Showing papers by "Eugene Braunwald published in 2000"

ACC/AHA guidelines for the management of patients with unstable angina and non-ST-segment elevation myocardial infarction: Executive summary and recommendations: 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)

Abstract: The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines was formed to make recommendations regarding the diagnosis and treatment of patients with known or suspected cardiovascular disease. Coronary artery disease (CAD) is the leading cause of death in the United States. Unstable angina (UA) and the closely related condition non–ST-segment elevation myocardial infarction (NSTEMI) are very common manifestations of this disease. These life-threatening disorders are a major cause of emergency medical care and hospitalizations in the United States. In 1996, the National Center for Health Statistics reported 1 433 000 hospitalizations for UA or NSTEMI. In recognition of the importance of the management of this common entity and of the rapid advances in the management of this condition, the need to revise guidelines published by the Agency for Health Care Policy and Research (AHCPR) and the National Heart, Lung and Blood Institute in 1994 was evident. This Task Force therefore formed the current committee to develop guidelines for the management of UA and NSTEMI. The present guidelines supersede the 1994 guidelines. The customary ACC/AHA classifications I, II, and III summarize both the evidence and expert opinion and provide final recommendations for both patient evaluation and therapy: Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective . Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. Class IIa: Weight of evidence/opinion is in favor of usefulness/efficacy. Class IIb: Usefulness/efficacy is less well established by evidence/opinion. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful. The weight of the evidence was ranked highest (A) if the data …

The TIMI Risk Score for Unstable Angina/Non–ST Elevation MI: A Method for Prognostication and Therapeutic Decision Making

Abstract: ContextPatients with unstable angina/non–ST-segment elevation myocardial infarction (MI) (UA/NSTEMI) present with a wide spectrum of risk for death and cardiac ischemic events.ObjectiveTo develop a simple risk score that has broad applicability, is easily calculated at patient presentation, does not require a computer, and identifies patients with different responses to treatments for UA/NSTEMI.Design, Setting, and PatientsTwo phase 3, international, randomized, double-blind trials (the Thrombolysis in Myocardial Infarction [TIMI] 11B trial [August 1996–March 1998] and the Efficacy and Safety of Subcutaneous Enoxaparin in Unstable Angina and Non-Q-Wave MI trial [ESSENCE; October 1994–May 1996]). A total of 1957 patients with UA/NSTEMI were assigned to receive unfractionated heparin (test cohort) and 1953 to receive enoxaparin in TIMI 11B; 1564 and 1607 were assigned respectively in ESSENCE. The 3 validation cohorts were the unfractionated heparin group from ESSENCE and both enoxaparin groups.Main Outcome MeasuresThe TIMI risk score was derived in the test cohort by selection of independent prognostic variables using multivariate logistic regression, assignment of value of 1 when a factor was present and 0 when it was absent, and summing the number of factors present to categorize patients into risk strata. Relative differences in response to therapeutic interventions were determined by comparing the slopes of the rates of events with increasing score in treatment groups and by testing for an interaction between risk score and treatment. Outcomes were TIMI risk score for developing at least 1 component of the primary end point (all-cause mortality, new or recurrent MI, or severe recurrent ischemia requiring urgent revascularization) through 14 days after randomization.ResultsThe 7 TIMI risk score predictor variables were age 65 years or older, at least 3 risk factors for coronary artery disease, prior coronary stenosis of 50% or more, ST-segment deviation on electrocardiogram at presentation, at least 2 anginal events in prior 24 hours, use of aspirin in prior 7 days, and elevated serum cardiac markers. Event rates increased significantly as the TIMI risk score increased in the test cohort in TIMI 11B: 4.7% for a score of 0/1; 8.3% for 2; 13.2% for 3; 19.9% for 4; 26.2% for 5; and 40.9% for 6/7 (P<.001 by χ2 for trend). The pattern of increasing event rates with increasing TIMI risk score was confirmed in all 3 validation groups (P<.001). The slope of the increase in event rates with increasing numbers of risk factors was significantly lower in the enoxaparin groups in both TIMI 11B (P = .01) and ESSENCE (P = .03) and there was a significant interaction between TIMI risk score and treatment (P = .02).ConclusionsIn patients with UA/NSTEMI, the TIMI risk score is a simple prognostication scheme that categorizes a patient's risk of death and ischemic events and provides a basis for therapeutic decision making.

TIMI risk score for ST-elevation myocardial infarction: A convenient, bedside, clinical score for risk assessment at presentation: An intravenous nPA for treatment of infarcting myocardium early II trial substudy.

Abstract: Background—Considerable variability in mortality risk exists among patients with ST-elevation myocardial infarction (STEMI). Complex multivariable models identify independent predictors and quantify their relative contribution to mortality risk but are too cumbersome to be readily applied in clinical practice. Methods and Results—We developed and evaluated a convenient bedside clinical risk score for predicting 30-day mortality at presentation of fibrinolytic-eligible patients with STEMI. The Thrombolysis in Myocardial Infarction (TIMI) risk score for STEMI was created as the simple arithmetic sum of independent predictors of mortality weighted according to the adjusted odds ratios from logistic regression analysis in the Intravenous nPA for Treatment of Infarcting Myocardium Early II trial (n=14 114). Mean 30-day mortality was 6.7%. Ten baseline variables, accounting for 97% of the predictive capacity of the multivariate model, constituted the TIMI risk score. The risk score showed a >40-fold graded incr...

Elevation of Tumor Necrosis Factor-α and Increased Risk of Recurrent Coronary Events After Myocardial Infarction

Abstract: Background—Levels of tumor necrosis factor-α (TNF-α) increase with acute ischemia. However, whether elevations of TNF-α in the stable phase after myocardial ischemia (MI) are associated with increa...

Relationship of TIMI myocardial perfusion grade to mortality after administration of thrombolytic drugs

Abstract: Background—Although improved epicardial blood flow (as assessed with either TIMI flow grades or TIMI frame count) has been related to reduced mortality after administration of thrombolytic drugs, the relationship of myocardial perfusion (as assessed on the coronary arteriogram) to mortality has not been examined. Methods and Results—A new, simple angiographic method, the TIMI myocardial perfusion (TMP) grade, was used to assess the filling and clearance of contrast in the myocardium in 762 patients in the TIMI (Thrombolysis In Myocardial Infarction) 10B trial, and its relationship to mortality was examined. TMP grade 0 was defined as no apparent tissue-level perfusion (no ground-glass appearance of blush or opacification of the myocardium) in the distribution of the culprit artery; TMP grade 1 indicates presence of myocardial blush but no clearance from the microvasculature (blush or a stain was present on the next injection); TMP grade 2 blush clears slowly (blush is strongly persistent and diminishes mi...

VLDL, apolipoproteins B, CIII, and E, and risk of recurrent coronary events in the cholesterol and recurrent events (CARE) trial

Abstract: Background—Plasma triglyceride concentration has been an inconsistent independent risk factor for coronary heart disease, perhaps because of the metabolic heterogeneity among VLDL particles, the main carriers of triglycerides in plasma. Methods and Results—We conducted a prospective, nested case-control study in the Cholesterol and Recurrent Events (CARE) trial, a randomized placebo-controlled trial of pravastatin in 4159 patients with myocardial infarction and average LDL concentrations at baseline (115 to 174 mg/dL, mean 139 mg/dL). Baseline concentrations of VLDL–apolipoprotein (apo) B (the VLDL particle concentration), VLDL lipids, and apoCIII and apoE in VLDL+LDL and in HDL were compared in patients who had either a myocardial infarction or coronary death (cases, n=418) with those in patients who did not have a cardiovascular event (control subjects, n=370) in 5 years of follow-up. VLDL-cholesterol, VLDL-triglyceride, VLDL-apoB, apoCIII and apoE in VLDL+LDL and apoE in HDL were all interrelated, and ...

Congestive Heart Failure: Fifty Years of Progress

Abstract: Volume 1 of Circulation provides an excellent snapshot of the understanding of the mechanisms and treatment of heart failure a half century ago. During that era, circulatory pathophysiology was at the center of investigative attention. For example, Tinsley Harrison and his group divided heart failure into “primary disorders of filling and primary disorders of emptying,”1 a forerunner of our current terms diastolic and systolic heart failure. The great Swedish clinical physiologist Gustav Nylin used 32P-labeled red blood cells for measuring cardiac output and cardiothoracic blood volume by the indicator-dilution method in normal subjects and in patients with heart failure.2 Andre Cournand’s group defined the pathophysiology of heart failure secondary to cor pulmonale, distinguished it from left ventricular failure, and compared the acute hemodynamic effects of digoxin in these 2 conditions.3 In a seminal paper, Raab and Lepeschkin extracted sympathin from the heart and established norepinephrine as the cardiac adrenergic neurotransmitter.4 In one of the earliest efforts to manage patients with chronic congestive heart failure on an outpatient basis, Vander Veer and colleagues demonstrated the effectiveness and tolerability of an oral form of the widely used parenteral diuretic mercuhydrin.5 In the 1950s, the role of hypertrophy in the heart’s adaptation to hemodynamic overload was examined. After Laplace’s law was applied to the heart and permitted the calculation of wall stress in the human heart,6 it became clear that myocardial hypertrophy prevents excessive elevation of wall stress consequent to hemodynamic overload.7 8 In the 1960s, there was a lively debate about the mechanism of heart failure secondary to pressure overload. The question was framed as follows: “Does failure of the ventricle as a pump occur in the presence of (an) inadequate contractile mass while the contractile function of each unit (of myocardium) is normal …

Effect of Pravastatin on Coronary Disease Events in Subgroups Defined by Coronary Risk Factors The Prospective Pravastatin Pooling Project

Abstract: Background—Previous trials have had insufficient numbers of coronary events to address definitively the effect of lipid-modifying therapy on coronary heart disease in subgroups of patients with varying baseline characteristics. Methods and Results—The data from 3 large randomized trials with pravastatin 40 mg were pooled and analyzed with the use of a prospectively defined protocol. Included were 19 768 patients, 102 559 person-years of follow-up, 2194 primary end points (coronary death or nonfatal myocardial infarction), and 3717 expanded end points (primary end point, CABG, or PTCA). Pravastatin significantly reduced relative risk in younger (<65 years) and older (≥65 years) patients, men and women, smokers and nonsmokers, and patients with or without diabetes or hypertension. The relative effect was smaller, but absolute risk reduction was similar in patients with hypertension compared with those without hypertension. Relative risk reduction was significant in predefined categories of baseline lipid co...

A Classification of Unstable Angina Revisited

Abstract: —Unstable angina is a critical phase of coronary heart disease with widely variable symptoms and prognosis. A decade ago, a classification of unstable angina based on clinical symptoms was introduced. This system was then validated by prospective clinical studies to correlate with the prognosis and was linked to angiographic and histological findings. It has been used to categorize patients in many large clinical trials. In recent years, the pathophysiological roles of platelet activation and inflammation in unstable angina have been elucidated. Subsequently, improved markers of myocardial injury, acute-phase proteins, and hemostatic markers that may be associated with clinical outcomes have been identified. Particularly, cardiac-specific troponin T and troponin I have been shown to represent the best predictors of early risk in patients with angina at rest. Accordingly, it is suggested that the original classification be extended by subclassifying one large group of unstable angina patients, ie, ...

Association between white blood cell count, epicardial blood flow, myocardial perfusion, and clinical outcomes in the setting of acute myocardial infarction: a thrombolysis in myocardial infarction 10 substudy.

Abstract: Background—Elevation of the white blood cell (WBC) count during acute myocardial infarction (AMI) is associated with adverse outcomes. We examined the relationship between the WBC count and angiographic findings to gain insight into this relationship. Results and Methods—We evaluated data from 975 patients in the Thrombolysis In Myocardial Infarction (TIMI) 10A and 10B trials. Patients with a closed artery at 60 and 90 minutes had higher a WBC count than patients with an open artery (P=0.02). Likewise, the presence of angiographically apparent thrombus was associated with a higher WBC count (11.5±5.2×109/L, n=290, versus 10.7±3.5×109/L, n=648; P=0.008). In addition, a higher WBC count was associated with poorer TIMI myocardial perfusion grades (4-way P=0.04). Mortality rates were higher in patients with a higher WBC count (0% for WBC count 0 to 5×109/L, 4.9% for WBC count 5 to 10×109/L, 3.8% for WBC count 10 to 15×109/L, 10.4% for WBC count >15×109/L; P=0.03). The development of new congestive heart failu...

Oral Glycoprotein IIb/IIIa Inhibition With Orbofiban in Patients With Unstable Coronary Syndromes (OPUS-TIMI 16) Trial

Abstract: Background—Although intravenous glycoprotein IIb/IIIa inhibitors are beneficial in patients with acute coronary syndromes, prolonged oral IIb/IIIa inhibition might provide an additional reduction in recurrent events. Methods and Results—Investigators at 888 hospitals in 29 countries enrolled 10 288 patients with acute coronary syndromes, which was defined as ischemic pain at rest within 72 hours of randomization, associated with positive cardiac markers, electrocardiographic changes, or prior cardiovascular disease. Patients received aspirin and were randomized to receive, for the duration of the trial, (1) 50 mg of orbofiban twice daily (50/50 group), (2) 50 mg of orbofiban twice daily for 30 days followed by 30 mg of orbofiban twice daily (50/30 group), or (3) a placebo. The primary composite end point was death, myocardial infarction, recurrent ischemia requiring rehospitalization, urgent revascularization, or stroke. The trial was terminated prematurely because of an unexpected increase in 30-day mort...

Abciximab improves both epicardial flow and myocardial reperfusion in ST-elevation myocardial infarction: Observations from the TIMI 14 trial

Abstract: Background —In the presence of ST-elevation myocardial infarction, patients with successful epicardial reperfusion (TIMI 3 flow) but persistent ST elevation on a 12-lead ECG are at high risk for subsequent death and left ventricular dysfunction. In the TIMI 14 trial, a dose-ranging angiographic study, combined therapy with abciximab plus reduced-dose tPA enhanced the speed and efficacy of epicardial reperfusion. We determined whether the combination of abciximab plus reduced-dose tPA provided additional benefit in terms of myocardial reperfusion, as evidenced by greater resolution of ST elevation. Methods and Results —All 346 patients with interpretable baseline and 90-minute ECGs, treated with either tPA alone or abciximab plus reduced-dose tPA (combination therapy), were included. Patients receiving combination therapy (n=221) had a 59% rate of complete (≥70%) ST resolution at 90 minutes versus 37% in those treated with tPA alone (n=125) ( P <0.0001). When the analysis was limited to patients with TIMI 3 flow, patients treated with combination therapy (n=151) remained significantly more likely to achieve complete ST resolution than those receiving tPA alone (n=80) (69% versus 44%; P =0.0002). Conclusions —Combination therapy with abciximab and reduced-dose tPA improves myocardial (microvascular) reperfusion, as reflected in greater ST-segment resolution, in addition to epicardial flow. This finding may translate into improved clinical outcomes by enhancing myocardial salvage.

St-segment resolution and infarct-related artery patency and flow after thrombolytic therapy

Abstract: Because patients who fail to achieve reperfusion after thrombolytic therapy remain at high risk for morbidity and mortality, noninvasive measures of infarct-related artery (IRA) patency are needed to identify candidates for rescue interventions. We prospectively studied 444 patients from the Thrombolysis In Myocardial Infarction (TIMI) 14 trial with interpretable baseline and 90 minute 12-lead electrocardiograms. The percent resolution of ST-segment deviation from baseline to 90 minutes was compared with 90-minute IRA TIMI flow grade, as determined in an angiographic core laboratory. Patients with complete (≥70%) ST resolution (n = 208; 47%) had a patency (TIMI 2 or 3 flow) rate of 94%, a TIMI 3 flow rate of 79%, and a 30-day mortality rate of 1.0%. Patients with partial (30% to 70%) or no (≤30%) ST resolution had significantly lower rates of patency (72% and 68%; p <0.0001 vs complete ST resolution) and TIMI 3 flow (50% and 44%; p <0.0001 vs complete ST resolution), and higher 30-day mortality (4.2% and 5.9%; p = 0.01 vs complete ST resolution). With use of electrocardiographic criteria alone, approximately 50% of patients can be classified as having a high (94%) probability of IRA patency and a very low risk for mortality. Angiography to determine patency of the IRA may be unnecessary in these patients. In patients without complete (≥70%) ST resolution, the IRA is still likely to be patent, and additional information from clinical variables or serum markers may help to identify candidates for coronary angiography. Patients with persistent ST elevation despite a patent IRA are at increased risk for mortality, likely due to extensive microvascular and tissue injury.

ACC/AHA guidelines for the management of patients with unstable angina and non-ST segment elevation myocardial infarction: Executive summary and recommendations: 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)

Abstract: Eugene Braunwald, MD, FACC, Chair; Elliott M. Antman, MD, FACC; John W. Beasley, MD, FAAFP; Robert M. Califf, MD, FACC; Melvin D. Cheitlin, MD, FACC; Judith S. Hochman, MD, FACC; Robert H. Jones, MD, FACC; Dean Kereiakes, MD, FACC; Joel Kupersmith, MD, FACC; Thomas N. Levin, MD, FSCAI, FACC; Carl J. Pepine, MD, FACC; John W. Schaeffer, MD, FACC; Earl E. Smith III, MD, FACEP; David E. Steward, MD, FACP; Pierre Theroux, MD, FACC

Combination reperfusion therapy with abciximab and reduced dose reteplase: results from TIMI 14

Abstract: Aims Abciximab has previously been shown to enhance thrombolysis and improve myocardial perfusion when combined with reduced doses of alteplase. The purpose of the reteplase phase of TIMI 14 was to evaluate the effects of abciximab when used in combination with a reduced dose of reteplase for ST-elevation myocardial infarction. Methods and Results Patients (n=299) with ST-elevation myocardial infarction were treated with aspirin and randomized to a control arm with standard dose reteplase (10+10 U given 30 min apart) or abciximab (bolus of 0.25 mg. kg(-1)and 12-h infusion of 0.125 microg. kg(-1). min(-1)) in combination with reduced doses of reteplase (5+5 U or 10+5 U). Control patients received standard weight-adjusted heparin (bolus of 70 U. kg(-1); infusion of 15 U. kg(-1). h(-1)), while each of the combination arms with abciximab and reduced dose reteplase received either low dose heparin (bolus of 60 U. kg(-1); infusion of 7 U. kg(-1). h(-1)) or very low dose heparin (bolus of 30 U. kg(-1); infusion of 4 U. kg(-1). h(-1)). The rate of TIMI 3 flow at 90 min was 70% for patients treated with 10+10 U of reteplase alone (n=87), 73% for those treated with 5+5 U of reteplase with abciximab (n=88), and 77% for those treated with 10+5 U of reteplase with abciximab (n=75). Complete (>/=70%) ST resolution at 90 min was seen in 56% of patients receiving a reduced dose of reteplase in combination with abciximab compared with 48% of patients receiving reteplase alone. Conclusions Reduced doses of reteplase when administered in combination with abciximab were associated with higher TIMI 3 flow rates than reported previously for reduced doses of reteplase without abciximab and were at least as high as for full dose reteplase alone

High Levels of Platelet Inhibition With Abciximab Despite Heightened Platelet Activation and Aggregation During Thrombolysis for Acute Myocardial Infarction Results From TIMI (Thrombolysis In Myocardial Infarction) 14

Abstract: Background—We evaluated platelet activation and aggregation in patients with acute myocardial infarction (AMI) treated with thrombolytic therapy alone or with reduced-dose thrombolysis and concomitant abciximab. Methods and Results—The study was performed in 20 control subjects and 51 patients with AMI before and after reperfusion with either alteplase or reteplase or reduced doses of these agents with concomitant abciximab. Platelet activation was assayed by platelet surface expression of P-selectin. Turbidometric platelet aggregation in response to ADP was measured in patients before thrombolytic therapy and 90 minutes and 24 hours after the beginning of thrombolytic therapy. P-selectin expression was greater at baseline in patients than normal control subjects (30.4% versus 9.8%, P<0.0001) but was identical between the 2 groups after stimulation with ADP (64.4% versus 69.3%, P=0.37). However, at 24 hours, basal P-selectin expression declined in patients (P=0.0025 versus baseline), whereas ADP-stimulate...

Comparison of a 60- versus 90-minute determination of ST-segment resolution after thrombolytic therapy for acute myocardial infarction

Abstract: Determination of ST-segment resolution 60 minutes after the administration of thrombolytic therapy allows accurate risk stratification for mortality and congestive heart failure. Patients with complete ST resolution at 60 minutes tended to be at lower risk for 30-day mortality than patients with complete ST resolution at 90 minutes.

Pharmacokinetics and pharmacodynamics of tenecteplase: results from a phase II study in patients with acute myocardial infarction

Abstract: Tenecteplase is a site-specific engineered tissue plasminogen activator (t-PA) variant that can be administered as a single intravenous bolus injection because of its slower plasma clearance. The objective of this study was to investigate the dose-ranging pharmacokinetics and pharmacodynamics of intravenous bolus tenecteplase compared with intravenous alteplase recombinant t-PA in patients with acute myocardial infarction. A total of 103 patients received intravenous bolus doses of 30, 40, or 50 mg tenecteplase, and 56 patients received 100 mg rt-PA as the accelerated 90-minute infusion regimen in this randomized, open-label study. Tenecteplase and r-tPA plasma concentrations were measured for 6 hours. Tenecteplase exhibited biphasic elimination from the plasma with a mean initial half-life of 22 minutes and a mean terminal half-life of 115 minutes. The mean plasma clearance was 105 mL/min and did not depend on tenecteplase dose over the dose range studied. In comparison, rt-PA has a fourfold faster plasma clearance. Pharmacokinetic-pharmacodynamic evaluation showed that a dose of approximately 0.5 mg/kg results in a plasma AUC value that provides a TIMI 3 flow at 90 minutes that is comparable to that reported with accelerated r-tPA. In conclusion, tenecteplase has a fourfold slower plasma clearance compared with rt-PA, allowing dosing as an i.v. bolus injection. Weight-adjusted dosing of tenecteplase may optimize the therapeutic regimen of tenecteplase.

Thrombolytic therapy for patients with myocardial infarction who are older than 75 years. Do the risks outweigh the benefits

Abstract: Thrombolytic therapy represents a major advance in the care of patients with acute myocardial infarction (AMI) that has developed over the past 2 decades. In a meta-analysis of the 9 largest randomized trials conducted between 1982 and 1992 and involving 58 000 patients, this treatment was shown to reduce 35-day mortality, particularly in patients younger than 75 years who had evidence of ST-segment elevation or bundle-branch block and who were treated within 12 hours of the onset of symptoms.1 Among the 5754 patients in these trials who were ≥75 years, thrombolytic therapy was associated with an absolute reduction in mortality of 1% (1 life saved for every 100 patients treated), a reduction that did not approach statistical significance. Given the powerful evidence of benefit in younger patients (including those between 65 and 74 years) and the potential benefit in older patients, guidelines for the care of AMI from the American Heart Association and the American College of Cardiology have supported the use of this treatment for patients ≥75 years who present with ST elevation within 12 hours of symptom onset as a class IIa indication, ie, one for which the “weight of evidence/opinion is in favor of usefulness/efficacy.”2 Contrary to this perspective, an observational study by Thiemann et al3 in this issue of Circulation indicates that thrombolytic therapy is not beneficial and could actually be harmful in patients older than 75 years. These investigators assessed the 30-day mortality among patients aged 65 to 86 years in the United States who were treated for an AMI during 1994 and 1995. In a primary analysis of 7864 patients who met clinical inclusion criteria for thrombolytic therapy, they compared those who did and who did not receive this treatment. Their findings are quite surprising. Among the >5000 patients aged 65 …

Results of the Treat Angina With Aggrastat and Determine the Cost of Therapy With an Invasive or Conservative Strategy (TACTICS-TIMI 18) Trial: A Comparison of Invasive Versus Conservative Strategy in Patients With Unstable Angina and Non–ST-Segment Elevation Myocardial Infarction

Abstract: Background : In the treatment of patients with unstable angina and non-ST segment elevation myocardial infarction (UA/NSTEMI), debate exists as to whether an early invasive vs. a conservative strategy is optimal therapy. Methods: In the international TACTICS-TIMI 18 trial, 2220 patients with UA/NSTEMI who had either electrocardiographic changes, …

Impact of Injections During Diagnostic Coronary Arteriography on Coronary Patency in the Setting of Acute Myocardial Infarction from the TIMI Trials

Abstract: Although the primary end point of many angiographic thrombolytic patency trials is assessed at 90 minutes, injections are often performed before this standard time point. The Thrombolysis In Myocardial Infarction (TIMI) Angiographic Core Laboratory uses the first injection at each time point (60, 75, and 90 minutes) after thrombolytic administration to assess the TIMI flow grade and the corrected TIMI frame count (CTFC). Whereas the coronary arteriogram is conventionally viewed as “diagnostic,” the frequency with which this first injection might be “therapeutic” and contribute to the mechanical opening of occluded coronary arteries is not well defined. We hypothesized that mechanical opening is infrequent, and we studied 4,021 consecutive first injections (815 that were occluded) in the TIMI 10B and 14 trials to define its frequency and to determine the potential impact that injections have on patency rates in thrombolytic trials.