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J Babb

Publications and source records attributed to J Babb.

9 recordsLinked to original sources
PubMed1992

One-year results of the Thrombolysis in Myocardial Infarction investigation (TIMI) Phase II Trial.

BACKGROUND: The Thrombolysis in Myocardial Infarction (TIMI) Phase II Trial randomized 3,339 patients to either an invasive (INV, n = 1,681) or a conservative (CON, n = 1,658) strategy after intravenous recombinant tissue-type plasminogen activator (rt-PA) for acute myocardial infarction. METHODS AND RESULTS: The patients assigned to the INV strategy routinely underwent cardiac catheterization, and when anatomically appropriate, percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting 18-48 hours after infarction. CON patients had these procedures only in response to the occurrence of spontaneous or provoked ischemia. One-year follow-up data are available in 3,316 patients (99.3%). The primary trial end point, death and nonfatal reinfarction, occurred in 14.7% of INV patients and in 15.2% of CON patients (p = NS). When analyzed individually, there was no difference (p = NS) in death (INV, 6.9%; CON, 7.4%) or recurrent infarction (INV, 9.4%; CON, 9.8%) between the two groups. Anginal status at 1 year was also similar. Cardiac catheterization and PTCA were performed more often in INV (98.0% and 61.2%, respectively) compared with CON (45.2% and 20.5%, respectively) patients. At 1 year, the cumulative number of patients who underwent coronary bypass surgery (INV, 17.5%; CON, 17.3%) was similar in the two groups. CONCLUSIONS: The INV and CON strategies resulted in similar favorable outcomes at 1 year of follow-up. In particular, the rates of mortality and reinfarction were not different and were impressively low in both groups. One possible advantage of the INV strategy was detected in subgroup analyses. In patients with a history of myocardial infarction, the data are suggestive that 1-year mortality was lower in INV patients (10.3%) than in CON patients (17.0%) (p = 0.03).

Angioplasty, Balloon, Coronary↗
PubMed1989

Diagnosis of acute myocardial infarction from two measurements of creatine kinase isoenzyme MB with use of nonparametric probability estimation.

By using bivariate probability estimation for the diagnosis of acute myocardial infarction (AMI) we show how to overcome the difficulties encountered for patients whose clinical presentation is atypical and those encountered when multiple isoenzyme determinations are treated by univariate methods. We use the values for creatine kinase isoenzyme MB measured at the time of admission and 12 h later to estimate the Bayes factors in favor of AMI. The Bayes factors are compiled into a table that the clinician can use to estimate the posterior probability that a patient has AMI. The table of Bayes factors is based on data for a sample of 802 non-AMI patients and 180 AMI patients. Further to validate the method, we randomly chose 200 of the non-AMI and 50 of the AMI patients as an evaluation sample, then used the remaining 602 non-AMI and 130 AMI patients to recompute the Bayes factors. These Bayes factors were used to find the probability of AMI for each of the 250 patients in the evaluation sample. The method resulted in only one false positive and no false negatives. For the misclassified patient the measurements at admission and 12 h later were 1 and 11 U/L; the posterior odds were 15 to 1 in favor of AMI, but in fact the patient was non-AMI.

Creatine Kinase↗
PubMed1988

Information induction for predicting acute myocardial infarction.

We show how to make an unsupervised discrimination of disease and nondisease states by measuring information and using newer notions of inductive reason. We also present a new theory of group-based reference values that is based on measuring information uncertainty. We use data on the isoenzymes creatine kinase-MB (CK-MB) and lactate dehydrogenase-1 (LD1) and on the percentage of LD1 from 101 patients with acute myocardial infarction (AMI) and from 41 patients with suspected, but unfounded, infarction (non-AMI). Calculating the Shannon entropy, a concept from information theory, of the data base allows determination of a difference in entropy values ("effective information"), which determines decision cutoff values that produce binary-base patterns yielding the fewest classification errors. Redundancy in testing is important because it provides the information to approach a goal of errorless discrimination by coding the test results and meeting the conditions of the "Noisy Channel Theorem" of information theory. This redundancy improves the predictive value of diagnosis by isolating the area of equivocation to evident patterns. Results for CK-MB and LD1 are 99% correct in assigning cases to AMI and non-AMI categories; adding %LD1 increases the proportion of errorless binary patterns from 25% to 90%.

Algorithms↗
PubMed1986

Lactate dehydrogenase isoenzyme-1/total ratio: accurate for determining the existence of myocardial infarction.

We have gradually revised our medical protocols for measuring creatine kinase MB isoenzyme (CK-MB) and lactate dehydrogenase isoenzyme-1 (LD-1) because of identifiable problems in the use of an interpretation of CK-MB isoenzyme associated with slowly evolving or small myocardial infarct, the use of thrombolytic therapy, or burn and trauma, each of which affects the rate of appearance and composition of isoenzymes present. Despite recent evidence of the efficacy of LD-1 isoenzyme measurement in the first 12 to 24 h of myocardial infarction, this test is not widely used because of overstated assumptions about the value of CK-MB. Here we studied the adequacy of the current isoenzyme assays by determining the value of CK-MB and LD-1 at optimum serum sampling times and establishing the contribution of individual and combined predictors to diagnostic efficiency. We conclude that the LD-1/total LD activity ratio in serum is superior to measurement of CK-MB or LD-1, or both, in the diagnosis of acute myocardial infarction. Moreover, this ratio is most valuable when interpretation of the result for CK-MB isoenzyme is equivocal in patients with small or evolving myocardial infarcts.

Analysis of Variance↗
PubMed1976

Diagnosis and management of pancreatic trauma.

The diagnosis and management of 76 patients with pancreatic trauma is reviewed. There was an overall mortality rate of 5 per cent. A preoperative serum amylase determination was a valuable parameter when assessing blunt trauma. Operative management required debridement and external drainage in approximately three-fourths of all injuries. Pancreatic resection was reserved for ductal disruption. Interruption of ductal integrity accounted for 47 per cent of all complications. Only one-third required reoperative therapy. Associated major vascular injuries accounted for all deaths.

Abdominal Injuries↗
PubMedDate not supplied

Taking precautions.

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Hand Disinfection↗