The management of antiplatelet therapy in acute coronary syndrome patients with thrombocytopenia: a clinical conundrum

Thrombosis in immune thrombocytopenia - current status and future perspectives

Immune thrombocytopenia (ITP) is an autoimmune disorder in which a combination of defective platelet production and enhanced clearance leads to thrombocytopenia. The primary aim for therapy in patients with this condition is the prevention of bleeding. However, more recently, increased rates of venous and arterial thrombotic events have been reported in ITP, even in the context of marked thrombocytopenia. In this review we discuss the epidemiology, aetiology and management of thrombotic events in these patients. We consider the impact of ITP therapies on the increased thrombotic risk, in particular the use of thrombopoietin-receptor agonists (TPO-RAs), as well as factors inherent to ITP itself. We also discuss the limited evidence available to guide clinicians in the treatment of these complex cases.

Baseline thrombocytopenia in acute coronary syndrome: The lower, the worse

BACKGROUND

Patients with baseline thrombocytopenia can have increased mortality and morbidity, but are typically excluded from randomized clinical trials studying acute coronary syndromes (ACS). We sought to better define the effect thrombocytopenia on clinical outcomes in ACS patients.

METHODS

Patients identified from the NCDR Chest Pain registry at Mayo Clinic Arizona from Oct 2015 to Sep 2018 were retrospectively classified into two groups: TP (platelet <150 × 10³ μL) and control (platelet ≥150 × 10³ μL). The groups were analyzed for the clinical outcome (all-cause mortality, major adverse cardiac events (MACE), and bleeding events). The TP group was divided into moderate-severe thrombocytopenia (TP_mod; platelet 50-100 × 10³ μL) and mild thrombocytopenia (TP_mild; platelet 100-150 × 10³ μL) for further analysis. P-value <0.05 is considered significant.

RESULTS

Five hundred and thirty-six patients were identified, and 72 patients (13%) had thrombocytopenia. The median follow-up time was 1.1 years. The TP group was older (TP vs. control: mean age 73 ± 13 years vs. 70 ± 13 years; P = 0.026). In patients discharged on dual-antiplatelet therapy, the TP group had higher all-cause mortality (23% vs. 7.3%; P = 0.007) but not major bleeding events (11% vs. 5.0%; P = 0.123). Only all-cause mortality increased with the severity of thrombocytopenia (TP_mod vs. TP_mild vs. control: 33% vs. 24% vs. 7.3%; P = 0.007).

CONCLUSIONS

In patients with ACS, baseline thrombocytopenia is associated with increased all-cause mortality and all bleeding events without net MACE benefit. Further study is needed to identify the optimal antiplatelet strategy in this higher risk population.

Challenges and Advances in Managing Thrombocytopenic Cancer Patients

Cancer patients have varying incidence, depth and duration of thrombocytopenia. The mainstay of managing severe chemotherapy-induced thrombocytopenia (CIT) in cancer is the use of platelet transfusions. While prophylactic platelet transfusions reduce the bleeding rate, multiple unmet needs remain, such as high residual rates of bleeding, and anticancer treatment dose reductions/delays. Accordingly, the following promising results in other settings, antifibrinolytic drugs have been evaluated for prevention and treatment of bleeding in patients with hematological malignancies and solid tumors. In addition, Thrombopoeitin receptor agonists have been studied for two major implications in cancer: treatment of severe thrombocytopenia associated with myelodysplastic syndrome and acute myeloid leukemia; primary and secondary prevention of CIT in solid tumors in order to maintain dose density and intensity of anti-cancer treatment. Furthermore, thrombocytopenic cancer patients are often prescribed antithrombotic medication for indications arising prior or post cancer diagnosis. Balancing the bleeding and thrombotic risks in such patients represents a unique clinical challenge. This review focuses upon non-transfusion-based approaches to managing thrombocytopenia and the associated bleeding risk in cancer, and also addresses the management of antithrombotic therapy in thrombocytopenic cancer patients.

The Impact of Baseline Thrombocytopenia on Late Bleeding and Mortality After Transcatheter Aortic Valve Implantation (From the Japanese Multicenter OCEAN-TAVI Registry)

Baseline thrombocytopenia was reported as a risk factor for bleeding or mortality in several medical areas, particularly in the cardiovascular field. This study aimed to assess the prognostic value of baseline thrombocytopenia in patients who had transcatheter aortic valve implantation. This study included 2,588 patients from the Optimized Catheter valvular intervention Japanese multicenter registry. Thrombocytopenia was defined as platelet count of <150 × 10⁹/L and was classified into moderate/severe (<100 × 10⁹/L) and mild (≧100-<150 × 10⁹/L). At 3 years after index procedure, the moderate/severe thrombocytopenia group had a significantly higher cumulative composite late bleeding than the no thrombocytopenia group (log-rank test, p < 0.0001). Moreover, the moderate/severe thrombocytopenia group had a significantly higher cumulative all-cause, cardiovascular, and noncardiovascular mortality rates than the no thrombocytopenia group (log-rank test, p < 0.0001, p = 0.0014, p < 0.0001, respectively). After adjusting for confounders, the excess risk of moderate/severe and mild thrombocytopenia relative to no thrombocytopenia for the composite bleeding remained significant (hazard ratio 2.66: [95% confidence interval: 1.35 to 4.88], p = 0.006 and hazard ratio 2.10: [95% confidence interval: 1.36 to 3.21], p = 0.001, respectively). In conclusion, baseline thrombocytopenia was associated with an increased risk of late bleeding and poor prognosis. Baseline platelet level could be a prognostic marker for risk stratification.

Impact of Thrombocytopenia on In-Hospital Outcome in Patients Undergoing Percutaneous Coronary Intervention

Background

Thrombocytopenia was intuitively considered to be associated with higher risk of bleeding and multiple comorbidities after percutaneous coronary intervention (PCI). However, controversial results exist, and the real-world clinical impact of thrombocytopenia in patients undergoing PCI is largely unknown. The aim of this study was to evaluate the influence of baseline thrombocytopenia on the prognosis of patients undergoing PCI.

Methods

Using the West China Hospital Inpatient Sample database, patients who underwent PCI were identified from August 2012 to January 2019. Baseline thrombocytopenia was defined as a preprocedural platelet count of 100 × 10⁹/L or less obtained from a routine blood sample taken within 48 hours before coronary PCI. The clinical effect of the advanced thrombocytopenia group (≤85 × 10⁹/L), according to the median value of platelet count in the thrombocytopenia cohort, was further assessed. The primary outcome was a composite of in-hospital death, bleeding events, and post-PCI transfusion.

Results

Of 9531 patients enrolled in our study, 936 had baseline thrombocytopenia and 8595 patients did not have. There were no significant differences in the primary outcome between the two groups. However, advanced thrombocytopenia was independently associated with higher risk of primary outcome (OR 1.67, 95% CI 1.06 to 2.65, p = 0.029). Acute coronary syndrome (ACS) patients with thrombocytopenia were associated with higher odds of major bleeding (BARC ≥ 2) (OR 2.56, 95% CI 1.24 to 5.44, p = 0.011). Compared with the nonthrombocytopenia group, the thrombocytopenia group with ticagrelor use had higher odds of major bleeding (OR 9.7, 95% CI 1.57 to 60.4 versus OR 0.22, 95% CI 0.03 to 1.69, interaction p = 0.025).

Conclusions

It seems feasible for patients with thrombocytopenia to receive PCI, but close attention should be paid to advanced thrombocytopenia, the risk of postprocedure bleeding in ACS patients, and the use of more potent P2Y₁₂ inhibitor.

The Pharmacological Approach to Oncologic Patients with Acute Coronary Syndrome

Among acute coronary syndrome (ACS) patients, 15% have concomitant cancer, especially in the first 6 months after their diagnosis, as well as in advanced metastatic stages. Lung, gastric, and pancreatic cancers are the most frequent malignancies associated with ACS. Chemotherapy and radiotherapy exert prothrombotic, vasospastic, and proinflammatory actions. The management of cancer patients with ACS is quite challenging: percutaneous revascularization is often underused, and antiplatelet and anticoagulant pharmacological therapy should be individually tailored to the thrombotic risk and to the bleeding complications. Sometimes oncological patients also show different degrees of thrombocytopenia, which further complicates the pharmacological strategies. The aim of this review is to summarize the current evidence regarding the treatment of ACS in cancer patients and to suggest the optimal management and therapy to reduce the risk of adverse coronary events after ACS in this high-risk population.

Incidence and Impact of Thrombocytopenia in Patients Undergoing Percutaneous Coronary Intervention With Drug-Eluting Stents

Platelets are crucial in the pathophysiology of coronary artery disease and are a major target of antithrombotic agents in patients receiving percutaneous coronary intervention (PCI). We sought to evaluate the incidence and prognostic impact of thrombocytopenia on clinical outcomes in patients undergoing PCI with drug-eluting stents (DES). We evaluated consecutive patients who received PCI with DES in the IRIS-DES registry between April 2008 and December 2017. Patients were divided into 2 groups based on the presence of thrombocytopenia (platelet count <150 × 10⁹/L) at baseline. The primary outcome was all-cause mortality, and secondary outcomes included the composite outcome of death, myocardial infarction (MI), and stroke, and major bleeding. Complete follow-up data were available for 1 to 5 years (median, 3.1). Among 26,553 eligible patients, 1,823 (6.9%) had thrombocytopenia at baseline. At 5 years, the incidences of all-cause mortality (15.6% vs 8.1%, p <0.001), composite outcome (23.2% vs 15.6%, p <0.001), and major bleeding (3.7% vs 2.2%, p <0.001) were significantly higher in patients with thrombocytopenia than in those without thrombocytopenia. In multivariable Cox proportional-hazards models, thrombocytopenia was significantly associated with increased risks of all-cause mortality (hazard ratio 1.26, 95% confidence interval 1.07 to 1.48, p = 0.01) and major bleeding (hazard ratio 1.41, 95% confidence interval 1.04 to 1.91, P=0.03). In conclusion, among who patients underwent PCI with DES, the incidence of thrombocytopenia was 6.9%. Baseline thrombocytopenia was significantly associated with increased risks of mortality and major bleeding.

Pharmacotherapeutic considerations for the management of cardiovascular diseases among hospitalized COVID-19 patients

INTRODUCTION

Cardiovascular diseases (CVDs) are among the most frequently identified comorbidities in hospitalized patients with COVID-19. Patients with CV comorbidities are typically prescribed with long-term medications. We reviewed the management of co-medications prescribed for CVDs among hospitalized COVID-19 patients.

AREAS COVERED

There is no specific contraindication or caution related to COVID-19 on the use of antihypertensives unless patients develop severe hypotension from septic shock where all antihypertensives should be discontinued or severe hyperkalemia in which continuation of renin-angiotensin system inhibitors is not desired. The continuation of antiplatelet or statin is not desired when severe thrombocytopenia or severe transminitis develop, respectively. Patients with atrial fibrillation receiving oral anticoagulants, particularly those who are critically ill, should be considered for substitution to parenteral anticoagulants.

EXPERT OPINION

An individualized approach to medication management among hospitalized COVID-19 patients with concurrent CVDs would seem prudent with attention paid to changes in clinical conditions and medications intended for COVID-19. The decision to modify prescribed long-term CV medications should be entailed by close follow-up to check if a revision on the decision is needed, with resumption of any long-term CV medication before discharge if it is discontinued during hospitalization for COVID-19, to ensure continuity of care.

The Clinical Conundrum of Managing Ischemic Stroke in Patients with Immune Thrombocytopenia

Guidelines are lacking for management of acute ischemic stroke and stroke prevention in patients with immune thrombocytopenia (ITP). Our aim is to highlight the dilemma inherent in managing patients with both significant bleeding and thrombotic risk factors. In this review, we present two patients with history of ITP who presented with acute ischemic stroke and received tissue plasminogen activator (tPA) and endovascular thrombectomy (EVT), a rare management strategy in this patient population. In addition, we identified 27 case reports of ischemic stroke in patients with ITP; none of them received tPA or EVT. Furthermore, there are 92 patients with significant thrombocytopenia with no available data regarding the cause of thrombocytopenia, who were acutely treated with tPA or EVT. Conclusive evidence cannot be determined based on these limited number of cases. Future multicenter prospective cohort studies in patients with ITP are needed to provide better evidence-based treatment plans. At present, treatment of acute ischemic stroke in patients with ITP requires close collaboration between hematology and vascular neurology experts to find a balance between the benefit and risk of hemorrhagic complications.

Dual anti-platelet therapy following percutaneous coronary intervention in a population of patients with thrombocytopenia at baseline: a meta-analysis

Background

In this meta-analysis, we aimed to systematically compare the post percutaneous coronary interventional (PCI) adverse bleeding events, stent thrombosis, stroke and other cardiovascular outcomes in a population of patients with and without thrombocytopenia at baseline who were followed up on dual antiplatelet therapy (DAPT).

Methods

Relevant English language articles which were published before June 2019 were retrieved from MEDLINE, http://www.ClinicalTrials.com, EMBASE, Cochrane central, and Google scholar briefly using specific terms such as percutaneous coronary intervention or dual antiplatelet therapy, and thrombocytopenia. All the participants were followed up on DAPT following discharge. Specific endpoints including bleeding events, stent thrombosis, stroke and other adverse cardiovascular events were assessed. The latest version of the RevMan software was used for the statistical assessment. Odd ratios (OR) with 95% confidence intervals (CI) based on a fixed or a random statistical model were used to represent the data graphically.

Results

A total number of 118,945 participants (from 8 studies) were included with 37,753 suffering from thrombocytopenia at baseline. Our results showed post procedural bleeding (OR: 1.89, 95% CI: 1.16–3.07; P = 0.01), access site bleeding (OR: 1.66, 95% CI: 1.15–2.39; P = 0.006), intra-cranial bleeding (OR: 1.78, 95% CI: 1.30–2.43; P = 0.0003), gastro-intestinal bleeding (OR: 1.44, 95% CI: 1.14–1.82; P = 0.002) and any major bleeding (OR: 1.67, 95% CI: 1.42–1.97; P = 0.00001) to be significantly higher in thrombocytopenic patients treated with DAPT after PCI. Total stroke (OR: 1.45, 95% CI: 1.18–1.78; P = 0.0004) specifically hemorrhagic stroke (OR: 1.67, 95% CI: 1.30–2.14; P = 0.0001) was also significantly higher in these patients with thrombocytopenia at baseline. All-cause mortality and major adverse cardiac events were also significantly higher. However, overall total stent thrombosis (OR: 1.18, 95% CI: 0.90–1.55; P = 0.24) including definite and probable stent thrombosis were not significantly different compared to the control group.

Conclusions

According to the results of this analysis, DAPT might have to be cautiously be used following PCI in a population of patients with thrombocytopenia at baseline due to the significantly higher bleeding rate including gastro-intestinal, intra-cranial bleeding and hemorrhagic stroke. Hence, special care might have to be taken when considering anti-platelet agents following PCI in these high risk patients. However, considering the present limitations of this analysis, this hypothesis will have to be confirmed in future trials.

Management of ST-segment-elevation myocardial infarction during the coronavirus disease 2019 (COVID-19) outbreak: Iranian"247" National Committee's position paper on primary percutaneous coronary intervention

World Health Organization has designated coronavirus disease 2019 (COVID‐19) as a pandemic. During the past several weeks, a considerable burden has been imposed on the Iranian's healthcare system. The present document reviewed the latest evidence and expert opinion regarding the management of ST‐segment‐elevation myocardial infarction during the outbreak of COVID‐19 and outlines a practical algorithm for it.

Expert consensus on the diagnosis and treatment of thrombocytopenia in adult critical care patients in China

Thrombocytopenia is a common complication of critical care patients. The rates of bleeding events and mortality are also significantly increased in critical care patients with thrombocytopenia. Therefore, the Critical Care Medicine Committee of Chinese People's Liberation Army (PLA) worked with Chinese Society of Laboratory Medicine, Chinese Medical Association to develop this consensus to provide guidance for clinical practice. The consensus includes five sections and 27 items: the definition of thrombocytopenia, etiology and pathophysiology, diagnosis and differential diagnosis, treatment and prevention.

Recurrent Acute Coronary Syndromes in a Patient with Idiopathic Thrombocytopenic Purpura

A 53-year-old man was admitted to a peripheral hospital with the diagnosis of acute myocardial infarction without ST elevation. Due to the concomitant presence of first-diagnosed thrombocytopenia (platelet count 50.000/μL), it was decided to be treated conservatively with clopidogrel. Five days later, he developed an acute myocardial infarction with ST elevation (STEMI) and was transferred to our department for primary percutaneous coronary intervention (PCI). Coronary angiography revealed three-vessel disease. The left anterior descending lesion was considered culprit, and PCI was successfully performed using a drug-eluting balloon. This approach was considered safer due to the risk of intolerance of prolonged dual antiplatelet therapy in case of stent implantation. Indeed, four days later, aspirin was discontinued, and the patient remained only on clopidogrel due to a platelet fall. Meanwhile, idiopathic thrombocytopenic purpura (ITP) was diagnosed by hematology consultation, and specific ITP treatment was initiated. Seven days following the procedure, the patient was transferred to the Hematology clinic, where a continuous rise of platelet count up to 115.000/μL while on clopidogrel was observed, and he was discharged from the hospital asymptomatic. Unfortunately, twenty days later, the patient died of a lung infection. In ITP patients with STEMI, primary PCI with drug-eluting balloon angioplasty may be a reasonable approach.

Optimal management of coronary artery disease in cancer patients

Owing to early diagnosis and rapid development of treatments for cancers, the five-year survival rate of all cancer types has markedly improved worldwide. Over time, however, there has been an increase in the number of cancer patients who develop coronary artery disease (CAD) due to different causes. First, many risk factors are shared between cancer and CAD. Second, inflammation and oxidative stress are common underlying pathogeneses in both disorders. Lastly, cancer therapy can result in endothelial injury, coronary artery spasm, and coagulation, thereby increasing the risk of CAD. As more cancer patients are being diagnosed with CAD, specialized cardiac care should be established to minimize the cardiovascular mortality of cancer survivors.

Impact of immune thrombocytopenic purpura on clinical outcomes in patients with acute myocardial infarction

Background

Patients with immune thrombocytopenic purpura (ITP) admitted with acute myocardial infarction (AMI) may be challenging to manage given their increased risk of bleeding complications. There is limited evidence in the literature guiding appropriate interventions in this population. The objective of this study is to determine the difference in clinical outcomes in AMI patients with and without ITP.

Methods

Using the United States national inpatient sample database, adults aged ≥18 years, who were hospitalized between 2007 and 2014 for AMI, were identified. Among those, patients with ITP were selected. A propensity‐matched cohort analysis was performed. The primary outcome was in‐hospital mortality. Secondary outcomes were coronary revascularization procedures, bleeding and cardiovascular complications, and length of stay (LOS).

Results

The propensity‐matched cohort included 851 ITP and 851 non‐ITP hospitalizations for AMI. There was no difference in mortality between ITP and non‐ITP patients with AMI (6% vs7.3%, OR:0.81; 95% CI:0.55‐1.19; P = .3). When compared to non‐ITP patients, ITP patients with AMI underwent fewer revascularization procedures (40.9% vs 45.9%, OR:0.81; 95% CI:0.67‐0.98; P = .03), but had a higher use of bare metal stents (15.4% vs 11.3%, OR:1.43; 95% CI:1.08‐1.90; P = .01), increased risk of bleeding complications (OR:1.80; CI:1.36‐2.38; P < .0001) and increased length of hospital stay (6.14 vs 5.4 days; mean ratio: 1.14; CI:1.05‐1.23; P = .002). More cardiovascular complications were observed in patients requiring transfusions.

Conclusions

Patients with ITP admitted for AMI had a similar in‐hospital mortality risk, but a significantly higher risk of bleeding complications and a longer LOS compared to those without ITP. Further studies are needed to assess optimal management strategies of AMI that minimize complications while improving outcomes in this population.

Using PAR4 Inhibition as an Anti-Thrombotic Approach: Why, How, and When?

Protease-activated receptors (PARs) are a family of four GPCRs with a variety of cellular functions, yet the only advanced clinical endeavours to target these receptors for therapeutic gain to date relates to the impairment of platelet function for anti-thrombotic therapy. The only approved PAR antagonist is the PAR1 inhibitor, vorapaxar—the sole anti-platelet drug against a new target approved in the past 20 years. However, there are two PARs on human platelets, PAR1 and PAR4, and more recent efforts have focused on the development of the first PAR4 antagonists, with first-in-class agents recently beginning clinical trial. Here, we review the rationale for this approach, outline the various modes of PAR4 inhibition, and speculate on the specific therapeutic potential of targeting PAR4 for the prevention of thrombotic conditions.

Thrombocytopenia and Coronary Artery Disease, the Existing Dilemmas

Background: Platelets play a pivotal role in the pathogenesis of acute coronary syndrome (ACS) and acute or chronic complications following percutaneous coronary intervention (PCI) as well. Platelet inhibition is a cornerstone treatment in the management of these patients. Thrombocytopenia in patients with ACS is uncommon. Idiopathic thrombocytopenic purpura (ITP) is a rare phenomenon; nevertheless, some case series presenting concomitant ACS and ITP have been described in the literature. The safety of antiplatelet therapy and PCI in patients who have ACS and thrombocytopenia is limited.

Case summary: We present a case of a 60-year-old patient with ITP who was admitted with unstable angina pectoris. On admission, the platelet count was 23 × 109/L. Coronary CT angiography revealed severe stenosis in the mid portion of RCA. After one-week treatment with high-dose Prednisolone, the platelet count recovered, and coronary catheterization was performed. Successful PCI to the RCA with drug-eluting stent was performed. The patient was discharged on dual antiplatelet therapy.

Conclusion: The case suggests that PCI is a suitable treatment for ITP patients with ACS. Hemostasis is the major concern in managing these patients. The treatment strategy may be based on platelet function rather than platelet count alone. Further analysis of antiplatelet therapies as mono or dual therapy are needed.

Defining high bleeding risk in patients undergoing percutaneous coronary intervention: a consensus document from the Academic Research Consortium for High Bleeding Risk

Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance, but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities, and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention-related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention.

Oral Anticoagulation in Patients With Liver Disease

Patients with liver disease are at increased risks of both thrombotic and bleeding complications. Many have atrial fibrillation (AF) or venous thromboembolism (VTE) necessitating oral anticoagulant agents (OACs). Recent evidence has contradicted the assumption that patients with liver disease are "auto-anticoagulated" and thus protected from thrombotic events. Warfarin and non-vitamin K-antagonist OACs have been shown to reduce thrombotic events safely in patients with either AF or VTE. However, patients with liver disease have largely been excluded from trials of OACs. Because all currently approved OACs undergo metabolism in the liver, hepatic dysfunction may cause increased bleeding. Thus, the optimal anticoagulation strategy for patients with AF or VTE who have liver disease remains unclear. This review discusses pharmacokinetic and clinical studies evaluating the efficacy and safety of OACs in patients with liver disease and provides a practical, clinically oriented approach to the management of OAC therapy in this population.

Association of Thrombocytopenia, Revascularization, and In-Hospital Outcomes in Patients with Acute Myocardial Infarction

BACKGROUND

The impact of thrombocytopenia on revascularization and outcomes in patients presenting with acute myocardial infarction remains poorly understood. We sought to evaluate associations between thrombocytopenia, in-hospital management, bleeding, and cardiovascular outcomes in patients hospitalized for acute myocardial infarction in the United States.

METHODS

Patients hospitalized from 2004 to 2014 with a primary diagnosis of acute myocardial infarction were identified from the National Inpatient Sample. Management of acute myocardial infarction was compared between patients with and without thrombocytopenia. Multivariable logistic regression models were used to estimate odds of in-hospital adverse events stratified by thrombocytopenia and adjusted for demographics, cardiovascular risk factors, comorbidities, and treatment.

RESULTS

A total of 6,717,769 patients were hospitalized with a primary diagnosis of acute myocardial infarction, and thrombocytopenia was reported in 219,351 (3.3%). Patients with thrombocytopenia were older, more likely to have other medical comorbidities, were more likely to undergo coronary artery bypass grafting (28.8% vs 8.2%, P < .001), and were less likely to receive a drug-eluting stent (15.5% vs 29.5%, P < .001). After multivariable adjustment, thrombocytopenia was independently associated with nearly twofold increased odds of in-hospital mortality (adjusted odds ratio 1.91; 95% confidence interval, 1.86-1.97). Thrombocytopenia was also independently associated with ischemic stroke, cardiogenic shock, cardiac arrest, and bleeding complications.

CONCLUSIONS

Patients with thrombocytopenia in the setting of acute myocardial infarction had increased odds of bleeding, cardiovascular outcomes, and mortality compared with patients without thrombocytopenia. Future investigations to mitigate the poor prognosis of patients with acute myocardial infarction and thrombocytopenia are warranted.

Incidence, Predictors, and Outcomes of Acquired Thrombocytopenia After Percutaneous Coronary Intervention: A Pooled, Patient-Level Analysis of the CHAMPION Trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition)

BACKGROUND

The influence of cangrelor on the incidence and outcomes of post-percutaneous coronary intervention (PCI) thrombocytopenia is not defined. We aimed to explore the incidence, predictors, and clinical impact of thrombocytopenia after PCI in cangrelor-treated patients.

METHODS AND RESULTS

This was a pooled, patient-level analysis of the CHAMPION trials (Cangrelor Versus Standard Therapy to Achieve Optimal Management of Platelet Inhibition), which compared cangrelor with clopidogrel for prevention of thrombotic complications during and after PCI. Acquired thrombocytopenia was defined as either a drop in platelet count to <100 000 after PCI or a drop of >50% between baseline and a follow-up. The main efficacy outcome was major adverse cardiac events. The primary safety outcome was noncoronary artery bypass grafting-related Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries-defined severe bleeding at 48 hours. Patients (23 783) were enrolled, and 3009 (12.7%) received a GPI (glycoprotein IIb/IIIa inhibitor). Acquired thrombocytopenia occurred in 200 patients (0.8%). The adjusted rate of major adverse cardiovascular events at 48 hours was significantly higher in patients who developed thrombocytopenia compared with those who did not (odds ratio, 3.00; 95% confidence interval, 1.89-4.69; P<0.001), as was major bleeding (odds ratio, 14.71; 95% confidence interval, 5.96-36.30; P<0.001). GPI use was the strongest independent predictor of acquired thrombocytopenia (odds ratio, 2.93; 95% confidence interval, 2.15-3.97; P<0.0001). There was no difference in the rate of acquired thrombocytopenia in patients randomized to cangrelor or clopidogrel.

CONCLUSIONS

Acquired thrombocytopenia after PCI is strongly associated with substantial early morbidity and mortality, as well as major bleeding. GPI use is a significant predictor of thrombocytopenia. Cangrelor is not associated with acquired thrombocytopenia, and its clinical efficacy and safety is consistent irrespective of thrombocytopenia occurrence.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov. Unique identifiers: NCT00305162, NCT00385138, and NCT01156571.

Defining High Bleeding Risk in Patients Undergoing Percutaneous Coronary Intervention

Identification and management of patients at high bleeding risk undergoing percutaneous coronary intervention are of major importance, but a lack of standardization in defining this population limits trial design, data interpretation, and clinical decision-making. The Academic Research Consortium for High Bleeding Risk (ARC-HBR) is a collaboration among leading research organizations, regulatory authorities, and physician-scientists from the United States, Asia, and Europe focusing on percutaneous coronary intervention-related bleeding. Two meetings of the 31-member consortium were held in Washington, DC, in April 2018 and in Paris, France, in October 2018. These meetings were organized by the Cardiovascular European Research Center on behalf of the ARC-HBR group and included representatives of the US Food and Drug Administration and the Japanese Pharmaceuticals and Medical Devices Agency, as well as observers from the pharmaceutical and medical device industries. A consensus definition of patients at high bleeding risk was developed that was based on review of the available evidence. The definition is intended to provide consistency in defining this population for clinical trials and to complement clinical decision-making and regulatory review. The proposed ARC-HBR consensus document represents the first pragmatic approach to a consistent definition of high bleeding risk in clinical trials evaluating the safety and effectiveness of devices and drug regimens for patients undergoing percutaneous coronary intervention.

Benefits and Risks of Anticoagulation in Acute Coronary Syndrome

BACKGROUND

Both antiplatelets and anticoagulants are necessary in the management of acute coronary syndrome (ACS), although the exact proportion of antithrombotic effect that each drug and class should ideally provide remains a matter of ongoing study.

AREA OF UNCERTAINTY

Defining the best combination between the antiplatelet agents and oral anticoagulants (OACs) can be challenging. The choice is particularly important for special categories of patients with ACS who have an indication of a long-term OAC.

DATA SOURCES

A literature search regarding benefits and risks of anticoagulation in ACS was conducted through MEDLINE and EMBASE (past 20 years until September 2018).

THERAPEUTIC ADVANCES

Many patients with ACS have an indication for long-term OACs. Those receiving dual antiplatelet therapy and anticoagulants are considered to be at a high bleeding risk. The addition of a vitamin K antagonist (VKA) imposes a target international normalized ratio of 2.0-3.0. When non-VKA oral anticoagulants are used, the lowest effective tested dose for stroke prevention should be applied. For most patients, triple therapy in the form of an OAC plus dual antiplatelet therapy [aspirin and P2Y12 inhibitors (usually clopidogrel)] should be considered for 3-6 months. Later, dual therapy (OAC plus aspirin or clopidogrel) should be considered for an additional 6 months. After 1 year, it is recommended that only the OAC is maintained. In cases of very high bleeding risk, triple therapy can be reduced to 1 month after ACS, continuing on dual therapy up to 1 year, and thereafter only anticoagulation. In general, the bleeding risk seems to be lower with non-VKA oral anticoagulants than VKA plus antiplatelet combination.

CONCLUSIONS

Many risk factors for ischemic events and bleeding overlap. The clinician's challenges include monitoring patients' adherence and global assessment of the antithrombotic effect that incorporates antiplatelet and anticoagulant effects.

Use of PRECISE-DAPT Score and Admission Platelet Count to Predict Mortality Risk in Patients With Acute Coronary Syndrome

The PREdicting bleeding Complications In patients undergoing Stent implantation and subsEquent Dual Antiplatelet Therapy (PRECISE-DAPT) score has been validated to predict bleeding complications in patients undergoing stent implantation and dual antiplatelet therapy. This score does not include the platelet count (PC), which has been shown to be an independent marker of mortality in patients with acute coronary syndrome (ACS). We assessed the role of the PRECISE-DAPT score calculated on admission for mortality risk prediction and evaluated whether the predictive accuracy of this score improved by adding the PC. In a retrospective cohort study of 1000 patients with ACS, after adjustment for relevant covariates, a PRECISE-DAPT score ≥25 was independently associated with mortality (hazard ratio [HR]: 7.91; 95% confidence interval [CI]: 4.37-14.30). When this score was combined with PC, compared to patients with PRECISE-DAPT <25 and PC ≥150 × 10⁹/L, the adjusted HR was 7.2 (95% CI 2.4-21.6) for those with PRECISE-DAPT <25 and PC <150 × 10⁹/L; 10.7 (95% CI: 5.2-21.9) for those with PRECISE-DAPT ≥25 and PC ≥150 × 10⁹/L; and 17.9 (95% CI 7.0-45.4) for those with PRECISE-DAPT ≥25 and PC <150 × 10⁹/L. Selecting thresholds for high-risk designation, the PRECISE-DAPT score integrated with PC had a higher prediction value, compared to the PRECISE-DAPT and Global Registry of Acute Coronary Events scores.

A 64-year-old man suffering from ST-elevation myocardial infarction and severe thrombocytopenia: Procedures in the case of a patient not fitting the guidelines

The objective of this case report is to present how the chronic condition significantly complicates life-saving procedures and influences further treatment decisions. A 64-year-old man suffering from arterial hypertension and immune thrombocytopenic purpura presented to the Emergency Department with anterior ST-elevation myocardial infarction. An immediate coronary angiography was performed where critical stenosis of the proximal left anterior descending was found. It was followed by primary percutaneous intervention with bare metal stent. In first laboratory results, extremely low platelet count was found (13 × 10⁹/L). Consulting haematologist advised the use of single antiplatelet therapy and from the second day of hospitalisation only clopidogrel was prescribed. On the sixth day of hospital stay, patient presented acute chest pain with ST elevation in anterior leads. Emergency coronary angiography confirmed acute stent thrombosis and aspiration thrombectomy was performed. It was therefore agreed to continue dual antiplatelet therapy for 4 weeks. As there are no clinical trials where patients with low platelet count are included, all therapeutic decisions must be made based on clinician’s experience and experts’ consensus. Both the risk of haemorrhagic complications and increased risk of thrombosis must be taken into consideration when deciding on patient’s treatment.

First Case Report of Successful PCI with Thrombocytopenia Treated with Partial Splenic Artery Embolization

Percutaneous coronary intervention (PCI) for patients with thrombocytopenia presents a difficult problem in that dual antiplatelet therapy (DAPT) after drug-eluting stent (DES) implantation is not suitable. This first case report describes our patient with angina pectoris and thrombocytopenia who we successfully treated with PCI after partial splenic artery embolization (PSE). A 70-year-old Japanese male was transferred to our hospital because of acute decompensated heart failure (ADHF). After medical treatment was administered, a coronary angiography (CAG) revealed three-vessel disease. He had severe thrombocytopenia (nadir of 27,000/μL) due to liver fibrosis. Coronary artery bypass grafting (CABG) and PCI were not feasible. PSE was performed, and splenic volume reduction was confirmed by computed tomography. As a result, the platelet count increased after PSE and we completed the PCI with a DES. Major bleeding complications and cardiac events did not occur under the DAPT. To the best of our knowledge, performing PSE before PCI for increasing a patient's platelet count for thrombocytopenia has never been reported. This method may be considered as one of the treatment strategies for angina patients with thrombocytopenia.

Bleeding risk assessment in elderly patients with acute coronary syndrome

Nowadays, elderly people represent a growing population segment with a well known increased risk of both ischemic and bleeding events. Current acute coronary syndrome guidelines, strongly recommend dual antiplatelet therapy (DAPT) with few specific references for aged patients due to lack of evidence. Patients aged ≥ 75 years are misrepresented in the classic derivation trials cohorts. Strategies to reduce the bleeding risk in this group of patients are urgently needed for the daily clinical practice. Identify the specific age related bleeding risk factors and the importance of an integral geriatric assessment remains challenging. Some of the available in-hospital and out-hospital bleeding risk scores have shown a lower to moderate predictive ability in older patients and no specific tools are developed in elderly population. The importance of an appropriate vascular access choice, type and duration of antiplatelet drugs is crucial to reduce the bleeding risk. Increase radial approaches and short DAPT duration leads to reduce hemorrhages. One interesting subgroup of patients is those who need chronic anticoagulation therapy after percutaneous coronary intervention, due to their very high risk of bleeding. New alternatives as dual therapy with oral anticoagulation and only one antiplatlet drug should be considered. In current review, we evaluate the available evidence about bleeding risk in elderly.

Impact of baseline thrombocytopenia on the long-term outcome of patients undergoing elective percutaneous coronary intervention: An analysis of 9,897 consecutive patients

OBJECTIVES

This study aimed to investigate the association between baseline thrombocytopenia and long-term clinical outcomes among patients undergoing elective percutaneous coronary intervention (PCI).

BACKGROUND

Thrombocytopenia (TP) commonly occurs among patients undergoing PCI. However, whether TP has any influence on the outcome of PCI patients remains controversial.

METHODS

We examined 9,897 consecutive patients who underwent elective PCI in Fuwai Hospital from January 2013 to December 2013. Baseline thrombocytopenia was defined as platelet count <150 × 109 /L. We compared data on demographic, clinical, laboratory, and 30-month outcomes between nonthrombocytopenic and thrombocytopenic patients. The primary outcome was death and major adverse cardiovascular events (MACE) during the 30-month follow-up. Logistic regression analyses were performed to identify risk factors of baseline thrombocytopenia.

RESULTS

Baseline thrombocytopenia developed in 1263 (12.76%) patients; of these, 1,172 (11.84%) patients had mild thrombocytopenia and 91 (0.92%) had the moderate or severe type. No differences in all-cause mortality, stent thrombosis, target vessel revascularization, MACE, or bleeding complications were detected between patients with and without thrombocytopenia. Further, advanced age, male sex, previous PCI history, previous myocardial infarction history, and diabetes mellitus history were found to be risk factors of baseline thrombocytopenia.

CONCLUSIONS

Although baseline thrombocytopenia was common among patients who underwent elective PCI, it did not appear to have a clinically significant effect on long-term adverse outcomes, particular bleeding risk. Our results indicated that it seems to be feasible for patients with mild to moderate thrombocytopenia to receive elective PCI as well as guideline-recommended duration of anti-platelet therapy.

Arterial events in cancer patients-the case of acute coronary thrombosis

Patients with cancer are at high risk for both venous and arterial thrombotic complications. A variety of factors account for the greater thrombotic risk, including the underlying malignancy and numerous cancer-directed therapies. The occurrence of an acute thrombotic event in patients with cancer is associated with substantial morbidity and mortality. Acute coronary syndrome (ACS) represents a particularly important cardiovascular complication in cancer patients. With cardio-vascular risk factors becoming more prevalent in an aging cancer population that is surviving longer, questions pertaining to the appropriate management of vascular toxicity are likely to assume even greater value in the coming years. In this article, we review the current understanding of ACS in patients with cancer. The predisposition to thrombosis in a malignant host and the cancer treatments most commonly associated with vascular toxicity are reviewed. Risk prediction and management strategies are discussed, and discrepancies in the clinical evidence are highlighted.

Management of antithrombotic therapy in adults with immune thrombocytopenia (ITP): a survey of ITP specialists and general hematologist-oncologists

While patients with immune thrombocytopenia (ITP) and low platelet counts are at risk for bleeding, they are not protected against arterial and venous thrombotic events. Frequently, hematologists are asked to consult on a patient with ITP requiring an antiplatelet (AP) agent or anticoagulant (AC). No direct evidence exists to guide hematologists in weighing the risk of thrombosis against the risk of bleeding in patients with ITP. Therefore, we performed a survey to determine the preferred management of AP/AC therapy in ITP patients. The survey described hypothetical patient scenarios and asked respondents to recommend a minimum platelet count for initiation of AP/AC therapy. We surveyed both hematologists with an international reputation in treatment of ITP (n = 48) and also general hematologist-oncologists in Oklahoma (n = 97). Response rates were 38/48 (79%) for the ITP specialists and 46/97 (47%) for general hematologist-oncologists. Overall, recommended platelet thresholds for antithrombotic therapy were similar between ITP specialists and general hematologist-oncologists. Although both groups recommended a minimum platelet count of 50 × 10⁹/L for AP and AC therapy in most scenarios, there was great variability in individual practice patterns among respondents. This study highlights the need for studies of patients with ITP who require AP/AC therapy to provide high-quality evidence for establishing optimal management strategies.

Antiplatelet agents in uncertain clinical scenarios-a bleeding nightmare

Despite over 40 years since the first percutaneous coronary intervention (PCI) was performed, the optimal dual antiplatelet therapy (DAPT) regime poses a significant challenge for clinicians, especially in certain scenarios. DAPT is the standard of care in PCI following an acute coronary syndrome (ACS) or for elective patients with obstructive coronary artery disease (CAD). There remains significant uncertainty regarding DAPT in patients at high risk of bleeding, such as the elderly and patients requiring anticoagulation. More and more clinicians are faced with a dilemma of weighing risks and benefits from the increasing list of potent, new antiplatelet agents and direct oral anticoagulants (DOACs) in a growing, aging population. Historically, most studies failed to recognize bleeding risk, instead focusing on ischemic risk. In recent years however, bleeding has been recognized as a very significant driver of morbidity and mortality in patients undergoing PCI. There is a paucity of data in this cohort leading to divergent and sometimes conflicting recommendations, largely based on expert consensus of opinion. In the current review, we critically evaluate the available evidence in these uncertain scenarios.

Arterial Thrombosis in Patients with Cancer

PURPOSE OF REVIEW

Cancer is a common cause of morbidity and mortality in the USA. While the association between venous thrombosis and malignancy is well established, arterial thrombosis has more recently been recognized as a serious complication of cancer and certain chemotherapeutic agents. This review aims to summarize the most recent literature regarding the incidence and risk factors for cancer-related arterial thrombosis, understand the pathophysiologic mechanisms of thrombosis, and highlight the specific diagnostic and treatment considerations relevant to cancer patients.

RECENT FINDINGS

Based on a recent study looking at the Surveillance, Epidemiology, and End Results (SEER) database, the incidence of arterial thromboembolic events (ATEs) in patients with cancer at 6 months is 4.7%; the presence of an ATE is predictive of worse outcomes. Certain drugs such as platinum-based agents, vascular endothelial growth factor inhibitors, tyrosine kinase inhibitors, and taxanes have been associated with high rates of ATEs. Increased platelet reactivity appears crucial to development of arterial thrombosis in cancer patients. Cancer patients have an increased risk of arterial thrombosis that is likely due to both a cancer-associated procoagulant state as well as the adverse effects of certain chemotherapeutic agents. Treatment of arterial thromboembolism in cancer patients typically requires a multidisciplinary approach in part due to high rates of thrombocytopenia and stent thrombosis in the setting of percutaneous interventions. More studies are needed to investigate optimal prophylaxis, surveillance strategies, and treatments of cancer-related arterial thromboembolic disease.