Effect of Tirofiban on new cerebral microbleeds after mechanical thrombectomy in patients with acute ischemic stroke.

OBJECTIVE: The aim of this study was to analyze the effect of tirofiban on new cerebral microhemorrhage after mechanical thrombectomy in patients with acute ischemic stroke. METHODS: In total, 203 patients with acute ischemic stroke treated by mechanical thrombectomy in our department of neurology were enrolled as the research objects. The patients were divided into two groups: the patients who used tirofiban within 24 h after surgery were assigned to the study group (78 subjects), while patients who did not use tirofiban were assigned to the conventional group (125 subjects). Magnetic resonance imaging was used to detect new-onset cerebral microbleeds in patients with stroke after surgery. The National Institute of Health Stroke Scale, modified ranking scale, and activity of daily living scale were used to assess the prognosis of patients, and the general data and the occurrence of adverse effects between two groups were compared to comprehensively evaluate the efficacy and safety of tirofiban. RESULTS: The proportion of atrial fibrillation in the research group was significantly lower than that in the conventional group. The research group had a much lower rate of new-onset cerebral microbleeds than the conventional group (p<0.001). There was no significant difference in the proportion of adverse reactions between the two groups (p>0.05). CONCLUSION: The application of tirofiban in mechanical thrombectomy of patients with acute ischemic stroke has high safety, effectively reduces the occurrence of new cerebral microhemorrhage, and provides a guarantee for patient safety.

Statistical analysis for efficacy of tirofiban combined with ozagrel in the treatment of progressive cerebral infarction patients out of thrombolytic therapy time window.

OBJECTIVES: To investigate the safety and efficacy of combined tirofiban-ozagrel therapy for treating progressive stroke patients out of thrombolytic therapy time window. METHODS: This prospective, double-blind, randomized controlled study included 337 patients who had experienced an acute ischemic stroke between November 2017 and December 2018. All patients were randomized into three groups: 1) the tirofiban/ozagrel group (n=113), 2) the tirofiban group (n=110), and 3) the ozagrel group (n=114). The platelet aggregation (PAG), thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB) levels in the patients from these groups were evaluated before starting treatment and then, at 24h, 7 days, and 14 days after treatment. The National Institutes of Health Stroke Scale (NIHSS) scores were evaluated before treatment and then, 24h, 1 week, 2 weeks, and 4 weeks after treatment. The Barthel Index (BI) score was used to measure safety, and the modified Rankin scale (mRS) was used to evaluate disability following 3 months of treatment. The risk factors affecting clinical outcomes were analyzed using logistic multivariate regression. RESULTS: The mean NIHSS score for all the patients was 13.17±3.13 before treatment, and no significant difference between the basic clinical parameters of the three patient groups was found. Following treatment, both PAG and FIB were significantly reduced compared with the baseline (p<0.05). The levels of PAG and FIB in the tirofiban/ozagrel group were significantly lower than those in the tirofiban and ozagrel groups at 24h and 7 days after treatment (p<0.05). The NIHSS score decreased significantly in all treatment groups (p<0.05). The tirofiban/ozagrel NIHSS scores were significantly lower than that of the tirofiban and ozagrel groups at 24h, 1 week, and 2 weeks post initiation (p<0.05 for all). There were no significant differences in the BI and mRS scores or the intracranial hemorrhage rates; further, age, sex, Trial of ORG 10172 in acute stroke treatment (TOAST) type, baseline NIHSS and 24-h NIHSS scores, baseline thrombus-related factors, and treatment methods were shown to not be independent risk factors for clinical outcomes. CONCLUSION: The combination of tirofiban and ozagrel, as well as monotherapy with either tirofiban or ozagrel, transiently improves the neural function of patients and reduces platelet aggregation and fibrinogen formation in the first 4 weeks following a stroke event; additionally, none of these treatments increased the risk for hemorrhage in these progressive stroke patients over a 3-month period.

Statistical analysis for efficacy of tirofiban combined with ozagrel in the treatment of progressive cerebral infarction patients out of thrombolytic therapy time window

OBJECTIVES: To investigate the safety and efficacy of combined tirofiban-ozagrel therapy for treating progressive stroke patients out of thrombolytic therapy time window. METHODS: This prospective, double-blind, randomized controlled study included 337 patients who had experienced an acute ischemic stroke between November 2017 and December 2018. All patients were randomized into three groups: 1) the tirofiban/ozagrel group (n=113), 2) the tirofiban group (n=110), and 3) the ozagrel group (n=114). The platelet aggregation (PAG), thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen (FIB) levels in the patients from these groups were evaluated before starting treatment and then, at 24h, 7 days, and 14 days after treatment. The National Institutes of Health Stroke Scale (NIHSS) scores were evaluated before treatment and then, 24h, 1 week, 2 weeks, and 4 weeks after treatment. The Barthel Index (BI) score was used to measure safety, and the modified Rankin scale (mRS) was used to evaluate disability following 3 months of treatment. The risk factors affecting clinical outcomes were analyzed using logistic multivariate regression. RESULTS: The mean NIHSS score for all the patients was 13.17±3.13 before treatment, and no significant difference between the basic clinical parameters of the three patient groups was found. Following treatment, both PAG and FIB were significantly reduced compared with the baseline (p<0.05). The levels of PAG and FIB in the tirofiban/ozagrel group were significantly lower than those in the tirofiban and ozagrel groups at 24h and 7 days after treatment (p<0.05). The NIHSS score decreased significantly in all treatment groups (p<0.05). The tirofiban/ozagrel NIHSS scores were significantly lower than that of the tirofiban and ozagrel groups at 24h, 1 week, and 2 weeks post initiation (p<0.05 for all). There were no significant differences in the BI and mRS scores or the intracranial hemorrhage rates; further, age, sex, Trial of ORG 10172 in acute stroke treatment (TOAST) type, baseline NIHSS and 24-h NIHSS scores, baseline thrombus-related factors, and treatment methods were shown to not be independent risk factors for clinical outcomes. CONCLUSION: The combination of tirofiban and ozagrel, as well as monotherapy with either tirofiban or ozagrel, transiently improves the neural function of patients and reduces platelet aggregation and fibrinogen formation in the first 4 weeks following a stroke event; additionally, none of these treatments increased the risk for hemorrhage in these progressive stroke patients over a 3-month period.

Eficácia e segurança da ponte de tirofiban como alternativa à suspensão da terapia antiplaquetária dupla em pacientes submetidos à cirurgia: uma revisão sistemática / Efficacy and safety of tirofiban bridge as an alternative to suspension of dual antiplatelet therapy in patients undergoing surgery: a systematic review

Resumo A ponte de tirofiban é uma alternativa à suspensão da terapia antiplaquetária dupla no perioperatório de pacientes com alto risco de trombose de stent e de sangramento. Objetivamos avaliar a eficácia e a segurança deste protocolo em pacientes submetidos à cirurgia em até 12 meses após intervenção coronária percutânea com stent. Realizamos uma revisão sistemática por meio de pesquisa nas bases PubMed, Web of Science, Cochrane, EMBASE, LILACS e SciELO e nas referências de artigos relevantes ao tema. Dos 107 trabalhos encontrados, cinco foram incluídos após análise dos critérios de elegibilidade e da qualidade metodológica, totalizando 422 pacientes, sendo 227 do grupo controle. Apesar das limitações reportadas, quatro dos cinco estudos incluídos indicam que a ponte de tirofiban é eficaz em reduzir eventos cardíacos adversos e segura ao não interferir no risco de eventos hemorrágicos ou sangramentos. Todavia, são necessários ensaios clínicos randomizados para evidências robustas.

Abstract Use of a tirofiban bridge is an alternative to simply withdrawing dual antiplatelet therapy prior to operating on patients at high risk of stent thrombosis and bleeding. We aimed to evaluate the efficacy and safety of this protocol in patients undergoing surgery within 12 months of a percutaneous coronary intervention involving stenting. We performed a systematic review based on searches of the PubMed, Web of Science, Cochrane, Embase, Lilacs, and Scielo databases and of the references of relevant articles on the topic. Five of the 107 studies identified were included after application of eligibility criteria and analysis of methodological quality, totaling 422 patients, 227 in control groups. Notwithstanding the limitations reported, four of the five studies included indicate that the tirofiban bridge technique is effective for reducing adverse cardiac events and is safe in terms of not interfering with the risk of hemorrhagic events or bleeding. However, randomized clinical trials are needed to provide robust evidence.

Clinical efficacy of tirofiban combined with a Solitaire stent in treating acute ischemic stroke.

This study explores the safety and effect of acute cerebral infarction treatment by microcatheter injection of tirofiban combined with a Solitaire AB stent and/or stent implantation. Emergency cerebral angiograms showing the responsible vascular occlusion of 120 acute cerebral infarction patients who underwent emergency endovascular thrombectomy were included in the study. These patients were randomly divided into two groups using the random number table method: treatment group (n=60) that received thrombectomy (with cerebral artery stents) combined with intracerebral injection of tirofiban and control group (n=60) that only received thrombectomy (with cerebral artery stents alone). The baseline data, cerebral angiography before and after surgery, hospitalization, and follow-up results of patients in these two groups were compared. Furthermore, the incidence of major adverse cerebrovascular events of these two groups was compared (90-day modified Rankin scale, a score of 0-2 indicates a good prognosis). The difference between baseline clinical data and brain angiography between these two groups was not statistically significant. Patients in the treatment group had a higher prevalence of thrombolysis in cerebral infarction grade 2b/3 than patients in the control group (88.3% (53/60) vs 66.7% (40/60), P=0.036). Moreover, the National Institutes of Health Stroke Scale scores 7 days after surgery and the 90-day prognosis were all better for the patients who received tirofiban (P=0.048 and P=0.024). Mechanical thrombectomy with Solitaire AB stents in combination with the injection of tirofiban through a microcatheter appears to be safe and effective for the endovascular treatment of acute ischemic stroke.

Clinical efficacy of tirofiban combined with a Solitaire stent in treating acute ischemic stroke

This study explores the safety and effect of acute cerebral infarction treatment by microcatheter injection of tirofiban combined with a Solitaire AB stent and/or stent implantation. Emergency cerebral angiograms showing the responsible vascular occlusion of 120 acute cerebral infarction patients who underwent emergency endovascular thrombectomy were included in the study. These patients were randomly divided into two groups using the random number table method: treatment group (n=60) that received thrombectomy (with cerebral artery stents) combined with intracerebral injection of tirofiban and control group (n=60) that only received thrombectomy (with cerebral artery stents alone). The baseline data, cerebral angiography before and after surgery, hospitalization, and follow-up results of patients in these two groups were compared. Furthermore, the incidence of major adverse cerebrovascular events of these two groups was compared (90-day modified Rankin scale, a score of 0-2 indicates a good prognosis). The difference between baseline clinical data and brain angiography between these two groups was not statistically significant. Patients in the treatment group had a higher prevalence of thrombolysis in cerebral infarction grade 2b/3 than patients in the control group (88.3% (53/60) vs 66.7% (40/60), P=0.036). Moreover, the National Institutes of Health Stroke Scale scores 7 days after surgery and the 90-day prognosis were all better for the patients who received tirofiban (P=0.048 and P=0.024). Mechanical thrombectomy with Solitaire AB stents in combination with the injection of tirofiban through a microcatheter appears to be safe and effective for the endovascular treatment of acute ischemic stroke.

In-Lab Upfront Use of Tirofiban May Reduce the Occurrence of No-Reflow During Primary Percutaneous Coronary Intervention. A Pilot Randomized Study.

BACKGROUND:: Despite successful opening of culprit coronary artery, myocardial reperfusion does not always follows primary percutaneous coronary intervention (PPCI). Glycoprotein IIb/IIIa inhibitors are used in the treatment of no-reflow (NR), but their role to prevent it is unproven. OBJECTIVE:: To evaluate the effect of in-lab administration of tirofiban on the incidence of NR in ST-elevation myocardial infarction (STEMI) treated with PPCI. METHODS:: STEMI patients treated with PPCI were randomized (24 tirofiban and 34 placebo) in this double-blinded study to assess the impact of intravenous tirofiban on the incidence of NR after PPCI according to angiographic and electrocardiographic methods. End-points of the study were: TIMI-epicardial flow grade; myocardial blush grade (MBG); resolution of ST-elevation < 70% (RST < 70%) at 90min and 24h after PPCI. RESULTS:: Baseline anthropometric, clinical and angiographic characteristics were balanced between the groups. The occurrence of TIMI flow < 3 was not significantly different between the tirofiban (25%) and placebo (35.3%) groups. MBG ≤ 2 did not occur in the tirofiban group, and was seen in 11.7% of patients in the placebo group (p=0.13). RST < 70% occurred in 41.6% x 55.8% (p=0.42) at 90min and in 29% x 55.9% (p=0.06) at 24h in tirofiban and placebo groups, respectively. Severe NR (RST ≤ 30%) was detected in 0% x 26.5% (p=0.01) at 90 min, and in 4.2% x 23.5% (p=0.06) at 24h in tirofiban and placebo groups, respectively. CONCLUSION:: This pilot study showed a trend toward reduction of NR associated with in-lab upfront use of tirofiban in STEMI patients treated with PPCI and paves the way for a full-scale study testing this hypothesis. FUNDAMENTO:: Mesmo com abertura da artéria coronária culpada bem sucedida, a reperfusão miocárdica nem sempre sucede a intervenção coronariana percutânea primária (ICPP). Inibidores da glicoproteína IIb/IIIa são usados no tratamento do fenômeno de não reperfusão (NR), mas seu papel para preveni-lo não está comprovado. OBJETIVO:: Avaliar o efeito da administração, em laboratório, de tirofibana sobre a incidência de NR em infarto agudo do miocárdio com supra do segmento ST (IAMCSST) tratado com ICPP. MÉTODOS:: Pacientes com IAMCSST tratados com ICPP foram randomizados (24 tirofibana e 34 placebo) neste estudo duplo-cego para avaliar o impacto de tirofibana intravenosa sobre a incidência de NR após ICPP de acordo com métodos angiográficos e eletrocardiográfico. Os desfechos do estudo foram: fluxo epicárdico TIMI (grau), grau de fluxo miocárdico (MBG), resolução da elevação do segmento ST < 70% (RST < 70%) aos 90 minutos e 24 horas após ICPP. RESULTADOS:: Características antropométricas, clínicas e angiográficas basais eram equilibradas entre os grupos. A ocorrência de fluxo TIMI < 3 não foi significativamente diferente entre os grupos tirofibana (25%) e placebo (35,3%). MBG ≤ 2 não ocorreu no grupo tirofibana, e foi detectado em 11,7% dos pacientes do grupo placebo (p=0,13). RST < 70% ocorreu em 41,6% x 55,8% (p=0.42) aos 90 minutos, e em 29% x 55,9% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. NR grave (RST ≤ 30%) ocorreu em 0% x 26,5% (p=0,01) aos 90 minutos, e em 4,2% x 23,5% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. CONCLUSÃO:: Este estudo piloto mostrou uma tendência de redução de NR associada ao uso, em laboratório, de tirofibana em pacientes com IAMCSST tratados com ICPP, e abre caminho para um estudo em escala real que teste essa hipótese.

In-Lab Upfront Use of Tirofiban May Reduce the Occurrence of No-Reflow During Primary Percutaneous Coronary Intervention. A Pilot Randomized Study / Uso de Tirofibana em Laboratório pode Reduzir Ocorrência de não Reperfusão Durante Intervenção Coronariana Percutânea Primária. Um Estudo Piloto Randomizado

Abstract Background: Despite successful opening of culprit coronary artery, myocardial reperfusion does not always follows primary percutaneous coronary intervention (PPCI). Glycoprotein IIb/IIIa inhibitors are used in the treatment of no-reflow (NR), but their role to prevent it is unproven. Objective: To evaluate the effect of in-lab administration of tirofiban on the incidence of NR in ST-elevation myocardial infarction (STEMI) treated with PPCI. Methods: STEMI patients treated with PPCI were randomized (24 tirofiban and 34 placebo) in this double-blinded study to assess the impact of intravenous tirofiban on the incidence of NR after PPCI according to angiographic and electrocardiographic methods. End-points of the study were: TIMI-epicardial flow grade; myocardial blush grade (MBG); resolution of ST-elevation < 70% (RST < 70%) at 90min and 24h after PPCI. Results: Baseline anthropometric, clinical and angiographic characteristics were balanced between the groups. The occurrence of TIMI flow < 3 was not significantly different between the tirofiban (25%) and placebo (35.3%) groups. MBG ≤ 2 did not occur in the tirofiban group, and was seen in 11.7% of patients in the placebo group (p=0.13). RST < 70% occurred in 41.6% x 55.8% (p=0.42) at 90min and in 29% x 55.9% (p=0.06) at 24h in tirofiban and placebo groups, respectively. Severe NR (RST ≤ 30%) was detected in 0% x 26.5% (p=0.01) at 90 min, and in 4.2% x 23.5% (p=0.06) at 24h in tirofiban and placebo groups, respectively. Conclusion: This pilot study showed a trend toward reduction of NR associated with in-lab upfront use of tirofiban in STEMI patients treated with PPCI and paves the way for a full-scale study testing this hypothesis.

Resumo Fundamento: Mesmo com abertura da artéria coronária culpada bem sucedida, a reperfusão miocárdica nem sempre sucede a intervenção coronariana percutânea primária (ICPP). Inibidores da glicoproteína IIb/IIIa são usados no tratamento do fenômeno de não reperfusão (NR), mas seu papel para preveni-lo não está comprovado. Objetivo: Avaliar o efeito da administração, em laboratório, de tirofibana sobre a incidência de NR em infarto agudo do miocárdio com supra do segmento ST (IAMCSST) tratado com ICPP. Métodos: Pacientes com IAMCSST tratados com ICPP foram randomizados (24 tirofibana e 34 placebo) neste estudo duplo-cego para avaliar o impacto de tirofibana intravenosa sobre a incidência de NR após ICPP de acordo com métodos angiográficos e eletrocardiográfico. Os desfechos do estudo foram: fluxo epicárdico TIMI (grau), grau de fluxo miocárdico (MBG), resolução da elevação do segmento ST < 70% (RST < 70%) aos 90 minutos e 24 horas após ICPP. Resultados: Características antropométricas, clínicas e angiográficas basais eram equilibradas entre os grupos. A ocorrência de fluxo TIMI < 3 não foi significativamente diferente entre os grupos tirofibana (25%) e placebo (35,3%). MBG ≤ 2 não ocorreu no grupo tirofibana, e foi detectado em 11,7% dos pacientes do grupo placebo (p=0,13). RST < 70% ocorreu em 41,6% x 55,8% (p=0.42) aos 90 minutos, e em 29% x 55,9% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. NR grave (RST ≤ 30%) ocorreu em 0% x 26,5% (p=0,01) aos 90 minutos, e em 4,2% x 23,5% (p=0,06) em 24 horas nos grupos tirofibana e placebo, respectivamente. Conclusão: Este estudo piloto mostrou uma tendência de redução de NR associada ao uso, em laboratório, de tirofibana em pacientes com IAMCSST tratados com ICPP, e abre caminho para um estudo em escala real que teste essa hipótese.

Gene mutations of platelet glycoproteins and response to tirofiban in acute coronary syndrome / Mutações gênicas das glicoproteínas plaquetárias e resposta ao tirofiban na síndrome coronariana aguda

CONTEXT AND OBJECTIVES: Glycoprotein inhibitors (abciximab, eptifibatide and tirofiban) are used in patients with unstable angina and non-ST-segment elevation myocardial infarction before percutaneous coronary intervention. Of these, tirofiban is the least effective. We hypothesized that the response to tirofiban might be associated with glycoprotein gene mutations. DESIGN AND SETTING: Prospective study at Emergency Unit, Heart Institute (InCor), University of São Paulo. METHOD: Intrahospital evolution and platelet aggregation in response to tirofiban were analyzed in relation to four glycoprotein mutations in 50 patients indicated for percutaneous coronary intervention: 17 (34%) with unstable angina and 33 (66%) with non-ST-segment elevation myocardial infarction. Platelet aggregation was analyzed using the Born method. Blood samples were obtained before and one hour after tirofiban infusion. Glycoproteins Ia (807C/T ), Ib (Thr/Met) , IIb (Ile/Ser ) and IIIa (PIA ) were the mutations selected. RESULTS: Hypertension, dyslipidemia, diabetes, smoking, previous coronary artery disease and stroke were similar between the groups. Mutant glycoprotein IIIa genotypes had lower platelet aggregation before tirofiban administration than that of the wild genotype (41.0% ± 22.1% versus 55.9% ± 20.8%; P = 0.035). Mutant glycoprotein IIIa genotypes correlated moderately with lower platelet inhibition (r = -0.31; P = 0.030). After tirofiban administration, platelet glycoprotein Ia, Ib, IIb and IIIa mutations did not influence the degree of inhibition of platelet aggregation or intrahospital mortality. CONCLUSIONS: Mutations of glycoproteins Ia, Ib, IIb and IIIa did not influence platelet aggregation in response to tirofiban in patients with unstable angina and non-ST-segment elevation myocardial infarction.

RESUMO CONTEXTO E OBJETIVOS: Inibidores da glicoproteína (abciximab, eptifibatide, tirofiban) são utilizados em pacientes com angina instável e infarto do miocárdio sem elevação do segmento ST (IAMSSST) antes da intervenção coronária percutânea. Dentre eles, o tirofiban é o menos eficaz. Nossa hipótese é que a resposta ao tirofiban possa estar associada a mutações no gene da glicoproteína. DESENHO E LOCAL: Estudo prospectivo na Unidade de Emergência do Instituto do Coração (InCor), Universidade de São Paulo (USP). MÉTODOS: Foram analisadas a evolução intra-hospitalar e agregabilidade plaquetária em resposta ao tirofiban de 4 mutações da glicoproteína em 50 pacientes com indicação para intervenção coronária percutânea, 17 (34%) com angina instável e 33 (66%) com IAMSSST. A agregação plaquetária foi analisada pelo método de Born. Amostras de sangue foram obtidas antes e uma hora após infusão do tirofiban. As glicoproteínas Ia (807C/T ), Ib (Thr/Met ), IIb (Ile/Ser ) e IIIa (PIA ) foram as mutações selecionadas. RESULTADOS: Hipertensão, dislipidemia, diabetes, tabagismo, doença coronariana e acidente vascular cerebral prévios foram semelhantes entre os grupos. Observou-se menor agregabilidade plaquetária dos genótipos mutantes da glicoproteína IIIa antes da administração de tirofiban do genótipo selvagem (41% ± 22% versus 56% ± 21%; P = 0,035). Genótipos mutantes da glicoproteína IIIa correlacionaram-se moderadamente com menor inibição plaquetária (r = -0,31; P = 0,030). Após a administração tirofiban, as mutações das glicoproteínas Ia, Ib, IIb, e IIIa não influenciaram o grau de inibição da agregação plaquetária e mortalidade intra-hospitalar. CONCLUSÕES: Mutações das glicoproteínas Ia, Ib, IIb e IIIa não influenciaram a agregação plaquetária em resposta ao tirofiban nos pacientes com angina instável e IAMSSST.

Gene mutations of platelet glycoproteins and response to tirofiban in acute coronary syndrome.

CONTEXT AND OBJECTIVES: Glycoprotein inhibitors (abciximab, eptifibatide and tirofiban) are used in patients with unstable angina and non-ST-segment elevation myocardial infarction before percutaneous coronary intervention. Of these, tirofiban is the least effective. We hypothesized that the response to tirofiban might be associated with glycoprotein gene mutations. DESIGN AND SETTING: Prospective study at Emergency Unit, Heart Institute (InCor), University of São Paulo. METHOD: Intrahospital evolution and platelet aggregation in response to tirofiban were analyzed in relation to four glycoprotein mutations in 50 patients indicated for percutaneous coronary intervention: 17 (34%) with unstable angina and 33 (66%) with non-ST-segment elevation myocardial infarction. Platelet aggregation was analyzed using the Born method. Blood samples were obtained before and one hour after tirofiban infusion. Glycoproteins Ia (807C/T ), Ib (Thr/Met) , IIb (Ile/Ser ) and IIIa (PIA ) were the mutations selected. RESULTS: Hypertension, dyslipidemia, diabetes, smoking, previous coronary artery disease and stroke were similar between the groups. Mutant glycoprotein IIIa genotypes had lower platelet aggregation before tirofiban administration than that of the wild genotype (41.0% ± 22.1% versus 55.9% ± 20.8%; P = 0.035). Mutant glycoprotein IIIa genotypes correlated moderately with lower platelet inhibition (r = -0.31; P = 0.030). After tirofiban administration, platelet glycoprotein Ia, Ib, IIb and IIIa mutations did not influence the degree of inhibition of platelet aggregation or intrahospital mortality. CONCLUSIONS: Mutations of glycoproteins Ia, Ib, IIb and IIIa did not influence platelet aggregation in response to tirofiban in patients with unstable angina and non-ST-segment elevation myocardial infarction.

Effect of intracoronary tirofiban on platelet alpha-granule membrane protein and myocardial perfusion level during emergency percutaneous coronary intervention.

This study aimed to investigate the effect of intracoronary application of tirofiban on platelet alpha-granule membrane protein (GMP-140) and myocardial perfusion levels during emergency percutaneous coronary intervention (PCI). A total of 70 patients who accepted emergency PCI treatment were randomly divided into tirofiban and control groups. We determined GMP-140 and troponin I (cTnI) levels before and 12 h after surgery, as well as N-terminal pro-brain natriuretic peptide levels 1 and 7 days after surgery in the two groups. The results showed that GMP-140 and cTnI levels were significantly (P < 0.01) lower in the tirofiban group than in the control group 12 h after operation (17.99 ± 1.01 vs 24.56 ± 1.96 µg/L and 50.96 ± 2.20 vs 58.69 ± 2.34 ng/mL, respectively). The D-value of the N-terminal pro-brain natriuretic peptide levels between 1 and 7 days after operation was significantly higher in the tirofiban group than in the control group (894.19 ± 90.91 vs 829.50 ± 84.18 pg/mL; P < 0.01). The intracoronary application of tirofiban during emergency PCI clearly reduced the GMP-140 level, inhibited the activation function of platelets, improved myocardial perfusion, and helped recover cardiac function in patients.

Effect of IIb-IIIa glycoprotein inhibitors in a partial limb amputation model submitted to warm ischemia in rats.

Viability and functional results of a segment replantation depend on the prevention of deleterious effects of ischemia. Prolonged ischemia leads to alterations in the microcirculation: thrombosis, edema, production of oxygen free radicals, and platelet aggregation. The effect of IIb-IIIa glycoprotein inhibitors was tested in a partial limb amputation model submitted to warm ischemia. The male Wistar rats were divided into four groups: G1 with 0 hours of ischemia and saline ( N = 20), G2 with 6 hours of ischemia and saline ( N = 24), G3 with 6 hours of ischemia and abciximab ( N = 23), and G4 with 6 hours of ischemia and tirofiban ( N = 29). The limbs were observed for 7 days and classified as viable or nonviable. Viability and mortality rates were obtained and analyzed by Q-square and Fisher exact tests ( P < 0.05). The viability rates were 100% (G1), 30% (G2), 77.78% (G3), and 80.95% (G4). G2 was statistically different from G1, G3, and G4. G1, G3, and G4 were not statistically different. Transoperative and postoperative mortalities were not statistically different. The administration of abciximab and tirofiban improved limb salvage after ischemia and reperfusion and did not modify mortality rates significantly.

[Protective effects of an inhibitor of glycoprotein IIb/IIIa in the hepatic and pulmonary disturbances secondary to ischemia and reperfusion injury of rat's liver]. / Efeito protetor de antagonista das gliproteínas IIb/IIa nas alterações hepáticas e pulmonares secundárias à isquemia e reperfusão do fígado em ratos.

UNLABELLED: BACKGROUND Hepatic ischemia-reperfusion injury is responsible for a considerable morbidity and mortality. AIM: To evaluate the effect of a platelet glycoprotein IIb/IIIa receptor inhibitor (tirofiban) on hepatic and pulmonary disturbances associated with hepatic ischemia-reperfusion injury. METHODS: Twenty-three Wistar rats divided in three groups: rats sham-operated (n = 6), rats submitted to ischemia-reperfusion that received saline solution (n = 8), and rats submitted to ischemia-reperfusion treated with 0.7 mg/kg of tirofiban (n = 9). Serum aminotransferases (AST and ALT) were also determined, and the study of hepatic tissue histology was carried out. The evaluation of the pulmonary disturbances was done using the Evans blue test and the tissular determination of myeloperoxidase. Hepatic mitochondrial oxidation and phosphorylation were also measured. RESULTS: There was an increase in the state 3 respiration, ADP/O ratio and respiration control rate in the group treated with tirofiban. This group had also lower levels of aminotransferases and the histological findings were significantly less intense. Pulmonary evaluation demonstrated decrease of the Evans blue test in the tirofiban group and an increase of its tissular determination of myeloperoxidase. CONCLUSION: The inhibition of glycoprotein IIb/IIIa receptor with tirofiban protected the hepatic disturbances and prevented the increase of pulmonary vascular permeability secondary to the ischemia-reperfusion injury of the liver.

Comparison of reperfusion regimens with or without tirofiban in ST-elevation acute myocardial infarction.

There is continued debate as to whether a combined reperfusion regimen with platelet glycoprotein IIb/IIIa inhibitors provides additional benefit in optimal myocardial reperfusion of patients with a ST-elevation acute myocardial infarction (AMI). In addition, the best angiographic method to evaluate optimal myocardial reperfusion is still controversial. Patients (n = 144) with a first AMI presenting <6 hours from onset of symptoms were randomized to receive a conjunctive strategy (n = 72) with low-dose alteplase (50 mg) and tirofiban (0.4 microg/kg/min/30 minute bolus; infusion of 0.1 microg/kg/minute), or tirofiban plus stenting percutaneous coronary intervention (PCI). Control patients (n = 72) received standard strategy with either full-dose alteplase (100 mg) or stenting PCI [correction]. All patients were submitted to coronary angiographic study at 90 minutes. The primary end point was Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow at 90 minutes. Secondary end points were TIMI myocardial perfusion (TMP) rates, a composite end point at 30 days (death, reinfarction, refractory ischemia, stroke, heart failure, revascularization procedures, or pulmonary edema), and bleeding or hematologic variables. The rate of TIMI 3 flow at 90 minutes for patients treated with alteplase alone was 42% compared with 64% for those who received low-dose alteplase and tirofiban. Standard stenting PCI achieved 81% of TIMI 3 flow compared with 92% when tirofiban was used. Significantly higher rates of TMP grade 3 were observed when tirofiban was used as the adjunctive treatment in both alteplase (66% vs 47%) and stenting PCI (73% vs 55%). Higher rates of the composite end point were observed in standard regimens compared with conjunctive regimens (hazard ratio 5.8, 95% confidence interval 1.27 to 26.6, p = 0.023). Regardless of reperfusion regimen, better outcomes were observed when a combination of TIMI 3 flow and TMP grade 3 was achieved. Beyond TIMI 3 flow rate, the TMP grade was an important determinant. The rates of major bleeding were similar (2.8%) for standard versus conjunctive regimens with tirofiban. Thus, tirofiban as a conjunctive therapy for lytic and stenting regimens not only improves TIMI 3 flow rates, but also the TMP3 rates, which are related to a better clinical outcome without an increase in the risk of major bleeding. This study supports the hypothesis that platelets play a key role not only in the atherothrombosis process, but also in the disturbances of microcirculation and tissue perfusion.