Adam J. Singer

Diagnostic accuracy of a point-of-care troponin i assay for acute myocardial infarction within 3 hours after presentation in early presenters to the emergency department with chest pain

BACKGROUNDnGuidelines recommend that serial cardiac marker testing to rule out acute myocardial infarction (AMI) be performed for 8 to 12 hours after symptom onset. We aim to determine the diagnostic accuracy of a contemporary point-of-care (POC) troponin I (TnI) assay within 3 hours for patients presenting within 8 hours of symptom onset.nnnMETHODSnThe MIDAS study collected blood from patients presenting with suspected acute coronary syndrome at presentation and at 90 minutes, 3 hours, and 6 hours in whom the emergency physician planned an objective cardiac ischemia evaluation. Criterion standard diagnoses were adjudicated by experienced clinicians using all available medical records per American Heart Association/American College of Cardiology criteria. Reviewers were blinded to the investigational marker, Cardio3 TnI POC. The Cardio3 TnI reference value was defined as >0.05 ng/mL. Measures of diagnostic accuracy are presented with 95% CI.nnnRESULTSnA total of 858 of 1107 patients met the inclusion criteria. The study cohort had 476 men (55.5%) with median age of 57.0 years (interquartile range 48.0-67.0 years). Median time from symptom onset to initial blood draw was 3.9 hours (interquartile range 2.7-5.2 hours). Acute myocardial infarction was diagnosed in 82 patients (9.6%). The sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio over 3 hours were 84.1, 93.4, 12.8, and 0.17, respectively. There was no significant improvement in diagnostic accuracy associated with adding 6-hour serial testing to the 3-hour sample.nnnCONCLUSIONnIn suspected patients with acute coronary syndrome presenting to the emergency department within 8 hours of symptom onset, 3 hours of serial testing with the Cardio3 TnI POC platform provides similar diagnostic accuracy for AMI as longer periods.

Level of training, wound care practices, and infection rates

This prospective, nonrandomized descriptive study compares the traumatic wound infection rates in patients based on level of training of emergency department (ED) practitioners. Wounds were evaluated in 1,163 patients. A wound registry data sheet was prospectively completed on all patients sutured in the ED. All practitioners were assigned a unique identification number. Follow-up data was obtained at the time of the return visit. Patients failing to return were contacted by telephone. Data were analyzed for patient wound infection rates by practitioner level of training. Patient wound infection rates by practitioner level of training were: medical students, 0/60 (0%); all resident physicians, 17/547 (3.1%); physician assistants, 11/305 (3.6%); and attending physicians 14/251 (5.6%), P was not significant. Comparison of junior (medical students and interns) to senior practitioners (all other practitioners) found no difference in infection rates (8/262 [3.1%] v 34/901 [3.8%], P = .58). In conclusion, carefully selected patients sutured by closely supervised medical students and junior residents have infection rates as low as those sutured by more experienced practitioners.

Octylcyanoacrylate versus polyurethane for treatment of burns in swine: a randomized trial.

In order to determine whether the enhanced reepithelialization of second-degree burns treated with octylcyanoacrylate (OCA) was due to its occlusive nature we compared reepithelialization (REP) and infection rates of second degree burns treated with OCA and polyurethane film (Tegaderm) in swine. Forty-four standardized partial thickness burns were created by applying an aluminum bar preheated to 80 degrees C to the backs of pigs for 20 s and randomly treated with OCA or Tegaderm. Full thickness biopsies were taken at 7, 10 and 14 days for blinded histopathological evaluation of rates of infection and reepithelialization. T-tests and chi(2) tests were used for group comparisons. There were no between group difference in the rates of reepithelialization and infection. All wounds were reepithelialized by day 14 and there were no infections in either group. We conclude that treatment of partial thickness burns with OCA spray or Tegaderm results in similar rates of reepithelialization and infection, suggesting that the beneficial effects of OCA on reepithelialization are due to its occlusive nature.

Central versus local adjudication of myocardial infarction in a cardiac biomarker trial

OBJECTIVESnThe impact of regulatory requirements, which require central adjudication for the diagnosis of acute myocardial infarction (AMI) in cardiac biomarker studies, is unclear. We determined the impact of local (at the site of subject enrollment) versus central adjudication of AMI on final diagnosis.nnnMETHODSnThis is a retrospective analysis of data from the Myeloperoxidase in the Diagnosis of Acute Coronary Syndromes Study, an 18-center prospective study of patients with suspected acute coronary syndromes, with enrollment from December 19, 2006, to September 20, 2007. Local adjudication of AMI was performed by a single site investigator at each center following the protocol-specified definition and according to the year 2000 definition of AMI, which based cardiac troponin (cTn) elevation on local cut points for each of the 13 different assays. After completion of the Myeloperoxidase in the Diagnosis of Acute Coronary Syndromes Study primary analysis and to evaluate a new troponin assay, a Food and Drug Administration-mandated central adjudication was performed by 3 investigators at different institutions. This adjudication used the 2007 Universal Definition of AMI, which differs by use of the manufacturers 99th percentile cTn cut point. We describe the outcome of this process and compare it with the local adjudication. Central adjudicators were not blinded to local adjudications. For central adjudication, discrepant diagnoses were resolved by consensus. Local versus central cTn cut points differed for 6 assays. Both definitions required a rise and/or fall of cTn. Discrepant cases were reviewed by the lead author. Difficult cases were defined as having a difference between local and central adjudication, an elevated cTn with a temporal rise and fall, and a negative or absent risk stratification test. Statistics were by χ(2), κ, and logistic regression.nnnRESULTSnOf 1,107 patients enrolled, 11 had indeterminate central adjudication, leaving 1,096 for analysis. In spite of high agreement across central versus local adjudicators, κ = 0.79 (95% CI [0.73, 0.85]), AMI was diagnosed more often by central adjudication, 134 (12.2%) versus 104 (9.5%), with 44 local diagnoses (4%) changed from non-AMI to AMI (n = 37) or AMI to non-AMI (n = 7) (P < .001). These 44 represented 34% (95% CI 26%-42%) of 141 cases in which either central or local adjudication was AMI. Of diagnoses changed to AMI, 3 reasons contributed approximately one-third each: the local use of a non-99th percentile cTn cutoff (32%), the possibility of human error (34%), and difficult cases (34%).nnnCONCLUSIONnDespite an acceptable κ, over a third of patients with a diagnosis of AMI were not assigned that diagnosis by both sets of adjudicators. This supports the importance of 1 standard method for diagnosis of AMI.