Changes in platelet function with inflammation in patients undergoing vascular surgery

Does one size really fit all? The case for personalized antiplatelet therapy in interventional cardiology

Cardiovascular disease is the leading cause of death worldwide. Dual antiplatelet therapy (DAPT), with aspirin plus a P2Y12 inhibitor, is currently recommended as a default for patients after acute coronary syndrome (ACS) and following percutaneous coronary intervention (PCI). However, controversies arise over the role of aspirin, the optimal duration of DAPT after drug-eluting stent (DES) implantation, the choice of P2Y12 inhibitor and the variability in individual responses to antiplatelet agents. Recent data indicate that monotherapy with a P2Y12 inhibitor may have adequate anti-ischemic effects with lower bleeding risk. Additionally, discrepancies in DAPT duration recommendations and the optimal P2Y12 inhibitor, provides more uncertainty. We ask the question "does one size really fits all?" or should a more personalized strategy should be implemented.

Intensive mannitol slow infusion post-stenting may attenuate stenting-related early adverse effects in patients with cerebral venous sinus stenosis

AIMS

To analyze intensive slow mannitol poststenting on attenuating stenting-related early adverse effects in cerebral venous sinus stenosis (CVSS).

METHODS

This real-world study enrolled subacute or chronic CVSS patients from January 2017 through March 2022 and divided them into DSA only and stenting post-DSA groups. The later group was subdivided into control (without extra mannitol use) and intensive slow mannitol subgroup (immediate extra mannitol 250-500 mL, 2 mL/min infusion post-stenting) after signed informed consent. All data were compared.

RESULTS

A total of 95 eligible patients entered into final analysis, in which 37 cases underwent DSA only and 58 cases underwent stenting post-DSA. Finally, 28 patients were entered into intensive slow mannitol subgroup and 30 in control. Stenting group vs. DSA group, HIT-6 scores and WBC counts were higher in the former (both p < 0.001). Intensive slow mannitol subgroup vs. control on the third day post-stenting, a statistically significant reductions were noticed in the former on WBC counts (6.19 ± 1.86 × 109 /L vs. 9.59 ± 2.05 × 109 /L); HIT-6 scores (degree of headache) (40.00 (38.00-40.00) vs. 49.00 (41.75-55.25)) and brain edema surrounding the stent on CT maps (17.86% vs.96.67%), all p < 0.001.

CONCLUSIONS

Stenting-related severe headache, inflammatory biomarkers elevation, and brain edema aggravation can be attenuated by intensive slow mannitol infusion.

Postoperative myocardial injury and platelet reactivity in patients undergoing vascular surgery: The platelet reactivity and postoperative myocardial injury after major vascular surgery (PROMISE) study

BACKGROUND

Postoperative myocardial injury (PMI) after major vascular surgery, detected by elevated cardiac troponin (cTn), has been associated with morbidity and mortality. It is unclear whether the pathophysiology of PMI is determined by increased platelet activity.

OBJECTIVE

To examine the relationship between platelet activation (P-selectin expression) and PMI in patients undergoing elective open abdominal aortic surgery.

METHODS

This prospective, single-centre, observational, cohort study included 33 patients undergoing elective open abdominal aortic surgery between March 2018 and April 2021. Patients were routinely treated with aspirin. Unstimulated platelet activation was measured by platelet bound P-selectin expression (range 0-100 %). Explorative coagulation measurements were: stimulated platelet aggregation measured with the VerifyNow® assay (aspirin cartridge), with the Multiplate® analyzer (ASPI, ADP and TRAP) and stimulated coagulation status evaluated by the TEG® Hemostasis Analyzer System (global hemostasis cartridge). The primary outcome was cTn release assessed by the fifth generation high-sensitive cTn assay. Multivariable generalized linear mixed models were used to evaluate the association between platelet function and cTn concentrations over time.

RESULTS

Ten patients (30.3 %) developed PMI. Increased P-selectin expression directly after surgery was associated with the cTn concentrations over 48 h (β = 1.39 (1.1-1.75), P = 0.0064). No association was found between P-selectin measured later after surgery (at 24 h or 48 h) and cTn concentrations. Furthermore, there was no association between the explorative coagulation parameters and cTn release.

CONCLUSION

Platelet reactivity, assessed by P-selectin expression measured directly after surgery is associated with PMI, assessed by elevated cTn concentrations in the early postoperative period in patients undergoing elective open abdominal aortic surgery.

Dual Antiplatelet Therapy Discontinuation, Platelet Reactivity, and Adverse Outcomes After Successful Percutaneous Coronary Intervention

OBJECTIVES

The purpose of this study was to assess the extent to which the association between premature dual antiplatelet therapy (DAPT) discontinuation and excess risk of thrombotic events varies according to the reason and timing of DAPT discontinuation and whether high on-treatment platelet reactivity (HPR) influences the risk of thrombotic events after premature DAPT discontinuation.

BACKGROUND

DAPT after percutaneous coronary intervention (PCI) suppresses platelet reactivity, and HPR on clopidogrel after PCI is associated with an increased risk of thrombotic events.

METHODS

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of 8,582 patients successfully treated with coronary drug-eluting stents that assessed HPR on clopidogrel. For patients who discontinued aspirin or clopidogrel at any time during the study, the reasons for discontinuation were systematically categorized.

RESULTS

Planned DAPT discontinuation occurred within 2 years in 3,203 (37.3%) patients. One thousand four hundred eighteen (16.5%) patients discontinued DAPT for unplanned reasons, including surgery or trauma (n = 768 [8.9%]), patient nonadherence (n = 321 [3.7%]), bleeding complications (n = 264 [3.1%]), and drug allergy or hypersensitivity (n = 113 [1.3%]). Unplanned but not planned DAPT discontinuation was associated with an increased risk of a major adverse cardiac event (MACE, defined as the composite of cardiac death, myocardial infarction, or stent thrombosis); with highest risk within 3 months after PCI (adjusted HR: 7.65, 95% CI: 2.77-21.10 vs adjusted HR: 2.47, 95% CI: 1.70-3.58 for unplanned DAPT discontinuation ≥3 weeks after PCI). MACE risk after DAPT discontinuation was not moderated by HPR (P_interaction = 0.91).

CONCLUSIONS

In this large-scale all-comers registry, premature DAPT discontinuation for unplanned reasons occurred in approximately 1 of 6 patients after DES implantation and was associated with a markedly increased risk of MACEs. (Assessment of Dual AntiPlatelet Therapy With Drug Eluting Stents [ADAPT-DES]; NCT00638794).

Antisense overlapping long non-coding RNA regulates coding arachidonate 12-lipoxygenase gene by translational interference

The arachidonate 12-lipoxygenase (ALOX12) enzyme catalyzes polyunsaturated fatty acids and facilitates generation of bioactive lipid mediators associated with various biological processes and disease pathologies. The human genome assembly revealed that the ALOX12 gene overlaps an antisense non-coding gene designated as ALOX12-antisense 1 (ALOX12-AS1). This arrangement indicates that the uncharacterized ALOX12-AS1 long non-coding RNA (lncRNA) may bind to the sense coding ALOX12 mRNA to form an antisense-sense duplex providing the basis of a novel ALOX12 regulatory mechanism. Therefore, this study was designed to determine whether the interaction of ALOX12-AS1 with ALOX12 mRNA functions as an anti-sense/sense duplex-mediated regulatory mechanism controlling the cellular content of ALOX12. Our findings indicate that two major isoforms of ALOX12-AS1 lncRNA are ubiquitously expressed in a variety of primary adult human tissues and different transformed cell types. RNA-FISH revealed cell-type-specific cytosolic as well as nuclear and nucleolar localization of the lncRNA. Interestingly, phorbol ester-induced nucleo-cytoplasmic translocation of the lncRNA in monocytic THP-1 cells resulted in a reduction of ALOX12 protein without a concomitant change in its mRNA level. This indicated ALOX12-AS1 operates via an antisense-sense duplex-mediated translational downregulation mechanism. This deduction was validated by demonstrating sense/antisense duplex formation and an association of the duplex with ribosomal proteins in HEK293 cells. Overall, this study revealed a hitherto unknown mechanism of antisense lncRNA-mediated translational downregulation of ALOX12 that adds to the existing regulatory mechanisms for the modulation of potent bioactive lipid mediators that contribute to both health and disease.

Association between platelet counts and morbidity and mortality after endovascular repair for type B aortic dissection

This study aimed to assess the association of postoperative platelet counts with early and late outcomes after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD). We retrospectively evaluated 892 patients with TBAD who underwent TEVAR from a prospectively maintained database. Postoperative nadir platelet counts were evaluated as a continuous variable, and a categorical variable (thrombocytopenia), which was defined as platelet count≤ the lowest 10% percentile (108 × 10⁹/l). Multivariable logistic regression analyses were conducted to assess the impact of postoperative thrombocytopenia on early outcomes, and multivariable cox regression analyses on long-term mortality. Patients with postoperative thrombocytopenia experienced significantly higher rates of postoperative mortality, prolonged intensive care unit stay, death, stroke, limb ischemia, mesenteric ischemia, acute kidney injury (AKI), and puncture-related hematoma (P< .05 for each), but similar rates of immediate type I endoleak and spinal cord ischemia. Multivariable logistic analyses showed that postoperative thrombocytopenia was independently associated with postoperative stroke, limb ischemia, and AKI. Similar results were observed when postoperative nadir platelet count was modeled as a continuous predictor (P< .05 for each). By multivariable Cox analyses, postoperative thrombocytopenia was an independent predictor for long-term all-cause mortality (hazard ratio 2.72, 95% CI, 1.72-4.29, P< .001). For every 30 × 10⁹/L decrease in postoperative platelet count, the risk of long-term all-cause mortality increased by 15% (HR 1.15; 95% CI 1.07-1.25; P< .001). Therefore, postoperative thrombocytopenia might be a useful tool for risk stratification after TEVAR.

Oxidative pathways of arachidonic acid as targets for regulation of platelet activation

Platelet activation plays an important role in acute and chronic cardiovascular disease states. Multiple pathways contribute to platelet activation including those dependent upon arachidonic acid. Arachidonic acid is released from the platelet membrane by phospholipase A2 action and is then metabolized in the cytosol by specific arachidonic acid oxidation enzymes including prostaglandin H synthase, 12-lipoxygenase, and cytochrome P450 to produce pro- and anti-inflammatory eicosanoids. This review aims to analyze the role of arachidonic acid oxidation on platelet activation, the enzymes that use it as a substrate associated as novel therapeutics target for antiplatelet drugs.