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Biomedical subjects

R M Califf

Publications and source records attributed to R M Califf.

At least 541 records · Page 30Linked to original sources
PubMed1984

Clinical characteristics and current management of medically refractory unstable angina.

Of 531 patients admitted to the Duke Coronary Care Unit with unstable angina (UA) from June 1981 to September 1982, 100 had persistent angina despite optimal medical therapy of nitrates, propranolol, and nifedipine. At catheterization, 70% of the refractory patients had left main (LM) or three-vessel disease (TVD), 68% had left ventricular end-diastolic pressures of greater than 12 mmHg, and 24% had ejection fractions (EF) of less than 0.40. Twenty-four patients were greater than 65 years of age, and 53 had associated major diseases. Forty-eight patients (Group I) had no evidence of myocardial infarction in the 30 days before catheterization, whereas 52 patients had an infarction precipitating the unstable angina within the preceding 30 days (Group II). Emergent coronary artery bypass grafting was performed in all 100 patients irrespective of ventricular function, hemodynamic status, or coronary anatomy. Management protocols included prompt surgical intervention, preoperative stabilization with the balloon pump in LM or TVD, meticulous myocardial protection, and complete coronary revascularization. An average of 3.6 grafts were placed in each patient. There were two hospital deaths in Group I, and two in Group II. Two-year survival was 90% in Group I and 88% in Group II, and 81% of surviving patients were NYHA Class I or II. Thus, refractory UA denotes particularly severe coronary disease with a high incidence of LM, TVD, and depressed EF. Baseline clinical characteristics, criteria for operation, and expected results in the postinfarction group seem to be similar to the unstable angina group in general. Cardiac anatomic and functional variables no longer constitute operative contraindications. Aggressive operative management is safe, and the current risk may be less dependent on coronary anatomy and ventricular function than previously appreciated.

Adult↗
PubMed1984

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). Survival probabilities at 1, 3, and 5 years were 0.88, 0.84, and 0.77, respectively. Of the 48 surgically treated patients (including four patients initially treated medically and one initially treated with coronary angioplasty), four had nonfatal infarctions (three in the perioperative period) and three died (all in the perioperative period). The survival probability in these patients at 1 year was 0.94 and remained unchanged at 3 and 5 years. Only one nonfatal infarction and no deaths have occurred in the group of surgically treated patients subsequent to hospital discharge. Three additional patients were treated with coronary angioplasty. The single most important prognostic factor in medically treated patients was the presence or absence of fixed obstructive coronary artery disease. Infarction-free survival probabilities at 1 and 3 years in the 23 patients without significant coronary artery disease were 1.0 and 0.89, compared with 0.51 and 0.46 in the 39 patients with significant coronary disease. Analysis by the Cox model showed that variant angina patients had a higher probability of death and nonfatal infarction than did those with nonvariant angina coronary disease if other important prognostic variables were held constant.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris, Variant↗
PubMed1984

Effects of physical conditioning on left ventricular ejection fraction in patients with coronary artery disease.

To address the hypothesis that physical conditioning may improve left ventricular function in patients with coronary artery disease, we performed first-pass radionuclide ventriculography in 53 patients at rest and during upright bicycle exercise before and after 6 to 12 months of exercise training. The peak bicycle workload achieved before the onset of fatigue, dyspnea, or angina increased by an average of 22% (p = .0001) after training, and mean heart rate at a workload equal to the pretraining maximum workload was decreased by 10 beats/min after training (p = .0002). Of 21 subjects with angina or exertional ST segment depression before training, 15 (71%) were able to exercise to the same workload without these manifestations of ischemia after training. Whereas neither mean resting left ventricular ejection fraction (LVEF) nor LVEF at peak exertion was significantly altered, mean LVEF at the pretraining maximum workload was increased from 0.50 to 0.54 (p = .002) after training. There was a significant correlation between the magnitude of training bradycardia and the increment in LVEF at the pretraining maximum workload (p = .009). We conclude that the relative bradycardia at comparable exercise workloads produced by exercise conditioning is associated with improvements in left ventricular performance as assessed by the LVEF. This observation is compatible with the hypothesis that training bradycardia in conditioned subjects with ischemic heart disease is associated with lower myocardial oxygen demand and lesser degrees of ischemia at comparable workloads. However, training effects on ventricular afterload or on ischemia contractile performance of the heart cannot be excluded.

Adult↗
PubMed1984

Myocardial infarction and stroke.

We used a computer data bank to evaluate 740 consecutive patients admitted to a cardiac care unit with myocardial infarction. Stroke occurred in 18 (2.4%) patients in the hospital; the anterior circulation was involved in 76% of strokes. Hospital mortality was 61% in patients with stroke and 13% in patients without stroke. Atrial arrhythmia was a significant (p less than or equal to 0.03) risk factor for stroke, but peak creatine kinase and ventricular arrhythmia were not. Cardiac pump failure, apical or anterior-lateral myocardial infarction, and history of previous stroke were associated with an increased risk of stroke. Clinical and pathologic data suggested an embolic etiology for most strokes that complicate acute myocardial infarction.

Adult↗
PubMed1983

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. This study suggests that at least part of the decrease in coronary heart disease mortality observed nationally is occurring in patients with established coronary disease.

Coronary Disease↗
PubMed1983

Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty.

To permit comparison of percutaneous transluminal coronary angioplasty (PTCA) with conventional therapy, the clinical outcome was established in patients who would have been suitable candidates for PTCA but who presented before the technique was available. Coronary angiograms were reviewed of patients who met the following criteria: single-vessel disease with proximal subtotal coronary stenosis, chest pain of at least class II, and cardiac catheterization before 1981. Angiograms were evaluated according to established criteria for PTCA by an experienced angiographer. One hundred ten patients (2.1% of the patient population) were judged suitable for PTCA. Clinical and catheterization findings closely resembled those of patients in the national PTCA registry. Five years after catheterization, 97% of PTCA candidates treated medically were alive and 85% had not had myocardial infarction. Forty-six patients had coronary artery bypass surgery within 6 months of catheterization and 10 other patients had subsequent surgery. Five years after surgery, 91% were alive and 87% had not had myocardial infarction. At 6 months of follow-up, 78% of all patients had improved at least 1 functional class, and 86% of all patients working before catheterization were still employed. Functional capacity was well maintained during long-term follow-up (median 6.5 years, range 1.4 to 12.2). These data indicate that PTCA candidates have an excellent prognosis for survival, a low risk of infarction, and well-maintained functional capacity when revascularization is reserved for those with inadequate control of symptoms by medical therapy.

Angioplasty, Balloon↗
PubMed1983

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.

Adult↗
PubMed1983

Comparative rates of resolution of QRS changes after operative and nonoperative acute myocardial infarcts.

An independently developed and previously validated QRS scoring system for estimating myocardial infarct size has been used to compare the development and regression of changes associated with myocardial infarcts occurring in 2 different clinical settings. It is known that QRS changes suggesting myocardial infarction occur after coronary artery bypass grafting. This study compares the magnitudes and time courses of these QRS changes in 40 patients with the QRS changes observed in a control group of 46 patients with nonoperative acute myocardial infarcts. Only patients in both groups who had a baseline electrocardiogram (ECG) with no evidence of previous myocardial infarcts, ventricular hypertrophy, or bundle branch block were included. Both groups attained similar peak QRS scores during the acute phase but different rates of resolution of scores were observed. During the subsequent 2 months, regression of QRS changes occurred more rapidly in the perioperative group than in the control group (43 versus 19%). Rates of regression were similar in both groups during the remainder of the follow-up period, attaining total decreases of 62% in the operative group and 37% in the nonoperative group by 18 months. These results could mean either that factors other than acute infarction are responsible for the perioperative QRS changes or that the infarct healing process in the 2 clinical settings are quite different.

Coronary Artery Bypass↗
PubMed1983

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%). In the 620 patients with significant coronary artery disease, patients with paired complexes or ventricular tachycardia had a lower 3 year survival rate (75%) than did patients with simple ventricular arrhythmias (83%) and patients with no ventricular arrhythmias (90%). Ventricular arrhythmias were found to add independent prognostic information to the noninvasive evaluation, including history, physical examination, chest roentgenogram, electrocardiogram and other exercise test variables (p = 0.03). Ventricular arrhythmias made no independent contribution once the cardiac catheterization data were known. In patients without significant coronary artery disease, no relation between ventricular arrhythmias and survival was found.

Arrhythmias, Cardiac↗
PubMed1983

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. The presence of a lesion proximal to the first septal perforator of the LAD was associated with decreased survival compared with the presence of a more distal lesion. For the entire group of one-vessel disease patients, total ischemic events (death and nonfatal infarction) occurred at similar rates regardless of the anatomic location of the lesion. Left ventricular ejection fraction was the baseline descriptor most strongly associated with survival, and the characteristics of the angina had the strongest relationship with nonfatal myocardial infarction. No differences in survival or total cardiac event rates were found with surgical or nonsurgical therapy. The relief of angina was superior with surgical therapy, although the majority of nonsurgically treated patients had significant relief of angina. The survival rate of patients with one-vessel coronary disease is excellent, and the risk of nonfatal infarction is low. Clinical strategies for the care of these patients must consider the long-term clinical course of one-vessel coronary disease.

Angina Pectoris↗
PubMed1983

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. In patients with new-onset angina (n = 329) there was a higher incidence of single-vessel disease (43% vs 27%) and a lower incidence of triple-vessel (23% vs 35%) and left main artery (5% vs 10%) disease compared with patients with chronic angina (n = 1398). Patients were classified by the presence or absence of preinfarction angina (severe and prolonged angina at rest requiring hospitalization to rule out myocardial infarction). In patients treated without surgery and who did not have preinfarction angina, survival at 1 year was 97% for patients with new-onset angina and 98% for those with chronic angina (p = .27). Among patients not treated surgically who did not have preinfarction angina, at 1 year 16% with new-onset angina and 7% with chronic angina had suffered a cardiac event (nonfatal myocardial infarction or death, p = .006). In patients treated surgically who did not have preinfarction angina, survival at 1 year was 96% both for those with new-onset angina and those with chronic angina (p = .99). The risk of an event in patients treated surgically at 1 year was not statistically different in patients with new-onset angina and those with chronic angina (12% vs 11%, p = .27). Survival and event-free rates were lower in patients with preinfarction angina than in patients who did not have it.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1983

Clinical value of coronary bypass graft evaluation with CT.

Computed tomography (CT) has a reported accuracy of 45%-97% in assessment of patency of coronary artery bypass grafts. Dynamic CT was done in 26 patients (47 grafts) with recurrent cardiac symptoms after graft surgery. Although CT was 79% accurate (with selective angiography as the standard), the authors do not believe that it provides sufficient information for the assessment of symptomatic patients. Four patients had high-grade stenoses in their grafts, and 50% of patients had significant progression of atherosclerosis in their native coronary arteries. Neither of these conditions could be detected by CT. The clinical contribution of CT will probably be greatest for routine screening of asymptomatic patients soon after operation. Technical problems with CT scanning for graft patency are discussed.

Angiography↗
PubMed1983

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. Early and rapidly progressive rehabilitation programs permit the safe discharge of patients with an uncomplicated course after 7 days. Functional exercise testing before, or soon after, early discharge may identify high-risk patients and alter their management.

Follow-Up Studies↗
PubMed1982

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. Information from the history, physical examination, and routine procedures should be used in assessing the yield of a new test. As an example, the method is applied to the use of the treadmill exercise test in evaluating the prognosis of patients with suspected coronary artery disease. The treadmill test is shown to provide surprisingly little prognostic information beyond that obtained from basic clinical measurements.

Catheterization↗
PubMed1982

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. When only noninvasive characteristics were considered, the score contributed independent prognostic information, and the complexity of ventricular arrhythmias as measured by this score was inversely related to survival. However, when invasive measurements were included, the ventricular arrhythmia score did not contribute independent prognostic information. Furthermore, ejection fraction was more useful than the ventricular arrhythmia score in identifying patients at high risk of sudden death.

Adrenergic beta-Antagonists↗
PubMed1982

Assessment of the use of the age- and sex-specific United States population as a control group for analysis of survival in coronary artery disease.

The use of the age- and sex-specific U.S. population as a control group for analysis of survival in coronary artery disease was assessed. Population-based survival rates were calculated for nonsurgically treated patients evaluated for coronary artery disease at Duke University Medical Center. Survival of the overall group of medically treated patients with significant coronary artery disease was lower than the corresponding age- and sex-specific U.S. population rates. However, survival of patients with significant disease who had normal left ventricular contraction and stable chest pain was similar to the age- and sex-specific population survival rates. Both the observed survival and the population-based survival estimates for patients with normal left ventricular contraction and stable pain were lower than the survival of patients with normal coronary arteriograms. Even after deaths from ischemic heart disease are eliminated from the population rates, survival of patients with normal coronary arteries exceeded the age-and sex-specific population survival. Because of biases inherent in the selection of patients for cardiac catheterization and the presence of other serious diseases in persons in the general population is not an adequate control group for rigorous analysis of the effect of therapy in coronary artery disease.

Actuarial Analysis↗
PubMed1982

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. Both the observational data base and randomized trial approaches are susceptible to criticism because the multiple comparisons and multiple experiments usually involved make the results of any one study not definitive. Either approach is useful in generating or confirming a hypothesis about particular subgroups. Regardless of the method used, proof that a particular therapy increases survival in any group or subgroup of patients with coronary artery disease usually requires confirmation by multiple studies. Finally, observational data base approach, because it capitalizes on data generated and paid for in the patient care process, offers the most feasible approach for evaluating whether changes in prognosis are occurring over time and whether such changes are independent of the mix of the patient population.

Clinical Trials as Topic↗