Anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia: A scoping review

INTRODUCTION

Data describing safety and tolerability of anticoagulation and antiplatelet therapy in hereditary hemorrhagic telangiectasia (HHT), the second-most-common inherited bleeding disorder, is limited.

METHODS

We performed a scoping review, searching MEDLINE and EMBASE from inception to March 2023 for eligible studies reporting detailed clinical data describing antithrombotic use in HHT. Data extracted included study design, patient population, and characteristics and outcomes of antithrombotic therapy.

RESULTS

Of 625 unique manuscripts identified through database search, 77 were included: 64 case reports/case series describing 65 patients and 13 cohort studies. Data were extracted on a total of 466 patients with HHT, covering 587 episodes of antithrombotic therapy. The most common reasons for antithrombotic therapy were venous thromboembolism (VTE) (44.6 %), atrial arrhythmias (17.8 %) and stroke (10.5 %). anticoagulation was used in in 356 episodes (61.9 %), antiplatelet therapy in 140 episodes (24.3 %), and both together in 50 episodes (8.7 %). Complications of therapy included worsened HHT-associated bleeding (primarily epistaxis and gastrointestinal bleeding) in 198 antithrombotic treatment episodes (38.9 %) and premature antithrombotic therapy discontinuation in 142 episodes (28.9 %). Bleeding-directed therapy (local ablative therapy and systemic therapies) were employed to address worsening bleeding in 14.6 % of episodes. No specific complications of therapy were reported in 322 total antithrombotic events (58.4 %). Rates of bleeding (8.3 % to 80 %), therapy discontinuation (14.3 % to 57.1 %), and other complications ranged considerably from study to study.

CONCLUSION

Current publications vary widely on the outcomes and tolerability of antithrombotics in HHT, but confirm the clinical challenge of adequate antithrombotic therapy in this population. More formal studies are needed to better guide optimal antithrombotic use in HHT.

Antiplatelet, cytotoxic activities and characterization of green-synthesized zinc oxide nanoparticles using aqueous extract of Nephrolepis exaltata

The goal of the current study was to synthesize zinc oxide nanoparticles (ZnO-NPs) using ZnCl₂.2H₂O salt precursor and an aqueous extract of Nephrolepis exaltata (N. exaltata), which act as a capping and reducing agent. N. exaltata plant extract-mediated ZnO-NPs were further characterized by various techniques, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR), UV-visible (UV-Vis), and energy-dispersive X-ray (EDX) analysis. The nanoscale crystalline phase of ZnO-NPs was analyzed by the XRD patterns. The FT-IR analysis revealed different functional groups of biomolecules involved in the reduction and stabilization of the ZnO-NPs. The light absorption and optical properties of ZnO-NPs were examined by UV-Vis spectroscopy at a wavelength of 380 nm. The spherical shape morphology of ZnO-NPs with mean particle size ranges between 60 and 80 nm was confirmed by SEM images. While the EDX analysis was used to identify the elemental composition of ZnO-NPs. Furthermore, the synthesized ZnO-NPs demonstrate potential antiplatelet activity by inhibiting the platelet aggregation induced by platelet activation factor (PAF) and arachidonic acid (AA). The results showed that synthesized ZnO-NPs were more effective in inhibiting platelet aggregation induced by AA with IC₅₀ (56% and 10 μg/mL) and PAF (63% and 10 μg/mL), respectively. However, the biocompatibility of ZnO-NPs was assessed in human lung cancer cell line (A549) under in vitro conditions. The cytotoxicity of synthesized nanoparticles revealed that cell viability decreased and the IC₅₀ was found to be 46.7% at a concentration of 75 μg/mL. The present work concluded the green synthesis of ZnO-NPs that was achieved by N. exaltata plant extract and showed good antiplatelet and cytotoxic activity, which demonstrates the lack of harmful effects making them more effective for use in pharmaceutical and medical fields to treat thrombotic disorders.

Factors related to postoperative vitreous hemorrhage after small-gauge vitrectomy in proliferative diabetic retinopathy patients

BACKGROUND

The role of anticoagulation or antiplatelet on post-vitrectomy vitreous hemorrhage (POVH) in patients with proliferative diabetic retinopathy (PDR) is rarely investigated in the small-gauge vitrectomy era. We investigate the relationship between the long-term use of those medications and POVH in a group of PDR patients.

METHODS

A retrospective cohort study was carried out in a group of PDR patients who underwent small-gauge vitrectomy in our center. The baseline data on diabetes, diabetic complications, long-term use of anticoagulants and antiplatelet agents, ocular findings, and vitrectomy details were collected. The occurrence of POVH was recorded during at least three-month follow-up. Factors related to POVH were analyzed using logistic analysis.

RESULTS

During a median follow-up of 16 weeks, 5% (11/220) of patients had POVH, and 75 had received antiplatelet or anticoagulation agents before the operation. Factors related to persistent POVH were the use of antiplatelet or anticoagulation agents (5.98, 1.75-20.45, p = 0.004), the presence of myocardial revascularization (130.65, 3.53-4834.50, p = 0.008), the presence of coronary artery disease (CAD) treated with medicine (56.52, 1.99-1604.06, p = 0.018), and younger age (0.86, 0.77-0.96, p = 0.012). For those receiving preoperative antiplatelet or anticoagulation agents, the probability of developing POVH was higher in the patients whose previous therapy was adjusted compared to those with continued therapy (p = 0.02 by Log-rank test).

CONCLUSIONS

We identified long-term use of anticoagulation or antiplatelet medication, the presence of CAD, and younger age as three independent factors related to POVH. In PDR patients on long-term antiplatelet or anticoagulation medications, particular attention should be given to controlling intraoperative bleeding, and follow-up for POVH should be scheduled.

The Impact of Convertase Subtilisin/Kexin Type 9 Monoclonal Antibodies with and without Apheresis on Platelet Aggregation in Familial Hypercholesterolemia

BACKGROUND AND AIMS

It is well known that elevated cholesterol is associated with enhanced platelet aggregation and patients suffering from familial hypercholesterolemia (FH) have a high risk of thrombotic cardiovascular events. Although decreasing cholesterol level is associated with attenuation of platelet hyperactivity, there are currently no data on the effect of convertase subtilisin/kexin type 9 monoclonal antibodies (PCSK9ab) on platelet reactivity in FH. The aim of the study was to analyse the impact of different therapies including PCSK9ab on platelet aggregation in FH.

METHODS

This study enrolled all 15 patients treated in the University Hospital Hradec Králové for FH. PCSK9ab have been administered in 12 of 15 patients while 8 patients were also undergoing lipid apheresis. Blood samples from all patients including pre- and post-apheresis period were tested for platelet aggregation triggered by 7 inducers, and the effect of 3 clinically used drugs (acetylsalicylic acid, ticagrelor and vorapaxar) was compared as well.

RESULTS

Although apheresis decreased the reactivity of platelets in general, platelet responses were not different between non-apheresis patients treated with PCSK9ab and apheresis patients (post-apheresis values) with the exception of ristocetin. However, when compared to age-matched healthy population, FH patients had significantly lower platelet aggregation responses to 4 out of 7 used inducers and higher profit from 2 out of 3 used antiplatelet drugs even after exclusion of FH patients regularly receiving conventional antiplatelet treatment.

CONCLUSION

This study showed for the first time the suitability of PCSK9ab treatment for reduction of platelet reactivity in FH patients.

Antiplatelet and anticoagulation therapy and the risk of pituitary apoplexy in pituitary adenoma patients

PURPOSE

Pituitary apoplexy can be a life threatening and vision compromising event. Antiplatelet and anticoagulation use has been reported as a contributing factor in pituitary apoplexy (PA). Utilizing one of the largest cohorts in the literature, this study aims to determine the risk of PA in patients on antiplatelet/anticoagulation (AP/AC) therapy.

METHODS

A single center, retrospective study was conducted on 342 pituitary adenoma patients, of which 77 patients presented with PA (23%). Several potential risk factors for PA were assessed, including: patient demographics, tumor characteristics, pre-operative hormone replacement, neurologic deficits, coagulation studies, platelet count, and AP/AC therapy.

RESULTS

Comparing patients with and without apoplexy, there was no significant difference in the proportion of patients taking aspirin (45 no apoplexy vs. 10 apoplexy; p = 0.5), clopidogrel (10 no apoplexy vs. 4 apoplexy; p = 0.5), and anticoagulation (7 no apoplexy vs. 3 apoplexy; p = 0.7). However, male sex (p-value < 0.001) was a predictor for apoplexy while pre-operative hormone treatment was a protective factor from apoplexy (p-value < 0.001). A non-clinical difference in INR was also noted as a predictor for apoplexy (no apoplexy: 1.01 ± 0.09, apoplexy: 1.07 ± 0.15; p < 0.001).

CONCLUSIONS

Although pituitary tumors have a high risk for spontaneous hemorrhage, the use of aspirin is not a risk for hemorrhage. Our study did not find an increased risk of apoplexy with clopidogrel or anticoagulation, but further investigation is needed with a larger cohort. Confirming other reports, male sex is associated with an increased risk for PA.

Differential prognosis of patients that are candidates for standard, short or prolonged dual antiplatelet treatment discharged after an acute coronary syndrome

BACKGROUND

Current evidence supports the efficacy of prolonged dual antiplatelet treatment (DAPT) for patients at high-ischemic risk and low bleeding risk as well as the efficacy and safety of short DAPT in high-bleeding risk (HBR) patients.

METHODS

We evaluated patterns of DAPT candidates in all patients discharged in 2 hospitals after an acute coronary syndrome (ACS). Patients categorized in 3 groups: 1) short-DAPT candidates if they met 1 major o 2 minor criteria for HBR, by the 2019 ARC-HBR criteria; 2) prolonged-DAPT candidates if were not HBR and had recurrent ACS, complex percutaneous coronary interventions or diabetes; 3) standard 12 months DAPT if were not include in the previous 2 groups. Major bleeding (MB) was registered according to 3 or 5 of the BARC consortium definitions.

RESULTS

We included 8252 patients and 3215 (39 %) were candidates for abbreviated DAPT, 3119 (37.8 %) for prolonged DAPT, and 1918 (23.2 %) for 12 m DAPT. Relevant differences were observed between the 3 categories beyond the bleeding risk. Median follow-up was 57 months. Multivariate analysis identified higher risk of all-cause mortality (HR: 1.96 95 % CI 1.45-2.67; p < 0.001), cardiovascular mortality (HR: 2.10 95 % CI 1.39-3.19; p < 0.011), MACE (HR: 1.69 95 % 1.50-2.02; p < 0.001) and MB (sHR: 3.41 95 % CI 1.45-8.02; p = 0.005) in candidates to short DAPT. Candidates to prolonged DAPT had higher risk of MACE (HR: 1.17 95 % CI 1.02-1.35; p = 0.027).

CONCLUSIONS

Almost two thirds of patients discharged after an ACS would be candidates for short or prolonged DAPT and these patients are at higher risk of MACE and mortality.

Antiplatelet use and CADASIL: a retrospective observational analysis

OBJECTIVES

Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL) is hallmarked by age-dependent accumulation of microangiopathy with antiplatelet medications commonly used for stroke prevention though without known therapeutic benefit. Our objective was to identify whether antiplatelet therapy impacted the incidence of acute ischemic stroke (AIS) or intracerebral hemorrhage (ICH) in those with reported CADASIL.

MATERIALS AND METHODS

Owing to the rarity of the disease, we performed a retrospective study of anonymized data from the international TriNetX Research Network (Oct 2015 through January 2021). Individuals had an ICD-10 code (I67.850) for CADASIL. The primary outcome was incidence of validated ICD-10 codes for AIS (I63) and ICH (I61) linked with unique hospital admission encounters. The primary exposure was use of an antiplatelet medication for at least 1 month prior to the primary outcome. Age-adjusted logistic regression was used for likelihood ratios.

RESULTS

We identified 455 individuals: 36% female, 40 (8.8%) antiplatelet exposed. Those with antiplatelet use were older (antiplatelet: 61±12 years vs. unexposed: 57±14 years, p = 0.034) with similar rates of AIS [antiplatelet: 23%(9/40) vs. unexposed: 14%(60/415); p=0.18] and ICH [antiplatelet: 3%(1/40) vs. unexposed: 5%(19/415); p = 0.54) and without significant impact on age-adjusted AIS likelihood (OR 1.62, 95%CI 0.73-3.60, p=0.23). Sample size precluded ICH regression analyses.

CONCLUSIONS

Our data suggests that antiplatelet use did not significantly impact incidence of AIS or ICH within a group of individuals with suspected CADASIL This study highlights the need for further understanding of the pathophysiology of CADASIL to lead to disease modifying treatments.

Antithrombotic agent usage before ictus in aneurysmal subarachnoid hemorrhage: relation to hemorrhage severity, clinical course, and outcome

BACKGROUND

The number of patients with aneurysmal subarachnoid hemorrhage (aSAH) who are on antithrombotic agents before ictus is rising. However, their effect on early brain injury and disease development remains unclear. The primary aim of this study was to determine if antithrombotic agents (antiplatelets and anticoagulants) were associated with a worse initial hemorrhage severity, rebleeding rate, clinical course, and functional recovery after aSAH.

METHODS

In this observational study, those 888 patients with aSAH, treated at the neurosurgical department, Uppsala University Hospital, between 2008 and 2018 were included. Demographic, clinical, radiological (Fisher and Hijdra score), and outcome (Extended Glasgow Outcome Scale one year post-ictus) variables were assessed.

RESULTS

Out of 888 aSAH patients, 14% were treated with antithrombotic agents before ictus. Seventy-five percent of these were on single therapy of antiplatelets, 23% on single therapy of anticoagulants, and 3% on a combination of antithrombotic agents. Those with antithrombotic agents pre-ictus were significantly older and exhibited more co-morbidities and a worse coagulation status according to lab tests. Antithrombotic agents, both as one group and as subtypes (antiplatelets and anticoagulants), were not associated with hemorrhage severity (Hijdra score/Fisher) nor rebleeding rate. The clinical course did not differ in terms of delayed ischemic neurological deficits or last-tier treatment with thiopental and decompressive craniectomy. These patients experienced a higher mortality and lower rate of favorable outcome in univariate analyses, but this did not hold true in multiple logistic regression analyses after adjustment for age and co-morbidities.

CONCLUSIONS

After adjustment for age and co-morbidities, antithrombotic agents before aSAH ictus were not associated with worse hemorrhage severity, rebleeding rate, clinical course, or long-term functional recovery.

Dual therapy with oral anticoagulation and single antiplatelet agent versus monotherapy with oral anticoagulation alone in patients with atrial fibrillation and stable ischemic heart disease: a systematic review and meta-analysis

BACKGROUND

In patients with atrial fibrillation (AF) and stable ischemic heart disease, recent guidelines recommend oral anticoagulant (OAC) monotherapy in preference to OAC + single antiplatelet agent (SAPT) dual therapy. However, these data are based on the results of only two randomized controlled trials (RCTs) and a relatively small group of patients. Thus, the safety and efficacy of this approach may be underpowered to detect a significant difference. We hypothesized that OAC monotherapy will have a reduced risk of bleeding, but similar all-cause mortality and ischemic outcomes as compared to dual therapy (OAC + SAPT).

METHODS

A systematic search of PubMed/MEDLINE, EMBASE, and Scopus was conducted. Safety outcomes included total bleeding, major bleeding, and others. Efficacy outcomes included all-cause mortality, cardiovascular mortality, myocardial infarction, stroke, and major adverse cardiovascular events (MACE). RCTs and observational studies were pooled separately (study design stratified meta-analysis). Subgroup analyses were performed for vitamin K antagonists and direct oral anticoagulants (DOACs). Pooled risk ratios (RR) with corresponding 95% confidence intervals (CI) were calculated using the Mantel-Haenszel method.

RESULTS

Meta-analysis of 2 RCTs comprising a total of 2905 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant increase in major bleeding (RR 1.51; 95% CI [1.10, 2.06]). There was no significant reduction in MACE (RR 1.10; [0.71, 1.72]), stroke (RR 1.29; [0.85, 1.95]), myocardial infarction (RR 0.57; [0.28, 1.16]), cardiovascular mortality (RR 1.22; [0.63, 2.35]), or all-cause mortality (RR 1.18 [0.52, 2.68]). Meta-analysis of 20 observational studies comprising 47,451 patients showed that dual therapy (OAC + SAPT) vs. OAC monotherapy was associated with a statistically significant higher total bleeding (RR 1.50; [1.20, 1.88]), major bleeding (RR = 1.49; [1.38, 1.61]), gastrointestinal bleeding (RR = 1.62; [1.15, 2.28]), and myocardial infarction (RR = 1.15; [1.05, 1.26]), without significantly lower MACE (RR 1.10; [0.97, 1.24]), stroke (RR 0.93; [0.73, 1.19]), cardiovascular mortality (RR 1.11; [0.95, 1.29]), or all-cause mortality (RR 0.93; [0.78, 1.11]). Subgroup analysis showed similar results for both vitamin K antagonists and DOACs, except a statistically significant higher intracranial bleeding with vitamin K antagonist + SAPT vs. vitamin K antagonist monotherapy (RR 1.89; [1.36-2.63]).

CONCLUSIONS

In patients with AF and stable ischemic heart disease, OAC + SAPT as compared to OAC monotherapy is associated with a significant increase in bleeding events without a significant reduction in thrombotic events, cardiovascular mortality, and all-cause mortality.

Cytosolic perfluorocarbon delivery to platelets via albumin for antithrombotic therapy

Thrombosis is a major contributor to global disease burden. Antiplatelet therapy is the critical approach to prevent thrombosis by reducing platelet reactivity. However, classical antiplatelet strategies generally interfere with platelet integrin α_IIbβ₃-mediated platelet activation, thereby facing severe bleeding risk. To break the limitation, we described an integrin α_IIbβ₃-independent antiplatelet method by cytosolic delivery of nanoscale perfluorocarbon (PFC) to platelets via albumin carrier. Denatured albumin was found to build high affinity with platelets to mediate cytosolic PFC delivery. While, cytosolic PFC impaired cytoskeleton reorganization during platelet activation to inhibit relevant platelet functions, but avoided to interfere with integrin α_IIbβ₃. We proved that this α_IIbβ₃-indenpendent antiplatelet pattern showed potential antiplatelet effect with low bleeding risk to prevent thrombosis in various thrombosis models. Together, cytosolic PFC delivery via albumin is a promising antiplatelet approach, and will provide an alternative regimen for current antithrombotic therapy.

Bleeding and thrombotic events in bevacizumab-treated patients with colorectal cancer on novel oral anticoagulants and antiplatelet medications

Background

Bevacizumab is a humanized monoclonal anti-VEGF antibody often given in combination with fluorouracil-based chemotherapy as therapy for metastatic colorectal cancer (mCRC). The bleeding and thrombotic event rates in the setting of concurrent novel oral anticoagulants with and without aspirin and bevacizumab treatment in patients with mCRC remain unclear.

Methods

462 patients with mCRC at Barnes-Jewish Hospital were identified between December 1, 2016 and December 1, 2021 and screened for concurrent treatment with bevacizumab and anticoagulant or antiplatelet therapy. Demographic and clinical information was extracted by electronic chart review.

Results

21 patients were identified who received bevacizumab and either apixaban or rivaroxaban for mCRC treatment. Aspirin was prescribed in some of these patients within three years of starting apixaban or rivaroxaban. Of the 13 patients without aspirin prescription, nine were given apixaban, and four were given rivaroxaban while on bevacizumab. Four out of nine of the patients who received apixaban had epistaxis, and only one case resulted in any treatment discontinuation. Three out of four of the patients who received rivaroxaban experienced bleeding, and one of these three patients discontinued bevacizumab. We also looked at eight patients who had received aspirin. Two out of seven patients who received apixaban/bevacizumab/aspirin experienced bleeding and discontinued a medication. The patient who received rivaroxaban/bevacizumab/aspirin experienced bleeding and discontinued bevacizumab. No patient experienced adverse thrombotic events.

Conclusions

Patients with mCRC treated with bevacizumab and apixaban with no history of aspirin use within three years have a relatively low risk of bleeding that warrants treatment discontinuation.

Perioperative Management of Oral Antithrombotics in Dentistry and Oral Surgery: Part 2

Part 1 of "Perioperative Management of Oral Antithrombotics in Dentistry and Oral Surgery" covered the physiological process of hemostasis and the pharmacology of both traditional and novel oral antiplatelets and anticoagulants. Part 2 of this review discusses various factors that are considered when developing a perioperative management plan for patients on oral antithrombotic therapy in consultation with dental professionals and managing physicians. Additionally included are how thrombotic and thromboembolic risks are assessed as well as how patient- and procedure-specific bleeding risks are evaluated. Special attention is given to the bleeding risks associated with procedures encountered when providing sedation and general anesthesia within the office-based dental environment.

Antiplatelet treatment patterns and outcomes of secondary stroke prevention in the United States

Objective

Patients who have an ischemic stroke (IS) or transient ischemic attack (TIA) are at risk of having a secondary stroke. Single antiplatelet therapy (SAPT) or dual antiplatelet therapy (DAPT) may be recommended for secondary stroke prevention (SSP), depending on severity and etiology. This study evaluated outpatient antiplatelet treatment patterns for SSP and outcomes after first hospitalization for IS/TIA among adults without atrial fibrillation in the United States.

Materials and methods

This retrospective observational study utilized data from an adjudicated administrative health claims database. Eligible patients had an imputed National Institutes of Health Stroke Scale index event score ≤7. Over-the-counter medication use (eg, aspirin) was not captured.

Results

Of 154,273 patients, 41,622 (27%) were prescribed antiplatelet therapy within 90 days of the event; 93.8% received SAPT, 6.1% received DAPT. The first line of antiplatelet therapy after discharge was started a mean of 17.0 days after the event; mean treatment duration was 61.9 days. The incidence rate for secondary IS was 5.53, 2.03, and 1.17 per person-year 90-days, 1-year, and 3-years following treatment initiation, respectively. Among patients matched for demographic and clinical characteristics, the risk of secondary IS was increased with DAPT versus SAPT (hazard ratio [95% CI]: 1.27 [1.20-1.34]; p < 0.0001).

Conclusions

Many patients were not prescribed or discontinued antiplatelet therapy within 90 days of hospitalization for IS/TIA and, in most cases, prescriptions were not compliant with SSP consensus guidelines. Patients remained at risk for IS, which was highest within 90 days. More effective strategies for SSP are needed to improve outcomes in this patient population.

A multicenter retrospective study evaluating the impact of desmopressin on hematoma expansion in patients with antiplatelet-associated intracranial hemorrhage

INTRODUCTION

Antiplatelet medications interfere with hemostasis which can contribute to increased risk of hematoma expansion and potentially worse outcomes in patients presenting with intracranial hemorrhages (ICH). Current Neurocritical Care Society guidelines recommend desmopressin (DDAVP) in patients with antiplatelet-associated ICH with evidence limited by small cohorts.

MATERIALS AND METHODS

Patients were included in our multi-center, retrospective study if they had computed tomographic (CT) scan confirmed ICH and were taking antiplatelet medications. Patients were excluded if hospital length of stay was <24 h, administered DDAVP dose was <0.3 μg/kg, no follow-up head CT scan was performed within the first 24 h after baseline, major neurosurgical intervention was performed in between CT scans, or the injury was an acute on chronic ICH. The primary outcome was incidence of hematoma expansion (defined as >20 % increase from baseline). Secondary outcomes were incidence of thrombotic complications within 7 days, largest absolute decrease in serum sodium within the first 24 h, and patient disposition.

RESULTS

Among the 209 patients included in the study, 118 patients received DDAVP while 91 did not. The frequency of hematoma expansion was similar between patients who received DDAVP and those who did not (16.1 % vs 17.6 %; P = 0.78). No difference in secondary outcomes was observed between the two groups.

CONCLUSIONS

These findings in conjunction with recently published literature may suggest minimal benefit or harm with DDAVP treatment. However, further study could elucidate any potential impact on long-term function outcomes.

Role of Antiplatelet Therapy in Hemodialysis Arteriovenous Graft Secondary Patency Following Successful Percutaneous Thrombectomy

PURPOSE

The purpose of this study was to elicit the relationship of antiplatelet therapy (AP) in maintaining arteriovenous graft (AVG) patency after successful percutaneous pharmacomechanical thrombectomy ("declot").

MATERIALS AND METHODS

This was an institutional review board-approved retrospective review of AVG declot procedures between July 2019 and August 2020. AVG characteristics, bleeding complications, anticoagulation and antiplatelet medication regimens, and thrombosis free survival were evaluated. Recurrent time-to-event analysis was performed using a Prentice-Williams-Peterson Gap time model was performed to evaluate AVG thrombosis free survival.

RESULTS

A total of 109 declots were technically successful and performed in 63 individual patients. The majority of procedures were performed in upper arm grafts (71%, n = 45). Dual antiplatelet (DAPT) was prescribed after 52 declots (48%), single antiplatelet was prescribed after 36 declots (33%), and anticoagulation was prescribed after 31 declots (28%). Median thrombosis free survival was 37 days (range 1-412 days) in the no antiplatelet group, 84 days (range 1-427 days) in the single antiplatelet group, and 93 days (range 3-407 days) in the DAPT group. Anti-platelet medications trended towards protective of AVG thrombosis in multivariate analysis (hazard ratio 0.84, 95% confidence interval 0.60-1.19); however, this did not reach statistical significance (P = 0.33). A total of 4 major and 5 minor bleeding events occurred.

CONCLUSION

The results of this study support further evaluation of AP therapy in preventing secondary rethrombosis of dialysis AVG.

Antioxidant and Antithrombotic Activities of Kenaf Seed (Hibiscus cannabinus) Coat Ethanol Extract in Sprague Dawley Rats

Oxidative stress has been implicated in deadly lifestyle diseases, and antioxidants from plant sources are the primary option in the treatment regime. Kenaf seeds are the storehouse of potential natural antioxidant phytoconstituents. Perhaps, none of the studies documented the phytoconstituents and their antioxidant potential from Kenaf seed coat so far. Thus, the current study focuses on exploring the protective effect of Kenaf Seed Coat Ethanol Extract (KSCEE) against sodium nitrite and diclofenac-induced oxidative stress in vitro (red blood cell and platelets model) and in vivo (female Sprague Dawely rat's model) along with the antithrombotic activity. The infrared spectrophotometry data showed the heterogeneous functional groups (CH, OH, C = C, C = C-C) and aromatic rings. Reverse phase high-performance liquid chromatography and gas chromatography-mass spectrometry chromatogram of KSCEE also evidenced the presence of several phytochemicals. KSCEE displayed about 76% of DPPH scavenging activity with an IC₅₀ value of 34.94 µg/ml. KSCEE significantly (***p < 0.001) normalized the stress markers such as lipid peroxidation, protein carbonyl content, superoxide dismutase, and catalase in sodium nitrite and diclofenac-induced oxidative stress in RBC, platelets, liver, kidney, and small intestine, respectively. Furthermore, KSCEE was found to protect the diclofenac-induced tissue destruction of the liver, kidney, and small intestine obtained from seven groups of female Sprague Dawely rats. KSCEE delayed the clotting time of platelet-rich plasma and platelet-poor plasma and activated partial thromboplastin time, suggesting its anticoagulant property. In addition, KSCEE also exhibited antiplatelet activity by inhibiting both adenosine diphosphate and epinephrine-induced platelet aggregation. In conclusion, KSCEE ameliorates the sodium nitrite and diclofenac-induced oxidative stress in red blood cells, platelets, and experimental animals along with antithrombotic properties.

Is it safe to discontinue antiplatelet medication after stent-assisted coil embolization? If so, when is the best time?

PURPOSE

Antiplatelet maintenance after stent-assisted coil embolization (SACE) is generally considered essential to avoid post-procedural thromboembolic complications. However, there is still debate as to whether it is safe to discontinue antiplatelet drugs after SACE or when is the best time to do so. We investigate herein the clinical outcomes experienced by patients who discontinue antiplatelet agents after SACE.

METHODS

From a prospective database, we retrieved the data for 120 consecutive patients (harboring 130 aneurysms) in whom antiplatelet agents were discontinued after SACE between January 2010 and December 2019. We defined thromboembolic complications associated with discontinuation as neurologic or radiographic ischemia that occurred within 6 months of discontinuation of antiplatelet agents; the lesion was required to be correlated with the stented artery.

RESULTS

The mean time of discontinuation of antiplatelet medication was 31.4 ± 18.3 months after SACE (median, 26 months). The majority of patients stopped antiplatelet medication between 18 and 36 months after SACE (74 patients, 61.6%). Laser-cut closed-cell stent was most commonly applied in 91 aneurysms (70.0%), followed by braided closed-cell (n=29; 22.3 %) and laser-cut open-cell stent 10 (7.7 %). No patients experienced cerebral ischemia related to discontinuation of antiplatelet medication.

CONCLUSION

Our preliminary study suggests that it may be safe to discontinue antiplatelet medication after SACE in patients at low risk for ischemia. The optimal time to discontinue might be around 18 to 36 months after SACE. Large cohort-based studies or randomized clinical trials are warranted to confirm these results.

Risk of thromboembolic events in relation to the management of anticoagulant and antiagregant therapy in patients subjected to endoscopic retrograde cholangiopancreatography

BACKGROUND AND OBJECTIVES

The main clinical practice guidelines recommend adequate periprocedural withdrawal and reintroduction of antithrombotic drugs in case of invasive techniques. The main objective of this study was to assess whether, in patients receiving anticoagulant or antiplatelet therapy, the suppression or reduction of the pharmacological dose for the performance of endoscopic retrograde cholangiopancreatography (ERCP) implies a greater risk of thromboembolic events.

PATIENTS AND METHODS

A prospective observational study was carried out, which included 644ERCP performed with therapeutic intention during 2019 at the Reina Sofía University Hospital with follow-up during the 30days after the endoscopic intervention.

RESULTS

Six patients presented a thromboembolic event, finding no differences between the incorrect withdrawal/reintroduction of antithrombotic treatment and a higher proportion of thromboembolic or hemorrhagic events after the procedure (P>.05). The incidence of thrombotic events was significantly higher in patients treated with heparin or apixaban (P=.001), as well as with a history of atrial fibrillation (P=.05), rheumatic valve disease (P=.037) and recurrent pulmonary embolism (P=.035), this being also an independent risk factor. Likewise, the incidence of hemorrhage in the 30days post-sphincterotomy was significantly lower in those with implantation of a biliary prosthesis (P=.04).

CONCLUSIONS

Inadequate periprocedural management of antithrombotic therapy is not associated with a significant increase in the incidence of thromboembolic events in the 30days after ERCP. However, close follow-up and surveillance during the days after this is essential in those patients with a condition that significantly increases the risk of thrombosis.

Dual Antiplatelet Therapy Does Not Increase Bleeding Risk in Percutaneous Gastrostomy Tube Placement: Network Meta-Analysis

BACKGROUND/OBJECTIVE

Gastrostomy tube (G tube) is a commonly performed procedure for nutritional support. Current guidelines recommend discontinuation of dual antiplatelet therapy (DAPT) prior to G tube placement to reduce bleeding risk.

AIMS

We aim to compare bleeding risk in single, dual and no antiplatelet therapy during G tube placement.

METHODS

We searched PubMed, Embase, Cochrane, and Web of Sciences to include comparative studies evaluating single antiplatelet (aspirin, clopidogrel), dual antiplatelet (DAPT, aspirin and clopidogrel), and no antiplatelet therapy. Direct as well as network meta-analyses comparing these arms were performed. Risk Differences (RD) with confidence intervals were calculated.

RESULTS

12 studies with 8471 patients were included. On direct meta-analysis, there was no significant difference noted between DAPT compared to Aspirin (RD 0.001 95% CI - 0.012 to 0.014, p = 0.87), Clopidogrel (RD 0.001 95% CI - 0.009 to 0.010, p = 0.92) or no antiplatelet group (RD 0.007 95% CI - 0.011 to 0.026, p = 0.44). Results were consistent on network meta-analysis and no difference was noted in bleeding rates when comparing DAPT with Aspirin (RD 0.001, 95% CI - 0.007 to 0.01, p = 0.76), Clopidogrel (RD 0.001, 95% CI - 0.01 to 0.011, p = 0.90) and no antiplatelet group (RD 0.002, 95% CI - 0.007 to 0.012, p = 0.62).

CONCLUSION

There is no significant difference in bleeding risk between DAPT, single antiplatelet or no antiplatelet therapy on a population level. On an individual level, risk of ischemic events should be weighed against the risk of bleeding based on patient circumstances and risk profile. Our findings offer to provide additional data to make an informed decision between patients and physicians to make clinical decisions by assessing individual risks and benefits for optimal care of complex patients.

Body Mass Index and Major Adverse Events During Chronic Antiplatelet Monotherapy After Percutaneous Coronary Intervention With Drug-Eluting Stents - Results From the HOST-EXAM Trial

BACKGROUND

This study evaluated the association of body mass index (BMI) with adverse clinical outcomes during chronic maintenance antiplatelet monotherapy after percutaneous coronary intervention (PCI) with drug-eluting stents (DES).Methods and Results: Overall, 5,112 patients were stratified (in kg/m²) into underweight (BMI ≤18.4), normal weight (18.5-22.9), overweight (23.0-24.9), obesity (25.0-29.9) and severe obesity (≥30.0) categories with randomized antiplatelet monotherapy of aspirin 100 mg or clopidogrel 75 mg once daily for 24 months. The primary endpoint was the composite of all-cause death, non-fatal myocardial infarction, stroke, readmission due to acute coronary syndrome and major bleeding of Bleeding Academic Research Consortium type ≥3. Compared with normal weight, the risk of primary composite outcomes was higher in the underweight (hazard ratio [HR] 2.183 [1.199-3.974]), but lower in the obesity (HR 0.730 [0.558-0.954]) and severe obesity (HR 0.518 [0.278-0.966]) categories, which is partly driven by the difference in all-cause death. The risk of major bleeding was significantly higher in the underweight (HR 4.140 [1.704-10.059]) than in the normal weight category. A decrease in categorical BMI was independently associated with the increased risk of primary composite outcomes.

CONCLUSIONS

Lower BMI is associated with a higher risk of primary composite outcomes, which is primarily related to the events of all-cause death or major bleeding during chronic maintenance antiplatelet monotherapy after PCI with DES.

Acute, periprocedural and longterm antithrombotic therapy in older adults: 2022 Update by the ESC Working Group on Thrombosis

The first international guidance on antithrombotic therapy in the elderly came from the European Society of Cardiology Working Group on Thrombosis in 2015. This same group has updated its previous report on antiplatelet and anticoagulant drugs for older patients with acute or chronic coronary syndromes, atrial fibrillation, or undergoing surgery or procedures typical of the elderly (transcatheter aortic valve implantation and left atrial appendage closure). The aim is to provide a succinct but comprehensive tool for readers to understand the bases of antithrombotic therapy in older patients, despite the complexities of comorbidities, comedications and uncertain ischaemic- vs. bleeding-risk balance. Fourteen updated consensus statements integrate recent trial data and other evidence, with a focus on high bleeding risk. Guideline recommendations, when present, are highlighted, as well as gaps in evidence. Key consensus points include efforts to improve medical adherence through deprescribing and polypill use; adoption of universal risk definitions for bleeding, myocardial infarction, stroke and cause-specific death; multiple bleeding-avoidance strategies, ranging from gastroprotection with aspirin use to selection of antithrombotic-drug composition, dosing and duration tailored to multiple variables (setting, history, overall risk, age, weight, renal function, comedications, procedures) that need special consideration when managing older adults.

Antiplatelet therapy indication in patients also prescribed direct oral anticoagulants

Direct oral anticoagulants (DOACs) are standard of care for venous thromboembolism (VTE) treatment and stroke prevention in atrial fibrillation (AF). Adding antiplatelet therapy (APT) to an oral anticoagulant (OAC) causes a 2-fold increase in major bleeding. As such, recent guidelines recommend limiting the duration and indication of combined therapy in patients already on an OAC. Despite these recommendations, approximately one-third of anticoagulated patients are prescribed concomitant APT. University of Utah Health patients receiving DOAC + APT between August 1, 2019 and November 30, 2019 were included. These were categorized into four groups by APT indication: primary atherosclerotic cardiovascular disease (ASCVD) prevention, ASCVD-no percutaneous coronary intervention (PCI), ASCVD-PCI ≤ 12 months prior, ASCVD-PCI > 12 months prior. The primary outcome was the proportion of DOAC patients receiving concomitant APT for each indication. During the study period, 347 patients received DOAC + APT, primarily for AF (59.1%) or VTE (33.1%), and the most common DOAC was apixaban (76.7%).The most common indication for APT was ASCVD-no PCI (47.3%), followed by ASCVD-PCI > 12 months prior (30.8%), primary ASCVD prevention (18.7%), and ASCVD-PCI ≤ 12 months prior (1.7%). Five patients (1.4%) were on APT with unclear indication. Based on recent guidelines limiting indications and duration of APT added to anticoagulation, over 95% of patients in this single-center study warranted re-assessment of APT indication, with stable ASCVD and primary prevention being prime targets for APT de-prescribing. This study highlights the tremendous potential to improve patient safety and reduce bleeding harm.

Association of antiplatelet or anticoagulant agents with in-hospital mortality among blunt torso trauma patients without severe traumatic brain injury: A retrospective analysis of the Japanese nationwide trauma registry

AIM

Patients with head trauma who take antiplatelet or anticoagulant (APAC) agents have a higher rate of mortality. However, the association between these agents and mortality among blunt torso trauma patients without severe traumatic brain injury remains unclear.

METHODS

Using the Japanese nationwide trauma registry, we conducted a retrospective cohort study including adult patients with blunt torso trauma without severe head trauma between January 2019 and December 2020. Eligible patients were divided into two groups based on whether or not they took any APAC agents. The primary outcome was in-hospital mortality. To adjust for potential confounding factors, we conducted random effects logistic regression to account for patients clustering within the hospitals. The model was adjusted for potential confounders, including age, mechanism of injury, Charlson comorbidity index, systolic blood pressure, and injury severity scale on arrival as potentially confounding factors.

RESULTS

During the study period, 16,201 patients were eligible for the analysis. A total of 832 patients (5.1%) were taking antiplatelet or anticoagulant agents. Overall in-hospital mortality was 774 patients (4.8%). APAC group had a higher risk of in-hospital mortality compared with the non-APAC group (6.9% vs. 4.7%; unadjusted OR, 1.51; 95% CI, 1.12-2.00; P < 0.01). After adjusting for potential confounder, there were no significant intergroup difference in a higher in-hospital mortality compared to with the non-APAC group (OR, 1.07; 95%CI, 0.65-1.77; P = 0.79).

CONCLUSION

The use of APAC agents before the injury was not associated with higher in-hospital mortality among blunt torso trauma patients without severe traumatic brain injury.

Antithrombotic Treatment in Coronary Artery Disease

Coronary artery disease exhibits growing mortality and morbidity worldwide despite the advances in pharmacotherapy and coronary intervention. Coronary artery disease is classified in the acute coronary syndromes and chronic coronary syndromes according to the most recent guidelines of the European Society of Cardiology. Antithrombotic treatment is the cornerstone of therapy in coronary artery disease due to the involvement of atherothrombosis in the pathophysiology of the disease. Administration of antiplatelet agents, anticoagulants and fibrinolytics reduce ischemic risk, which is amplified early post-acute coronary syndromes or post percutaneous coronary intervention; though, antithrombotic treatment increases the risk for bleeding. The balance between ischemic and bleeding risk is difficult to achieve and is affected by patient characteristics, procedural parameters, concomitant medications and pharmacologic characteristics of the antithrombotic agents. Several pharmacological strategies have been evaluated in patients with coronary artery disease, such as the effectiveness and safety of antithrombotic agents, optimal dual antiplatelet treatment schemes and duration, aspirin de-escalation strategies of dual antiplatelet regimens, dual inhibition pathway strategies as well as triple antithrombotic therapy. Future studies are needed in order to investigate the gaps in our knowledge, including special populations.

Dabigatran: Clinical correlation of drug and its dose with risk of stroke and bleeding

Background

Dabigatran is the first oral direct thrombin inhibitor which is endorsed by Food and Drug Administration in the prevention of embolic events in patients with nonvalvular atrial fibrillation. Suitable dose of the drug for the patient is selected based on CHA2DS2-VASc score and HAS-BLED score.

Aim

To determine and compare the risk of occurrence of stroke and bleeding after the initiation of dabigatran therapy in patients prescribed with this drug.

Methods

Patients with more than 18 years who were prescribed with dabigatran during 2017-2019 in a tertiary care hospital were selected for the study. Most of the patient's prescriptions contained an antiplatelet, so a comparison was made between the clinical outcomes of patients given with dabigatran alone and dabigatran with an antiplatelet because antiplatelet can have effects on the safety as well as efficacy profile of dabigatran.

Results

Out of 75 patients enrolled in the study, 42 patients were in the dabigatran with the antiplatelet group and 33 were in the dabigatran alone group. In both the groups, there was a significant reduction in CHA2DS2-VASc score, i.e., 2.58 ± 1.32-1.94 ± 1.21 in dabigatran-treated patients within 6 months, and the score was lowered from 3.76 ± 1.22 to 2.92 ± 1.22 in other groups. The mean value of the HAS-BLED score of dabigatran was reduced from 1.15 ± 0.83 to 0.84 ± 0.78 and that of dabigatran with antiplatelet group from 2.10 ± 0.94 to 1.74 ± 0.92.

Conclusion

It was observed that within 6 months, both the treatment groups showed a reduction in the risk scores. The dabigatran group had lower background risks of stroke and bleeding in comparison to the dabigatran plus antiplatelet group.