Biomedical subjects
R M Califf
Publications and source records attributed to R M Califf.
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 </=24 hours and having either ischemic electrocardiographic changes without persistent ST-segment elevation or elevated creatine kinase MB levels. Patients were randomly assigned to receive a bolus and infusion of either eptifibatide or placebo in addition to standard therapy. The primary end point was a composite of death or nonfatal myocardial infarction within 30 days. RESULTS: Of the 9406 patients with known smoking status, 2677 were current smokers, 3086 were former smokers, and 3643 were nonsmokers. Cigarette smokers had better 30-day outcomes (12.3%, 16.8%, and 15.4% for smokers, former smokers, and nonsmokers, respectively; P =.001). However, after adjusting for differences in baseline clinical variables, smoking status was not a predictor of 30-day outcome (P =.45). There was a reduction in the composite end point overall with eptifibatide compared with placebo (14.3% vs 15. 7%, P =.054) but no interaction between smoking status and treatment strategy (P =.68). CONCLUSIONS: Among patients with ACS without persistent ST-segment elevation, cigarette smokers had better short-term outcomes because of their more favorable clinical profile. Although prior studies have suggested that smokers more commonly have platelet-rich thrombi than nonsmokers, eptifibatide did not result in more improvement in their outcome compared with former smokers or nonsmokers.
Predictors of death and reinfarction at 30 days after primary angioplasty: the GUSTO IIb and RAPPORT trials.
BACKGROUND: Thirty-day death among recipients of fibrinolytic therapy for acute myocardial infarction (MI) is tightly correlated with easily obtainable key demographic and clinical parameters such as age, blood pressure, heart rate, and infarct location. Similar data for primary angioplasty are not available. METHODS AND RESULTS: Data from 2 large, contemporary, primary angioplasty trials were formally combined and analyzed with respect to death and death/repeat MI at 30 days through the use of multivariate logistic regression models. The 1048 patients had a median age of 62 years, and 26% were women. Thirty-eight percent had an anterior infarction. The patients underwent angioplasty at a median delay from symptom onset of 3.8 hours. Death was independently predicted by increasing age (adjusted odds ratio [OR] per decade 2.32, 95% confidence interval [CI] 1.60 to 3.42), whereas a history of smoking (OR 0.29, CI 0.13 to 0.64), Thrombolysis in Myocardial Infarction (TIMI) flow grade 3 after angioplasty (OR vs TIMI <3 0.21, CI 0.10 to 0.45) and higher systolic blood pressure (OR per 10 mm Hg 0.73, CI 0.62 to 0. 87) were associated with lower mortality rates. Death or repeat MI was independently associated with increasing age (OR per decade 1.40, CI 1.13 to 1.76) and anterior location of the index MI (OR 1.89, CI 1.12 to 3.20). TIMI grade 3 flow (OR vs TIMI <3 0.40, CI 0.23 to 0. 68) and higher systolic blood pressure (OR per 10 mm Hg 0.79, CI 0. 71 to 0.89) were associated with a lower incidence of death/repeat MI. Time to angioplasty, heart rate, extent of coronary artery disease, participation in 1 of the 2 trials, and all common coronary risk factors did not significantly predict outcome. CONCLUSIONS: Death and reinfarction after primary angioplasty are predominantly predicted by age, hemodynamic instability, and the attainment of TIMI 3 flow in the infarct artery.
Rationale and design of the OPTIME CHF trial: outcomes of a prospective trial of intravenous milrinone for exacerbations of chronic heart failure.
BACKGROUND: The optimal management of an acute exacerbation of chronic heart failure (CHF) is uncertain. There is little randomized evidence available to support the various treatment strategies for patients hospitalized with an exacerbation of CHF. Inotropic agents may produce beneficial hemodynamic effects, and although they are currently used in these patients, their effect on clinical response and impact on clinical outcome is unclear. We present a unique and simple study designed to determine whether a treatment strategy for CHF exacerbations that includes an intravenous agent with inotropic properties can reduce hospital length of stay and lead to improved patient outcome. METHODS: The OPTIME CHF (Outcomes of a Prospective Trial of Intravenous Milrinone for Exacerbations of Chronic Heart Failure) trial is an ongoing multicenter, randomized, placebo-controlled trial of a treatment strategy for patients with acute exacerbations of CHF. The design of this study provides a novel approach to the evaluation of treatment strategies in the care of this population. The OPTIME CHF design uses early initiation of intravenous milrinone as both an adjunct to the best the medical therapy and to facilitate optimal dosing of standard oral therapy for heart failure. Patients with known systolic heart failure requiring hospital admission for a CHF exacerbation are randomly assigned within 48 hours of admission to receive a 48-hour infusion of either intravenous milrinone or placebo. The primary end point of this design is a reduction in the total hospital days for cardiovascular events within 60 days after therapy. Enrollment of 1000 patients began July 7, 1997, at 80 US centers and is projected to conclude in late 1999.
Redefining medical treatment in the management of unstable angina.
In 1994, the Agency for Health Care Policy and Research sponsored the development of guidelines for diagnosing and managing patients with unstable angina. Since their publication, several important developments have occurred. The prognostic value of biochemical assays for cardiac-specific troponins T and I have been shown in many studies. The possible role for C-reactive protein in determining prognosis deserves further investigation. Substantial clinical benefits have been obtained with intravenous inhibitors of the platelet glycoprotein (GP) IIb-IIIa receptor (abciximab, eptifibatide, tirofiban) and with one of the low-molecular-weight heparins (enoxaparin). The therapeutic potential of other low-molecular-weight heparins, direct thrombin inhibitors, and oral GP IIb-IIIa inhibitors remains to be clarified. On the basis of this evidence, consideration should be given to measuring serum levels of a cardiac troponin (either T or I) and using intravenous GP IIb-IIIa inhibitors and low-molecular-weight heparin in the standard management of patients with unstable angina.
Abciximab and bleeding during coronary surgery: results from the EPILOG and EPISTENT trials. Improve Long-term Outcome with abciximab GP IIb/IIIa blockade. Evaluation of Platelet IIb/IIIa Inhibition in STENTing.
BACKGROUND: Abciximab during percutaneous coronary revascularization reduces ischemic complications, but concern exists regarding increased bleeding risk should emergency coronary surgical procedures be required. METHODS: Outcomes were assessed among 85 patients who required coronary artery bypass grafting operations after coronary intervention in two randomized placebo-controlled trials of abciximab. Comparisons were made between patients in the pooled placebo and abciximab groups. RESULTS: The incidence of coronary surgical procedures was 2.17% and 1.28% among patients randomized to placebo and abciximab, respectively (p = 0.021). Platelet transfusions were administered to 32% and 52% of patients in the placebo and abciximab groups, respectively (p = 0.059). Rates of major blood loss were 79% and 88% in the placebo and abciximab groups, respectively (p = 0.27); transfusions of packed red blood cells or whole blood were administered in 74% and 80% of patients, respectively (p = 0.53). Surgical reexploration for bleeding was required in 3% and 12% of patients, respectively. Death and myocardial infarction tended to occur less frequently among patients who had received abciximab. CONCLUSIONS: Urgent coronary artery bypass grafting operations can be performed without an incremental increase in major hemorrhagic risk among patients on abciximab therapy.
Recurrent ischemia during continuous 12-lead ECG-ischemia monitoring in patients with acute coronary syndromes treated with eptifibatide: relation with death and myocardial infarction. PURSUIT ECG-Ischemia Monitoring Substudy Investigators. Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy.
Computer-assisted continuous monitoring of the ST-segment allows detection and quantification of recurrent ischemia in patients with acute coronary syndromes. In a substudy of the PURSUIT (Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy) trial, this technique was used to evaluate the effects of the glycoprotein IIb/IIIa inhibitor eptifibatide on the incidence and severity of recurrent ischemia, and to investigate the relationship between recurrent ischemia and the occurrence of subsequent death or myocardial (re)infarction. A total of 258 patients with unstable angina or evolving myocardial infarction without ST elevation were monitored for 24 hours during infusion with either eptifibatide or placebo with a computer-assisted 12-lead ECG-ischemia monitoring device. Recurrent ischemic episodes were identified by an automated computer algorithm. Two hundred and sixteen patients (84%) had ECG recordings suitable for analysis. Ischemic episodes were detected in 35 (33%) of the 105 eptifibatide patients and in 32 (29%) of the 111 placebo patients (not significant). No difference in ischemic burden was apparent between both treatment groups. Patients who exhibited 2 or more episodes of recurrent ischemia more frequently died or suffered a myocardial infarction, both at 7 and 30 days, as well as through the 6-month follow-up. A greater ischemic burden was significantly related to adverse outcome during the 6-month follow-up period. Real-time computer-assisted continuous multilead ECG-ischemia monitoring may help to identify patients with unstable coronary syndromes at increased risk of adverse outcome and, thus, allow for better prognostic triage and more appropriate selection of therapeutic strategies. Integration of these systems in coronary care units and emergency wards should, therefore, be recommended.
Platelet glycoprotein IIb/IIIa receptor blockade in coronary artery disease.
New strategies for profound inhibition of platelet activity at the injured coronary plaque focus on blockade of the platelet surface membrane glycoprotein IIb/IIIa receptor, which binds circulating fibrinogen or von Willebrand factor and crosslinks platelets as the final common pathway to platelet aggregation. Intravenous agents directed against this receptor include the chimeric monoclonal antibody fragment abciximab, the peptide inhibitor eptifibatide and nonpeptide mimetics tirofiban and lamifiban. Over 33,000 patients have been evaluated in 11 large-scale, placebo-controlled trials of these agents. During percutaneous coronary intervention, an absolute reduction of 1.5% to 6.5% in the 30-day risk of death, myocardial infarction or repeat urgent revascularization has been observed, with some variability in treatment effect among the agents tested (abciximab, eptifibatide and tirofiban). Treatment effect is achieved early with every modality of revascularization and is maintained over the long-term (up to three years). Increased bleeding risk may be minimized by reduction and weight-adjustment of concomitant heparin dosing. In the acute coronary syndromes without ST segment elevation, absolute 1.5% to 3.2% reductions in 30-day rates of death or myocardial (re-) infarction have been achieved with two to four day courses of eptifibatide or tirofiban. Clinical benefit accrues during the period of drug infusion and is durable. Treatment effect may be enhanced among patients undergoing early coronary revascularization, with evidence of stabilization before intervention and suppression of postprocedural ischemic events. Thus, blockade of the platelet glycoprotein IIb/IIIa receptor reduces ischemic complications when used as an adjunct to percutaneous coronary intervention or the management of acute ischemic syndromes.
Diabetes mellitus and outcome after primary coronary angioplasty for acute myocardial infarction: lessons from the GUSTO-IIb Angioplasty Substudy. Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes.
OBJECTIVES: We sought to compare the efficacy of primary angioplasty in diabetics versus nondiabetics and to evaluate the relative benefits of angioplasty over thrombolytic therapy among diabetics. BACKGROUND: Primary angioplasty for myocardial infarction is at least as effective as thrombolytic therapy in the general population. However, the influence of diabetic status on outcome after primary angioplasty versus thrombolysis remains unknown. METHODS: Patients in the Global Use of Strategies To Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) Angioplasty Substudy were randomized to receive either primary angioplasty or accelerated alteplase. The interaction of diabetic status (diabetics n = 177, nondiabetics n = 961) and treatment strategy with the occurrence of the primary end point (death, nonfatal reinfarction or nonfatal, disabling stroke at 30 days) was analyzed (power to detect a 40% relative reduction in the primary end point with alpha = 0.05 and beta = 0.20). Among patients who were randomized to and underwent primary angioplasty, procedural success (defined as residual stenosis <50% and TIMI grade 3 flow) was assessed based on diabetic status. RESULTS: Compared with nondiabetics, diabetics had worse baseline clinical and angiographic profiles. Despite more severe stenosis and poorer flow in the culprit artery, procedural success with angioplasty was similar for diabetics (n = 81; 70.4%) and nondiabetics (n = 391; 72.4%). Outcome at 30 days was better for nondiabetics randomized to angioplasty versus alteplase (adjusted odds ratio, 0.62; 95% confidence interval, 0.41-0.96) with a similar trend for diabetics (0.70, [0.29-1.72]). We noted no interaction between diabetic status and treatment strategy on outcome (p = 0.88). CONCLUSIONS: Primary angioplasty was similarly successful in diabetics and nondiabetics and appeared to be more effective than thrombolytic therapy among diabetics with acute infarction.
Occurrence and clinical significance of pseudothrombocytopenia during abciximab therapy.
OBJECTIVES: This study determined the incidence of pseudothrombocytopenia during abciximab therapy administered for percutaneous coronary interventions and compared the clinical course of patients with pseudothrombocytopenia with the clinical courses of patients with thrombocytopenia and patients with normal platelet counts. BACKGROUND: Although pseudothrombocytopenia has been previously reported during therapy with abciximab, the incidence and significance of this occurrence are unknown. The failure to differentiate pseudothrombocytopenia from thrombocytopenia could lead to unnecessary interruption of abciximab infusions or to platelet transfusions. METHODS: The incidences of pseudothrombocytopenia and thrombocytopenia were determined in four large placebo-controlled abciximab trials: c7E3 Fab Antiplatelet Therapy in Unstable Refractory Angina (CAPTURE), Evaluation of 7E3 for the Prevention of Ischemic Complications (EPIC), Evaluation of Percutaneous Transluminal Coronary Angioplasty to Improve Long-term Outcome of c7E3 GpIIb/IIIa Receptor Blockade (EPILOG) and Evaluation of Platelet IIb/IIIa Inhibitor for Stenting (EPISTENT). The clinical features, bleeding complications and major clinical outcomes of patients with pseudothrombocytopenia and those with thrombocytopenia were compared with each other and with those of patients with normal platelet count. RESULTS: Pseudothrombocytopenia occurred in 2.1% (95% confidence intervals [CI]: 1.7%, 2.5%) of abciximab-treated patients and in 0.6% of placebo-treated patients (p < 0.001). Thrombocytopenia occurred in 3.7% (95% CI: 3.2%, 4.2%) of abciximab-treated patients and in 1.8% (95% CI: 1.3%, 2.3%) of placebo-treated patients (p < 0.001). Patients with thrombocytopenia had significantly higher rates of major bleeding, major decreases in hemoglobin and increased transfusion requirements of both blood and platelets compared with those without thrombocytopenia. By contrast, pseudothrombocytopenic patients did not differ from patients with normal platelet counts in any of the measures of blood loss or transfusion requirements. Thrombocytopenic patients, but not those with pseudothrombocytopenia, had increased rates of revascularization at 30 days and six months. As previously reported, there was also a higher rate of death and myocardial infarction in the thrombocytopenic patients. CONCLUSIONS: Pseudothrombocytopenia is the cause of more than one third (36.3%) of low platelet counts in patients undergoing coronary interventions who are treated with abciximab. This study demonstrates that pseudothrombocytopenia is a benign laboratory condition that does not increase bleeding, stroke, transfusion requirements or the need for repeat revascularization. It is important to recognize pseudothrombocytopenia so that the beneficial effects of abciximab are not lost by premature termination of therapy.
Results from late-breaking clinical trials sessions at ACCIS 2000 and ACC 2000. American College of Cardiology.
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Randomized trial of low molecular weight heparin (enoxaparin) versus unfractionated heparin for unstable coronary artery disease: one-year results of the ESSENCE Study. Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q Wave Coronary Events.
OBJECTIVES: We sought to determine whether the observed benefits of enoxaparin were maintained beyond the early phase; a one-year follow-up survey was undertaken for patients enrolled in the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q wave Coronary Events (ESSENCE) study. BACKGROUND: We have previously reported a significant benefit of low molecular weight as compared with unfractionated heparin (UFH) in the 14- and 30-day incidence of a composite end point of death, myocardial infarction (MI) or recurrent angina in patients with unstable angina or non-Qwave MI. METHODS: The study recruited 3,171 patients with recent-onset rest angina and underlying ischemic heart disease. All patients received oral aspirin daily and were randomized to receive enoxaparin subcutaneously every 12 h or UFH (intravenous bolus followed by continuous infusion) in a double-blind, double-dummy fashion for a median of 2.6 days. RESULTS: The incidence of the composite triple end point at one year was lower among patients receiving enoxaparin as compared with those receiving UFH (32.0% vs. 35.7%, p = 0.022), with a trend toward a lower incidence of the secondary composite end point of death or MI (11.5% vs. 13.5%, p = 0.082). At one year, the need for diagnostic catheterization and coronary revascularization was lower in the enoxaparin group (55.8% vs. 59.4%, p = 0.036 and 35.9% vs. 41.2%, p = 0.002, respectively). CONCLUSIONS: In patients with unstable angina or non-Qwave MI, enoxaparin therapy significantly reduced the rates of recurrent ischemic events and invasive diagnostic and therapeutic procedures in the short term with sustained benefit at one year.
Platelet glycoprotein IIb/IIIa blockade and outcome of cardiogenic shock complicating acute coronary syndromes without persistent ST-segment elevation.
OBJECTIVES: The study examined whether antiplatelet treatment with eptifibatide affected the frequency and outcome of shock among patients in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial who had acute coronary syndromes but not persistent ST-segment elevation. BACKGROUND: Preliminary reports suggest a salutary effect of antiplatelet agents when shock complicates acute myocardial infarction. METHODS: We analyzed the impact of antiplatelet treatment with eptifibatide on the frequency and outcome of cardiogenic shock developing after enrollment. PURSUIT was a double-blind, randomized trial that examined the efficacy of eptifibatide (180 microg/kg bolus + continuous infusion of 2.0 microg/kg/min for < or =96 h) versus placebo among patients who had acute coronary syndromes but not persistent ST-segment elevation. RESULTS: Shock developed in 2.5% of the 9,449 patients at a median (25th, 75th interquartiles) of 94.0 (38, 206) h. Death by 30 days occurred in 65.8% of shock patients. Patients who had acute myocardial infarction upon enrollment had a greater incidence of shock (2.9% vs. 2.1%, p = 0.01), developed shock earlier (40.2% <48 h vs. 20.9%, p = 0.001), and had higher 30-day mortality from shock (77.2% vs. 52.7%, p = 0.001). Randomization to eptifibatide did not affect the occurrence of shock (p = 0.71, adjusted odds ratio [OR] = 0.95, 95% confidence interval [CI] = 0.72-1.25). However, shock patients treated with eptifibatide had significantly reduced adjusted odds of 30-day death (p = 0.03, adjusted OR = 0.51, 95% CI = 0.28-0.94). CONCLUSIONS: Patients with shock treated with eptifibatide had significantly reduced adjusted odds of death, suggesting a salutary effect of antiplatelet therapy on shock. This finding warrants verification in specifically designed studies.
ACC/AHA guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on the Management of Patients With Unstable Angina).
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Patient characteristics associated with care by a cardiologist among adults hospitalized with severe congestive heart failure. SUPPORT Investigators. Study to Understand Prognoses and Preferences for Outcomes and Risks of Treatments.
OBJECTIVES: The goal of this study was to determine factors associated with receiving cardiologist care among patients with an acute exacerbation of congestive heart failure. BACKGROUND: Because cardiologist care for acute cardiovascular illness may improve care, barriers to specialty care could impact patient outcomes. METHODS: We studied 1,298 patients hospitalized with acute exacerbation of congestive heart failure who were cared for by cardiologists or generalist physicians. Using multivariable logistic models we determined factors independently associated with attending cardiologist care. RESULTS: Patients were less likely to receive care from a cardiologist if they were black (adjusted odds ratio [AOR] 0.53, 95% confidence interval [CI] 0.35, 0.80), had an income of less than $11,000 (AOR 0.65, 95% CI 0.45, 0.93) or were older than 80 years of age (AOR 0.23, 95% CI 0.12, 0.46). Patients were more likely to receive cardiologist care if they had college level education (AOR 1.89, 95% CI 1.02, 3.51), a history of myocardial infarction (AOR 1.59, 95% CI 1.17, 2.16), a serum sodium less than 133 on admission (AOR 1.96, 95% CI 1.30, 2.95) or a systolic blood pressure less than 90 on admission (AOR 1.97, 95% CI 1.20, 3.24). Patients who stated a desire for life extending care were also more likely to receive care from a cardiologist (AOR 1.40, 95% CI 1.04, 1.90). CONCLUSIONS: After adjusting for severity of illness and patient preferences for care, patient sociodemographic factors were strongly associated with receiving care from a cardiologist. Future investigations are required to determine whether these associations represent unmeasured preferences for care or inequities in our health care system.
Predictors of cardiogenic shock after thrombolytic therapy for acute myocardial infarction.
OBJECTIVES: This study characterized clinical factors predictive of cardiogenic shock developing after thrombolytic therapy for acute myocardial infarction (AMI). BACKGROUND: Cardiogenic shock remains a common and ominous complication of AMI. By identifying patients at risk of developing shock, preventive measures may be implemented to avert its development. METHODS: We analyzed baseline variables associated with the development of shock after thrombolytic therapy in the Global Utilization of Streptikonase and Tissue-Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) trial. Using a Cox proportional hazards model, we devised a scoring system predicting the risk of shock. This model was then validated in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO-III) cohort. RESULTS: Shock developed in 1,889 patients a median of 11.6 h after enrollment. The major factors associated with increased adjusted risk of shock were age (chi2 = 285, hazard ratio [95% confidence interval] 1.47 [1.40, 1.53]), systolic blood pressure (chi2 = 280), heart rate (chi2 = 225) and Killip class (chi2 = 161, hazard ratio 1.70 [1.52, 1.90] and 2.95 [2.39, 3.63] for Killip II versus I and Killip III versus I, respectively) upon presentation. Together, these four variables accounted for >85% of the predictive information. These findings were transformed into an algorithm with a validated concordance index of 0.758. Applied to the GUSTO-III cohort, the four variables accounted for > 95% of the predictive information, and the validated concordance index was 0.796. CONCLUSIONS: A scoring system accurately predicts the risk of shock after thrombolytic therapy for AMI based primarily on the patient's age and physical examination on presentation.
Inhibition of platelet aggregation with a glycoprotein IIb-IIIa antagonist does not prevent thrombin generation in patients undergoing thrombolysis for acute myocardial infarction.
Thrombin activity has been implicated as a mechanism for failed reperfusion and reocclusion following thrombolysis. Aggregating platelets provide a phospholipid surface on which prothrombin is cleaved to form thrombin. We examined markers of thrombin generation and activity in patients enrolled in a randomized, placebo-controlled, dose escalating trial of the platelet glycoprotein IIb-IIIa inhibitor eptifibatide (Integrilintrade mark) administered concomitantly with tissue plasminogen activator for the treatment of myocardial infarction. Measurements were obtained at baseline, at 90 minutes, and at 6, 12, and 24 hours after starting therapy. Eptifibatide inhibited platelet aggregation in response to 20 microM ADP. Levels of fibrinopeptide A (FPA), thrombin-antithrombin complexes (TAT), and prothrombin fragment 1.2 (F1.2) were not lower in patients treated with eptifibatide than in the control group. In the course of dose escalation, two groups of patients received the same 135 microg/kg bolus of eptifibatide, one with and one without a heparin bolus. FPA levels were dramatically lower in the heparin-treated patients. Levels of FPA, TAT, and F1.2 were not higher in patients with than in those without recurrent ischemia, or in patients without than in those with Thrombolysis in Myocardial Infarction (TIMI) grade 3 angiographic flow at 90 minutes. These data suggest that thrombin generation and activity persist following thrombolysis, despite inhibition of platelet aggregation, and that treatment with inhibitors of thrombin activity may be required even when glycoprotein IIb-IIIa inhibitors are used.
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.