Evaluation of CK-MB isoform analysis for early diagnosis of myocardial infarction.

Measurement of CK-MB and its isoforms by high-voltage electrophoresis has been proposed as a sensitive test for early detection of myocardial infarction (MI). We performed a prospective study of this test in 231 patients presenting to the Emergency Department with symptoms consistent with ischemic chest pain. Blood specimens were obtained at 0, 1, and 3 h following presentation, and plasma was immediately frozen and analyzed within 1 week by high-voltage electrophoresis for total CK-MB and isoforms. The test was considered positive whenever total CK-MB was elevated (>6 U/L) or the cardiac isoform MB2 was relatively increased (MB2 > 2 U/L and MB2/MB1 > 1.7). This test had a sensitivity of 68% overall and 55% for specimens collected within 3 h of symptom onset. It was positive within 3 h of presentation in 36/39 (92%) of patients with confirmed MI. Specificity was 92% overall and did not vary with time after symptoms. The CK-MB alone, at the cutoff of 6 U/L, had lower sensitivity overall (56%; p = 0.01) and within 3 h of onset (39%; p = 0.03), and higher specificity overall (98%; p < 0.001). Lowering the cutoff for CK-MB alone to match the sensitivity of the isoform test caused a greater loss of specificity. It is concluded that analysis of CK-MB by high-voltage electrophoresis is an effective method for rapid diagnosis of MI, with the isoform analysis enhancing early sensitivity.

Prospective, randomized, controlled trial of tissue adhesive (2-octylcyanoacrylate) vs standard wound closure techniques for laceration repair. Stony Brook Octylcyanoacrylate Study Group.

OBJECTIVE: To compare a new tissue adhesive, 2-octylcyanoacrylate, with standard wound closure techniques for the repair of traumatic lacerations. METHODS: A prospective, randomized, controlled clinical trial enrolled consecutive patients > 1 year of age with non-bite, non-crush-induced lacerations who presented < 6 hours after injury. Structured closed-question data sheets were completed at the time of laceration repair and suture removal. Patients were randomly assigned to treatment with either 2-octylcyanoacrylate or standard wound closure. Infection was determined at the time of suture removal. Long-term cosmetic appearance (> 3 months) was assessed by physicians using a previously validated categorical cosmetic scale and by patients using a 100-mm visual analog scale. RESULTS: There were 63 patients randomized to the octylcyanoacrylate group and 61 patients treated with standard wound closure techniques. The 2 treatment groups were similar with respect to age, gender, race, medical history, and wound characteristics. At the 5-to-10-day follow-up, only 1 wound was infected and only 2 wounds required reclosure due to dehiscence. These 3 patients received treatment with octylcyanoacrylate. At long-term follow-up, the cosmetic appearances were similar according to the patients (octylcyanoacrylate, 83.8 +/- 19.4 mm vs standard techniques, 82.5 +/- 17.6 mm; p = 0.72) and the physicians (optimal cosmetic appearance, 77% vs 80%; p = 0.67). CONCLUSIONS: Wounds treated with octylcyanoacrylate and standard wound closure techniques have similar cosmetic appearances 3 months later.

Long-term evaluation of cosmetic appearance of repaired lacerations: validation of telephone assessment. The Stony Brook Wound Registry Study Group.

OBJECTIVE: Patients with lacerations are most concerned about the ultimate cosmetic appearance of their wound. We evaluated methods to assess the long-term cosmetic appearance by telephone survey. METHODS: Patients with lacerations repaired in the ED were contacted by telephone and had direct examination a mean of 112 days after injury. At the time of telephone contact to schedule the ED follow-up visit, patients completed a structured survey instrument. Patients rated their laceration appearance from 0 to 100, and completed a 6-item categorical assessment of cosmetic appearance. During ED follow-up, patients assessed satisfaction with a 100-mm visual analog scale (VAS), a 0 to 100 numerical scale, and the same 6-item categorical scale. The criterion standard was the validated 6-item categorical scale used by physicians. A score of 6 is optimal; less than 6 is suboptimal. RESULTS: A total of 103 patients participated (mean age 17 years; 55% male subjects). Wounds were mostly located on the head (72%) and upper extremity (24%). Mean wound length was 1.9 cm. On all numerical scales (numerical assessment by telephone, assessment in the ED by VAS, and by 0 to 100 scale in the ED) the patients considered the wound better when the physicians considered the cosmetic appearance to be optimal (87 mm versus 71 mm; 90 mm versus 73 mm; 90 mm versus 73 mm, respectively; P < .01 for all comparisons). The relationship between the 0 to 100 numerical rating scale used in the ED and that used during the telephone survey revealed a strong relationship. The scales had a mean difference of 2.1 mm (95% confidence interval -26 to 30 mm). However, patient categorical scale assessment from the phone interview was not concordant with physician assessment in the ED (kappa = .12). CONCLUSION: The long-term cosmetic appearance of lacerations repaired in the ED can be assessed by asking patients to grade their lacerations from 0 to 100 over the telephone. By contrast, categorical assessment over the telephone is not concordant with physician assessment in the ED. This information may allow easier assessment of injuries and their long-term consequences.

Performance of two clinical decision rules for knee radiography.

We designed a prospective observational study to attempt to validate two recently described clinical decision rules for knee radiography. Consecutive patients aged > or = 15 yr with acute knee injuries occurring less than 1 wk prior to presentation were included for study. Patients with distracting conditions, open knee injuries, or previous surgery were excluded. Each patient was assessed for 7 historical and 15 physical examination criteria that were recorded on a standardized data collection instrument. Radiographs were ordered at the discretion of the attending physician and were read by two board-certified radiologists. When radiographs were not ordered, structured telephone follow-up was performed after 3 wk. The main outcome parameter was the presence or absence of a clinically significant fracture. There were 351 patients in the study; 26 (7%) had knee fractures. Fractures were significantly associated with an increased prevalence for two of the three criteria in the rule derived by Bauer: inability to weight bear immediately or in the emergency department (ED; 76.9% of patients with a fracture vs. 29.8% of patients without a fracture) and effusion (53.8% vs. 28.9%, respectively). Ecchymosis was not significantly associated with fracture (19.2% with fracture vs. 9% with no fracture). Use of the Bauer rule would have led to a radiographic evaluation of 22 of the 26 patients with knee fractures (sensitivity = 84.6%, specificity = 48.9%). Fractures were associated with a significantly increased prevalence for three of the five criteria in the decision rule proposed by Stiell: isolated patella tenderness (30.8% with fracture vs. 14.5% with no fracture), inability to flex the knee to 90 degrees (42.3% vs. 19.7%, respectively), and inability to weight bear immediately and in the ED (57.7% vs. 18.8%, respectively). Age > or = 55 yr (23.1% vs. 12.0%, respectively) and fibula head tenderness (11.5% vs. 5.5%, respectively) were not significantly associated with fracture. Use of the Stiell rule would have led to radiographic evaluation of 22 of the 26 patients with knee fractures (sensitivity = 84.6%, specificity = 49.8%). We conclude that neither clinical decision rule is 100% sensitive. Further refinement will be necessary to identify all patients with knee fractures.

Are monitored telemetry beds necessary for patients with nontraumatic chest pain and normal or nonspecific electrocardiograms?

We evaluated the frequency of cardiovascular complications in chest pain patients with normal or non-specific electrocardiograms admitted to noncardiac care unit monitored beds and found that none of 261 patients had life-threatening dysrrhythmias requiring treatment.

Evaluation of a new assay for cardiac troponin I vs creatine kinase-MB for the diagnosis of acute myocardial infarction. Biochemical Markers for Acute Myocardial Ischemia (BAMI) Study Group.

OBJECTIVE: To compare a new assay for cardiac troponin 1 (cTn-1) with an assay for creatine kinase-MB (CK-MB) for the diagnosis of acute myocardial infarction (AMI). METHODS: A prospective cross-sectional study of patients presenting with symptoms consistent with cardiac ischemia was performed at a university teaching hospital. Serum sampling for cTn-1 and CK-MB was performed at 0, 1, 3, 8, and 16 hours after presentation. Normal values were defined as CK-MB < or = 7 ng/mL and a relative index < or = 2%, cTn-I < or = 1.4 ng/mL. Final diagnosis was made using World Health Organization criteria, including standard enzyme sampling. Consecutive patients with AMI were compared with a randomly selected subset of patients without AMI to determine the sensitivity and specificity of cTn-I and CK-MB assays for AMI, stratified by time from symptom onset. The ability of the biochemical cardiac markers obtained within 6 hours of symptom onset to predict later complications or need for interventions was assessed using odds ratios (ORs). RESULTS: Thirty-five patients who had AMI were compared with 136 patients who did not have AMI. The sensitivities and specificities of the cTn-I and CK-MB assays, stratified by time from symptom onset, were: [table: see text]. Patients who had elevations in either CK-MB or cTn-I within 6 hours of symptom onset were at increased risk for cardiovascular complications and/or interventions (CK-MB, OR 5.8; cTn-I, OR 6.3). CONCLUSION: cTn-I was as sensitive and specific for AMI as was CK-MB in ED patients who presented within 24 hours of symptom onset. However, cTn-I was more sensitive in patients who presented > or = 24 hours after symptom onset. Elevations of either marker within 6 hours of symptom onset predict an increased risk of complications and/or need for interventions.

Evaluation of cardiac STATus CK-MB/myoglobin device for rapidly ruling out acute myocardial infarction.

The Cardiac STATus CK-MB/Myoglobin device is highly sensitive and has a high negative predictive value within 3 hours of patient presentation. The device may play a role in the re-triage of patients from the CCU to less intensive settings, resulting in a net cost savings.

Improved specificity of myoglobin plus carbonic anhydrase assay versus that of creatine kinase-MB for early diagnosis of acute myocardial infarction.

STUDY OBJECTIVE: Carbonic anhydrase III (CA-III) is an enzyme released from skeletal muscle in a fixed ratio with myoglobin during cell injury, but unlike myoglobin it is not found in cardiac muscle. This study compared the clinical utility of serum myoglobin (S-Mgb) in conjunction with the ratio of S-Mgb to CA-III (S-Mgb/CA-III) versus creatine kinase-MB (CK-MB) for the early diagnosis of acute myocardial infarction (AMI). METHODS: This prospective observational study set at a university teaching hospital emergency department enrolled 251 consecutive consenting patients who presented with symptoms consistent with cardiac ischemia or infarction of less than 12 hours' duration. Patients with trauma or kidney failure were excluded. Standardized history and physical examination data were recorded, as were the results of serial blood sampling for S-Mgb, CA-III, and CK-MB at 0, 1, and 3 hours after patient presentation. A positive test for the study assays was defined as an S-Mgb concentration of more than 110 ng/mL with an S-Mgb/CA-III of 3.21 or higher by receiver operating characteristic analysis. Data were analyzed with McNemar's chi 2 test for symmetry and confidence intervals (CIs), using the exact method. RESULTS: Thirty (12%) of the 251 patients were found to have AMI by World Health Organization criteria. Mean time from symptom onset to presentation was 3.2 hours. The use of S-Mgb plus S-Mgb/CA-III compared with CK-MB for identification of AMI in patients presenting within 3 hours of symptom onset yielded respective sensitivities of 47.8% versus 17.4% (P = .02); specificities of 98.9% versus 100% (P = NS); positive predictive values of 84.6% (95% CI, 54.6% to 98.1%) versus 100% (95% CI, 39.8% to 100%); and negative predictive values of 93.5% (95% CI, 90.0% to 96.6%) versus 90.0% (95% CI, 84.8% to 93.9%). CONCLUSION: S-Mgb in conjunction with S-Mgb/CA-III was significantly more sensitive than CK-MB yet equally as specific for the early diagnosis of patients with AMI.