O2C2Me4)] (10) is identified, showing a rare instance of complete deborylation of a HBpin molecule. 1 and HBcat (catecholborane) also give a product mixture, one of which is the borylated ligand [(NNL)Bcat] (11). HBpin with 4 as the Mg precursor takes the ligand borylation route more selectively to give [(NNL)Bpin] (12). Last, 1 reacts with iPrNH2BH3 to give [(NNL)Mg{NH(iPr)BH3}] (13), which shows a slow and fractional conversion into the dinuclear mixed hydrido amidoborane [(NNL)2Mg2(µ-H){(µ-NH(iPr)BH3}] (14) by partial ß-hydride elimination. In comparison, [(NNL)Mg(iPrNHBH3)(dmap)] (15) arising from the DMAP-bound 2 and iPrNH2BH3 is stable toward such elimination.

Racial disparities in trend, clinical characteristics and outcomes in Takotsubo syndrome.

INTRODUCTION: Takotsubo syndrome (TTS) is an acute transient nonischemic cardiomyopathy often characterized by its hallmark feature of left ventricular apical ballooning. The correlation between racial backgrounds and the prognosis of individuals with TTS remains poorly defined. Our study aimed to explore the influence of race on the trends, clinical presentations, and outcomes in patients diagnosed with TTS. METHODS: We queried the National Inpatient Sample (NIS) database from 2016 to 2020 and identified hospitalizations with TTS. We compared the clinical features and outcomes across three different races - non-Hispanic White (NHW), non-Hispanic Black (NHB), and Hispanic population. The primary outcome was in-hospital mortality. RESULTS: 76,505 weighted hospitalizations for TTS were identified, of which 65,495 (85.6%) were non-Hispanic White, 5,830 (7.6%) were non-Hispanic Black, and 5,180 (6.8%) were Hispanics. After propensity-score matching, NHB patients had higher odds of acute kidney injury (OR: 1.49, 95% CI: 1.21-1.84, p < 0.001) and mechanical ventilation (OR: 1.33, 95% CI: 1.04-1.68, p = 0.02). Hispanic patients had a higher incidence of acute kidney injury requiring dialysis when compared to NHW patients (OR: 2.53, 95% CI: 1.11-5.77, p = 0.027). There was no significant difference in terms of in-hospital mortality between NHB and Hispanic patients when compared to NHW patients. Notably, Hispanic populations experienced a higher mortality rate during the COVID-19 period. CONCLUSION: Our study suggested significant differences in the outcomes of TTS across different racial groups. Hispanic populations experienced a higher mortality rate with TTS during the COVID-19 era. Further research should emphasize discovering the factors contributing to the observed disparities.

The Prevalence of Internet Use as a Source of Information Among Patients With Hypertension.

Background and objective The incidence of hypertension is growing at an alarming rate globally. In the United States, nearly half of the adult population suffers from hypertension, a disease potentially associated with long-term dire consequences and comorbidities. While Internet access has proliferated, and free Internet-based education resources for healthy lifestyles have exponentially increased over the past two decades, little is known about whether Internet-based information can be or is used as a self-learning tool for hypertension management in a community setting. With almost no published data, if and to what degree Internet-based, self-directed learning tools are used for hypertension management needs to be assessed. In light of this, we aimed to evaluate the prevalence of Internet use as a source of information in patients with known diagnoses of hypertension who presented to our Internal Medicine clinic at Texas Tech University Health Sciences Center, El Paso. Materials and methods We conducted a single-center, cohort-based observational study at our teaching hospital's internal medicine clinic. A survey questionnaire was distributed to all adults aged more than 18 years with a known diagnosis of hypertension. Consent for participation was obtained from all participants. Of the total studied population, 93.6% (190/203) were of Hispanic descent. Moreover, 67.5% (137/203) identified as female. Of note, 22.7% (46/203) reported using the Internet to learn about hypertension. Internet users were younger, with a mean age of 61.4 years compared to 68.7 (p=0.02) years for non-Internet users, attended institutions of a higher grade of education, and mostly received information regarding hypertension from their families (91.3% vs 2.5%, p<0.001). While most patients used the Internet for making treatment decisions and were satisfied with their choices, more than a quarter felt confused and anxious after using Internet-based resources. Results Most patients in the study were found to not use the Internet as a resource tool for hypertension management (157/203; 77.3%). Among the 22.7% of patients who used the Internet for hypertension management, the most commonly utilized resource was Google.com, as an initial step to hypertension research (26/46, 58.6%, p<0.001), followed by multiple resources within a predetermined list on the provided survey (14/46, 30.4%). The survey also assessed the reasons for using Internet-based resources, with the primary reason being evaluating treatment options (19/46, 41.5%), followed by developing coping skills (13/46, 28.2%), and lastly aiding in decision-making (10/46, 21.5%). Conclusions Internet-based educational tools are mushrooming as the Internet is becoming more pervasive. This study shows that within this predominant Hispanic population, nearly one-quarter of patients with hypertension are using Internet-based, self-learning tools. This highlights a slow shift in medical education which providers have to be prepared for as patients will be using these tools as secondary information sources for medical decision-making more frequently going forward. Further studies need to be conducted to evaluate the current and longitudinal impact of these new information sources.

Sex Differences and Clinical Outcomes in Patients With Myocardial Infarction With Nonobstructive Coronary Arteries: A Meta-Analysis.

BACKGROUND: Although myocardial infarction with nonobstructive coronary arteries (MINOCA) is more common in women, it is unknown whether sex is a risk factor for adverse outcomes in patients with MINOCA. We aimed to investigate the relationship between sex differences and outcomes of patients with MINOCA. METHODS AND RESULTS: A systematic literature search was performed in PubMed, Embase, and Cochrane databases from their inception until August 2023 for relevant studies. End points were pooled using the Hartung-Knapp-Sidik-Jonkman random-effects model as odds ratio (OR) with 95% CIs. Nine studies, involving 30 281 patients with MINOCA (comprising 18 079 women and 12 202 men), were included in the study. Women were older and had a higher prevalence of hypertension, diabetes, and stroke compared with men. The median duration of follow-up was 3.5 years, with an interquartile range of 2.2 to 4.2 years. Pooled analysis revealed no statistically significant difference in the risk of all-cause mortality (OR, 1.03 [95% CI, 0.87-1.22]), major adverse cardiovascular events (OR, 1.18 [95% CI, 0.89-1.58]), heart failure (OR, 1.32 [95% CI, 0.57-3.03]), stroke (OR, 1.13 [95% CI, 0.56-2.26]), and myocardial infarction (OR, 1.04 [95% CI, 0.29-3.76]) between the 2 groups. Regarding short-term outcomes, women had a significantly higher risk of in-hospital major adverse cardiovascular events compared with men (OR, 1.33 [95% CI, 1.16-1.53]) whereas there was no significant difference in the risk of in-hospital mortality (OR, 0.90 [95% CI, 0.64-1.28]) between the 2 patient groups. CONCLUSIONS: Despite the differences in demographics and comorbidity profiles, there was no significant difference in the long-term outcomes for patients with MINOCA between sexes. However, it is noteworthy that women experienced a higher risk of in-hospital major adverse cardiovascular events compared with men.

Anticoagulation in the Management of Acute Pulmonary Embolism-A Review.

Venous thromboembolism (VTE) is a very frequent cardiovascular entity that encompasses deep vein thrombosis and pulmonary embolism (PE). This last entity represents a major cause of cardiovascular morbidity and mortality. The incidence of PE and the rate of PE-related morbidity significantly increase with age, race, and underlying medical conditions, such as malignancy. Given the recent advances in diagnostic strategies and algorithms, patients can be risk assessed and treated promptly to avoid disease progression. Anticoagulation is the mainstay of treatment for acute PE that is not hemodynamically unstable. Direct oral anticoagulants, such as apixaban, rivaroxaban, or edoxaban, are currently the preferred agents for the treatment of patients who present with acute PE or for long-term treatment. Treatment duration should be continued for at least 3 months, and all patients should be assessed for extended duration of therapy based on the precipitating factors that led to the development of the VTE. Novel anticoagulant agents targeting factor XI/XIa are currently being investigated in phases 2 and 3 clinical trials, representing an attractive option in anticoagulation therapies in patients with VTE. For hemodynamically unstable patients, systemic thrombolysis is the treatment of choice, and it may also be of benefit-in reduced dose-for patients with intermediate to high risk who are at risk of hemodynamic collapse.

After stent implantation for ACS, ticagrelor monotherapy after <1 mo of DAPT vs. 12 mo of DAPT improved 1-y net clinical benefit.

SOURCE CITATION: Hong SJ, Lee SJ, Suh Y, et al; T-PASS (Ticagrelor Monotherapy in Patients Treated With New-Generation Drug-Eluting Stents for Acute Coronary Syndrome) Investigators. Stopping aspirin within 1 month after stenting for ticagrelor monotherapy in acute coronary syndrome: the T-PASS randomized noninferiority trial. Circulation. 2024;149:562-573. 37878786.

Autoimmune Rheumatic Diseases and Outcomes Following Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis.

Autoimmune Rheumatic Diseases (AIRDs) are associated with increased cardiovascular mortality. However, the post-percutaneous coronary intervention (PCI) outcomes in this population present a research gap, given the limited and discordant findings in existing studies. We conducted a systematic review and meta-analysis to assess the relationship between AIRDs and clinical outcomes after PCI; 9 studies with 7,027,270 patients (126,914 with AIRD, 6,900,356 without AIRD) were included. The AIRD cohort was characterized by an older age, a predominantly female demographic, and a greater prevalence of hypertension and diabetes mellitus. Over a mean follow-up period of 4.6 ± 3.5 years, AIRD patients demonstrated significantly higher odds of all-cause mortality (odds ratio (OR) 1.45, 95% CI: 1.25-1.78, P < .001) and major adverse cardiovascular events (MACE) (OR 1.63, 95% CI: 1.01-2.62, P = .04) compared with non-AIRD patients. Sensitivity analysis using adjusted estimates, confirmed the higher all-cause mortality (hazard ratio 1.32, 95% CI: 1.05-1.64, P = .01). Patients with rheumatoid arthritis had a significantly elevated odds of all-cause mortality (OR 1.50, 95% CI: 1.27-1.77) and MACE (OR 1.18, 95% CI: 1.14-1.21). Our study demonstrated an association between AIRDs and suboptimal long-term outcomes post-PCI. Prospective studies are warranted to explore the risk factors of unfavorable prognoses in patients with AIRDs.

Fluorenyl-tethered N-heterocyclic carbene (NHC): an exclusive C-donor ligand for heteroleptic calcium and strontium chemistry.

Exclusive C-donating ligands are rarely used with kinetically labile heavier alkaline earths (Ca, Sr, Ba). We report herein the aptitude of a combination of NHC with fluorenyl connected by a flexible -(CH2)2- linker as a ligand support for heteroleptic Ca- and Sr-N(SiMe3)2 and iodides. The Ca-N(SiMe3)2 complex even catalyzes the intramolecular hydroamination of aminoalkenes to showcase the effectiveness of this ligand framework.