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)

Navigating P2Y12 inhibition in the labyrinth of cardio-oncology care: cangrelor bridging in patients with cancer

Cangrelor, a potent intravenous P2Y12 platelet inhibitor, has demonstrated effectiveness in reducing ischemic events without a corresponding increase in severe bleeding during percutaneous coronary intervention, as evidenced by the CHAMPION-PHOENIX trial. Its off-label role as a bridging antiplatelet agent for patients facing high thrombotic risks who must temporarily stop oral P2Y12 inhibitor therapy further underscores its clinical utility. This is the first case series to shed light on the application of cangrelor in cancer patients needing to pause dual antiplatelet therapy for a range of medical interventions, marking it as a pioneering effort in this domain. The inclusion of patients with a variety of cancer types and cardiovascular conditions in this series underlines the adaptability and critical role of cangrelor in managing the dual challenges of bleeding risk and the need for uninterrupted antiplatelet protection. By offering a bridge for high-risk cancer patients who have recently undergone percutaneous coronary intervention and need to halt oral P2Y12 inhibitors temporarily, cangrelor presents a practical solution. Early findings indicate it can be discontinued safely 2-4 h before medical procedures, allowing for the effective reintroduction of oral P2Y12 inhibitors without adverse effects. This evidence calls for expanded research to validate and extend these preliminary observations, emphasizing the importance of further investigation into cangrelor's applications in complex patient care scenarios.

Tirofiban-induced thrombocytopenia

Tirofiban is a small non-peptide ligand-mimetic Glycoprotein (GP) IIb/IIIa inhibitor which can reversibly bind to the arginine-glycine-aspartic acid (RGD) recognition site of GP IIb/IIIa to prevent platelet aggregation. It reduces the incidence of thrombotic cardiovascular events in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Although generally considered safe, tirofiban has been reported to be associated with thrombocytopenia in several case reports and clinical trials. The pathogenesis for this adverse reaction is not entirely understood, is thought to be due to immune-mediated reaction. This side effect caused by tirofiban is especially concerning given how frequently it is used in the practice of contemporary cardiovascular care. The present review provides an overview of the pathophysiology, clinical presentation, management, and risk factors associated with tirofiban-induced thrombocytopenia.

Bleeding avoidance strategies in percutaneous coronary intervention

For many years, bleeding has been perceived as an unavoidable consequence of strategies aimed at reducing thrombotic complications in patients undergoing percutaneous coronary intervention (PCI). However, the paradigm has now shifted towards bleeding being recognized as a prognostically unfavourable event to the same extent as having a new or recurrent ischaemic or thrombotic complication. As such, in parallel with progress in device and drug development for PCI, there is clinical interest in developing strategies that maximize not only the efficacy but also the safety (for example, by minimizing bleeding) of any antithrombotic treatment or procedural aspect before, during or after PCI. In this Review, we discuss contemporary data and aspects of bleeding avoidance strategies in PCI, including risk stratification, timing of revascularization, pretreatment with antiplatelet agents, selection of vascular access, choice of coronary stents and antithrombotic treatment regimens.

Tackling the gap in platelet inhibition with oral antiplatelet agents in high-risk patients undergoing percutaneous coronary intervention

Introduction: Oral P2Y₁₂ inhibitors represent the mainstay therapy for the prevention of thrombotic complications in patients presenting with an acute coronary syndrome and/or undergoing percutaneous coronary intervention (PCI). However, the onset of antiplatelet action of the oral P2Y₁₂ inhibitors is affected by their need to be absorbed in the gastrointestinal (GI) tract before becoming systemically available.Areas covered: Following oral intake of P2Y₁₂ inhibitors, the timeframe required for GI absorption leads to a window of inadequate antiplatelet protection during which patients are at increased thrombotic risk. The onset of action of the oral P2Y₁₂ inhibitors is even further delayed in high-risk patients, underscoring the need to define strategies to bridge the gap in platelet inhibitory effects following their intake.Expert opinion: Multiple mechanisms may impair GI absorption leading to a delay in the onset of action of oral P2Y₁₂ inhibitors. Several strategies have been tested to overcome the gap in platelet inhibition in high-risk patients undergoing PCI. These include administration of crushed or chewed tablets to improve the dissolution rate and use of opioid receptor antagonists or metoclopramide to counteract impairment of gastric motility induced by opioids. However, intravenous antiplatelet therapies represent the most effective strategy to bridge such gap in platelet inhibition.

A systematic review and meta-analysis of impact of baseline thrombocytopenia on cardiovascular outcomes and mortality in patients undergoing percutaneous coronary intervention

BACKGROUND

Thrombocytopenia (TP) is associated with higher incidence of bleeding in the setting of percutaneous coronary intervention (PCI) leading to increased morbidity and mortality. Herein, we report a meta-analysis evaluating the effects of baseline thrombocytopenia (bTP) on cardiovascular outcomes in patients undergoing PCI.

METHODS

Literature search was performed using PubMed, Embase, Cochrane library and clinicaltrials.gov from inception till October 2019. Patients were divided into two groups: Patients with (a) no Thrombocytopenia (nTP) (b) bTP before PCI. Primary endpoints were in-hospital, and all-cause mortality rates at the longest follow-up. The main summary estimate was random effects risk ratio (RR) with 95% confidence intervals (CIs).

RESULTS

A total of 6,51,543 patients from 10 retrospective studies were included. There was increased in-hospital all-cause mortality (RR 2.58 [1.7-3.8], p < .001) and bleeding (RR 2.37 [1.41-3.98], p < .005), in the bTP group compared to the nTP group. There was no difference for in-hopsital major adverse cardiovascular outcomes (MACE) (RR 1.38 [0.94-2.0], p < .10), post-PCI MI (RR 1.17 [0.9-1.5], p = .19) and TVR (RR 1.65 [0.8-3.6], p = .21), respectively. Outcomes at longest follow-up showed increased incidence of all-cause mortality (RR 1.86 [1.2-2.9], p < .006) and bleeding (RR 1.72 [1.1-2.9], p = .04) in bTP group, while there was no significant difference for post-PCI MI (RR 1.07 [0.91-1.3], p = .42), MACE (RR 1.86 [0.69-1.8], p = .68) and TVR (RR 1.1 [0.9-1.2], p = .93) between both groups.

CONCLUSIONS

bTP in patients undergoing PCI is associated with increased mortality and predicts risk of bleeding.

Efficacy and safety of abciximab versus tirofiban in addition to ticagrelor in STEMI patients undergoing primary percutaneous intervention

Platelet glycoprotein IIb/IIIa inhibitors (GPIs) have been part of the adjuvant treatment of acute coronary syndrome for years. However, real-life data regarding the efficacy and safety of GPIs under the current indications are lacking in the setting of potent platelet inhibition. The objectives were to assess the efficacy and safety of abciximab versus tirofiban in patients with ST-elevation acute myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI) and pretreated with ticagrelor, and to identify independent predictor factors of efficacy, bleeding and platelet drop. Three hundred sixty-two patients were divided by GPI administered. Clinical, laboratory, angiographic and outcome characteristics were compared. The primary objective was a composite efficacy endpoint (death from any cause, nonfatal myocardial infarction and nonfatal stroke) at 30 days. The secondary objectives were its individual components, safety (bleeding) and the impact on platelet count during hospital stay. The composite efficacy endpoint was similar in the abciximab and tirofiban groups (6.1% vs 7.3%; p = .632). There were also no differences in cardiovascular death (2.5% vs 2.4%; p = .958), nonfatal myocardial infarction (3% vs 4.3%; p = .521) and nonfatal stroke (0.5% vs 1.8%; p = .332). Tirofiban administration was associated with a higher incidence of bleeding (11.6% vs 22%; p = .008) with no differences in BARC ≥ 3b bleeding (3.6 vs 2.5%; p = .760). In STEMI patients undergoing PPCI with ticagrelor, abciximab and tirofiban had similar rates in the composite efficacy endpoint at 30 days. The 30-day bleeding rate was significantly higher in the tirofiban group. Tirofiban administration was an independent predictor of both bleeding and platelet count drop.

Antiplatelet Therapy with Cangrelor in Patients Undergoing Surgery after Coronary Stent Implantation: A Real-World Bridging Protocol Experience

Objective  The aim of the study is to describe the real-world use of the P2Y 12 inhibitor cangrelor as a bridging strategy in patients at high thrombotic risk after percutaneous coronary intervention (PCI) and referred to surgery requiring perioperative withdrawal of dual antiplatelet therapy (DAPT). Materials and Methods  We collected data from nine Italian centers on patients with previous PCI who were still on DAPT and undergoing nondeferrable surgery requiring DAPT discontinuation. A perioperative standardized bridging protocol with cangrelor was used. Results  Between December 2017 and April 2019, 24 patients (mean age 72 years; male 79%) were enrolled. All patients were at high thrombotic risk after PCI and required nondeferrable intermediate to high bleeding risk surgery requiring DAPT discontinuation (4.6 ± 1.7 days). Cangrelor infusion was started at a bridging dose (0.75 µg/kg/min) 3 days before planned surgery and was discontinued 6.6 ± 1.5 hours prior to surgical incision. In 55% of patients, cangrelor was resumed at 9 ± 6 hours following surgery for a mean of 39 ± 38 hours. One cardiac death was reported after 3 hours of cangrelor discontinuation prior to surgery. No ischemic outcomes occurred after surgery and up to 30-days follow-up. The mean hemoglobin drop was <2 g/dL; nine patients received blood transfusions consistent with the type of surgery, but no life-threatening or fatal bleeding occurred. Conclusion  Perioperative bridging therapy with cangrelor is a feasible approach for stented patients at high thrombotic risk and referred to surgery requiring DAPT discontinuation. Larger studies are warranted to support the safety of this strategy.

Impact of Acquired Thrombocytopenia on Cardiovascular Outcomes in Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

Acquired thrombocytopenia (aTP) is associated with a high frequency of bleeding and ischemic complications in patients undergoing percutaneous coronary intervention (PCI). Herein, we report a meta-analysis evaluating the adverse effects of aTP on cardiovascular outcomes and mortality post-PCI.

METHODS

A literature search was performed using PubMed, Embase, Cochrane and, clinicaltrials.gov from the inception of these databases through October 2019. Patients were divided into two groups: 1) No Thrombocytopenia (nTP) and 2) Acquired Thrombocytopenia (aTP) after PCI. Primary endpoints were in-hospital, 30-day and all-cause mortality rates at the longest follow-up. The main summary estimate was random effects Risk ratio (RR) with 95% confidence intervals (CIs).

RESULTS

Seven studies involving 57,247 participants were included. There was significantly increased in-hospital all-cause mortality (HR 10.73 [6.82-16.88]), MACE (HR 2.96 [2.24-3.94]), major bleeding (HR 4.78 [3.54-6.47]), and target vessel revascularization (TVR) (HR 7.53 [2.8-20.2]), in the aTP group compared to the nTP group. Similarly, aTP group had a statistically significant increased incidence of 30-day all-cause mortality (HR 6.08), MACE (HR 2.77), post-PCI MI (HR 1.98), TVR (HR 5.2), and major bleeding (HR 12.73). Outcomes at longest follow-up showed increased incidence of all-cause mortality (HR 3.98 [1.53-10.33]) and MACE (HR 1.24 [0.99-1.54]) in aTP group, while there was no significant difference for post-PCI MI (HR 0.94 [0.37-2.39]) and TVR (HR 0.96 [0.69-1.32]) between both groups.

CONCLUSIONS

Acquired Thrombocytopenia after PCI is associated with increased morbidity, mortality, adverse bleeding events and the need for in-hospital and 30-day TVR.

A case report of absolute thrombocytopenia with ticagrelor

BACKGROUND

We report a rare case of absolute thrombocytopenia with ticagrelor after 6 h of single loading dose of ticagrelor.

CASE SUMMARY

A 68-year-old male with ischaemic cardiomyopathy, hypertension, and dyslipidaemia presented with chest pain. He was found to be in new-onset atrial flutter and ruled in for a non-ST-segment elevation myocardial infarction. An echocardiogram showed decreased left ventricular ejection fraction, estimated at 15-20% and serum troponin peaked at 0.2 ng/dL, baseline platelet count was 203 × 10³/µL. He underwent a drug-eluting stent placement to the right coronary artery with excellent angiographic results. He received 3000 units of unfractionated heparin and 180 mg of ticagrelor during the procedure. About 6 h after the procedure, he had coffee ground emesis. A complete blood count revealed a platelet count of 2 × 10³ and 0 × 10³/µL on repeat testing. Peripheral smear did not show any evidence of platelet clumping and schistocytes, serum haptoglobin and lactate dehydrogenase were normal. Ticagrelor and heparin were discontinued, while the aspirin was continued. Five units of platelet were transfused. The platelet count improved to 200 × 10³/µL. Since his CHADS₂VASC score was 3, he was discharged on apixaban and clopidogrel in addition to other medication. No thrombocytopenia was seen on outpatient follow-up.

DISCUSSION

The common side effects of ticagrelor include bleeding, dyspnoea, gynaecomastia, and rarely thrombotic thrombocytopenic purpura. Although extremely rare, absolute or profound thrombocytopenia can occur with ticagrelor, hours after administration and should be considered when other potential causes of thrombocytopenia have been ruled out.

Platelet Inhibition With Cangrelor and Crushed Ticagrelor in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

The platelet inhibitory effects induced by oral P2Y₁₂ receptor antagonists are delayed in patients with ST-segment-elevation myocardial infarction undergoing primary percutaneous coronary intervention (P-PCI). In turn, this leads to a gap in platelet inhibition, exposing patients to an increased risk of early thrombotic complications and underscoring the need to define strategies associated with more effective platelet inhibition in the peri-primary percutaneous coronary intervention period. Cangrelor is an intravenous P2Y₁₂ inhibitor with prompt and potent antiplatelet effects. However, to date, there are limited data on the effects of cangrelor used in combination with ticagrelor in patients undergoing primary percutaneous coronary intervention. Moreover, questions have emerged on the potential for drug-drug interactions during the transition from cangrelor to oral P2Y₁₂ inhibitors.

METHODS

This was a prospective, randomized, double-blind, placebo-controlled pharmacodynamic study conducted in patients undergoing primary percutaneous coronary intervention (n=50) who were randomized to treatment with either cangrelor or matching placebo (bolus followed by 2-hour infusion). All patients received ticagrelor 180-mg loading dose administered as crushed tablets at the time of cangrelor/placebo bolus administration. Pharmacodynamic analyses were performed at 8 time points. Pharmacodynamic effects were measured as P2Y₁₂ reaction units by VerifyNow and platelet reactivity index by vasodilator-stimulated phosphoprotein.

RESULTS

Compared with placebo, cangrelor was associated with reduced P2Y₁₂ reaction units as early as 5 minutes after bolus, which persisted during the entire duration of drug infusion, including at 30 minutes (63 [32-93] versus 214 [183-245]; mean difference, 152 [95% CI, 108-195]; P<0·001; primary end point). Parallel findings were shown with platelet reactivity index. Accordingly, high on-treatment platelet reactivity rates were reduced with cangrelor. After discontinuation of cangrelor/placebo infusion, there were no differences in levels of platelet reactivity between groups, ruling out a drug-drug interaction when cangrelor and ticagrelor are concomitantly administered.

CONCLUSIONS

In patients undergoing primary percutaneous coronary intervention, cangrelor is an effective strategy to bridge the gap in platelet inhibition associated with the use of oral P2Y₁₂ inhibition induced by ticagrelor. Ticagrelor can be administered as a crushed formulation concomitantly with cangrelor without any apparent drug-drug interaction. The clinical implications of these pharmacodynamic findings warrant investigation in an adequately powered clinical trial.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT03247738.

Intravenous antiplatelet therapies (glycoprotein IIb/IIIa receptor inhibitors and cangrelor) in percutaneous coronary intervention: from pharmacology to indications for clinical use

Oral antiplatelet drugs are crucially important for patients with acute coronary syndrome or stable coronary artery disease undergoing percutaneous coronary intervention (PCI). In recent decades, several clinical trials have focused on reducing periprocedural ischemic events in patients undergoing PCI by means of more rapid platelet inhibition with the use of intravenous antiplatelet drugs. Glycoprotein IIb/IIIa receptor inhibitors (GPIs) block the final common pathway of platelet aggregation and enable potent inhibition in the peri-PCI period. In recent years, however, the use of GPIs has decreased due to bleeding concerns and the availability of more potent oral P2Y12 inhibitors. Cangrelor is an intravenous P2Y12 receptor antagonist. In a large-scale regulatory trial, cangrelor administration during PCI allowed for rapid, potent and rapidly reversible inhibition of platelet aggregation, with an anti-ischemic benefit and no increase in major bleeding. This article aims to provide an overview of general pharmacology, supporting evidence and current status of intravenous antiplatelet therapies (GPIs and cangrelor), with a focus on contemporary indications for their clinical use.