BACKGROUND: Noncardiac surgery (NCS) following percutaneous coronary intervention (PCI) with stenting is sometimes associated with major adverse cardiac events (MACEs). Second-generation drug-eluting stents (DES) were developed to decrease the incidence of MACE seen with bare metal and first-generation DES. METHODS: The medical records of all adult patients who underwent second-generation DES placement between July 29, 2008 and July 28, 2011 followed by NCS between September 22, 2008 and July 1, 2013 were reviewed. All episodes of MACE following surgery were recorded. RESULTS: A total of 282 patients (74.8% male) were identified who underwent NCS after PCI with second-generation DES. MACE occurred in 15 patients (5.3%), including 11 deaths. The incidence of MACE changed significantly with time from PCI to NCS: 17.1%, 10.0%, 0.0%, and 3.1% for patients undergoing NCS at 0–90, 91–180, 181–365, and ≥366 days, respectively. Compared with those having NCS ≥366 days after PCI, the odds ratio for MACE (95% confidence interval) was 6.4 (1.9 to 21.3) at 0–90 days and 3.4 (0.8 to 15.3) at 91–180 days. Seven days prior to NCS, 146 (52%) patients were on dual antiplatelet therapy (DAPT), 106 (38%) were on aspirin, and 30 (11%) did not receive antiplatelet therapy. Excessive surgical bleeding occurred in 19 cases (6.7%). While observed bleeding rates were lowest in those not receiving antiplatelet therapy, there were no statistically significant differences based on the presence or absence of antiplatelet therapy (3% [1/30] for no antiplatelet therapy compared to 6% [6/106] for aspirin monotherapy and 8% [12/146] for DAPT; Fisher exact test: P = .655). CONCLUSIONS: The incidence of MACE in patients with second-generation DES undergoing NCS was 5.3% and was highest in the first 180 days following DES implantation. The rate of excessive surgical bleeding was 6.7% with the highest observed rate in those on DAPT. However, differences by the presence or absence of antiplatelet therapy were not significant, and future large observational studies will be necessary to further define bleeding risk with continued DAPT.
Abstract 883: Alvocidib-mediated inhibition of CDK9 upregulates BIM via suppression of miR17-92
Abstract The positive-transcription elongation factor (P-TEFb) complex is critical in stimulating the transcription of non-abortive transcripts by RNA polymerase II. The CDK9/cyclin-T heterodimer comprises the P-TEFb complex and promotes transcription elongation through phosphorylation of serine 2 of the heptapeptide repeats of the c-terminal domain of RNA Polymerase II (RNAPII-CTD). Alvocidib, a potent CDK9 inhibitor, has been shown to suppress expression of MCL-1 and Myc mRNAs, and clinical pharmacodynamic data suggest that alvocidib's activity is primarily mediated through the suppression of MCL-1 mRNA and protein expression. In addition to MCL-1 suppression, we hypothesized that CDK9 inhibition affects other RNA Polymerase II target RNAs, such as microRNAs. Recently, it was reported that inhibition of bromodomain and extraterminal domain (BET) protein by JQ1 suppresses miR17-92 expression. miR17-92 negatively regulates expression of the pro-apoptotic BH3-only protein, BIM, leading to suppression of BIM expression, thereby decreasing the cells' ability to induce apoptosis. It was hypothesized that CDK9 kinase activity is key to miR17-92 expression and suppression of BIM expression and that targeting CDK9 would lead to a decrease in miR17-92, and increases in BIM. MV4-11, OCI-AML3, MOLM13, and THP1 AML cell lines were used to determine the effects of alvocidib treatment on microRNAs. RT-qPCR was utilized to determine microRNA expression levels of miR17-92 and mRNA levels of BIM and other markers. Protein changes were determined using standard gel electrophoresis and immunoblotting technique. CellTiter-Glo and Caspase-Glo were used for all cell viability and apoptosis assays interrogating alvocidib. With CDK9 inhibition mediated via alvocidib, a dose- and time-dependent decrease in miR17-92 expression in MV4-11, OCI-AML3, MOLM13, and THP1 cells was observed. A decrease was observed even 3 hours post-treatment, persisting for up to 24 hours. MicroRNA suppression following treatment ranged in magnitude, with a maximal effect of between 3.3 to 4.2-fold suppression, depending on the cell line and timepoint. This suppression coincided with an increase in BIM mRNA and protein expression in the MV4-11, OCI-AML3, and MOLM13 cells. However, BIM protein increase was not observed in THP1 cells. Maximal increase in BIM mRNA levels reached 5.4-fold in the MV4-11 cell line. Our data suggest that CDK9 inhibition suppresses RNA Polymerase II-mediated expression of miR17-92, which in turn leads to increased expression of BIM. Combined with MCL-1 reduction, increased BIM protein expression mediated by alvocidib leads to enhanced apoptosis. Taken together, the data provide additional understanding of CDK9 as a potential therapeutic target, and are consistent with the hypothesis that CDK9 activity is necessary for miR17-92 expression. Citation Format: Hillary Haws, Hubert F. Arokium, James L. Bogenberger, Adam Siddiqui-Jain, David J. Bearss, Raoul Tibes, Steven L. Warner, Clifford J. Whatcott. Alvocidib-mediated inhibition of CDK9 upregulates BIM via suppression of miR17-92 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 883.
Abstract 2144: Enhanced expression of β-catenin and Axl receptor tyrosine kinase in chronic lymphocytic leukemia (CLL) B-cells with co-culture on marrow stromal cells: Implications for drug resistance
Abstract Our study in CLL delineated a unique mechanism of how bone marrow stromal cells (BMSCs), may influence CLL B-cell signaling and drug resistance via modifying β-catenin and Axl status in leukemic cells. Purified primary CLL B-cells (n= 31) from previously untreated CLL patients were cultured alone or co-cultured with primary BMSCs from either normal individuals (n=23) or CLL patients (n=12) at a 50:1 ratio in AIMV medium. After 48 hours, separated CLL B-cells or BMSCs were examined by immunoprecipitation/Western blot analyses and real-time PCRs. We observed significant increases in expression of Axl at both mRNA and protein levels in CLL B-cells co-cultured with BMSCs compared to CLL B-cells cultured alone. We also detected significantly increased expression of β-catenin at the protein level in co-cultured CLL B-cells. But, we did not see any significant change in β-catenin or Axl expression in BMSCs co-cultured with CLL B-cells. The CLL B-cells from co-culture had an upregulation in downstream P-ERK-1/2 but no change in P-AKT(Ser473). High nuclear active-β-catenin and P-ERK-1/2 levels were also detected in co-cultured CLL B-cells. ERK associates with and inactivates GSK-3β resulting in the up-regulation of β-catenin. We next checked for P-GSK-3β(Ser9) in co-cultured CLL B-cells. Upregulation in P-GSK-3β(Ser9) suggests inactivation of GSK-3β and β-catenin accumulation in co-cultured CLL B-cells. Additionally, we determined the phosphorylation status of Axl in CLL B-cells in co-culture compared with cultured alone. There was no change either at Y702 or total tyrosine phosphorylation in CLL B cells. Thus, we assume that the role of Axl in co-cultured leukemic B-cells is independent of its kinase activity. Next we determined the effect of Axl inhibitor TP-0903 on CLL B-cells in co-culture vs cultured alone. Interestingly, both Axl and β-catenin expression levels were further upregulated in CLL B-cells exposed to TP-0903 compared to CLL B-cells without TP-0903 in co-culture, indicating possible roles for both Axl and β-catenin in stromal mediated CLL B-cell drug resistance. However, TP-0903 decreased P-Axl(Y702) as well as an Axl downstream mediator, P-Akt(S473) and reduced Mcl-1 expression in CLL B-cells even in presence of BMSCs. This was associated with induction of cell death and overrode BMSC mediated protection. Treatments of fludarabine or chlorambucil also led to increase in expressions of both β-catenin and Axl in co-cultured CLL B-cells. Moreover, inhibition of P-ERK-1/2 with inhibitor PD98059 in CLL B-cells cultured with BMSCs inhibited β-catenin as well as Axl expression levels. Here we show that stroma mediated increased expression in both β-catenin and Axl likely contribute to the survival and drug resistance of B-cells from patients with CLL. Understanding their role in drug metabolism is underway. Citation Format: Sutapa Sinha, Charla Secreto, Justin Boysen, Steven L. Warner, David J. Bearss, Asish Ghosh, Neil E. Kay. Enhanced expression of β-catenin and Axl receptor tyrosine kinase in chronic lymphocytic leukemia (CLL) B-cells with co-culture on marrow stromal cells: Implications for drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2144.
Anesthesia and the developing brain: A way forward for laboratory and clinical research
Summary All commonly used general anesthetics have been shown to cause neurotoxicity in animal models, including nonhuman primates. Opinion, however, remains divided over how cumulative evidence from preclinical and human studies in this field should be interpreted and its translation to current practices in pediatric anesthesia and surgery. A group of international experts in laboratory and clinical sciences recently convened in Genoa, Italy, to evaluate the current state of both laboratory and clinical research and discuss future directions for basic, translational, and clinical studies in this field. This paper describes those discussions and conclusions. A central goal identified was the importance of continuing to pursue laboratory research efforts to better understand the biological pathways underlying anesthesia neurotoxicity. The distinction between basic and translational experimental designs in this field was highlighted, and it was acknowledged that it will be important for future animal research to try to causally link structural changes with long‐term cognitive abnormalities. While inherent limitations will continue to affect the ability of even large observational cohorts to determine if anesthesia impacts neurodevelopment or behavioral outcomes, the importance of conducting further large well‐designed cohort studies was also emphasized. Adequately powered cohorts could clarify which populations are at increased risk, provide information on environmental and healthcare‐related risk modifiers, and guide future interventional trials. If anesthetics cause structural or functional adverse neurological effects in young children, alternative or mitigating strategies need to be considered. While protective or mitigating strategies have been repeatedly studied in animals, there are currently no human data to support alternative anesthetic strategies in clinical practice. Lastly, it was noted that there is still considerable debate over the clinical relevance of anesthesia neurotoxicity, and the need to evaluate the impact of other aspects of perioperative care on neurodevelopment must also be considered.
Feasibility of a Perioperative Text Messaging Smoking Cessation Program for Surgical Patients
Although surgical patients who smoke could benefit from perioperative abstinence, few currently receive support. This pilot study determined the feasibility and acceptability of a perioperative text messaging smoking cessation program. One hundred patients (73% of eligible patients approached) enrolled in a surgery-specific messaging service, receiving 1–3 daily messages about smoking and surgical recovery for 30 days. Only 17 patients unenrolled, the majority responded to prompting messages, and satisfaction with the program was high. Surgical patients are amenable to text message–based interventions; a future efficacy trial of text messaging smoking cessation support in surgical patients is warranted.
Endotracheal Tube Obstruction: Recognition and Management
ObjectiveTo evaluate circulating cytokine profiles in patients with antineutrophil cytoplasmic antibody–associated vasculitis (AAV), classified by antineutrophil cytoplasmic antibody (ANCA) specificity (proteinase 3 ANCA [PR3‐ANCA] versus myeloperoxidase ANCA [MPO‐ANCA]) or by clinical diagnosis (granulomatosis with polyangiitis [GPA] versus microscopic polyangiitis [MPA]).MethodsA panel of 29 cytokines was tested in 186 patients with active AAV at inclusion into the Rituximab in AAV trial. Cytokine concentrations were compared between groups within each classification system. Multivariable analyses adjusted for age, sex, and renal insufficiency were performed, with each biomarker as a dependent variable and ANCA specificity and clinical diagnosis as explanatory variables of interest.ResultsLevels of 9 circulating cytokines (interleukin‐6 [IL‐6], granulocyte–macrophage colony‐stimulating factor [GM‐CSF], IL‐15, IL‐18, CXCL8/IL‐8, CCL‐17/thymus and activation–regulated chemokine [TARC], IL‐18 binding protein [IL‐18 BP], soluble IL‐2 receptor α [sIL‐2Rα], and nerve growth factor β [NGFβ]) were significantly higher in PR3‐AAV than MPO‐AAV, 4 cytokines (sIL6R, soluble tumor necrosis factor receptor type II [sTNFRII], neutrophil gelatinase–associated lipocalin [NGAL], and soluble intercellular adhesion molecule 1 [sICAM‐1]) were higher in MPO‐AAV than in PR3‐AAV, 6 cytokines (IL‐6, GM‐CSF, IL‐15, IL‐18, sIL‐2Rα, and NGFβ) were higher in GPA than in MPA, and 3 cytokines (osteopontin, sTNFRII, and NGAL) were higher in MPA than in GPA (all P < 0.05). For nearly all cytokines, the difference between PR3‐AAV and MPO‐AAV was larger than that between GPA and MPA. The multivariate analysis showed that 8 cytokines (IL‐15, IL‐8, IL‐18 BP, NGF‐β, sICAM‐1, TARC, osteopontin, and kidney injury molecule 1 (P < 0.05) distinguished patients with AAV better (lower P values and larger effect sizes) when grouped by ANCA specificity than by clinical diagnosis.ConclusionDistinct cytokine profiles were identified for PR3‐AAV versus MPO‐AAV and for GPA versus MPA. Differences in these circulating immune mediators are more strongly associated with ANCA specificity than with clinical diagnosis, suggesting that heterogeneity in the AAV subtypes extends beyond clinical phenotypes.