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Biomedical subjects

W B Gibler

Publications and source records attributed to W B Gibler.

At least 37 records · Page 2Linked to original sources
PubMed1999

National Academy of Clinical Biochemistry Standards of Laboratory Practice: recommendations for the use of cardiac markers in coronary artery diseases.

The Sixth Conference on the "Standards of Laboratory Practice Series", sponsored by the National Academy of Clinical Biochemistry (NACB), was held on August 4-5, 1998, at the Annual Meeting of the American Association for Clinical Chemistry, in Chicago, IL. An expert committee was assembled to write recommendations on the use of cardiac markers in coronary artery diseases. The NACB Committee prepared a preliminary draft of the guidelines, made them available on the World Wide Web (www.nacb.org), and distributed them before the presentations. The recommendations were divided into four areas: the use of markers in the triage of patients with chest pain, acute coronary syndromes, clinical applications other than acute myocardial infarction and research, and assay platforms and markers of acute myocardial infarction. The recommendations were revised and subsequently re-presented in part at the "Biomarkers in Acute Cardiac Syndromes Conference", sponsored by the Jewish Hospital Heart and Lung Institute, Louisville KY, on October 16-17, 1998. This report lists each recommendation, its scientific justification, and a summary of discussions from conference participants and reviewers. Approximately 100 individuals responded to various versions of these recommendations via direct correspondences, telephone calls to Committee members, electronic mail correspondence to the Committee Chairman, or oral questions and comments raised during one of the two conference presentations. Some of the recommendations were changed to reflect the consensus opinion. In cases in which there was no consensus, the Committee included pertinent discussion without necessarily changing the original recommendations. At times, the Committee members felt that although a particular recommendation might not be the current standard of care today, they anticipate that it likely will be adopted in the near future.

Biomarkers↗
PubMed1998

Use of the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI) to assist with triage of patients with chest pain or other symptoms suggestive of acute cardiac ischemia. A multicenter, controlled clinical trial.

BACKGROUND: Approximately 6 million U.S. patients present to emergency departments annually with symptoms suggesting acute cardiac ischemia. Triage decisions for these patients are important but remain difficult. OBJECTIVE: To test whether computerized prediction of the probability of acute ischemia, used with electrocardiography, improves the accuracy of triage decisions. DESIGN: Controlled clinical trial. SETTING: 10 hospital emergency departments in the midwestern, southeastern, and northeastern United States. PATIENTS: 10689 patients with chest pain or other symptoms suggestive of acute cardiac ischemia. INTERVENTION: The probability of acute ischemia predicted by the acute cardiac ischemia time-insensitive predictive instrument (ACI-TIPI), either automatically printed or not printed on patients' electrocardiograms. MEASUREMENTS: Emergency department triage to a coronary care unit (CCU), telemetry unit, ward, or home. Other measurements were the bed capacity of the CCU relative to that of the telemetry unit; training or supervision status of the triaging physician; and patient diagnoses and outcomes based on clinical, electrocardiographic, and creatine kinase data. RESULTS: For patients without cardiac ischemia, in hospitals with high-capacity CCUs and relatively low-capacity cardiac telemetry units, use of ACI-TIPI was associated with a reduction in CCU admissions from 15% to 12%, a change of -16% (95% CI, -30% to 0%), and an increase in emergency department discharges to home from 49% to 52%, a change of 6% (CI, 0% to 14%; overall P=0.09). Across all hospitals, for patients evaluated by unsupervised residents, use of ACI-TIPI was associated with a reduction in CCU admissions from 14% to 10%, a change of -32% (CI, -55% to 3%); a reduction in telemetry unit admissions from 39% to 31%, a change of -20% (CI, -34% to -2%); and an increase in discharges to home from 45% to 56%, a change of 25% (CI, 8% to 45%; overall P=0.008). Among patients with stable angina, in hospitals with high-capacity CCUs, use of ACI-TIPI was associated with a reduction in CCU admissions from 26% to 13%, a change of -50% (CI, -70% to -17%), and an increase in discharges to home from 20% to 22%, a change of 10% (CI, -29% to 71%; overall P=0.02). At hospitals with high-capacity telemetry units, use of ACI-TIPI was associated with a reduction in telemetry unit admissions from 68% to 59%, a change of -14% (CI, -27% to 1%), and an increase in emergency department discharges to home from 10% to 21%, a change of 100% (CI, 22% to 230%; overall P=0.02). Among patients with acute myocardial infarction or unstable angina, use of ACI-TIPI did not change appropriate admission (96%) to the CCU or telemetry unit at hospitals with high-capacity CCUs or telemetry units. CONCLUSIONS: Use of ACI-TIPI was associated with reduced hospitalization among emergency department patients without acute cardiac ischemia. This result varied as expected according to the CCU and cardiac telemetry unit capacities and physician supervision at individual hospitals. Appropriate admission for unstable angina or acute infarction was not affected. If ACI-TIPI is used widely in the United States, its potential incremental impact may be more than 200000 fewer unnecessary hospitalizations and more than 100000 fewer unnecessary CCU admissions.

Acute Disease↗
PubMed1998

Rationale and clinical evidence for the use of GP IIb/IIIa inhibitors in acute coronary syndromes.

Platelet glycoprotein (GP) IIb/IIIa blockade has the potential to advance treatment of acute coronary syndromes, both as a primary pharmacologic approach and an adjunct to interventional treatment strategies. The benefits of GP IIb/IIIa inhibition with the chimeric monoclonal antibody abciximab in preventing ischemic complications of interventional treatment have been well defined in patients with unstable angina. In the future, major therapeutic applications for this class of agents may include the stabilization of patients with unstable angina and potentially as single medical therapy, as several recently completed trials have suggested. Evidence also is accumulating on the use of GP IIb/IIIa blockade as adjunctive therapy in fibrinolytic approaches to treatment of acute myocardial infarction. Several ongoing trials are evaluating the safety and efficacy of this novel strategy. This article reflects a distillation of the views and consensus regarding the prospective use of GP IIb/IIIa inhibitors in patients with acute coronary syndromes expressed by a group of international experts convened in Davos, Switzerland, February 16, 1997. This report attempts to review clinical progress to date, formulate recommendations, and map out potentially fruitful lines of inquiry for future investigation.

Acute Disease↗
PubMed1998

Prospective use of glycoprotein IIb/IIIa receptor blockers in the emergency department setting.

Platelets play a pivotal role in the pathophysiology of acute coronary syndromes (ACS) and thus are logical therapeutic targets for treatment of this disease process. Platelet glycoprotein (GP) IIb/IIIa receptor antagonists, which interrupt the final common pathway of platelet aggregation, have been proved to reduce the 30-day incidence of death, acute myocardial infarction (MI), and urgent revascularization in both high-risk and low-risk patients undergoing percutaneous intervention procedures. Three-year follow-up has indicated that these benefits appear durable. Recent large-scale randomized trials have demonstrated the value of GP IIb/IIIa receptor inhibitors in reducing the risk of death and MI in patients with unstable angina or those with MI with non-Q-wave abnormalities who are receiving pharmacologic management. In addition, emerging evidence suggests a future role for GP IIb/IIIa receptor inhibitors as an adjunct to low-dose fibrinolytic therapy in patients with acute MI. As the list of indications for GP IIb/IIIa receptor antagonists expands to encompass the full spectrum of ACS, there is increasing interest in the potential use of these agents in the emergency department setting. The integration of GP IIb/IIIa receptor inhibitors into ED protocols will ultimately depend largely on whether these drugs prove to be safe and effective regardless of the direction of ST-segment deviation, and irrespective of whether definitive therapy will be invasive or conservative.

Acute Disease↗
PubMed1998

Measurement of cardiac troponin T is an effective method for predicting complications among emergency department patients with chest pain.

STUDY OBJECTIVES: To determine the test performance characteristics of serum cardiac troponin T (cTnT) measurement for diagnosis of acute myocardial infarction (AMI), and to determine the ability of cTnT to stratify emergency department patients with chest pain into high- and low-risk groups for cardiac complications. METHODS: We conducted a prospective observational cohort study with convenience sampling in a tertiary care, urban ED. The study sample comprised 667 patients presenting to the ED with a complaint of chest pain or other symptoms suggesting acute ischemic coronary syndrome (AICS). Patients were assigned to different blood sampling protocols for cTnT therapy on the basis of their ECG at presentation: nondiagnostic for AMI at 0, 3, 6, 9, 12, and 24 hours after ED presentation; or ECG diagnostic for AMI at 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 12, 18, and 24 hours after ED presentation. RESULTS: Of 667 patients, 34 had AMI diagnosed within 24 hours of ED arrival. Using a .2 microgram/L discrimination level for cTnT, sensitivity for AMI within 24 hours of ED arrival was 97% (95% confidence interval, 91.4% to 99.9%), and specificity was 92% (89.8%-94.1%). When the effects of age, race, sex, and creatine kinase-MB isoenzyme subunit test results were controlled, a patient with cTnT of .2 microgram/L or greater was 3.5 (1.4 to 9.1) times more likely to have a cardiac complication within 60 days of ED arrival than a patient with a cTnT value below .2 microgram/L. CONCLUSION: Measurement of cTnT will accurately identify myocardial necrosis in patients presenting to the ED with possible AICS. Elevated cTnT values identify patients at increased risk of cardiac complications.

Adult↗
PubMed1998

Rationale and clinical evidence for the use of GP IIb/IIIa inhibitors in acute coronary syndromes.

Platelet glycoprotein (GP) IIb/IIIa blockade has the potential to advance treatment of acute coronary syndromes, both as a primary pharmacologic approach and an adjunct to interventional treatment strategies. The benefits of GP IIb/IIIa inhibition with the chimeric monoclonal antibody abciximab in preventing ischemic complications of interventional treatment have been well defined in patients with unstable angina. In the future, major therapeutic applications for this class of agents may include the stabilization of patients with unstable angina and potentially as single medical therapy, as several recently completed trials have suggested. Evidence also is accumulating on the use of GP IIb/IIIa blockade as adjunctive therapy in fibrinolytic approaches to treatment of acute myocardial infarction. Several ongoing trials are evaluating the safety and efficacy of this novel strategy. This article reflects a distillation of the views and consensus regarding the prospective use of GP IIb/IIIa inhibitors in patients with acute coronary syndromes expressed by a group of international experts convened in Davos, Switzerland, February 16, 1997. This report attempts to review clinical progress to date, formulate recommendations, and map out potentially fruitful lines of inquiry for future investigation.

Abciximab↗
PubMed1998

Prospective use of platelet glycoprotein IIb/IIIa receptor blockers in the emergency department setting.

Platelets play a pivotal role in the pathophysiology of acute coronary syndromes (ACS) and thus are logical therapeutic targets for treatment of this disease process. Platelet glycoprotein (GP IIb/IIIa receptor antagonists, which interrupt the final common pathway of platelet aggregation, have been proven to reduce the 30-day incidence of death, acute myocardial infarction (MI), and urgent revascularization in both high-risk and low-risk patients undergoing percutaneous intervention procedures. Three-year follow-up has indicated that these benefits appear durable. Recent large-scale randomized trials have demonstrated the value of GP IIb/IIIa receptor inhibitors in reducing the risk of death and MI in unstable angina/non-Q-wave MI patients receiving pharmacologic management. And, emerging evidence suggests a future role for GP IIb/IIIa receptor inhibitors as an adjunct to low-dose fibrinolytic therapy in patients with acute MI. As the list of indications for GP IIb/IIIa receptor antagonists expands to encompass the full spectrum of ACS, there is increasing interest in the potential use of these agents in the emergency department setting. The integration of GP IIb/IIIa receptor inhibitors into emergency department protocols will ultimately depend largely on whether these drugs prove to be safe and effective regardless of the direction of ST-segment deviation, and irrespective of whether definitive therapy will be invasive or conservative.

Algorithms↗
PubMed1997

Serial creatine kinase-MB results are a sensitive indicator of acute myocardial infarction in chest pain patients with nondiagnostic electrocardiograms: the second Emergency Medicine Cardiac Research Group Study.

OBJECTIVE: To determine the test performance characteristics of serial creatine kinase-MB (CK-MB) mass measurements for acute myocardial infarction (MI) in patients presenting to the ED with chest pain and nondiagnostic ECGs. METHODS: A prospective, observational test performance study was conducted. Hemodynamically stable patients aged > or = 25 years with chest discomfort, but without ECGs diagnostic for MI, were enrolled at 7 university teaching hospitals. Presenting ECGs showing > 1-mV ST-segment elevation in > or = 2 electrically contiguous leads were considered diagnostic for MI; patients with diagnostic ECGs on presentation were excluded. Real-time, serial CK-MB mass levels were obtained using a rapid serum immunochemical assay at the time of ED presentation (0-hour) and 3 hours later (3-hour). The following testing schemes were evaluated for their sensitivity and specificity for detection of MI during patient evaluation in the ED: 1) an elevated (> or = 8 ng/mL) presenting CK-MB level; 2) an elevated presenting and/or 3-hour CK-MB level; 3) a significant increase (i.e., > or = 3 ng/mL) within the range of normal limits for CK-MB concentrations during the 3-hour period (delta CK-MB); and/or 4) development of ST-segment elevation during the 3 hours (second ECG). RESULTS: Of the 1,042 patients enrolled, 777 (74.6%) were hospitalized, including all 67 MI patients (8.6% of admissions). As a function of duration of time in the ED, the test performance characteristics of serial CK-MBs for MI (and cumulative data for the additional ECG) were: [table: see text] The 0-hour to 3-hour CK-MB positive and negative predictive values were 52% to 55% and 96% to 99%, respectively. The sensitivities of serial CK-MB results as a function of the interval following chest discomfort onset were: [table: see text] CONCLUSION: Serial CK-MB monoclonal antibody mass measurements in the ED can identify MI patients with initially nondiagnostic ECGs. CK-MB sensitivity significantly increases over 3 hours of observation of stable chest discomfort patients in the ED; it also increases as a function of the total interval from onset until enzyme measurement.

Adult↗
PubMed1996

Multicenter study of creatine kinase-MB use: effect on chest pain clinical decision making.

OBJECTIVE: To determine whether creatine kinase-MB isomer (CK-MB) levels affect initial physician decisions regarding patients with potential cardiac chest pain. METHODS: A prospective, multicenter, observational cohort study was performed at seven university teaching hospital EDs. Hemodynamically stable chest pain patients > or = 25 years old and without ST-segment elevation on their ECGs were observed with one to two sets of CK-MB level determinations obtained three hours apart prior to disposition. The physicians committed to a dichotomous (yes/no) absolute decision regarding the diagnosis of myocardial infarction (MI), need for hospital admission, and need for coronary care unit (CCU) admission both before and after enzyme results were obtained. The physicians ranked the perceived importance of initial history and physical, serial clinical observation, initial ECG, and CK-MB level to their decision making (rank score: 1 = most important, 4 = least important). RESULTS: Of the 1,042 patients enrolled, 777 (74.6%) were admitted to the hospital. For the 67 MI patients (8.6% of the admissions), changes in absolute decisions about the diagnosis of MI and planned CCU admission were associated with increased CK-MB importance (p = 0.04 and p = 0.02, respectively). Of the 146 patients who had new-onset angina or unstable angina, changes in absolute decisions were not associated with CK-MB importance. No patient who had MI or unstable angina was released from the ED. There were three of 67 (4%) MI patients and one of 146 (1%) unstable/new-onset angina patients initially slated for release home who were admitted to the hospital. CONCLUSIONS: For a minority of the patients who had subsequently proven MI, the CK-MB result helped guide disposition decisions. The CK-MB availability did not adversely impact the disposition of the patients who had unstable or new-onset angina.

Aged↗
PubMed1995

A rapid diagnostic and treatment center for patients with chest pain in the emergency department.

STUDY OBJECTIVE: To evaluate a comprehensive diagnostic 9-hour evaluation (Heart ER Program) for patients with possible acute ischemic coronary syndromes. DESIGN: Retrospective review of consecutive patients. SETTING: Urban tertiary care emergency department. PARTICIPANTS: A total of 1,010 patients with symptoms suggestive of acute ischemic coronary syndrome was enrolled in the Heart ER Program over the first 32 months of operation. Patients with history of coronary artery disease, hemodynamic instability, acute ST-segment elevation or depression of more than 1 mm, or a clinical syndrome consistent with unstable angina were directly admitted to the hospital. INTERVENTION: Patients underwent serial testing for creatine kinase (CK-MB) on presentation to the Heart ER and 3, 6, and 9 hours later with continuous 12-lead ECGs/serial ST-segment trend monitoring for 9 hours. Two-dimensional echocardiography and graded exercise testing were performed in the ED after the 9-hour evaluation period. RESULTS: Of 1,010 patients, 829 (82.1%) were released home from the ED; 153 (15.1%) required admission for further cardiac evaluation. Fifty-two of 153 (33.9%) admitted patients were found to have a cardiac cause for their symptoms; 43 had acute ischemic coronary syndromes (12, acute myocardial infarction; 31, angina or unstable angina). CONCLUSION: The Heart ER program provides an effective method for evaluating low- to moderate-risk patients with possible acute ischemic coronary syndrome in the ED setting.

Adult↗