Open multicentre study of the P2T receptor antagonist AR-C69931MX assessing safety, tolerability and activity in patients with acute coronary syndromes.

Platelet aggregation is the central process in the pathophysiology of acute coronary syndromes. ADP contributes to thrombosis by activating platelets, and AR-C69931MX is a specific antagonist of this process acting at the P2T receptor. At 5 hospitals, 39 patients with unstable angina or non-Q wave myocardial infarction, who were receiving aspirin and heparin, were administered intravenous AR-C69931MX with stepped dose increments over 3 h to a plateau of either 2 microg/kg/min for 21 h (Part 1; n = 12) or up to 69 h (Part 2; n = 13) or 4 microg/kg/min for up to 69 h (Part 3: n = 14). Safety parameters, platelet aggregation (PA) induced by ADP 3 micromol/L (impedance aggregometry), bleeding time (BT) and plasma concentrations of AR-C69931XX were assessed. AR-C69931MX was well tolerated. 33 patients completed the study. There were no deaths at 30 days and no serious adverse events attributed to AR-C69931MX. Trivial bleeding (56%) was common. At 24 h, mean inhibition of PA was 96.0 +/- 8.6, 94.9 +/- 14.4 and 98.7 +/- 2.1% and BT was 9.5 +/- 8.4, 14.0 +/- 9.7 and 16.0 +/- 11.1 min for Parts 1, 2 and 3 respectively. At 1 h post-infusion, mean inhibition of PA was 36.2 +/- 39.2, 20.7 +/- 25.9 and 40.7 +/- 36.7% respectively. 90% patients had a plasma half-life for AR-C69931XX of <9 min. In conclusion, AR-C69931MX is a potent, short-acting platelet ADP receptor antagonist suitable for further studies as an antithrombotic agent.

Therapeutic value of eptifibatide at community hospitals transferring patients to tertiary referral centers early after admission for acute coronary syndromes. PURSUIT Investigators.

OBJECTIVES: We aimed to evaluate the benefits of the glycoprotein (GP) IIb/IIIa antagonist, eptifibatide, after patients with acute coronary syndromes (ACS) were admitted to hospitals that approach revascularization for ACS through early transfer to tertiary referral centers. BACKGROUND: Across a variety of hospital settings, GP IIb/IIIa inhibition, after patients were admitted to the hospital for non-ST segment elevation ACS, is associated with a reduction in death or myocardial infarction (MI) before and during a percutaneous coronary intervention. METHODS: The outcomes of 429 patients from 153 sites in the Platelet glycoprotein IIb/IIIa in unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, who were transferred during study drug infusion ("transfer patients"), were compared with those of 1,987 patients who either remained in the hospital at those sites or were transferred after study drug termination ("nontransfer patients"). RESULTS: The baseline characteristics of transfer and nontransfer patients were similar. Patients receiving eptifibatide were transferred less frequently than those receiving placebo (16% vs. 20%, p = 0.014). Transfer patients underwent more procedures and experienced a greater 30-day incidence of death or MI, as compared with nontransfer patients (21% vs. 12%, p = 0.001). Eptifibatide was associated with a reduction in death or MI through 30 days, independent of transfer status (2.5% absolute reduction), as well as for those transferred (5.5% absolute reduction). CONCLUSIONS: For patients with ACS admitted to community hospitals, eptifibatide is associated with a reduced need for transfer and improved clinical outcomes.

Predictors of outcome in patients with acute coronary syndromes without persistent ST-segment elevation. Results from an international trial of 9461 patients. The PURSUIT Investigators.

BACKGROUND: Appropriate treatment policies should include an accurate estimate of a patient's baseline risk. Risk modeling to date has been underutilized in patients with acute coronary syndromes without persistent ST-segment elevation. METHODS AND RESULTS: We analyzed the relation between baseline characteristics and the 30-day incidence of death and the composite of death or myocardial (re)infarction in 9461 patients with acute coronary syndromes without persistent ST-segment elevation enrolled in the PURSUIT trial [Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin (eptifibatide) Therapy]. Variables examined included demographics, history, hemodynamic condition, and symptom duration. Risk models were created with multivariable logistic regression and validated by bootstrapping techniques. There was a 3.6% mortality rate and 11.4% infarction rate by 30 days. More than 20 significant predictors for mortality and for the composite end point were identified. The most important baseline determinants of death were age (adjusted chi(2)=95), heart rate (chi(2)=32), systolic blood pressure (chi(2)=20), ST-segment depression (chi(2)=20), signs of heart failure (chi(2)=18), and cardiac enzymes (chi(2)=15). Determinants of mortality were generally also predictive of death or myocardial (re)infarction. Differences were observed, however, in the relative prognostic importance of predictive variables for mortality alone or the composite end point; for example, sex was a more important determinant of the composite end point (chi(2)=21) than of death alone (chi(2)=10). The accuracy of the prediction of the composite end point was less than that of mortality (C-index 0.67 versus 0.81). CONCLUSIONS: The occurrence of adverse events after presentation with acute coronary syndromes is affected by multiple factors. These factors should be considered in the clinical decision-making process.

Cigarette smoking status and outcome among patients with acute coronary syndromes without persistent ST-segment elevation: effect of inhibition of platelet glycoprotein IIb/IIIa with eptifibatide. The PURSUIT trial investigators.

BACKGROUND: Studies have shown that cigarette smokers constitute a substantial proportion of patients with acute coronary syndromes (ACS) and have platelet-rich coronary thrombi. We characterized the influence of smoking status on outcome of patients with ACS without persistent ST-segment elevation and tested the hypothesis that selective inhibition of the platelet glycoprotein IIb/IIIa receptor with eptifibatide would improve outcomes among cigarette smokers. METHODS: The study population included patients enrolled in the PURSUIT trial (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy) with known smoking status presenting with ischemic chest pain

Geographic variability in outcomes within an international trial of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes. Results from PURSUIT.

AIMS: Variations in outcome of patients from different geographic regions have been observed in many large international trials. We analysed the factors that might contribute to the geographic variations in patient outcome and treatment effect as observed in the PURSUIT trial. METHODS: In PURSUIT, 9461 patients with acute coronary syndromes without persistent ST-elevation were randomized to the platelet inhibitor eptifibatide or placebo for 72 h in 27 countries in four geographic regions: Western (n=3697) and Eastern Europe (n=1541) as well as North (n=3827) and Latin America (n=396). The primary end-point was the 30-day composite of death or myocardial infarction. In the initial univariate analysis, the treatment effect appeared greater in N. America than in W. Europe, while no benefit was apparent in L. America and E. Europe. However, the confidence intervals were wide and overlapping. To study these differences, a subdivision in an early and late patient outcome and treatment effect was made. Accordingly, we analysed the rate of death or infarction at 72 h censored for percutaneous coronary intervention and the rate between 3 and 30 days, respectively. Additional analyses were performed with different definitions of myocardial infarction using progressively higher thresholds of CK(-MB) elevation. Multivariable analysis was used to evaluate the relation between region and outcome and to determine the adjusted odds ratios for the eptifibatide treatment effect. RESULTS: Major differences in baseline demographics were apparent among the four regions; in particular, more patients from E. Europe had characteristics associated with impaired outcome. Interventional treatment also varied considerably, with more patients from N. America undergoing revascularization. Despite differences in the 72 h event rate, eptifibatide showed a consistent trend towards a reduction in the composite end-point among all four regions and for all definitions of infarction. Relative reductions ranged from 17-42% in W. Europe, 23-35% in N. America, 0-33% in E. Europe, and 55-82% in L. America. After multivariable adjustment, the pattern of benefit with eptifibatide was consistent among the regions. In patients undergoing percutaneous coronary intervention during study drug infusion in W. Europe (n=266) and N. America (n=931), the relative reduction in myocardial infarction during medical therapy ranged from 56-75% in W. Europe and 14-67% in N. America, while the reduction in procedure-related events ranged from 12-44% and 25-61% for different definitions of infarction. After multivariable adjustment neither benefit nor rebound were apparent after study drug discontinuation, or after 3 days in all regions, except in L. America. In general, the differences in outcome and treatment effect were greatest when the protocol definition of myocardial infarction (CK(-MB) >1 upper normal limit) was applied. Under stricter definitions, these differences became smaller and disappeared with the investigator's assessment. CONCLUSION: The analysis suggests that the apparent differences in patient outcome and eptifibatide treatment effect can be explained largely by differences in baseline demographics and adjunctive treatment strategies as well as by the methodology of myocardial infarction definition and the adjudication process.

Early percutaneous coronary intervention, platelet inhibition with eptifibatide, and clinical outcomes in patients with acute coronary syndromes. PURSUIT Investigators.

BACKGROUND: Platelet glycoprotein (GP) IIb/IIIa antagonists prevent the composite end point of death or myocardial infarction (MI) in patients with acute coronary syndromes. There is uncertainty about whether this effect is confined to patients who have percutaneous coronary interventions (PCIs) and whether PCIs further prevent death or MI in patients already treated with GP IIb/IIIa antagonists. METHODS AND RESULTS: PURSUIT patients were treated with the GP IIb/IIIa antagonist eptifibatide or placebo; PCIs were performed according to physician practices. In 2253 of 9641 patients (23.4%), PCI was performed by 30 days. Early (<72 hours) PCI was performed in 1228 (12.7%). In 34 placebo patients (5.5%) and 10 treated with eptifibatide (1.7%) (P=0.001), MI preceded early PCI. In patients censored for PCI across the 30-day period, there was a significant reduction in the primary composite end point in eptifibatide patients (P=0.035). Eptifibatide reduced 30-day events in patients who had early PCI (11.6% versus 16.7%, P=0.01) and in patients who did not (14.6% versus 15.6%, P=0.23). After adjustment for PCI propensity, there was no evidence that eptifibatide treatment effect differed between patients with or without early PCI (P for interaction=0.634). PCI was not associated with a reduction of the primary composite end point but was associated with a reduced (nonspecified) composite of death or Q-wave MI. This association disappeared after adjustment for propensity for early PCI. CONCLUSIONS: Eptifibatide reduced the composite rates of death or MI in PCI patients and those managed conservatively.

Prior aspirin use predicts worse outcomes in patients with non-ST-elevation acute coronary syndromes. PURSUIT Investigators. Platelet IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy.

Aspirin is beneficial in the prevention and treatment of cardiovascular events, but patients who have events while taking aspirin may have worse outcomes than those not on aspirin. We investigated the association between prior aspirin use and clinical outcomes in 9,461 patients with non-ST-elevation acute coronary syndromes enrolled in the Platelet IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial, before and after adjustment for baseline factors. We also examined whether eptifibatide has a differential treatment effect in prior aspirin users. Prior aspirin users were less likely to have an enrollment myocardial infarction (MI) (vs unstable angina) (43.9% vs 48.8%, p = 0.001) but more likely to have death or MI at 30 days (16.1% vs 13.0%, p = 0.001) and at 6 months (19.9% vs 15.9%, p = 0.001). After adjustment, prior aspirin users remained less likely to have an enrollment MI (odds ratio 0.88, 95% confidence interval 0.79 to 0.97) and more likely to have death or MI at 30 days (odds ratio 1.16, 95% confidence interval 1.00 to 1.33) but not at 6 months (odds ratio 1.14, 95% confidence interval 0.98 to 1.33). In a multivariable model, eptifibatide did not have a different treatment effect in prior aspirin users compared with nonusers (p = 0.534). Prior aspirin users had fewer enrollment MIs but worse long-term outcomes than nonusers. We found no evidence for a different treatment effect of eptifibatide in prior aspirin users.

Differential effects of glycoprotein IIb/IIIa antagonists on platelet microaggregate and macroaggregate formation and effect of anticoagulant on antagonist potency. Implications for assay methodology and comparison of different antagonists.

BACKGROUND: Citrated platelet-rich plasma (PRP) turbidimetry is used for assessing pharmacodynamic effects of glycoprotein (GP) IIb/IIIa antagonists in clinical trials. However, citrate can enhance the potency of at least eptifibatide (Integrilin), and turbidimetry is insensitive to microaggregate formation. We compared PRP turbidimetry, as a measure of macroaggregate formation, with single-platelet counting in both whole blood and PRP as a measure of microaggregate formation, using both citrate and hirudin anticoagulation. METHODS AND RESULTS: Three GP IIb/IIIa antagonists, eptifibatide, MK-0852, and GR144053, were compared in PRP (turbidimetry) and whole blood (platelet counting with an Ultra-Flo 100 Platelet Counter), with ADP and collagen used as agonists. Compared with hirudin, citrate enhanced the potency of eptifibatide by up to 4-fold in both PRP and whole blood (P<0.0005), modestly enhanced MK-0852 potency (P=0.001), and had no effect on GR144053. Potency measured in PRP was 2- to 3-fold greater compared with whole blood for MK-0852 and GR144053 but 3- to 4-fold greater for eptifibatide. Simultaneous turbidimetry and platelet counting performed in PRP indicated that this is because GP IIb/IIIa antagonists are more potent inhibitors of in vitro macroaggregation than microaggregation, this effect being greater for eptifibatide in hirudinized PRP compared with GR144053 (P=0.032). CONCLUSIONS: GP IIb/IIIa antagonist potency is variably enhanced by citrate. Macroaggregation is inhibited more effectively than microaggregation, most markedly in the case of eptifibatide in hirudinized blood. These observations have implications for the interpretation and comparison of pharmacodynamic assays and possibly for the risk/benefit ratio of different agents.

Influence of diabetes mellitus on clinical outcome in the thrombolytic era of acute myocardial infarction. GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries.

OBJECTIVES: This study was undertaken to define and better understand the characteristics and outcomes of patients with diabetes treated for acute myocardial infarction with contemporary thrombolysis. BACKGROUND: Although thrombolysis has substantially improved survival of patients with myocardial infarction, diabetes mellitus remains an independent predictor for a poor prognosis. METHODS: We characterized the contemporary relation between diabetes and outcome after myocardial infarction treated with thrombolytic agents from a large international cohort. Of 41,021 patients randomized to receive accelerated tissue-type plasminogen activator (t-PA), streptokinase or a combination of both agents in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries study, there were 5,944 patients with diabetes and 34,888 patients without diabetes. RESULTS: Patients with diabetes were older and more likely to be female, to present with anterior wall infarction, to receive thrombolysis later and to have triple-vessel coronary artery disease. Mortality at 30 days was highest among diabetic patients treated with insulin (12.5%) compared with non-insulin-treated diabetic (9.7%) and nondiabetic (6.2%) patients (p < 0.001). Mortality was lowest among those with diabetes receiving accelerated t-PA, which is consistent with the results of the overall patient cohort. Although stroke occurred more frequently among diabetic (1.9%) than nondiabetic patients (1.4%, p < 0.001), there was no significant difference in the rates of intracranial hemorrhage. Cardiac failure, shock, atrioventricular block and atrial flutter/ fibrillation were more common among diabetic patients. The proportion of patients undergoing revascularization was similar between patients with and without diabetes, although diabetic patients were more likely to undergo coronary artery bypass graft surgery (10.4% vs. 8.3%). Diabetes remained an independent predictor for mortality at 1-year follow-up (14.5% vs. 8.9%, p < 0.001). CONCLUSIONS: Diabetes, alone and in association with its comorbidities, portends a substantially worse 30-day and 1-year prognosis for patients with myocardial infarction.

Comparisons of characteristics and outcomes among women and men with acute myocardial infarction treated with thrombolytic therapy. GUSTO-I investigators.

OBJECTIVE: To compare baseline characteristics, complications, and treatment-specific outcomes of women and men with acute myocardial infarction treated with thrombolytic therapy. DESIGN: Randomized controlled trial. PATIENTS AND SETTING: A total of 10315 women and 30706 men with acute myocardial infarction treated in 1081 hospitals in 15 countries as part of the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I). INTERVENTION: One of four thrombolytic regimens: (1) streptokinase with subcutaneous heparin; (2) streptokinase with intravenous heparin; (3) streptokinase plus alteplase (tissue-type plasminogen activator) with intravenous heparin; or (4) accelerated alteplase with intravenous heparin. MAIN OUTCOME MEASURES: Mortality, stroke, and nonfatal complications during 30-day follow-up. RESULTS: Women were on average 7 years older than men and delayed 18 minutes (median) longer after symptom onset before presenting to the hospital. After adjustment for age, women more often had a history of diabetes, hypertension, and smoking than men. Time to treatment was significantly longer in women (1.2 vs 1.0 hours; P<.001). Women had more nonfatal complications after treatment, including shock (9% vs 5%; P<.001), congestive heart failure (22% vs 14%; P<.001), serious bleeding (15% vs 7%; P<.001), and reinfarction (5.1% vs 3.6%; P<.001). Women had twice as many total strokes as men (2.1% vs 1.2%; P<.001), secondary to their older age at presentation. The unadjusted mortality rate was twice as high in women as men (11.3% vs 5.5%; P<.001); the relative risk (RR) of death was greater among women than men after adjustment for differences in baseline characteristics (RR=1.15; 95% confidence interval, 1.0 to 1.31). Although women and men underwent angiography at similar rates, there were small but significant differences in their rates of revascularization procedures (angioplasty: 35% of women and 32% of men; bypass surgery: 7% of women and 9% of men; P<.001 for both). The higher rate of stroke in women after treatment with alteplase (2.0% vs 1.9% with streptokinase and intravenous heparin) was offset by a greater relative reduction in mortality (10.3% vs 11.1%). CONCLUSION: Women who received thrombolytic therapy for treatment of acute myocardial infarction were at greater risk for both fatal and nonfatal complications than men.

Evaluation of paradoxic beneficial effects of smoking in patients receiving thrombolytic therapy for acute myocardial infarction: mechanism of the "smoker's paradox" from the GUSTO-I trial, with angiographic insights. Global Utilization of Streptokinase and Tissue-Plasminogen Activator for Occluded Coronary Arteries.

OBJECTIVES: Our purpose was to evaluate the relation between smoking and the outcomes of patients receiving thrombolysis for acute myocardial infarction. BACKGROUND: A paradoxic beneficial effect has been observed in smokers with a myocardial infarction. We analyzed outcomes and baseline characteristics of 11,975 nonsmokers, 11,117 ex-smokers and 17,507 current smokers in a multinational trial of thrombolysis for acute myocardial infarction. METHODS: Patients were randomized to one of four thrombolytic protocols. An angiographic substudy in 2,431 patients evaluated reperfusion, reocclusion and ventricular function. Effects of smoking were evaluated by logistic regression analysis after adjustment for age and gender. A mortality model evaluated the simultaneous effect of baseline characteristics on the prognostic importance of smoking. These processes were performed with data from both the main trial and the angiographic substudy; then angiographic factors (coronary anatomy, patency and ejection fraction) were added to the model. RESULTS: Smokers were significantly younger by a mean of 11 years) and had less comorbidity or severe coronary artery disease than nonsmokers. Nonsmokers had significantly higher hospital and 30-day mortality rates (9.9% and 10.3%, respectively) than smokers (3.7% vs. 4%, respectively, both p < 0.001) and more in-hospital complications. The unadjusted odds ratio for 30-day mortality in nonsmokers was 3.36 (95% confidence interval [CI] 2.08 to 5.41), 1.21 (95% CI 0.71 to 2.08) after adjustment for age and gender and 1.08 (95% CI 0.59 to 1.96) after adjustment for all clinical baseline characteristics. CONCLUSIONS: Smokers receiving thrombolysis for acute myocardial infarction presented 11 years earlier than nonsmokers, which generally accounted for their better outcome. When other differences in clinical and angiographic baseline factors and therapeutic responses were evaluated, no significant difference in mortality was seen between smokers and nonsmokers.

Effects of ticlopidine administered to healthy volunteers on platelet function in whole blood.

Ticlopidine is thought to be a selective inhibitor of ADP-induced platelet function. Here we have investigated the effects of ticlopidine on platelet function in whole blood induced by ADP and by other platelet agonists. Whole blood was used because it was considered that ADP derived from red cells might act synergistically with other platelet agonists to enhance platelet responses, and that ticlopidine might interfere with this process. Measurements were performed using blood from 16 healthy volunteers before ticlopidine administration, after taking ticlopidine 250 mg daily for 10 days, after taking ticlopidine 250 mg twice daily for a further 10 days, and after 14 days off treatment. Ticlopidine proved to be a very effective inhibitor of the platelet aggregation induced by ADP; it was most effective in enhancing the reversibility of the aggregation response. The drug modestly but significantly reduced streptokinase, adrenaline, collagen, sodium arachidonate, PAF and U46619 - induced platelet aggregation. The drug significantly reduced the extent of the release reaction (14C-5HT release) induced by ADP, streptokinase, PAF, ristocetin and sodium arachidonate, and also reduced the extent of the synergistic 14C-5HT release induced by combinations of ADP and PAF, ADP and adrenaline and PAF and adrenaline. The various inhibitory effects of ticlopidine were evident after treatment with 250 mg daily but were more pronounced after 250 mg twice daily. All values had returned to normal after 14 days off treatment. Ticlopidine had no effect on serum thromboxane B2 production nor on several parameters of coagulation and fibrinolysis. We conclude that ticlopidine is an effective inhibitor of ADP-induced platelet aggregation and also the platelet aggregation and 14C-5HT release induced in whole blood by a number of platelet agonists and combinations of agonists. These latter effects are probably mainly via a selective effect on ADP. The inhibitory effects of the drug are dose-related.

Verification of smoking history in patients after infarction using urinary nicotine and cotinine measurements.

Urinary concentrations of nicotine and its major metabolite cotinine were measured in volunteers whose smoking habits were known to test the reliability of the measurements as indicators of current smoking. In the non-smokers detectable concentrations were always below the confidence limits set for the method, while in smokers the concentrations were always above these limits. After subjects stopped smoking cotinine appeared in the urine for longer than nicotine and was still detectable at least 36 hours after the last cigarette had been smoked. When this method was used to verify the smoking histories given by patients attending an infarction clinic it was estimated that 46-53% of previous smokers had actually stopped smoking compared with the 63% who said that they had done so. It is suggested that simultaneous assays of urinary nicotine and cotinine may be a useful means of verifying patients' current smoking habits.

Serum lipid concentrations and blood pressure in obese women.

In 70 obese women no correlation was found between body weight and serum cholesterol or triglyceride concentrations, but there was a significant correlation between weight and blood pressure. Weight reduction by diet or jejunoileal shunt was not accompanied by any significant change in serum lipid concentrations other than the decrease in serum cholesterol expected after intestinal bypass. Twelve months after bypass surgery was carried out on 14 patients, however, both systolic and diastolic blood pressures were significantly reduced and at levels appropriate to the patients' new weights. These results suggest that obesity in women cannot be taken to indicate the presence of hyperlipidaemia and that sustained weight loss may lower blood pressure.

Intravenous urography in the management of acute retention.

A retrospective analysis of the frequency of requests for an intravenous urogram (I.V.P.) in men with acute retention of urine showed that this investigation was performed in 82%. In no instance, however, did the urographic findings influence the decision to operate or the type of operation performed. The introduction of a specialised urological service did not reduce the number of I.V.P.s requested because most referrals to the urologist were made after the I.V.P. Patients who had an I.V.P. waited on average 8 days from admission to operation compared with 3-5 days for those who did not. We conclude that no purpose is served by a routine I.V.P. in every male patient admitted to hospital with acute retention of urine.

Endomyocardial fibrosis associated with daunorubicin therapy.

A case of endomyocardial fibrosis in a patient with acute myeloblastic leukaemia treated by daunorubicin is reported. The pathological findings are indistinguishable from tropical endomyocardial fibrosis.

Symptomatic hypoglycaemia, liver glycogen depletion and cirrhosis following jejuno-ileal bypass for gross obesity.

A new complication following jejuno-ileal bypass for gross obesity is described. The patient suffered from hypoglycaemic attacks which were associated with total depletion of liver glycogen together with a progressive micronodular cirrhosis. Increased dietary protein and calorie content relieved her symptoms, restored liver glycogen but had no effect on the development of the cirrhosis over the next 12 months.