Platelet FcγRIIa as a Marker of Cardiovascular Risk After Myocardial Infarction.

BACKGROUND: A previous single-center study of patients with myocardial infarction (MI) showed that platelet FcγRIIa (pFCG) can distinguish patients at higher and lower risk of subsequent MI, stroke, and death. OBJECTIVES: The authors performed an 800-patient 25-center study to validate the prognostic implications of pFCG. METHODS: Patients with type 1 MI (ST-segment elevation and non-ST-segment elevation) were enrolled in a prospective noninterventional trial during their index hospitalization. Enrolled patients had at least 2 of the following characteristics: age ≥65 years, multivessel coronary artery disease, previous MI, chronic kidney disease, or diabetes mellitus. Flow cytometry was used to quantify pFCG at a core laboratory. A predefined threshold was used to identify high and low pFCG. Patients were queried every 6 months by telephone with a standardized questionnaire. Events were confirmed by review of medical records. RESULTS: Treatment with antithrombotic therapy (aspirin, P2Y12 inhibitors, and anticoagulants) was similar in patients with high and low pFCG. The primary composite endpoint (MI, stroke, death) occurred more frequently in patients with high pFCG (HR: 2.09; 95% CI: 1.34-3.26; P = 0.001). Among individual components of the composite, both death (HR: 2.57; 95% CI: 1.50-4.40; P = 0.001) and MI (HR: 3.24; 95% CI: 1.64-6.37; P = 0.001) were more frequent in patients with high pFCG. CONCLUSIONS: Quantifying pFCG identifies patients at higher and lower risk of subsequent cardiovascular events. This prognostic information will be useful in clinical decisions regarding the intensity and duration of antiplatelet therapy. (Assessment of Individual Risk of Cardiovascular Events by Platelet FcγRIIa; NCT05175261).

Assessing prognosis by quantifying FcγRIIa on fixed platelets.

Introduction: FcγRIIa amplifies platelet activation and higher platelet FcγRIIa identifies patients at greater risk of subsequent cardiovascular events. We report the accuracy and precision of a modified test to quantify FcγRIIa on previously fixed platelets (pFCG test).Methods & results: An antibody clone (5G1) was developed after exposure of mice to formaldehyde treated FcγRIIa. Accuracy and precision of the modified test was evaluated with biologic specimens (platelets) and engineered synthetic cells conjugated with FcγRIIa (Slingshot Biosciences). The modified pFCG test on fixed platelets (using 5G1) consistently identified modestly more (∼300 molecules) of FcγRIIa on platelets compared with the pFCG test on nonfixed platelets (using clone FL18.26). With biologic specimens, the intra-assay coefficient of variation (CV) was 2.1 ± 0.1% (standard error of the mean, n = 750). The interassay CV was assessed intraday (4.5 ± 1%) and interday (up to 5 days after fixation, 6.5 ± 0.4%, n = 50). The pFCG test performed on Slingshot Synthetic cells conjugated with FcγRIIa demonstrated accuracy, linearity (R2 = 0.984) and similar interassay CV both intraday (2% ± 0.6%) and interday (20 nonconsecutive days, 9.9% ± 2.1%).Conclusion: In summary, modification of the pFCG test to be performed on fixed platelets allows accurate quantification of pFCG with high precision.

[Box: see text].

Exploring the potential cost-effectiveness of a novel platelet assay for guiding dual antiplatelet therapy duration in acute coronary syndrome patients following percutaneous coronary intervention.

OBJECTIVE: Duration of dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI) influences ischemic and bleeding events. Platelet expression of constant fragment of immunoglobulin, low affinity IIa, receptor (FcγRIIa) independently predicts risk of ischemic complications and is proposed as a tool to guide individualized care. METHODS: We used a Markov model to predict lifetime ischemic and bleeding events and healthcare costs in acute myocardial infarction (MI) patients treated with PCI and DAPT and to project cost-effectiveness of platelet FcγRIIa-assay-guided care (30:3 months DAPT for patients at high: low ischemic risk) versus current standard care (12 months DAPT) from the perspective of the US healthcare system. Model inputs included assay sensitivity and specificity, ischemic and bleeding event rates, and impacts on quality of life, mortality, and costs. Assay cost was $90. Sensitivity analyses were conducted over a range of plausible clinical and cost assumptions. RESULTS: Under base case assumptions, platelet FcγRIIa-assay-guided DAPT duration was projected to increase lifetime costs by $19 versus standard care, with an associated incremental cost-effectiveness ratio (ICER) of $436 per quality-adjusted life-year (QALY) gained. Assay-guided DAPT duration was consistent with high-value care (ICER < $50 000/QALY gained) over a broad range of alternative assumptions. CONCLUSION: Based on a decision-analytic model, for patients with MI treated with PCI, the additional costs of the platelet FcγRIIa assay for guiding DAPT duration would be largely offset by reductions in downstream event-related costs, and assay-guided care would be highly cost-effective by current standards. These findings require confirmation in prospective studies and in a randomized clinical trial of assay-guided versus nonassay-guided DAPT duration.

Incidence rate of hospitalization and mortality in the first year following initial diagnosis of cardiac amyloidosis in the US claims databases.

OBJECTIVE: This study aimed to determine rates of hospitalization and in-hospital mortality in the first year following amyloidosis diagnosis with cardiac involvement using observational databases. METHODS: Three administrative claims databases, IBM MarketScan® Commercial Claims and Encounters (CCAE), IBM MarketScan® Multi-State Medicare Database (MDCR), and Optum's de-identified Clinformatics® Data Mart Database (Optum) were analyzed. Adults ≥18 years old, with a diagnosis of amyloidosis and evidence of cardiac involvement (i.e. heart failure, heart block, or cardiomyopathy) but no hepatic/renal failure prior to amyloidosis diagnosis were included for analysis. The primary analyses identified patients between 01-01-2010 and 31-12-2017 period. We calculated the rates of hospitalization and in-hospital mortality within 1 year after the initial diagnosis of amyloidosis. A sensitivity analysis was conducted for patients identified in Optum database during 2004-2011 period, which provided additional mortality information. RESULTS: A total of 419, 654, and 922 patients from CCAE, MDCR, and Optum were identified during 2010-2017 period, with mean age of 55.6, 77.8, and 74.2 years, respectively. Within 1 year following initial amyloidosis diagnosis, incidence rates (95% confidence interval [CI]) of hospitalization were 78.4 (66.3, 90.4), 78.6 (69.2, 87.9), and 61.2 (54.4, 68.0) per 100 person-years, rates of in-hospital mortality were 16.5 (11.8, 21.3), 8.4 (5.7, 11.0), and 17.7 (14.5, 21.0) per 100 person-years, in CCAE, MDCR, and Optum, respectively. The mortality rate from the sensitivity analysis among patients identified in Optum 2004-2011 period was higher compared with Optum 2010-2017 period. CONCLUSIONS: The results from this study indicate that amyloidosis with cardiac involvement is a condition with high rates of hospitalization and mortality in the first year after initial diagnosis. Future studies are needed to further evaluate the outcomes within the subtypes of amyloidosis and understand the risk factors associated with poor prognoses.

Drug Development in Kidney Disease: Proceedings From a Multistakeholder Conference.

Occasional bursts of discovery and innovation have appeared during the otherwise stagnant past several decades of drug development in nephrology. Among other recent drug discoveries, the unexpected kidney benefits observed with sodium/glucose cotransporter 2 inhibitors may herald a renaissance of drug development in kidney disease. This recent progress highlights the need to further promote and stimulate research and development of promising therapies that may ameliorate the morbidity and mortality associated with kidney disease. To help identify and address barriers to drug development in nephrology, the Duke Clinical Research Institute convened a conference in April 2019 that included stakeholders from academia, industry, government agencies, and patient advocacy. From these discussions, several opportunities were identified to improve every stage of drug development for kidney disease from early discovery to implementation into practice. Key topics reviewed in this article are the utility of interconnected data and site research networks, surrogate end points, pragmatic and adaptive trial designs, the promising uses of real-world data, and methods to improve the generalizability of trial results and uptake of approved drugs for kidney-related diseases.

Randomized phase 2 trial comparing JNJ-9375, a thrombin-directed antibody, with apixaban for prevention of venous thrombosis.

BACKGROUND: JNJ-9375 is an antibody against exosite 1 on thrombin, inhibits substrate binding but not catalytic activity. OBJECTIVE: To examine the possibility that JNJ-9375 attenuates thrombosis without affecting hemostasis, we compared the efficacy and safety of JNJ-9375 and apixaban. METHODS: In this double-blind, double-dummy phase 2 trial, 308 patients undergoing knee arthroplasty were randomized to receive either a single postoperative intravenous infusion of JNJ-9375 in doses ranging from 0.3 to 1.8 mg/kg or apixaban (2.5 mg twice daily). The primary efficacy endpoint was the incidence of venous thromboembolism (assessed by mandatory unilateral venography or confirmed symptomatic events). The primary safety outcome was the composite of major, clinically relevant nonmajor, and minimal bleeding. Thrombin times were measured to assess JNJ-9375 activity. RESULTS: A total of 239 of the 308 patients (77.6%) were included in the modified intention-to-treat analysis. Of these, 238 had evaluable venograms and one had symptomatic deep-vein thrombosis confirmed by ultrasound. Despite dose-dependent thrombin time prolongation, the primary efficacy outcome occurred in 59 of 190 patients (31.1%) in the combined JNJ-9375 groups as compared with 6 of 49 patients (12.2%) given apixaban (odds ratio 3.2; two-sided 80% confidence interval 1.8-5.8; P = .011). The excess events with JNJ-9375 compared with apixaban were consistent across all JNJ-9375 dosing cohorts and there was no evidence of improved efficacy with higher JNJ-9375 doses. There were no major bleeds with JNJ-9375 or apixaban, and rates of any bleeding were similar with the highest and lowest JNJ-9375 doses. CONCLUSIONS: JNJ-9375 was safe but less effective than apixaban. This may reflect weak thrombin inhibition or inability of JNJ-9375 to attenuate the growth of thrombi that formed before drug administration.

Benefit-risk assessment of rivaroxaban versus enoxaparin for the prevention of venous thromboembolism after total hip or knee arthroplasty.

PURPOSE: Venous thromboembolism is a common complication after major orthopedic surgery. When prescribing anticoagulant prophylaxis, clinicians weigh the benefits of thromboprophylaxis against bleeding risk and other adverse events. Previous benefit-risk analyses of the REgulation of Coagulation in ORthopaedic surgery to prevent Deep vein thrombosis and pulmonary embolism (RECORD) randomized clinical studies of rivaroxaban versus enoxaparin after total hip (THA) or knee (TKA) arthroplasty generally used pooled THA and TKA results, counted fatal bleeding as both an efficacy and a safety event, and included the active and placebo-controlled portions of RECORD2, which might confound benefit-risk assessments. We conducted a post hoc analysis without these constraints to assess benefit-risk for rivaroxaban versus enoxaparin in the RECORD studies. PATIENTS AND METHODS: Data from the safety population of the two THA and two TKA studies were pooled separately. The primary analysis compared the temporal course of event rates and rate differences between rivaroxaban and enoxaparin prophylaxis for symptomatic venous thromboembolism plus all-cause mortality (efficacy events) versus nonfatal major bleeding (safety events). Additionally, these rates were used to derive measures of net clinical benefit, number needed to treat (NNT), and number needed to harm (NNH) for these two end points. RESULTS: After THA or TKA, and compared with enoxaparin, rivaroxaban therapy resulted in more efficacy events prevented than safety events caused, with benefits exceeding harms early and throughout treatment and follow-up. Relative to enoxaparin, rivaroxaban treatment prevented six efficacy events per harm event caused for THA, with NNT =262/NNH =1,711. For TKA, rivaroxaban treatment prevented four to five efficacy events per harm event caused, with NNT =102/NNH =442. Sensitivity analysis that included surgical-site bleeding resulted in NNH =345 for THA and NNH =208 for TKA. CONCLUSION: In the RECORD studies, considering death, symptomatic venous thromboembolism, and major bleeding, rivaroxaban resulted in greater benefits than harms compared with enoxaparin. When incorporating surgical-site bleeding, rivaroxaban also results in greater benefit than harm for TKA and is balanced with enoxaparin for THA.

Rivaroxaban: a novel oral anticoagulant for the prevention and treatment of several thrombosis-mediated conditions.

The development of rivaroxaban (XARELTO®) is an important new medical advance in the field of oral anticoagulation. Thrombosis-mediated conditions constitute a major burden for patients, healthcare systems, and society. For more than 60 years, the prevention and treatment of these conditions have been dominated by oral vitamin K antagonists (such as warfarin) and the injectable heparins. Thrombosis can lead to several conditions, including deep vein thrombosis, pulmonary embolism, myocardial infarction, stroke, and/or death. Prevention and treatment of thrombosis with an effective, convenient-to-use oral anticoagulant with a favorable safety profile is critical, especially in an aging society in which the risk of thrombosis, and the potential for bleeding complications, is increasing. Rivaroxaban acts to prevent and treat thrombosis by potently inhibiting coagulation Factor Xa in the blood. Factor Xa converts prothrombin to thrombin, which initiates the formation of blood clots by converting fibrinogen to clot-forming fibrin and leads to platelet activation. After a large and novel clinical development program in over 75,000 patients to date, rivaroxaban has received approval for multiple indications in the United States, European Union, and other countries worldwide to prevent and treat several thrombosis-mediated conditions. This review will highlight some of the unique aspects of the rivaroxaban development program.

Effects on platelet function of a direct acting antagonist of coagulation factor Xa.

Because novel direct acting anticoagulants are being tested in the secondary prevention of cardiovascular events, we assessed potential effects of a direct acting antagonist of Factor Xa on platelet function. Blood from patients with known coronary artery disease who were treated with aspirin but no other antithrombotic agent was spiked in vitro with rivaroxaban alone or in combination with a direct acting P2Y12 antagonist (cangrelor). To limit cofounding effects of anticoagulants and to enable interaction between coagulation factors, blood was anticoagulated only with a specific inhibitor of Factor XIIa, corn trypsin inhibitor. Polymerization of fibrin was prevented with the peptide GPRP. Activation of platelets was determined with the use of flow cytometry in response to lipidated tissue factor, thrombin, the collagen mimetic convulxin, and adenosine diphosphate (ADP). Rivaroxaban inhibited the activation of platelets induced by tissue factor and to a lesser extent activation induced by thrombin, effects that were accentuated when combined with cangrelor. Rivaroxaban did not attenuate convulxin-induced activation of platelets; however, a limited but consistent attenuation of ADP-induced platelet activation was seen with blood anticoagulated with rivaroxaban. Effects of rivaroxaban on ADP-induced platelet activation were not mediated by thrombin, tissue factor, or platelet-leukocyte aggregation. In conclusion, rivaroxaban attenuated in vitro the activation of platelets mediated by thrombin. In light of the pivotal role of thrombin in platelet activation after rupture of an atherosclerotic plaque, rivaroxaban should attenuate platelet activation in vivo, an effect that is accentuated by combination with a P2Y12 antagonist.

Cardiovascular safety profile of dapoxetine during the premarketing evaluation.

The cardiovascular safety profile of dapoxetine, a novel selective serotonin reuptake inhibitor (SSRI) developed as an on-demand oral treatment for premature ejaculation (PE) in men, is evaluated. The cardiovascular assessment of dapoxetine was conducted throughout all stages of drug development, with findings from preclinical safety pharmacology studies, phase I clinical pharmacology studies investigating the effect of dapoxetine on QT/corrected QT (QTc) intervals in healthy men, and phase III, randomized, placebo-controlled studies evaluating the safety (and efficacy) of the drug. Preclinical safety pharmacology studies did not suggest an adverse electrophysiologic or hemodynamic effect with concentrations of dapoxetine up to 2-fold greater than recommended doses. Phase I clinical pharmacology studies demonstrated that dapoxetine did not prolong the QT/QTc interval and had neither clinically significant electrocardiographic effects nor evidence of delayed repolarization or conduction effects, with dosing up to 4-fold greater than the maximum recommended dosage. Phase III clinical studies of dapoxetine in men with PE indicated that dapoxetine was generally safe and well tolerated with the dosing regimens used (30 mg and 60 mg as required). Events of syncope were reported during the clinical development program, with the majority occurring during study visits (on site) on day 1 following administration of the first dose when various procedures (e.g. orthostatic maneuvers, venipunctures) were performed, suggesting that the procedures contributed to the incidence of syncope. This was consistent with previous reports showing that these and similar factors contribute to or trigger vasovagal syncope. Findings of the dapoxetine development program demonstrate that dapoxetine is associated with vasovagal-mediated (neurocardiogenic) syncope. No other associated significant cardiovascular adverse events were identified.

A Comparison of Cardiovascular Biomarkers in Patients Treated for Three Months with Etoricoxib, Celecoxib, Ibuprofen, and Placebo.

OBJECTIVES: Selective cyclooxygenase (COX)-2 inhibitors are effective analgesic and anti-inflammatory agents with improved gastrointestinal safety and tolerability compared with traditional NSAIDs. However, data from long-term, placebo-controlled studies have shown an increased risk of thrombotic cardiovascular (CV) events for COX-2 inhibitors. Changes in levels of CV biomarkers are potentially useful surrogate measures of pathologic changes associated with CV risk. METHODS: We randomized 433 patients with osteoarthritis to etoricoxib 90 mg once daily, celecoxib 200 mg twice daily, ibuprofen 800 mg three times daily, or placebo for 12 weeks. The hypothesis was that etoricoxib would be non-inferior or superior to placebo in effect on C-reactive protein (CRP), LDL-cholesterol, homocysteine, and fibrinogen. RESULTS: Relative to placebo, etoricoxib was noninferior for effect on CRP (decreased 7.8% vs. placebo; 97.5% CI of the difference: -30.5, 22.4), LDL-C (-4.0% vs. placebo; 97.5% CI: -10.6, 3.2), homocysteine (-3.9% vs. placebo; 97.5% CI: -11.6, 4.6), and fibrinogen (-3.7% vs. placebo; 97.5% CI: -9.4, 2.3). Etoricoxib was not different from placebo, celecoxib, or ibuprofen for any biomarker. CONCLUSION: Etoricoxib was comparable to placebo, celecoxib, and ibuprofen for effects on the CV risk markers measured.

The relationship of obesity to ischemic outcomes following coronary stent placement in contemporary practice.

OBJECTIVES: We analyzed the relationship of obesity, determined by body mass index (BMI), to short- and long-term outcomes in the TARGET trial. BACKGROUND: : Previous studies have conflicting findings regarding the relationship of BMI to outcomes following percutaneous coronary intervention (PCI). METHODS: The TARGET trial studied the use of glycoprotein (GP) IIb/IIIa inhibition in patients undergoing planned coronary stent placement. RESULTS: Eighty-one percent of all patients were overweight (BMI > 25), 36% were obese (BMI > 30), and United States patients were more frequently obese (38.7% vs. 25.8%, P < 0.001). Obese patients had a similar 30-day ischemic event rate compared with nonobese patients, but less major bleeding (0.4% vs. 1.1%, P = 0.013). Six-month death and myocardial infarction rates were similar in obese and nonobese patients. There was a J-shaped relationship between 6-month target vessel revascularization (TVR) and BMI with the lowest incidence of TVR at BMI 27.5. Six-month TVR was higher in the morbidly (BMI > 35) obese (12.4% vs 8.7%, P < 0.05). In extremely (BMI > 32) obese patients, this relationship was more significant (TVR 11.3% vs. 8.5%, P = 0.007), particularly in patients <65 years of age (TVR 12.3% vs. 8.4%, P = 0.003). CONCLUSION: The majority of patients undergoing PCI are overweight, especially in the United States. Extreme obesity is associated with a significant increase in TVR following intent-to-stent PCI, especially in patients <65 years of age. With routine use of GP IIb/IIIa inhibitors, other long- and short-term ischemic events are similar in obese and nonobese patients. However, obese patients have significantly less major bleeding.

Early invasive strategy improves outcomes in patients with acute coronary syndrome with previous coronary artery bypass graft surgery: a report from TACTICS-TIMI 18.

BACKGROUND: Patients with previous coronary artery bypass graft surgery (CABG) have been classified as a high-risk subset of patients who experience non-ST elevation acute coronary syndrome (ACS). Recent studies suggest that an early invasive strategy is beneficial in moderate- and high-risk patients with non-ST elevation ACS. We hypothesized that an early invasive strategy is associated with improved outcomes in patients with non-ST elevation ACS with prior CABG. METHODS AND RESULTS: In the Treat Angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis in Myocardial Infarction 18 trial (TACTICS-TIMI 18), 2220 patients with non-ST segment elevation ACS were randomized to an early invasive or conservative (selectively invasive) strategy. All patients were treated with aspirin, heparin, and tirofiban. Four hundred eighty-four (22%) of these patients had undergone CABG before enrollment. We analyzed whether patients with previous CABG had different 6-month outcomes and whether an early invasive strategy was associated with an improvement in long-term outcomes. Prior CABG was associated with a higher risk of adverse outcomes by 6 months, including a higher rate of readmission for ACS (17.4% vs 11.0%, P < 0.001) and a higher incidence of the composite end point of death, myocardial infarction, or rehospitalization for ACS (22.3% vs 16.4%, P = 0.002). There was a trend toward a higher incidence of myocardial infarction (7.1% vs 5.3%, P = 0.051). An early invasive strategy was associated with a reduction in the composite of death or myocardial infarction (odds ratio [OR], 0.58; 95% confidence interval [CI], 0.31-1.0; P = 0.089) and a significant reduction in the incidence of myocardial infarction at 6 months (OR, 0.44; 95% CI, 0.21-0.93; P=0.032). CONCLUSIONS: Patients with non-ST segment elevation ACS who have had previous CABG are a high-risk subset. An early invasive strategy reduces risk of myocardial infarction in this high-risk group.

Correlation between the TIMI risk score and high-risk angiographic findings in non-ST-elevation acute coronary syndromes: observations from the Platelet Receptor Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms (PRISM-PLUS) trial.

BACKGROUND: The TIMI risk score for unstable angina and non-ST elevation myocardial infarction is an effective tool for predicting the risk of death and ischemic events among patients with non-ST elevation acute coronary syndromes, as well as for identifying those who are likely to benefit most from low-molecular-weight heparin and glycoprotein IIb/IIIa inhibition. METHODS: To explore the pathobiologic basis for this interaction, we evaluated the relationship between the risk score, assessed at presentation, and angiographic findings among patients with non-ST elevation acute coronary syndromes. Angiographic data regarding thrombus, epicardial flow, and lesion severity were available for 1491 patients from the angiographic substudy of PRISM-PLUS. RESULTS: Patients with risk scores of 5 to 7 (N = 435) were more likely to have a severe culprit stenosis (81% vs 58%, P < .001) and multivessel disease (80% vs 43%, P < .001) compared to those with scores of 0 to 2 (N = 220). The probability of left main disease (P = .01), visible thrombus, and impaired flow in the culprit lesion also increased progressively with rising risk scores (P < .001). Of the risk indicators that comprise the score, history of coronary disease, advanced age, and ST changes showed the strongest association with severe epicardial disease. Positive biomarkers of necrosis, ST changes, and prior aspirin use emerged as stronger correlates of visible thrombus and/or impaired culprit artery flow. CONCLUSIONS: The TIMI risk score identifies patients who are more likely to have intracoronary thrombus, impaired flow, and increased burden of coronary atherosclerosis. These findings likely explain in part the particular benefit of potent antithrombin and antiplatelet agents among patients with higher risk scores.

The relation of renal function to ischemic and bleeding outcomes with 2 different glycoprotein IIb/IIIa inhibitors: the do Tirofiban and ReoPro Give Similar Efficacy Outcome (TARGET) trial.

BACKGROUND: Renal function significantly impacts morbidity and mortality after a percutaneous coronary intervention. Platelet glycoprotein (GP) IIb/IIIa inhibitors reduce ischemic complications during percutaneous coronary intervention; little is known of whether their safety and efficacy are influenced by renal function. In particular, whether outcome differences exist between agents that are renally excreted (tirofiban) or not (abciximab) in patients with mild renal impairment is not known. METHODS: The TARGET trial randomized 4623 patients to tirofiban or abciximab. In this analysis, patients were grouped in creatinine clearance quartiles (<70, 70-90, 90-114, >114 mL/min) and analyzed for efficacy and bleeding risk. Univariate and multivariate analyses were performed to identify interactions between GP IIb/IIIa inhibitor used and creatinine clearance with respect to ischemic outcomes and bleeding. RESULTS: Using unadjusted logistic regression tests for trend, 30-day death/myocardial infarction/urgent target vessel revascularization was greater in patients with lower creatinine clearances (7.3%, 8.5%, 5.1%, and 5.8%, P = .005), as were both major and minor bleeding. There was no interaction between assigned GP IIb/IIIa inhibitor, creatinine clearance and ischemic outcome, major bleeding or minor bleeding. CONCLUSIONS: Both ischemic and bleeding complications are highest in the lowest creatinine clearance quartile of patients treated with GP IIb/IIIa inhibitors. Although tirofiban is renally cleared and abciximab is not, there was no interaction between these GP IIb/IIIa inhibitors and creatinine clearance regarding ischemic or bleeding events.

Analysis of bleeding complications associated with glycoprotein IIb/IIIa receptors blockade in patients with high-risk acute coronary syndromes: insights from the PRISM-PLUS study.

We aim to characterize the hemorrhagic complications and predictors of increased bleeding risk in a population of patients with high-risk acute coronary syndromes (ACS), enrolled in the PRISM-PLUS study. Patients treated with heparin plus tirofiban had more bleeding events compared to patients treated with heparin alone. No significant increase in major bleeding, thrombocytopenia, blood loss and blood products transfusions was observed among the patients who received the combination therapy. Several clinical variables were independently associated with increased risk of bleeding for both treatment groups: advanced age, lower body weight, female gender, decreased creatinine clearance (<30 ml/min). Females, patients with impaired renal function, patients requiring percutaneous coronary intervention (PCI), especially prolonged PCI (>100 min duration) or coronary artery bypass surgery (CABG) were at risk for increased major bleeding complications. Increased blood loss was also found in females, patients with elevated diastolic blood pressure, PCI, duration of PCI>100 min or CABG. No incremental risk was detected with the addition of tirofiban to heparin in patients at risk for major bleeding or increased blood loss. We concluded that identification of patients with high-risk ACS, at risk for bleeding complications and blood loss can be done with specific clinical variables. Tirofiban added to heparin increased minor hemorrhagic complications. Although there was no significant increase in major bleeding, thrombocytopenia and blood transfusions with the combination of tirofiban plus heparin, the power to detect a statistically significant difference in these endpoints was limited by the small number of events.

Prognostic implications of elevated troponin in patients with suspected acute coronary syndrome but no critical epicardial coronary disease: a TACTICS-TIMI-18 substudy.

OBJECTIVES: The purpose of this study is to determine whether there is clinical significance to elevated troponin I in patients with suspected acute coronary syndromes (ACS) with non-critical angiographic coronary stenosis. BACKGROUND: Elevation of troponin in patients admitted with ACS symptoms with non-critical coronary artery disease (CAD) may result from coronary atherothrombosis not evident using standard angiography or from other ischemic and non-ischemic causes that may confer increased risk for future events. METHODS: Patients with ACS enrolled in the Treat Angina With Aggrastat and Determine Cost of Therapy With Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction (TACTICS-TIMI)-18 were included. Of 2,220 patients enrolled in the trial, 895 were eligible. Patients were divided into four groups according to troponin status on admission and presence of significant angiographic stenosis. Baseline brain natriuretic peptide (BNP) and C-reactive protein (CRP) were obtained on all patients. RESULTS: The median troponin I levels were 0.71 ng/ml in patients with CAD compared with 0.02 ng/ml in patients without CAD (p <0.0001). Troponin-positive patients with or without angiographic CAD had higher CRP and BNP levels compared with troponin-negative patients (p <0.01 for both). The rates of death or reinfarction at six months were 0% in troponin-negative patients with no CAD, 3.1% in troponin-positive patients with no CAD, 5.8% in troponin-negative patients with CAD, and 8.6% in troponin-positive patients with CAD (p=0.012). CONCLUSIONS: Elevated troponin in ACS is associated with a higher risk for death or reinfarction, even among patients who do not have significant angiographic CAD. The mechanisms conferring this adverse prognosis merit further study.

Are statins being underdosed in clinical practice? Data from TACTICS-TIMI 18.

BACKGROUND: Although clinical trials in the 1990s have found significant reductions in cardiovascular events with fixed doses of statins, specifically 40 mg of simvastatin or pravastatin, in clinical practice, treatment is usually initiated at lower doses. It is not clear, however, if the doses are then titrated upward after the initial dosing. METHODS: We examined the dosing for patients receiving statins at the time of entry and at 6 months follow-up in the Treat angina with Aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction (TACTICS-TIMI) 18 trial, and their relationship to the measured low-density lipoprotein cholesterol (LDL-C) on admission. RESULTS: In the TACTICS-TIMI 18 trial, 727 of 2220 (33%) patients with unstable angina and non-ST elevation MI were on statins at study entry, of whom 371 had both LDL-C measurements and statin dose recorded on admission: 132 (36%) received atorvastatin, 126 (34%) simvastatin, 58 (16%) pravastatin, and the remainder lovastatin, fluvastatin, or cerivastatin. Only 18% and 38% of patients were treated with the 40-mg dose of simvastatin or pravastatin, respectively. Only 3 patients on atorvastatin were treated with 80 mg. At entry, 46% of these patients had LDL-C < or =100 mg/dL (and even among all patients with either prior MI, CABG, PTCA, or diabetes, only 33% had LDL-C < or =100 mg/dL, increasing modestly to 48% for those also on a statin). At 6 months after the UA/NSTEMI event, although more patients (1113, 50%) were on statins, the doses used were not higher then those used at baseline. CONCLUSION: We observed that the doses of statins in clinical practice were usually lower than those used in the clinical efficacy trials. Furthermore, LDL-C of < or =100 mg/dL was achieved in fewer then 50% of acute coronary syndrome patients receiving statins at time of presentation. These data suggest that, in addition to previously documented underutilization of statins in clinical practice, there is also underdosing of this important class of drugs.

Safety of stress testing during the evolution of unstable angina pectoris or non-ST-elevation myocardial infarction.

Patients (n = 1,106) were chosen from the conservative arm of the Treat Angina with aggrastat and determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction (TACTICS-TIMI) 18 trial. Only 1 patient had a myocardial infarction and another died on the day of stress testing (mortality 0.12%). In patients with unstable angina pectoris or non-ST-elevation myocardial infarction treated with aspirin, heparin, and tirofiban, performance of an exercise or a pharmacologic stress test in selected patients within 48 to 72 hours after admission appears to be associated with a low risk of complications.

Association of elevated B-type natriuretic peptide levels with angiographic findings among patients with unstable angina and non-ST-segment elevation myocardial infarction.

OBJECTIVES: We hypothesized that elevated B-type natriuretic peptide (BNP) levels would be associated with a greater severity of angiographic disease and a greater extent of myocardium at risk. BACKGROUND: Elevations of BNP have been associated with increased risk of adverse outcomes in patients with unstable angina and non-ST-segment elevation myocardial infarction (UA/NSTEMI). METHODS: Of the 2,220 patients with UA/NSTEMI enrolled in the Treat Angina with Aggrastat and Determine Cost of Therapy with an Invasive or Conservative Strategy-Thrombolysis In Myocardial Infarction-18 (TACTICS-TIMI-18) trial, 276 randomized to the invasive arm had both baseline BNP levels and angiographic core laboratory data. Patients were categorized according to their baseline BNP levels as < or =80 or >80 pg/ml. RESULTS: A total of 233 patients (84%) had BNP levels >80 pg/ml, and 43 (16%) had admission BNP levels >80 pg/ml. Patients with BNP >80 pg/ml had tighter culprit vessel stenosis on quantitative coronary angiography (median stenosis 76% vs. 67%, p = 0.004) and a higher (slower) corrected TIMI frame count (median CTFC 43 vs. 30, p = 0.018) in the culprit vessel. The median BNP level was higher in patients with a left anterior descending coronary artery (LAD) versus non-LAD culprit lesion location (median BNP level 40 vs. 24 pg/ml, p = 0.005), and the culprit artery was more often the LAD in patients with BNP >80 pg/ml compared with < or =80 pg/ml (44% vs. 30%, p = 0.06). CONCLUSIONS: Among patients with UA/NSTEMI, elevated BNP levels are associated with tighter culprit stenosis, higher CTFC, and LAD involvement. These findings suggest that elevated BNP may be associated with a greater severity and extent of myocardial ischemic territory during the index event and may partly explain the association between elevated BNP and adverse outcomes.