Multimodal imaging-based treatment recommendations for managing submacular hemorrhage.

Submacular haemorrhage (SMH) is an emergency, and the most important immediate action in the treatment of SMH is the early displacement or evacuation of subretinal heme from below the fovea, followed by simultaneous or sequential treatment of the underlying cause. Photoreceptor damage can occur immediately after the onset of SMH for a variety of reasons, including toxins released from the blood, the diffusion barrier created by the blood for oxygen delivery and nutrition to the outer retinal layers, and shearing forces on the outer retinal layers, resulting in permanent visual deterioration. A clinician's decision to treat SMH is influenced by a number of factors, including presenting visual acuity, duration of visual symptoms, SMH aetiology and characteristics, availability of intraocular gases and tissue plasminogen activator, and pars plana vitrectomy facilities. For many clinicians, the duration of visual symptoms is the most important and first consideration when planning SMH treatment. Very little emphasis is given to the SMH's imaging characteristics. Currently, there are several treatment options for SMH removal. There is a need to develop a simplified treatment algorithm for SMH that is less reliant on the patient's visual complaints, considers heme characteristics on basic retinal imaging, and has the potential to achieve uniform and predictable treatment outcomes in real-world situations. In this short article, we discuss the various factors that can assist clinicians in the management of SMH and present a simplified treatment algorithm based on the SMH's retinal imaging characteristics.

A multimodal treatment of basilar artery re-occlusion - case report.

BACKGROUND: Stroke due to basilar artery occlusion (BAO) is a severe neurovascular condition with only recently proven effectiveness of mechanical thrombectomy as treatment. Early re-occlusion of the basilar artery (RE-BAO) is an even more challenging form of stroke to treat, associated with poor outcomes and still no optimal treatment guidelines. There are only a few reported cases covering this topic thus far. CASE PRESENTATION: We present a 52-year-old male patient with RE-BAO treated with a combination of bridging intravenous (IV) tissue plasminogen activator (tPA), mechanical thrombectomy (MT), rescue intraarterial (IA) tPA, and after re-occlusion, repeated bridging IV tPA and repeated MT in a 75-hour time span. DISCUSSION: In previous trials applying IA tPA after MT showed promising results in patients with anterior circulation stroke. However, our case report implies that using a combined treatment of IV tPA before and IA tPA after MT in posterior circulation shows similar results. CONCLUSION: To our knowledge, this is the first case of RE-BAO managed with the aforementioned multimodal treatment. Such an approach recently showed promising results in the anterior circulation, and our report supports the effectiveness of multimodal recanalization treatment in the posterior circulation as well.

Successful Treatment of Central Retinal Artery Occlusion With Tissue Plasminogen Activator Followed by Recurrent Retinal Ischemia.

Purpose: To describe the use of intra-arterial tissue plasminogen activator (tPA) to treat central retinal artery occlusion (CRAO). Methods: A case and its findings were analyzed. Results: A 45-year-old man diagnosed with a CRAO and had cerebral angiography and treatment with intra-arterial tPA. After treatment, follow-up included optical coherence tomography (OCT), fundus photography, fluorescein angiography, and OCT angiography. The visual acuity (VA) improved from hand motions to 20/30 immediately after fibrinolysis. A vascular occlusion event the next day resulted in a decrease in VA to 20/400. After initiation of dual antiplatelet therapy, the patient's VA improved to 20/20. As the retina recovered, the evolution of retinal ischemic changes to a finding similar to paracentral acute middle maculopathy was seen on imaging. Conclusions: This is the first report describing a patient safely started on dual antiplatelet therapy that led to vision improvement after initial treatment with intra-arterial tPA for a CRAO resulted in recurrent vision loss.

Differences in Acute Expression of Matrix Metalloproteinases-9, 3, and 2 Related to the Duration of Brain Ischemia and Tissue Plasminogen Activator Treatment in Experimental Stroke.

Matrix metalloproteinases (MMPs) such as MMP-9, 3, and 2 degrade the cellular matrix and are believed to play a crucial role in ischemic stroke. We examined how the duration of ischemia (up to 4 h) and treatment with recombinant tissue plasminogen activator altered the comparative expression of these MMPs in experimental ischemic stroke with reperfusion. Both prolonged ischemia and r-tPA treatment markedly increased MMP-9 expression in the ischemic hemisphere (all p < 0.0001). The duration of ischemia and r-tPA treatment also significantly increased MMP-2 expression (p < 0.01-0.001) in the ischemic hemisphere (p < 0.01) but to a lesser degree than MMP-9. In contrast, MMP-3 expression significantly decreased in the ischemic hemisphere (p < 0.001) with increasing duration of ischemia and r-tPA treatment (p < 0.05-0001). MMP-9 expression was prominent in the vascular compartment and leukocytes. MMP-2 expression was evident in the vascular compartment and MMP-3 in NeuN+ neurons. Prolonging the duration of ischemia (up to 4 h) before reperfusion increased brain hemorrhage, infarction, swelling, and neurologic disability in both saline-treated (control) and r-tPA-treated mice. MMP-9 and MMP-2 expression were significantly positively correlated with, and MMP-3 was significantly negatively correlated with, infarct volume, swelling, and brain hemorrhage. We conclude that in experimental ischemic stroke with reperfusion, the duration of ischemia and r-tPA treatment significantly altered MMP-9, 3, and 2 expression, ischemic brain injury, and neurological disability. Each MMP showed unique patterns of expression that are strongly correlated with the severity of brain infarction, swelling, and hemorrhage. In summary, in experimental ischemic stroke in male mice with reperfusion, the duration of ischemia, and r-tPA treatment significantly altered the immunofluorescent expression of MMP-9, 3, and 2, ischemic brain injury, and neurological disability. In this model, each MMP showed unique patterns of expression that were strongly correlated with the severity of brain infarction, swelling, and hemorrhage.

Assessing mortality and safety of IV thrombolysis in ischemic stroke patients on direct oral anticoagulants (DOACs): A systematic review and meta-analysis.

BACKGROUND: Intravenous thrombolysis (IVT) is considered a standard reperfusion therapy for acute ischemic stroke (AIS) patients presenting within 4.5 hours of the last known well (LKW). Current guidelines contraindicate the use of IVT in patients within the window who are on Direct Oral Anticoagulants (DOACs) and took their last dose within 48 hours of presentation, due to a risk of symptomatic intracranial hemorrhage (sICH). OBJECTIVE: To assess the safety of IVT as management of AIS in patients who take DOACs. METHODS: A thorough literature search of four databases (PubMed, Scopus, Medline, Google Scholar, Web of science and ScienceDirect) was done from inception until May 2023. Double-arm studies that reported outcomes of mortality, sICH, and mRS scores were selected. Results from these studies were presented as odds ratios (ORs) with 95 % confidence intervals (CIs) and were pooled using a random-effects model. RESULTS: Four eligible studies were included with a total of 238,425 stroke patients who underwent IVT (3330 in the DOAC arm and 235,217 in the placebo arm). The group with prior DOAC intake showed a significant decrease in sICH development and an increase in functional independence at 90 days compared to the control group. No significant association was seen between prior DOAC use and any serious alteplase-related complication within 36 hours, serious systemic or life-threatening hemorrhage within 36 hours, mortality within 3 months, or mRS score at 3 months. CONCLUSION: The pooled analysis suggests that IVT is a safe management option for acute ischemic stroke in patients with DOAC intake before symptom onset without an increased risk of serious adverse events.

The changes of tPA/PAI-1 system are associated with the ratio of BDNF/proBDNF in major depressive disorder and SSRIs antidepressant treatment.

Increasing evidence demonstrates that brain-derived neurotrophic factor (BDNF) can be regarded as a biomarker for major depression. Our previous work found that the ratio of mature BDNF (mBDNF) to precursor-BDNF (proBDNF) was a pivotal factor in the pathogenesis of major depressive disorder (MDD). But the mechanism behind the ratio is still obscure. Tissue plasminogen activator (tPA) and plasminogen activator inhibitor-1 (PAI-1) both play essential roles in depression by regulating the ratio of BDNF/proBDNF. In present study, we analyzed BDNF, proBDNF, tPA and PAI-1 in the peripheral blood in 57 MDD patients pre- and post-treatment and in 57 healthy controls. We verified that BDNF and tPA levels were significantly decreased, whereas proBDNF and PAI-1 levels elevated obviously in MDD group pre-treatment. And after 4 weeks SSRIs treatment, the BDNF and tPA levels increased while the proBDNF and PAI-1 levels reduced. The MDD pre-treatment group had the lowest ratio of BDNF to proBDNF compared to MDD post-treatment group and control group. Though the ratio of tPA/PAI-1 in MDD pre-treatment had not reached the significance, it was still the lowest one among the three groups. The combination of tPA + PAI + BDNF showed the best diagnostic value for MDD. In summary, our data suggested that the interaction between tPA and PAI-1 implicated to the MDD and the antidepressant treatment which might through regulating the BDNF/proBDNF ratio. The combination of tPA, PAI-1 and BDNF might offer a helpful way for MDD diagnosis.

Tissue plasminogen activator for acute branch atheromatous disease exhibits transient improvement and worsening.

BACKGROUND: Tissue plasminogen activator (tPA) is an effective treatment for acute ischemic stroke. Although initial improvement is observed when administered for branch atheromatous disease (BAD), some cases subsequently worsen. Clinical data on the characteristics of these patients is lacking, and the benefits of tPA are unclear. OBJECTIVE: To analyze rebound cases and elucidate the clinical characteristics and outcomes associated with tPA administration in BAD. METHODS: This multicenter retrospective study was conducted in Japan. Worsening after initial improvement of a condition is termed as rebound, and such cases were compared with other types of ischemic stroke in patients with and without rebound. The characteristics of patients with BAD who rebounded were examined. RESULTS: The study included 93 patients. Among the patients who were administered tPA, the NIHSS scores at 24 h and 7 days post-tPA were significantly higher in patients with BAD than in patients with other types of infarcts. The group with BAD exhibited a significantly higher rate of rebound than other groups (37.5 % vs. 0 %, P < 0.001). However, no differences were observed in outcomes between patients who experienced rebound after tPA administration and those who did not. CONCLUSIONS: Reevaluation and changing the strategy of tPA use in patients with BAD may be necessary. However, this study does not totally discourage its use, as specific patients can benefit.

Poria cocos Extract Alleviates tPA-Induced Hemorrhagic Transformation after Ischemic Stroke through Regulation of Microglia M1/M2 Phenotypes Polarization.

Delayed thrombolytic therapy with tissue plasminogen activator (tPA), the only FDA-approved drug for ischemic stroke, can cause catastrophic hemorrhagic transformation (HT) after ischemic stroke. However, it remains largely unknown how microglial polarization dynamically changes in HT. Poria cocos is a widely used functional edible fungus in Asia and has been used for more than 2000 years as a food and medicine in China. Our preliminary study found that P. cocos extract (PCE) significantly reduced the volume of cerebral infarction. We performed the effects of PCE on tPA-induced HT in rat models of autologous thromboembolism middle cerebral artery occlusion in vivo and BV-2 cells injured by oxygen-glucose deprivation/reperfusion in vitro. Hemorrhage test and triphenyltetrazolium chloride staining were performed to examine the efficiency of PCE. The expression level of proteins associated with microglia polarization was detected using Western blotting and immunofluorescence staining. Small interfering RNA transfection reveals the regulatory mechanism of PCE on microglia polarization. PCE plus tPA reduced hemorrhage and infarct volumes after ischemic stroke. During tPA-induced HT, M1 microglia increased over time from 3 days onward and remained high for at least 7 days, reaching the peak at 7 days, M2 microglia gradually increased after 3 days and continued to increase for at least 14 days. Furthermore, PCE inhibited the secretion of pro-inflammatory cytokines in M1 microglia and improved the secretion of anti-inflammatory cytokines in M2 microglia, which related to the regulation of the IRF5-IRF4 axis. This current study indicates that PCE alleviates tPA-induced HT after ischemic stroke by modulating microglia M1/M2 phenotype polarization.

Safety and Efficacy Comparison of Tenecteplase and Alteplase for Clinically Suspected Large Vessel Occlusion Strokes without Thrombectomy.

INTRODUCTION: Tenecteplase is a thrombolytic with higher fibrin affinity and is potentially better in clot lysis. A higher spontaneous recanalisation rate for large vessel occlusion (LVO) strokes had been shown in comparison studies with alteplase. Results of the LVO studies reflect the composite effect of the thrombolytic and thrombectomy, as patients would be treated by thrombectomy had they not been recanalised by intravenous thrombolysis alone. Thrombectomy is not readily available in many parts of the world. Our study aimed to compare the outcomes of suspected LVO patients treated with tenecteplase versus alteplase only, without the confounding effect of thrombectomy. METHODS: This is a retrospective review. Data of patients given tenecteplase from May 2020 to August 2023 and those given alteplase 0.9 mg/kg from January 2019 to August 2023 were retrieved. Due to fluctuation in supply of tenecteplase during the COVID pandemic, some LVO patients were given alteplase. Patients with anterior circulation, clinically suspected LVO strokes (defined as National Institutes of Health Stroke Scale (NIHSS) score ≥6, plus cortical signs or hyperdense vessel sign), with thrombolysis given within 4.5 h of stroke onset were analysed. Patients with thrombectomy done were excluded. Safety and efficacy outcomes were compared. RESULTS: There were 245 tenecteplase-treated patients treated between May 1, 2020, and August 31, 2023, and 732 patients were treated with alteplase between January 1, 2019, to August 31, 2023. Out of these, 148 tenecteplase patients and 138 alteplase 0.9 mg/kg patients fulfilled the study criteria. The symptomatic intracerebral haemorrhage rate was non-significantly lower in the tenecteplase group (2.1% vs. 5.8%, p = 0.13). There were no significant differences in the rate of ≥8-point NIHSS improvement (23.6% vs. 23.7%, p = 1) or the ≥4-point improvement (40.5% vs. 40.7%, p = 1) at 24 h. At 3 months, 21.6% of tenecteplase patients had good functional outcome (modified Rankin scale [mRS] 0-2), compared to 26.3% in the alteplase group (p = 0.40). CONCLUSION: In this pragmatic study of clinically suspected anterior circulation LVO patients without thrombectomy, outcome solely reflects the effects of tenecteplase. Tenecteplase showed comparable safety and efficacy to alteplase, but the result should be interpreted with caution in view of its small sample size and non-randomised study design.

Alcohol use disorder disrupts BDNF maturation via the PAI-1 pathway which could be reversible with abstinence.

The plasminogen activator inhibitor-1 (PAI-1)→mature brain-derived neurotrophic factor (mBDNF) pathway plays a pivotal role in the conversion of probrain-BDNF (ProBDNF) to mBDNF, but its clinical relevance in patients with alcohol use disorder (AUD) remains unknown. Enzyme-linked immunosorbent assays were used to examine the relevant protein levels of components of the PAI-1→mBDNF pathway in plasma samples from three groups of subjects, and statistical analysis was performed using analysis of variance (ANOVA) and one-way repeated-measures ANOVA. Our findings revealed significant alterations induced by alcohol. (1) AUD was associated with significant decreases in tissue plasminogen activator (tPA), mBDNF, and tropomyosin receptor kinase B (TrkB); significant increases in PAI-1, ProBDNF, and P75 neurotrophin receptor (P75NTR); and inhibited conversion of ProBDNF to mBDNF. (2) Following abstinence, the levels of tPA, mBDNF, and TrkB in the AUD group significantly increased, whereas the levels of PAI-1, ProBDNF, and P75NTR significantly decreased, promoting the conversion of ProBDNF to mBDNF. These clinical outcomes collectively suggest that AUD inhibits the conversion of ProBDNF to mBDNF and that abstinence reverses this process. The PAI-1→mBDNF cleavage pathway is hypothesized to be associated with AUD and abstinence treatment.

The islet tissue plasminogen activator/plasmin system is upregulated with human islet amyloid polypeptide aggregation and protects beta cells from aggregation-induced toxicity.

AIMS/HYPOTHESIS: Apart from its fibrinolytic activity, the tissue plasminogen activator (tPA)/plasmin system has been reported to cleave the peptide amyloid beta, attenuating brain amyloid deposition in Alzheimer's disease. As aggregation of human islet amyloid polypeptide (hIAPP) is toxic to beta cells, we sought to determine whether activation of the fibrinolytic system can also reduce islet amyloid deposition and its cytotoxic effects, which are both observed in type 2 diabetes. METHODS: The expression of Plat (encoding tPA) and plasmin activity were measured in isolated islets from amyloid-prone hIAPP transgenic mice or non-transgenic control islets expressing non-amyloidogenic mouse islet amyloid polypeptide cultured in the absence or presence of the amyloid inhibitor Congo Red. Plat expression was also determined in hIAPP-treated primary islet endothelial cells, bone marrow-derived macrophages (BMDM) and INS-1 cells, in order to determine the islet cell type(s) producing tPA in response to hIAPP aggregation. Cell-free thioflavin-T assays and MS were used to respectively monitor hIAPP aggregation kinetics and investigate plasmin cleavage of hIAPP. Cell viability was assessed in INS-1 beta cells treated with hIAPP with or without plasmin. Finally, to confirm the findings in human samples, PLAT expression was measured in freshly isolated islets from donors with and without type 2 diabetes. RESULTS: In isolated islets from transgenic mice, islet Plat expression and plasmin activity increased significantly with the process of amyloid deposition (p≤0.01, n=5); these effects were not observed in islets from non-transgenic mice and were blocked by Congo Red (p≤0.01, n=4). In response to hIAPP exposure, Plat expression increased in BMDM and INS-1 cells vs vehicle-treated cells (p≤0.05, n=4), but not in islet endothelial cells. Plasmin reduced hIAPP fibril formation in a dose-dependent manner in a cell-free system, and restored hIAPP-induced loss of cell viability in INS-1 beta cells (p≤0.01, n=5). Plasmin cleaved monomeric hIAPP, inducing a rapid decrease in the abundance of full-length hIAPP and the appearance of hIAPP 1-11 and 12-37 fragments. hIAPP 12-37, which contains the critical amyloidogenic region, was not toxic to INS-1 cells. Finally, PLAT expression was significantly increased by 2.4-fold in islets from donors with type 2 diabetes (n=4) vs islets from donors without type 2 diabetes (n=7) (p≤0.05). CONCLUSIONS/INTERPRETATION: The fibrinolytic system is upregulated in islets with hIAPP aggregation. Plasmin rapidly degrades hIAPP, limiting its aggregation into amyloid and thus protecting beta cells from hIAPP-induced toxicity. Thus, increasing islet plasmin activity might be a strategy to limit beta cell loss in type 2 diabetes.

Platelet-to-neutrophil ratio predicts hemorrhagic transformation and unfavorable outcomes in acute ischemic stroke with intravenous thrombolysis.

BACKGROUND: Acute ischemic stroke (AIS) retains a notable stance in global disease burden, with thrombolysis via recombinant tissue plasminogen activator (rtPA) serving as a viable management approach, albeit with variable outcomes and the potential for complications like hemorrhagic transformation (HT). The platelet-to-neutrophil ratio (P/NR) has been considered for its potential prognostic value in AIS, yet its capacity to predict outcomes following rtPA administration demands further exploration. AIM: To elucidate the prognostic utility of P/NR in predicting HT and clinical outcomes following intravenous rtPA administration in AIS patients. METHODS: Data from 418 AIS patients treated with intravenous rtPA at Thammasat University Hospital from January 2018 to June 2021 were retrospectively analyzed. The relationship between P/NR and clinical outcomes [early neurological deterioration (E-ND), HT, delayed ND (D-ND), and 3-mo outcomes] was scrutinized. RESULTS: Notable variables, such as age, diabetes, and stroke history, exhibited statistical disparities when comparing patients with and without E-ND, HT, D-ND, and 3-mo outcomes. P/NR prognostication revealed an optimal cutoff of 43.4 with a 60.3% sensitivity and a 52.5% specificity for 90-d outcomes. P/NR prognostic accuracy was statistically significant for 90-d outcomes [area under the curve (AUC) = 0.562], D-ND (AUC = 0.584), and HT (AUC = 0.607). CONCLUSION: P/NR demonstrated an association with adverse 3-mo clinical outcomes, HT, and D-ND in AIS patients post-rtPA administration, indicating its potential as a predictive tool for complications and prognoses. This infers that a diminished P/NR may serve as a novel prognostic indicator, assisting clinicians in identifying AIS patients at elevated risk for unfavorable outcomes following rtPA therapy.

Effects of intracameral tissue plasminogen activator injection on posterior capsular opacification, fibrin formation, and intraocular pressure in dogs after phacoemulsification.

OBJECTIVE: To evaluate whether intracameral tissue plasminogen activator (tPA) injection is effective in regulating posterior capsular opacification (PCO), fibrin formation and intraocular pressure (IOP) after cataract surgery. ANIMAL STUDIED: Prospective study involving 30 eyes of 21 dogs that underwent phacoemulsification. PROCEDURES: Thirty eyes were randomly divided into two groups of 15 eyes (control and tPA groups). Intracameral tPA (25 µg/0.1 mL) was injected into tPA group eyes before corneal incision closure but not into the eyes of the control group. The grades of anterior fibrin formation and PCO were compared based on slit lamp biomicroscope examination at 1 and 2 weeks, 1 month, and 2-3 months postoperatively. IOP was measured using applanation tonometry every 30 min for 4 h immediately after operation and on the following morning. The IOP of the two groups at each time was compared. RESULTS: The grade of anterior fibrin formation and that of PCO were not significantly different between the two groups at any time point (p > .05). However, the IOP of the tPA group was significantly lower than that of the control group at each point on the day of surgery (p < .05). No complications were observed with tPA injection, except for temporary hyphema (for 3 days) in one eye. CONCLUSIONS: Although the intracameral tPA injection did not affect anterior fibrin formation and PCO, it effectively maintained normal IOP immediately after phacoemulsification. Thus, our findings provide valuable insights into the potential benefits of intracameral tPA injection in achieving immediate IOP control after phacoemulsification.

A single-center study of reference intervals for TAT, PIC, TM and t-PAIC in healthy older Chinese adults.

OBJECTIVE: To explore the distribution of thrombin-antithrombin complex (TAT), plasmin-α2-antiplasmin inhibitor complex (PIC), thrombomodulin (TM), and tissue plasminogen activator-inhibitor complex (t-PAIC) in healthy older Chinese adults, and establish the reference intervals (RIs). METHODS: The Biotech Shine i2900 chemiluminescence immune assay was used to measure the plasma concentrations of TAT, PIC, TM, and t-PAIC in 1628 adults ≥ 60 years. The RIs were established using the 2.5th and 97.5th percentiles of the distribution. RESULTS: TAT levels were lower in males than females across all ages. Differences between the ages of 60-79 and ≥ 80 in both sex groups were statistically significant, with an upward trend with age. PIC levels showed no difference between the sexes but increased with age in both groups. TM levels did not differ between the sex groups, with slight fluctuation with age. The level in females aged 60-69 was slightly higher than that in the other groups; the difference was statistically significant. T-PAIC levels were not significantly different between the sex groups, with less fluctuation with sex and age. The level in males ≥ 80 years old was slightly lower than that in the other groups; the difference was statistically significant. The RIs for all markers in healthy older Chinese adults were determined and statistically reported by age and sex. For TAT, the RIs for males aged 60-79 and ≥ 80 are 0.51-2.30 ng/mL and 0.88-3.72 ng/mL, respectively, whereas for females aged 60-79 and ≥ 80, the RIs are 0.68-2.82 ng/mL and 1.02-3.67 ng/mL, respectively. For PIC, the RIs for the age groups 60-69, 70-79, and ≥ 80 are 0.10-0.89 µg/mL, 0.12-1.00 µg/mL, and 0.21-1.04 µg/mL, respectively. The RI of TM for females aged 60-69 is 3.32-13.22 TU/mL, whereas it is 2.96-13.26 TU/mL for the other groups. The RI of t-PAIC for males aged ≥ 80 is 1.63-10.68 ng/mL, whereas it is 2.33-11.34 ng/mL for the other groups. CONCLUSIONS: Discrepancies exist in thrombus markers among different sex and age groups. The RIs of TAT, PIC, TM and t-PAIC for healthy older Chinese adults were successfully established.

Pharmacokinetics and pharmacodynamics of low doses of recombinant tissue plasminogen activator to establish a model for biosimilarity comparisons.

Background: Recombinant tissue plasminogen activator (rt-PA) is a thrombolytic agent and essential in emergency medical care. Given recent supply shortages, the availability of biosimilar products is an urgent medical need. However, biosimilarity trials are difficult to perform in critically ill patients. Objectives: The aim of this pilot study was to investigate the pharmacokinetics and pharmacodynamics of low rt-PA doses to establish a model for testing proposed biosimilars in healthy volunteers. Methods: Eight healthy volunteers received 0.02 to 0.05 mg/kg rt-PA on 3 study days; blood samples were obtained every 4 minutes after the end of the bolus infusion to measure rt-PA antigen levels by enzyme immunoassay, and the pharmacodynamics were assessed with rotational thromboelastometry. Results: Bolus infusion of low rt-PA doses was safe and well tolerated. Maximal plasma concentrations and the area under the curve increased dose-dependently. Time-concentration curves were clearly separated between the lower and the higher doses. As expected, the half-live of rt-PA was short (4.5-5 min), and representative for therapeutic doses. The intrasubject coefficient variations were moderate (<25%). Bolus infusion of rt-PA dose-dependently shortened lysis time and lysis onset time in both dose groups and caused maximum clot lysis of 100% in all participants. Conclusion: In conclusion, the pharmacokinetics of rt-PA was dose linear and displayed limited intrasubject variability even at subtherapeutic doses. The half-life and thus clearance of rt-PA was representative of full therapeutic doses. The lysis time was shortened in a dose and time-dependent fashion and was clearly distinguishable between doses. Thus, the model appears to be suitable and sensitive to test biosimilarity.

Combined treatment of submacular hemorrhage with low-dose subretinal recombinant tissue plasminogen activator and intravitreal conbercept.

BACKGROUND: Pars Plana Vitrectomy (PPV) combined with subretinal injection of low-dose recombinant tissue plasminogen activator (rt-PA) and intravitreal injection of Conbercept as a novel therapy for submacular hemorrhage (SMH) requires evaluation. METHODS: In a retrospective interventional clinical study, 14 eyes of 14 patients with SMH underwent PPV along with rt-PA (subretinal) and Conbercept (intravitreal) injections. The main outcomes included best-corrected visual acuities (BCVAs), degrees of blood displacement, and adverse events. All patients completed at least 6-month follow-up visits. RESULTS: Mean BCVAs significantly improved at 7 days (22.29 ± 15.35), 1 month (30.71 ± 16.42), 3 months (38.29 ± 13.72), 4 months (38.86 ± 14.15), and 6 months (41.21 ± 14.91) post-treatment compared to baseline (16.36 ± 13.97) (F = 12.89, P = 0.004). The peak improvement in BCVAs occurred at 6 months postoperatively. The procedure effectively eliminated subfoveal hemorrhages in all eyes, with clots removal and absorption occurring within one month and complete regression by 3-month follow-up visits. Postoperatively, two cases of AMD resulted in discoid scars on the fundus. No instances of rt-PA-related retinal toxicity were observed during the follow-up period. CONCLUSION: The combined approach of PPV with low-dose rt-PA and anti-VEGF shows promise in enhancing both vision and anatomical structure in SMH therapy. Individualized treatment plans tailored to the primary disease should be developed to optimize visual prognoses. TRIAL REGISTRATION: Retrospectively registered No.ChiCTR2100053034. Registration date: 10/11/2021.

Ultraslow low-dose thrombolytic therapy in patients with acute mechanical prosthetic heart valve thrombosis - A prospective cohort study.

BACKGROUND: While surgery still remains the gold standard treatment for mechanical prosthetic valve thrombosis (MPVT) by many guidelines, the ultraslow low-dose thrombolytic regimen has been reported as a promising alternative. METHODS: In this prospective single-center cohort, patients with acute MPVT were treated with an ultraslow low-dose thrombolytic regimen consisting of 25 mg infusion of recombinant tissue-type plasminogen activator (rtPA) over 25 h. The regimen could be repeated in case of failure until resolution/occurrence of adverse events or a maximum cumulative dose of 150 mg. The primary outcome was the complete MPVT resolution rate; other outcomes included first-dose success rate, major bleeding, thromboembolic events, mortality, and total thrombolytic dose/duration. RESULTS: Between April 2018 to January 2024, 135 episodes of acute MPVT were treated with an ultraslow low-dose thrombolytic regimen in 118 patients. In 118/135 (87.4 %) episodes, right-sided prosthetic valve was involved. Complete success was achieved in 88.1 % of cases, with 39.5 % responding after the first dose. The median total dose was 50 mg over a median of 30 h. Only one fatal intracranial hemorrhage occurred (0.7 %), with no other bleeding or thromboembolic complications. CONCLUSION: The ultraslow low-dose thrombolytic regimen appears to exhibit high efficacy and acceptable safety in treating acute MPVT. Further large clinical trials are essential for validating these preliminary findings.

Fibrinolysis associated proteins and lipopolysaccharide bioactivity in plasma and cerebrospinal fluid in multiple sclerosis.

The coagulation cascade and fibrinolysis have links with neuroinflammation and increased activation of the coagulation system has been reported in MS patients. We quantified levels of D-dimer, tissue plasminogen activator (tPA), plasminogen activator inhibitor-1 (PAI-1) and the bioactivity of bacterial lipopolysaccharide (LPS) in cerebrospinal fluid (CSF) and plasma from newly diagnosed untreated MS patients and controls. These molecules showed multiple correlations with each other as well as with age, HLA-DRB1*15:01, body-mass-index and CSF IgG. Our results confirm previous findings of increased plasma PAI-1 and LPS in MS patients compared to controls indicating changes in platelet function and gut permeability in MS.

Contraindications to tissue plasminogen activator thrombolysis for acute lower extremity ischemia.

OBJECTIVE: Previous randomized prospective trials have demonstrated the effectiveness of transcatheter tissue plasminogen activator (tPA) thrombolysis in treating acute limb ischemia (ALI) compared to conventional surgery. These pivotal trials have also highlighted contraindications for these procedures. Given recent advancements in techniques and technology, our aim is to reassess the relevance of these contraindications in contemporary practice. METHODS: A retrospective chart analysis was performed utilizing the inpatient medical records of consecutive individuals who underwent tPA treatment for acute limb ischemia (ALI) from September 2016 to April 2022. Inclusion criteria encompassed patients aged 18 and above displaying clinical symptoms and imaging evidence of ALI within 14 days. All patients received tPA with suction thrombectomy following the fast-track thrombolysis protocol. In cases where a persistent thrombus or stenosis was detected, catheter-directed thrombolysis was considered overnight, and patients underwent angiography and reassessment in the operating room subsequently. RESULTS: Patients were classified into two groups based on the STILE trial's established contraindications for endovascular treatment in acute limb ischemia (ALI). If a patient had any of these contraindications, they were placed in the contraindicated group. This resulted in 24 patients (32%) in the contraindicated group and 52 patients (68%) in the non-contraindicated group. No statistically significant demographic variations were observed between these groups. Contraindications in our study included uncontrolled hypertension (12/24, 50%), recent invasive procedures (7/27, 29%), history of cerebrovascular accident (CVA) within 6 months (3/24, 12%), and intracranial malformation/neoplasms (2/24, 8%). Three patients within the non-contraindicated group experienced bleeding complications: two with puncture site bleeds and one with nasal bleeding. In contrast, one patient in the contraindicated group had transient postoperative hematuria. There were no significant differences in bleeding complications observed between the two groups (p = .771). Additionally, no amputations were observed within our population. CONCLUSIONS: In light of our study results and advancements in endovascular therapies, we can now safely and efficiently treat patients who were previously considered contraindicated for such treatments. It is essential to individualize treatments and carefully balance the risks and benefits of endovascular versus open surgical revascularization for these patients. Additionally, we believe that the nearly 30-year-old guidelines for endovascular therapies need to be revisited and updated to align with modern technology.

Treatment outcome of bridge mechanical thrombectomy with different IV-tPA dosages in the standard and extended time window in real-world practice.

BACKGROUND: Differences of treatment outcome between full or reduced dose of tissue plasminogen activator (tPA) for bridge mechanical thrombectomy (MT) in the extended time window have not been clearly established. We aimed to present real-world results of bridge MT with different tPA dosages in the standard and extended windows. MATERIALS AND METHODS: Patients with anterior circulation stroke treated with MT between 2017 and 2021 at two stroke referral centers were retrospectively reviewed. Bridge MT with tPA were categorized as full (0.9 mg/kg) or reduced (<0.9 mg/kg) dose. Standard window (SW) cohort was defined as MT performed within 6 h of acute ischemic stroke onset, while those beyond 6 h as the extended window (EW) cohort. 90 days Modified Rankin Scale (mRS) score, technical treatment success, in-hospital mortality, and post-treatment hemorrhage were analyzed. RESULTS: A total of 423 patients met the inclusion criteria, 218 of which treated in the SW, while 205 treated in the EW. Within the SW cohort, the full-dose tPA group demonstrated a higher proportion of good functional outcome (GFO) at 90 days (mRS0-3) versus reduced (49% vs 21%, p = 0.0358). The overall GFO of SW was higher than that of the EW cohort (33% vs 20%, p = 0.0480). Within the EW cohort, GFO was similar between full and reduced dose groups. Successful reperfusion rate was lower in SW versus EW cohorts (39% vs 58%, p = 0.0199). CONCLUSION: In real-world practice, the GFO of bridge MT is better than MT alone. The tPA dosage is not a determining factor of GFO in EW MT.