"Left main equivalent" coronary artery disease: its clinical presentation and prognostic significance with nonsurgical therapy.

The clinical characteristics and nonsurgical prognosis of 55 patients with "left main (LM) equivalent" coronary artery disease (CAD) were evaluated and defined as: (1) greater than or equal to 75% diameter reduction of the left anterior descending coronary artery (LAD) before the takeoff of any large septal perforator or anterolateral (diagonal) branches; (2) greater than or equal to 75% diameter reduction of the left circumflex artery (LC) before the takeoff of any large marginal branch; and (3) absence of greater than or equal to 50% stenosis of the LM coronary artery. Compared with nonsurgically treated patients with greater than or equal to 75% stenosis of the LM artery, patients with LM equivalent CAD had a shorter duration of symptoms (median of 51 months vs 66 months) and more often had a Q wave on the electrocardiogram (60 vs 39%). Survival in patients with LM equivalent CAD (78% at 1 year and 55% at 5 years) was better than that in patients with LM disease with nonsurgical therapy (65% at 1 year and 40% at 5 years) (p = 0.

Clinical characteristics and long-term survival of patients with variant angina.

We studied 109 consecutive patients with variant angina who underwent cardiac catheterization over an 11 year period. All patients were followed for at least 6 months or until death, and 46 patients (22 treated medically and 24 treated surgically) were followed for 5 years or more. Of the 62 patients initially treated medically, 14 had nonfatal myocardial infarctions (12 within 1 month of catheterization) and 12 died (six within 6 months).

Regression modelling strategies for improved prognostic prediction.

Regression models such as the Cox proportional hazards model have had increasing use in modelling and estimating the prognosis of patients with a variety of diseases. Many applications involve a large number of variables to be modelled using a relatively small patient sample. Problems of overfitting and of identifying important covariates are exacerbated in analysing prognosis because the accuracy of a model is more a function of the number of events than of the sample size.

Prognostic indicators from radionuclide angiography in medically treated patients with coronary artery disease.

The purpose of this investigation was to determine which variables obtained when performing radionuclide angiography predict subsequent survival or total events (cardiovascular death or nonfatal myocardial infarction) in stable patients with symptomatic coronary artery disease (CAD). Univariable and multivariable analyses of 6 variables, including ejection fraction (EF) at rest and exercise, change in EF with exercise, development of ischemic chest pain or electrocardiographic changes, left ventricular (LV) wall motion abnormalities and exercise time were examined in 386 patients followed up to 4.5 years.

The effect of crossovers on estimates of survival in medically treated patients with coronary artery disease.

Among 1661 consecutive patients with significant coronary artery disease treated medically at the Duke University Medical Center, 239 have undergone aortocoronary bypass surgery after at least 6 months of medical management. The purpose of this investigation was twofold: (1) to identify the distinguishing characteristics of these treatment crossovers; and (2) to illustrate a method of estimating the effect that withdrawing the crossovers from the analysis would have on the survival of the medically managed patients. Of 81 baseline characteristics compared, 25 were significantly (p less than 0.

Prognostic value of ventricular arrhythmias associated with treadmill exercise testing in patients studied with cardiac catheterization for suspected ischemic heart disease.

The prognostic information provided by ventricular arrhythmias associated with treadmill exercise testing was evaluated in 1,293 consecutive nonsurgically treated patients undergoing an exercise test within 6 weeks of cardiac catheterization. The 236 patients with simple ventricular arrhythmias (at least one premature ventricular complex, but without paired complexes or ventricular tachycardia) had a higher prevalence of significant coronary artery disease (57 versus 44%), three vessel disease (31 versus 17%) and abnormal left ventricular function (43 versus 24%) than did patients without ventricular arrhythmias. Patients with paired complexes or ventricular tachycardia had an even higher prevalence of significant coronary artery disease (75%), three vessel disease (39%) and abnormal left ventricular function (54%).

Estimating the likelihood of significant coronary artery disease.

Among 23 clinical characteristics examined in 3,627 consecutive, symptomatic patients referred for cardiac catheterization between 1969 and 1979, nine were found to be important for estimating the likelihood a patient had significant coronary artery disease. A model using these characteristics accurately estimated the likelihood of disease when applied prospectively to 1,811 patients referred since 1979 and when used to estimate the prevalence of disease in subgroups reported in the literature. Since accurate estimates of the likelihood of significant disease that are based on clinical characteristics are reproducible, they should be used in interpreting the results of additional noninvasive tests and in quantitating the added diagnostic value.

The prognosis for patients with new-onset angina who have undergone cardiac catheterization.

We investigated the prognostic significance of new-onset angina in patients in whom coronary anatomic characteristics were known. New onset angina was defined as angina of less than 3 months duration. Consecutive patients (n = 1727) with significant coronary artery disease (diagnosed at cardiac catheterization) and who had not had a prior myocardial infarction or congestive heart failure were studied.

Natural history of cerebral complications of coronary artery bypass graft surgery.

We reviewed 1,669 patients who survived coronary artery bypass graft surgery between 1969 and 1981. A total of 75 cerebral complications were identified, including (1) altered mental state, (2) stroke, and (3) seizure in 64 patients (3.8%).

The use of radionuclide angiography in the diagnosis of coronary artery disease--a logistic regression analysis.

We applied logistic regression analysis to a group of 736 patients with chest pain to determine which radionuclide angiographic (RNA) parameters were most useful in the diagnosis of significant coronary artery disease. The most useful parameters were exercise ejection fraction, exercise heart rate, "ischemia score," and the presence of a regional wall motion abnormality at exercise. Ten clinical variables were used in one logistic regression model to estimate each patient's pretest probability of disease.

Early discharge after acute myocardial infarction.

Approximately 50% of patients hospitalized with acute myocardial infarction have an uncomplicated course and an excellent prognosis. To be considered as having an uncomplicated course, patients should not have ventricular tachycardia or fibrillation, second or third degree atrioventricular block, pulmonary edema, cardiogenic shock, infarct extension, persistent hypotension, sinus tachycardia, or sustained supraventricular tachycardia occurring within the first 4 days of hospitalization. Patients with recurrent angina in the postinfarction period may also be at increased risk.

An improving prognosis over time in medically treated patients with coronary artery disease.

The national mortality rate from coronary heart disease has decreased during the past decade, for reasons that are not yet clear. The mortality rate and the total number of cardiovascular events both decreased during the last 10 years in 1,911 medically treated patients with significant coronary artery disease. This decrease cannot be explained by less sick patients being referred for evaluation.

Seasonal variation in anthelmintic response by cattle to dermally applied levamisole.

Four experiments in 1978-79, and 2 in 1982 designed to define the optimum dose rate of dermally applied formulations of levamisole are described. These experiments showed that the absorption of levamisole with resultant blood levels and anthelmintic activity is strongly influenced by temperature. In warm to hot conditions percutaneous absorption is rapid and high blood levels with high anthelmintic activity against Haemonchus placei, Ostertagi sp, Trichostrongylus sp, Cooperia sp, Oesophagostomum radiatum, O.

Adverse effects of nifedipine therapy on hypertrophic obstructive cardiomyopathy.

A 62-year-old man with obstructive hypertrophic cardiomyopathy was given sublingual nifedipine, 10 mg, during invasive hemodynamic monitoring. After 15 minutes, his left ventricular outflow gradient increased from 22 to 80 mm Hg while arterial pressure fell from 152/70 to 122/64 mm Hg. Left ventricular end-diastolic pressure increased from 15 to 22 mm Hg.

Outcome in one-vessel coronary artery disease.

We analyzed the clinical outcomes in 688 patients with isolated stenosis of one major coronary artery. The survival rate among patients with disease of the right coronary artery (RCA) was higher than that among patients with left anterior descending (LAD) or left circumflex coronary artery (LCA) disease. The survival rate among patients in all three anatomic subgroups exceeded 90% at 5 years.

Prognostic implications of ventricular arrhythmias during 24 hour ambulatory monitoring in patients undergoing cardiac catheterization for coronary artery disease.

The prognostic importance of ventricular arrhythmias detected during 24 hour ambulatory monitoring was evaluated in 395 patients with and 260 patients without significant coronary artery disease. Ventricular arrhythmias were found to be strongly related to abnormal left ventricular function. A modification of the Lown grading system (ventricular arrhythmia score) was the most useful scheme for classifying ventricular arrhythmias according to prognostic importance.

Problems and advantages of an observational data base approach to evaluating the effect of therapy on outcome.

In this report, we summarize the strengths and problems of an observational data base approach to evaluating therapy and studying patient outcomes in long-term chronic disease. Because this approach includes a greater spectrum of patients than randomized clinical trials, it offers a definite advantage with regard to the elucidation of prognostic factors and the application of results to specific patients. The major difficulty with the observational data base approach is that the important prognostic factors must be known for treatment comparisons to be valid.

Evaluating the yield of medical tests.

A method is presented for evaluating the amount of information a medical test provides about individual patients. Emphasis is placed on the role of a test in the evaluation of patients with a chronic disease. In this context, the yield of a test is best interpreted by analyzing the prognostic information it furnishes.

Fifth day fits: a syndrome of neonatal convulsions.

A new syndrome of neonatal convulsions is described. Ninety cases were documented from one maternity hospital between 1973 and 1977. The appearance of this syndrome increased the annual incidence of neonatal convulsions from fewer than 3 to more than 16 per 1000 live births.

Why does migraine improve during a clinical trial? Further results from a trial of cervical manipulation for migraine.

It is generally accepted that migraine is sensitive to intervention, whether in a treatment situation or in a clinical trial, and a "placebo effect" is often suggested. The influence of a number of non-specific therapeutic ingredients was examined in a recent six-month trial of cervical manipulation for migraine, and results of a 20-month follow-up are reported. During the trial migraine attacks reduced significantly by 28%, and reduced a further 19% up to the follow-up period.

A controlled trial of cervical manipulation of migraine.

The efficacy of cervical manipulation for migraine was evaluated. In a six-month trial, 85 volunteers suffering from migraine were randomly allocated to three treatment groups. One group received cervical manipulation performed by a medical practitioner or by a physiotherapist, another received cervical manipulation performed by a chiropractor, while the control group received mobilization performed by a medical practitioner or by a physiotherapist.