Effects of tirofiban plus heparin versus heparin alone on troponin I levels in patients with acute coronary syndromes

Ticagrelor to Reduce Myocardial Injury in Patients With High-Risk Coronary Artery Plaque

OBJECTIVES

The goal of this study was to determine whether ticagrelor reduces high-sensitivity troponin I concentrations in patients with established coronary artery disease and high-risk coronary plaque.

BACKGROUND

High-risk coronary atherosclerotic plaque is associated with higher plasma troponin concentrations suggesting ongoing myocardial injury that may be a target for dual antiplatelet therapy.

METHODS

In a randomized, double-blind, placebo-controlled trial, patients with multivessel coronary artery disease underwent coronary 18F-fluoride positron emission tomography/coronary computed tomography scanning and measurement of high-sensitivity cardiac troponin I. Patients were randomized (1:1) to receive ticagrelor 90 mg twice daily or matched placebo. The primary endpoint was troponin I concentration at 30 days in patients with increased coronary 18F-fluoride uptake.

RESULTS

In total, 202 patients were randomized to treatment, and 191 met the pre-specified criteria for inclusion in the primary analysis. In patients with increased coronary 18F-fluoride uptake (120 of 191), there was no evidence that ticagrelor had an effect on plasma troponin concentrations at 30 days (ratio of geometric means for ticagrelor vs. placebo: 1.11; 95% confidence interval: 0.90 to 1.36; p = 0.32). Over 1 year, ticagrelor had no effect on troponin concentrations in patients with increased coronary 18F-fluoride uptake (ratio of geometric means: 0.86; 95% confidence interval: 0.63 to 1.17; p = 0.33).

CONCLUSIONS

Dual antiplatelet therapy with ticagrelor did not reduce plasma troponin concentrations in patients with high-risk coronary plaque, suggesting that subclinical plaque thrombosis does not contribute to ongoing myocardial injury in this setting. (Dual Antiplatelet Therapy to Reduce Myocardial Injury [DIAMOND]; NCT02110303).

Early high-dose rosuvastatin and cardioprotection in the protective effect of rosuvastatin and antiplatelet therapy on contrast-induced acute kidney injury and myocardial damage in patients with acute coronary syndrome (PRATO-ACS) study

BACKGROUND

There is a strong correlation between adverse clinical events and peak values of myocardial necrosis markers in non-ST-elevation acute coronary syndrome patients. In this clinical setting, high-dose statin treatment exerts acute beneficial effects against renal and myocardial damage. The aim of this report was to evaluate if, on admission, high-dose rosuvastatin can exert cardioprotective effects when administered in addition to high-dose clopidogrel.

METHODS

In the PRATO-ACS trial, 504 consecutive statin-naïve non-ST-elevation acute coronary syndrome patients scheduled for early invasive strategy and pretreated with high-dose clopidogrel were randomly assigned to rosuvastatin (40 mg on admission followed by 20 mg/d; statin group, n = 252) or no statin treatment (control group, n = 252). Serial myocardial biomarker samples were collected before and after angiography and/or percutaneous coronary intervention. The primary end point was the peak level of cardiac troponin I (cTnI) during the index event.

RESULTS

Statin-treated patients presented median cTnI peak values similar to controls (3.9 [0.6-12.8] vs 3.5 [1.2-11.9] ng/mL, respectively; P = .60]; no differences were found between the 2 groups in cTnI and creatine kinase-MB values at any time point, in either preangiography and postangiography peak values or their cumulative release. In patients submitted to percutaneous coronary intervention, periprocedural myocardial infarction occurred in 8 (4.7%) of 171 statin-treated and 7 (4.3%) of 162 control patients (P = .87).

CONCLUSION

In the PRATO-ACS trial, early high-dose rosuvastatin did not show cardioprotective effects when administered in addition to high-dose clopidogrel.

Traumatic dissection of a coronary artery: detection by multislice computed tomography and use of tirofiban as a reversible platelet inhibitor

We report on a trauma victim without history of or risk factors for cardiac disease, who suffered coronary artery dissection caused by blunt chest injury (BCI). Myocardial ischaemia was detected by multislice computed tomography (MSCT) promptly after trauma centre admission and managed by immediate revascularisation. Thoracic trauma may cause myocardial ischaemia in the absence of a specific risk profile. MSCT, as part of initial work-up in severely injured patients, may support differential diagnosis after BCI. Tirofiban and unfractionated heparin as short-acting anticoagulants warrant stent patency and concurrently offer the possibility of quick recovery of haemostasis in case of haemorrhage.

Predicting a late positive serum troponin in initially troponin-negative patients with non-ST-elevation acute coronary syndrome: clinical predictors and validated risk score results from the TIMI IIIB and GUSTO IIA studies

BACKGROUND

Troponin testing is useful for evaluating patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS); however, a significant percentage of patients are troponin negative at presentation and develop late rise of the marker.

METHODS

Patients in the TIMI IIIB study were assessed with respect to their troponin I (TnI) status at presentation and 12 hours. Multivariable analysis identified independent clinical factors associated with TnI rise at 12 hours among subjects initially TnI negative. A score predicting late TnI rise in TIMI IIIB was developed using these factors and validated among patients in the GUSTO IIA study.

RESULTS

Of 1342 subjects in TIMI IIIB, 200 (14.9%) were negative at baseline, but developed an elevated TnI (> or = 0.4 ng/mL) at 12 hours. Six independent predictors of late TnI rise were identified: ST-segment deviation (odds ratio [OR] 3.52, 95% CI 2.38-5.23, P < .001), presentation < 8 hours from symptom onset (OR 2.91, 95% CI 1.92-4.40, P < .001), no prior percutaneous coronary intervention (OR 2.88, 95% CI 1.54-5.39, P = .001), no prior beta-blocker use (OR 1.74, 95% CI 1.15-2.63, P = .008), unheralded angina (OR 1.65, 95% CI 1.12-2.42, P = .01), and a history of myocardial infarction (OR 1.59, 95% CI 1.06-2.37, P = .02). ST deviation, presentation < 8 hours from symptoms, and no prior percutaneous coronary intervention were given a score of 2 points, whereas a score of 1 point was assigned to the other factors. Among baseline TnI-negative patients, a rising score was paralleled by an increasing prevalence of late TnI rise from 0% (with a score of 0) to 69% (with a score of 9) (P < .001). In confirmation, the score was able to similarly predict late troponin T rise among 855 patients in the GUSTO IIA study (P < .0001).

CONCLUSION

Development of late troponin rise is common in non-ST-segment elevation acute coronary syndromes. Six easily ascertained variables may be used to identify those at higher risk for late rise in troponin levels after an initially negative presentation.

Effects of tirofiban plus clopidogrel versus clopidogrel plus provisional abciximab on biomarkers of myocardial necrosis in patients with non-ST-elevation acute coronary syndromes treated with early aggressive approach. Results of the CLOpidogrel, upstream TIrofiban, in cath Lab Downstream Abciximab (CLOTILDA) study

BACKGROUND

In non-ST-elevation acute coronary syndromes (NSTE-ACS), a strong correlation between adverse clinical events and peak values of myocardial necrosis markers has been found. In this study, we evaluated whether the adjunctive treatment with upstream tirofiban reduces the peak levels of cardiac troponin I and creatine kinase-MB (CK-MB) fraction in patients with NSTE-ACS undergoing early invasive strategy and pretreated with aspirin, heparin, and clopidogrel.

METHODS

A total of 300 patients were randomized to receive tirofiban (group 1) or not (group 2). Serial marker samples were collected before and after coronary angiography in all cases and after percutaneous coronary intervention (PCI) when performed.

RESULTS

Between the 2 groups, no differences were observed in clinical and angiographic findings. Percutaneous coronary intervention was globally performed in 198 patients (66%). Of 99 group 2 patients, 26 (26%) received abciximab just before PCI. No significant differences between the 2 groups were observed with regard to cardiac troponin I and CK-MB values at admission and at 6, 12, and 24 hours thereafter; peak values before coronary angiography; and peak values of index event. In addition, the cumulative biomarkers release of the index event was similar between the 2 groups. Major bleeding rate was 2% in group 1 and 1% in group 2 (P = not significant). Composite incidence of death, myocardial infarction, or rehospitalization for ACS at 30 days was 9% in group 1 and 10% in group 2.

CONCLUSIONS

In patients with NSTE-ACS undergoing early invasive strategy, the adjunctive administration of upstream tirofiban did not reduce the peak values and the cumulative release of myocardial necrosis markers, compared with aspirin, heparin, and clopidogrel given on admission and associated with selective use of abciximab just before PCI.

The early glycoprotein IIb/IIIa inhibition in non-ST-segment elevation acute coronary syndrome (EARLY ACS) trial: a randomized placebo-controlled trial evaluating the clinical benefits of early front-loaded eptifibatide in the treatment of patients with non-ST-segment elevation acute coronary syndrome--study design and rationale

BACKGROUND

The recent North American and European practice guidelines in patients with non-ST-segment elevation acute coronary syndrome (nSTE ACS) recommend glycoprotein IIb/IIIa (GpIIb-IIIa) inhibition in patients undergoing an early invasive treatment strategy. However, the guidelines are not explicit regarding the timing of initiation of GpIIb-IIIa antagonists, and there is marked variation in clinical practice regarding their use.

STUDY DESIGN

The EARLY ACS trial will enroll 10,500 patients in a prospective, randomized, double blind, international, multicenter investigation of early eptifibatide compared with placebo (with provisional eptifibatide in the catheterization laboratory) in patients with high-risk nSTE ACS in whom an invasive strategy is planned no sooner than the next calendar day. The primary efficacy end point is the 96-hour composite of all-cause mortality, nonfatal myocardial infarction, recurrent ischemia requiring urgent revascularization, or need for thrombotic bailout with GpIIb-IIIa inhibitor during percutaneous coronary intervention. The key secondary end point is the composite of death or nonfatal myocardial infarction within 30 days of enrollment.

IMPLICATIONS

The EARLY ACS trial will be the largest study to date to evaluate the utility of early GpIIb-IIIa inhibition in patients with nSTE ACS in whom an invasive approach is planned. This trial will provide important evidence regarding the benefit of initiating eptifibatide early after presentation with high-risk ACS versus delayed provisional use after coronary angiography. Furthermore, it will explore the ability of biomarkers to identify high-risk patients who may benefit from such an early aggressive approach.

Effects of tirofiban on acute systemic inflammatory response in elective percutaneous coronary interventions

OBJECTIVE

In this study the effect of a specific glycoprotein IIb/IIIa inhibitor, tirofiban [which also has antiplatelet activity on acute systemic inflammatory responses (IR) during elective percutaneous coronary intervention (PCI)] was evaluated.

PATIENTS AND METHODS

Patients with stable angina pectoris and similar baseline characteristics who angiographically had a single lesion in their coronary arteries with a PCI performed on that lesion were enrolled in the study. One group of patients (control group, n = 52) received 0.9% NaCl (15 mL/h for 24 h) and the other group (tirofiban group, n = 55) had tirofiban (10 microg/kg bolus infusion in 3 min and 0.15 microg/kg/min for 24 h) in addition to stenting without pre-dilatation. The effect of interventional procedure on levels of cardiac troponin T (cTnT) and several parameters of acute IR (leukocytes, fibrinogen, C-reactive protein, interleukin-1, interleukin-6, interleukin-8 and tumor necrotizing factor-alpha) was assessed on blood samples obtained from all patients before PCI and at pre-specified time points after PCI.

RESULTS

During the follow-up after PCI, the number of patients becoming cTnT-positive (> 0.1 ng/mL) was greater in the control group [12 (23%) patients vs. 3 (5%) patients, p = 0.01]. However, both groups had changes (generally observed as elevations) in their levels of all inflammatory parameters during the study and C-reactive protein, interleukin-6 and tumor necrotizing factor-alpha levels were elevated significantly. Yet, no significant difference occurred between groups due to these changes in any phase of the study (p > 0.05).

CONCLUSIONS

Based on the findings of this study, it was concluded that although tirofiban limits development of myocardial necrosis during elective PCI, it does not directly affect the acute systemic inflammatory responses.

A randomized, placebo-controlled trial of early eptifibatide for non-ST-segment elevation acute coronary syndromes

BACKGROUND

The acute benefits of platelet glycoprotein IIb/IIIa inhibitors for non-ST-segment elevation acute coronary syndromes (NSTE ACS) remain unclear.

METHODS

In this pilot trial, 311 patients with NSTE ACS were randomly assigned in the emergency department to double-blinded therapy with eptifibatide or placebo for 12 to 24 hours before crossover to open-label eptifibatide. Serial creatine-kinase MB (CK-MB) and quantitative cardiac troponin T levels were collected during the first 24 hours to assess the impact of early platelet glycoprotein IIb/IIIa blockade on infarct size as measured by cardiac markers.

RESULTS

Median peak CK-MB (10.3 vs 11.8 ng/mL; P =.71) and peak quantitative cardiac troponin T levels (0.2 vs 0.3 ng/mL; P =.95) were similar between treatment groups, respectively. Median calculated peak CK-MB values (41 vs 40 ng/mL; P =.72) and area under the CK-MB curve measurements (980 vs 764 microg/min/L; P =.68) from curve-fitting analyses that could be performed in 106 of 311 patients were also similar.

CONCLUSIONS

In this pilot trial, early administration of eptifibatide in the emergency department did not modulate serologic measurements of infarct size in patients with NSTE ACS.

Optimizing glycoprotein IIb/IIIa receptor antagonist use for the non-ST–segment elevation acute coronary syndromes: risk stratification and therapeutic intervention

Despite extensive data supporting their use for non-ST-segment elevation acute coronary syndromes, glycoprotein (GP) IIb/IIIa antagonists are underutilized. This is likely the consequence of confusion as to which patients should receive these agents, as well as to the most appropriate timing and venue for their initiation. We will review the advances in the understanding of GP IIb/IIIa antagonist therapy, emphasizing methods of identifying those most likely to benefit from the use of GP IIb/IIIa receptor blockade. In addition, we will consider appropriate methods/venues for use of GP IIb/IIIa receptor antagonism, including its role in an "early invasive" catheterization strategy.

Early use of glycoprotein IIb/IIIa inhibitors in the ED treatment of non-ST-segment elevation acute coronary syndromes: a local quality improvement initiative

A prospective observational study was conducted in 2,007 patients experiencing chest pain to determine impact of local quality improvement (QI) measures on the use of glycoprotein (GP) IIb/IIIa inhibitors in the ED treatment of high-risk patients with non-ST-segment elevation acute coronary syndromes (ACS). Patients with injury on the initial ECG or new sustained injury on continuous ECG were excluded. QI interventions were as follows: control (0-4 mo): no interventions (standardized protocols and prewritten orders in place 4 months prior); phase I (5-8 mo): simple education/awareness program with posted drug information pamphlets and eligibility criteria; phase II (9-12 mo): mandated QI form with real-time feedback and focused one-on-one physician education championed by an ED physician QI advocate. A total of 179 (8.9%) of the study patients met predefined high-risk criteria. Of these, a total of 41 (23.0%) patients had GP IIb/IIIa inhibitor therapy initiated in the ED. Percent of high-risk patients receiving therapy increased from 6.0% during the control phase to 16.1% during phase I and 50.9% during phase II. After controlling for patient demographics, patients treated during phase I had a 2.8 times increased odds (95% confidence interval CI: 0.8-10.3; P =.11 [not significant]) of receiving GP IIb/IIIa inhibitor relative to the control phase, and patients treated during phase II had a 20.2 times increased odds (95% CI: 6.1-66.9; P <.0001) of treatment. In conclusion, local QI measures incorporating standardized protocols, preprinted orders, physician education, and interactive feedback championed by an ED QI physician advocate can increase early use of GP IIb/IIIa inhibitors in the ED treatment of high-risk patients presenting with chest pain.

[Biological markers of myocardial necrosis]

New biological markers of myocardial injury have improved the management of patients with acute coronary syndromes. Among these markers, the most relevant are the cardiac troponins (troponin I and troponin T) because of their cardiospecificity, and myoglobin because of its combination of diagnostic sensitivity and usefulness for an early diagnosis. The serial analysis and combined use of both markers fulfill all diagnostic and prognostic requirements, and are helpful in indicating therapeutic strategies for acute coronary syndromes. However, these markers also have limitations, and their concentrations should always be interpreted in the light of the patient's clinical status.

"Routine invasive" versus "selective invasive" approaches to non-ST-segment elevation acute coronary syndromes management in the post-stent/platelet inhibition era

Is a "routine invasive" or "selective invasive" strategy the best approach for patients with non-ST-segment elevation acute coronary syndrome (ACS)? A "selective invasive" strategy incorporates ischemia-guided use of aggressive medical therapy followed by angiography and revascularization for angina or stress-induced myocardial ischemia. The "routine invasive" strategy (cardiac catheterization followed by percutaneous coronary intervention within 24 to 48 h of symptom-onset) is frequently employed, but no randomized, controlled trials have demonstrated improved clinical outcomes. Recently, the second Fragmin and fast Revascularization during InStability in Coronary artery disease (FRISC-II) and the Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction (TACTICS TIMI-18) trials found significant reductions in death, recurrent myocardial infarction, or hospitalization for biomarker-positive ACS. Also, the third Randomized Intervention Trial of unstable Angina (RITA-3) recently reported a halving of refractory angina and reduction in the use of antianginal medication with early intervention. Early trials failed to demonstrate the superiority of the "routine invasive" approach, presumably because of fewer revascularizations, unavailability of stents, and more recent use of glycoprotein IIb/IIIa inhibitors and low-molecular-weight heparins. The FRISC-II, TACTICS TIMI-18, and RITA-3 studies indicate that higher-risk patients benefit from early revascularization, but that aggressive antiplatelet, antithrombin, and anti-ischemic therapy are also important. While all three trials support an "early invasive" approach in intermediate- and high-risk patients, other trials support a more "conservative" approach in those without electrocardiographic changes or enzyme elevations. Optimal management should incorporate both strategies.

The role of pharmacotherapy and catheter-based intervention in the management of patients with non-ST-segment elevation acute coronary syndromes

The American College of Cardiology/American Heart Association Task Force on Practice Guidelines has published recommendations regarding diagnosis and treatment of patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS). The acute ischemia pathway presented in these guidelines encompasses both an early invasive strategy and an early conservative strategy. The recognition of the role of platelet biology in ACS led to the development of glycoprotein (GP) IIb/IIIa receptor antagonists for the management of patients with NSTE ACS. Based on studies of risk stratification models for NSTE ACS, as well as a better understanding of the underlying biology of serum markers of myocardial necrosis, refinements have been made in identifying which patients benefit most from intravenous platelet receptor antagonism and the use of early invasive strategies. The available data suggest that for the NSTE ACS patient with intermediate- to high-risk features, the early initiation of intravenous platelet receptor antagonism with a small molecule GP IIb/IIIa receptor blocker, followed by timely cardiac catheterization with attempts at revascularization is the superior management strategy. In the majority of cases where such patients present to a facility without cardiac catheterization capability, stabilization with antiplatelet, antithrombotic, and anti-ischemic therapies should be undertaken prior to timely tertiary percutaneous coronary intervention referral.

Risk stratification in non-ST segment elevation acute coronary syndromes with special focus on recent guidelines

Patients with unstable angina or non-ST segment elevation (non-Q-wave) myocardial infarction are a heterogeneous group with respect to their risk of developing clinically significant adverse events such as subsequent myocardial infarction and death. Recent guidelines promote risk stratification of these patients, targeting high-risk patients for maximal antithrombotic and antiischemic therapy and low-risk patients for early discharge. We reviewed current and future modalities for risk stratification of patients and the predictive value of these methods in context with available pharmacologic agents. Unfortunately, most of the data identifying a particular pharmacologic regimen as beneficial in high-risk patients are retrospectively derived from large trials. Until prospective studies that use markers to guide therapy are available, clinicians should be familiar with the use of these risk markers and their application to the role of a given management strategy, including pharmacologic therapy.

Comparison of early invasive and conservative strategies in patients with unstable coronary syndromes treated with the glycoprotein IIb/IIIa inhibitor tirofiban

BACKGROUND

There is continued debate as to whether a routine, early invasive strategy is superior to a conservative strategy for the management of unstable angina and myocardial infarction without ST-segment elevation.

METHODS

We enrolled 2220 patients with unstable angina and myocardial infarction without ST-segment elevation who had electrocardiographic evidence of changes in the ST segment or T wave, elevated levels of cardiac markers, a history of coronary artery disease, or all three findings. All patients were treated with aspirin, heparin, and the glycoprotein IIb/IIIa inhibitor tirofiban. They were randomly assigned to an early invasive strategy, which included routine catheterization within 4 to 48 hours and revascularization as appropriate, or to a more conservative (selectively invasive) strategy, in which catheterization was performed only if the patient had objective evidence of recurrent ischemia or an abnormal stress test. The primary end point was a composite of death, nonfatal myocardial infarction, and rehospitalization for an acute coronary syndrome at six months.

RESULTS

At six months, the rate of the primary end point was 15.9 percent with use of the early invasive strategy and 19.4 percent with use of the conservative strategy (odds ratio, 0.78; 95 percent confidence interval, 0.62 to 0.97; P=0.025). The rate of death or nonfatal myocardial infarction at six months was similarly reduced (7.3 percent vs. 9.5 percent; odds ratio, 0.74; 95 percent confidence interval, 0.54 to 1.00; P<0.05).

CONCLUSIONS

In patients with unstable angina and myocardial infarction without ST-segment elevation who were treated with the glycoprotein IIb/IIIa inhibitor tirofiban, the use of an early invasive strategy significantly reduced the incidence of major cardiac events. These data support a policy involving broader use of the early inhibition of glycoprotein IIb/IIIa in combination with an early invasive strategy in such patients.

Benefit of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes and troponin t-positive status: the paragon-B troponin T substudy

BACKGROUND

Troponin T (TnT) is valuable for short- and long-term risk stratification of patients with acute coronary syndromes (ACS). It also may predict which ACS patients will benefit from glycoprotein (GP) IIb/IIIa blockade.

METHODS AND RESULTS

We prospectively studied 1160 patients with non-ST-segment elevation ACS randomized in PARAGON-B to receive lamifiban, an intravenous GP IIb/IIIa antagonist, or placebo. TnT levels were obtained before study treatment began and 24 to 72 hours later; assays were performed by a blinded core laboratory. At baseline, 40.2% of patients were TnT-positive (>/=0.1 ng/mL); these patients were older and more often male or smokers. Patients positive at baseline had a significantly higher rate of the primary end point (composite of death, myocardial [re]infarction, or severe recurrent ischemia at 30 days; odds ratio, 1.5; 95% CI, 1.1 to 2.1) than those who were TnT-negative. Lamifiban was associated with significant reduction in the primary end point (from 19.4% to 11.0%, P=0.01) among TnT-positive patients but not among TnT-negative patients (11.2% for placebo versus 10.8% for lamifiban, P=0.86; P=0.08 for test of interaction between TnT status and treatment assignment). This pattern held for the end points of death alone and death or myocardial (re)infarction at 30 days. Peak TnT level at 48 hours did not differ with lamifiban treatment.

CONCLUSIONS

TnT predicts poor short-term outcomes in non-ST-segment elevation ACS. Treatment benefit with lamifiban is limited almost exclusively to TnT-positive patients, reducing 30-day adverse outcomes to a rate nearly identical to that of negative patients.

Unstable angina pectoris and non-Q-wave myocardial infarction

Unstable angina pectoris and non-Q-wave myocardial infarction are clinical syndromes that share many pathophysiologic and clinical features. In the spectrum of coronary artery disease, these syndromes lie between chronic stable angina and Q-wave myocardial infarction. Although both conditions are associated with significant morbidity and mortality, patients presenting with these syndromes can be further risk stratified into higher and lower risk based on a number of readily available clinical features and biochemical parameters. Such risk stratification can allow for more tailored treatment and better resource allocation. Although routine early coronary angiography and revascularization has not been shown to be superior to conservative management, certain high-risk patients may benefit from a more aggressive strategy. Medical therapy with the use of antiplatelet, anticoagulant, and antiischemic agents remains the cornerstone of emergent treatment for patients presenting with these syndromes. The recent demonstration of a reduction in both morbidity and mortality with the glycoprotein IIb/IIIa antagonists has further expanded the armamentarium of available agents. Following initial stabilization, risk stratification with stress testing can help identify patients with a large residual ischemic burden who may benefit from coronary angiography with revascularization if feasible.