Search PubMed⌕ Search

Biomedical subjects

R M Califf

Publications and source records attributed to R M Califf.

553 records · Page 31Linked to original sources
PubMed1978

Relationships among ventricular arrhythmias, coronary artery disease, and angiographic and electrocardiographic indicators of myocardial fibrosis.

This study was performed to determine the relationships among angiographic, hemodynamic, clinical, and electrocardiographic data and premature ventricular contractions (PVCs). Arrhythmias were analyzed by 24 hour Holter monitor in 244 patients evaluated for chest pain by coronary angiography and left ventriculography. Using a categorical linear model, the presence of myocardial fibrosis as indicated by both abnormal left ventricular contraction (LVC) and abnormal initial QRS on electrocardiogram was found to be the only independent predictor of both frequent and complex ventricular arrhythmias (P less than .0001). All other descriptors, including the number of diseased vessels (greater than or equal to 75% obstruction), were dependent upon abnormal LVC in their association with PVCs. When the right anterior oblique view of the left ventriculogram was divided into nine segments to allow automated quantiative analysis of LVC, the prevalence of frequent PVCs was directly related to the number of abnormally contracting segments. Of patients with 0 abnormal segments, 11% had greater than or equal to 2 PVC/hr, in contrast to 44%, 73% and 100% of patients with 1-3, 4-6, and 7-9 abnormal wall segments, respectively (P less than 0.01). A similar quantitative relationship was found between premature ventricular contractions and abnormal initial forces indicating previous myocardial infarction on the electrocardiogram.

Adult↗
PubMedDate not supplied

Relationship of depression to increased risk of mortality and rehospitalization in patients with congestive heart failure.

BACKGROUND: Patients with congestive heart failure (CHF) may have a high prevalence of depression, which may increase the risk of adverse outcomes. OBJECTIVE: To determine the prevalence and relationship of depression to outcomes of patients hospitalized with CHF. METHODS: We screened patients aged 18 years or older having New York Heart Association class II or greater CHF, an ejection fraction of 35% or less, or both, admitted between March 1, 1997, and June 30, 1998, to the cardiology service of one hospital. Patients with a Beck Depression Inventory score of 10 or higher underwent a modified National Institute of Mental Health Diagnostic Interview Schedule to identify major depressive disorder. Primary care providers coordinated standard treatment for CHF and other medical and psychiatric disorders. We assessed all-cause mortality and readmission (rehospitalization) rates 3 months and 1 year after depression assessment. Logistic regression analyses were used to evaluate the independent prognostic value of depression after adjustment for clinical risk factors. RESULTS: Of 374 patients screened, 35.3% had a Beck Depression Inventory score of 10 or higher and 13.9% had major depressive disorder. Overall mortality was 7.9% at 3 months and 16.2% at 1 year. Major depression was associated with increased mortality at 3 months (odds ratio, 2.5 vs no depression; P =.08) and at 1 year (odds ratio, 2.23; P =.04) and readmission at 3 months (odds ratio, 1.90; P =.04) and at 1 year (odds ratio, 3.07; P =.005). These increased risks were independent of age, New York Heart Association class, baseline ejection fraction, and ischemic etiology of CHF. CONCLUSIONS: Major depression is common in patients hospitalized with CHF and is independently associated with a poor prognosis.

Adult↗
PubMedDate not supplied

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. We used a general index of predictive discrimination to measure the ability of a model developed on training samples of varying sizes to predict survival in an independent test sample of patients suspected of having coronary artery disease. We compared three methods of model fitting: (1) standard 'step-up' variable selection, (2) incomplete principal components regression, and (3) Cox model regression after developing clinical indices from variable clusters. We found regression using principal components to offer superior predictions in the test sample, whereas regression using indices offers easily interpretable models nearly as good as the principal components models. Standard variable selection has a number of deficiencies.

Coronary Disease↗
PubMedDate not supplied

Serum cholesterol in patients undergoing cardiac catheterization for suspected coronary artery disease: diagnostic and prognostic implications.

The Duke Data Bank for Cardiovascular Diseases is an observational data bank capturing baseline, treatment, and follow-up information on patients referred for evaluation of suspected coronary artery disease. From 6829 patients referred between 1969 and 1990 for diagnostic angiography, baseline cholesterol levels were determined as part of the standard clinical procedure. Baseline total cholesterol values were found to be related to the presence of coronary disease in men and women, although in the elderly little evidence for a significant relationship was found. Formal tests for interactions revealed a significant interaction between age and cholesterol but not between gender and cholesterol. In subgroup analyses using the Cox proportional hazards model, no relationship was found between cholesterol and either cardiovascular death or total cardiac events (death or nonfatal myocardial infarction) in 2038 medically treated patients with 5 to 20 years of follow-up. In the subgroup of 1798 surgically treated patients, there was also no relationship between baseline cholesterol level and these end points. Finally, detailed lipid analysis was done at baseline and 6-month angiography in a second population of 759 patients undergoing percutaneous coronary angioplasty between 1986 and 1989. No substantial relationship between baseline or follow-up cholesterol, low-density or high-density lipoproteins, or triglyceride levels and restenosis was found.

Aged↗
PubMedDate not supplied

Risk factors, angiographic patterns, and outcomes in patients with ventricular septal defect complicating acute myocardial infarction. GUSTO-I (Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries) Trial Investigators.

BACKGROUND: Ventricular septal defect (VSD) complicating acute myocardial infarction has been studied primarily in small, prethrombolytic-era trials. Our goal was to determine clinical predictors and angiographic and clinical outcomes of this complication in the thrombolytic era. METHODS AND RESULTS: We compared enrollment characteristics, angiographic patterns, and outcomes (30-day and 1-year mortality) of patients enrolled in the Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO-I) trial with and without a confirmed diagnosis of VSD. Univariable and multivariable analyses were used to assess relations between enrollment factors and the development of VSD. In all, 84 of the 41 021 patients (0.2%) developed VSD, a smaller percentage than reported in the prethrombolytic era. The median time from symptom onset to VSD diagnosis was 1 day. Enrollment factors most associated with this complication were advanced age, anterior infarction, female sex, and no previous smoking. The infarct artery was more often the left anterior descending and more likely to be totally occluded in patients who developed VSD. Mortality at 30 days was higher in patients with VSDs than in those without this complication (73.8% versus 6.8%, P<0.001). Patients with VSDs selected for surgical repair (n=34) had better outcomes than patients treated medically (n=35; 30-day mortality, 47% versus 94%). CONCLUSIONS: Compared with historical control subjects, patients who undergo thrombolysis within 6 hours of infarction onset may have a reduced risk of later VSD. If patients develop this mechanical complication, however, it typically occurs sooner than described in the prethrombolytic era. Despite improvements in medical therapy and percutaneous and surgical techniques, mortality with this complication remains extremely high.

Age Factors↗
PubMedDate not supplied

Clinical outcomes of therapeutic agents that block the platelet glycoprotein IIb/IIIa integrin in ischemic heart disease.

BACKGROUND: Several platelet glycoprotein (GP) IIb/IIIa receptor antagonists have been evaluated in clinical trials. We conducted a systematic overview (meta-analysis) to assess the effect of these compounds on death, myocardial infarction (MI), and revascularization. METHODS AND RESULTS: ORs were calculated for 16 randomized, controlled trials of GP IIb/IIIa inhibitors. An empirical Bayesian random-effects model combined the outcomes of 32 135 patients. There was a significant mortality reduction by GP IIb/IIIa inhibitors at 48 to 96 hours, with an OR of 0.70 (95% CI, 0. 51 to 0.96; P<0.03), equivalent to a reduction of 1 death per 1000 patients treated. Mortality benefits at 30 days (OR, 0.87; 95% CI, 0. 74 to 1.02; P=0.08) and 6 months (OR, 0.97; 95% CI, 0.86 to 1.10; P=0.67) were not statistically significant. For the combined end point of death or MI, there was a highly significant (P<0.001) benefit for GP IIb/IIIa inhibitors at each time point. The 30-day OR was 0.76 (95% CI, 0.66 to 0.87), or 20 fewer events per 1000 patients treated. For the composite end point of death, MI, or revascularization, there was also a highly significant (P<0.001) benefit for GP IIb/IIIa inhibitors. At 30 days, the OR was 0.77 (95% CI, 0.68 to 0.86), or 30 fewer events per 1000 patients treated. The risk differences for death, death or MI, and composite outcomes were similar at 6 months, indicating a sustained absolute improvement. Similar benefit was seen when trials were subgrouped by therapeutic indication (percutaneous intervention versus acute coronary syndromes). CONCLUSIONS: Application of this new therapeutic class to clinical practice promises substantial benefit for both indications.

Double-Blind Method↗
PubMedDate not supplied

The exclusion of women from clinical trials of thrombolytic therapy: implications for developing the thrombolytic predictive instrument database.

The thrombolytic predictive instrument (TPI) was developed to identify those patients most likely to benefit from thrombolytic therapy for acute myocardial infarction as well as to facilitate the earliest possible administration of this treatment. The TPI consists of predictive models derived from clinical data obtained from both clinical trials and data registries. These models are subject to potential bias due to combinations of primary data from different sources. The purpose of this investigation was to assess the influence of gender in developing the TPI database. In this database, there were 1,096 (22%) women and 3,826 (78%) men; only 38% of the women were enrolled in clinical trials, whereas 46% of the men were (p < 0.0001). Within clinical trials, there were few significant eligibility differences between women and men, as the vast majority of patients met eligibility standards for entry in these trials. However, within clinical registries, the women were older (p < 0.0001) and more often had elevated blood pressure on admission (p = 0.002). Multivariate logistic regression indicated that after adjustment for significant predictors of trial inclusion, women were 25% less likely to be included in clinical trials (odds ratio = 0.76, 95% confidence interval = 0.60, 0.96). In order to counter bias introduced by the exclusion of women from clinical trials, the TPI database included patients from non-trial settings. Carefully including patients from clinical registries or non-trial settings may be an important strategy in constructing generally applicable predictive instruments.

Aged↗
PubMedDate not supplied

Prognostic importance of social and economic resources among medically treated patients with angiographically documented coronary artery disease.

OBJECTIVE: To evaluate the hypothesis that diminished social and economic resources impact adversely on cardiovascular mortality in patients with coronary artery disease. DESIGN: Inception cohort study of patients undergoing cardiac catheterization from 1974 through 1980 and followed up through 1989. SETTING: Tertiary care university medical center. PATIENTS: Consecutive sample of 1965 medically treated patients with stenosis 75% or greater of at least one major coronary artery. Five hundred patients were not enrolled due to logistic problems; 33 refused; 64 had missing data on key medical variables. The final study population included 1368 patients, 82% male, with a median age of 52 years. MAIN OUTCOME MEASURE: Survival time until cardiovascular death. RESULTS: Independent of all known baseline invasive and noninvasive medical prognostic factors, patients with annual household incomes of $40,000 or more had an unadjusted 5-year survival of 0.91, compared with 0.76 in patients with incomes of $10,000 or less (Cox model adjusted hazard ratio, 1.9; 95% confidence interval, 1.57 to 2.32; P = .002). Similarly, unmarried patients without a confidant had an unadjusted 5-year survival rate of 0.50, compared with 0.82 in patients who were married, had a confidant, or both (adjusted hazard ratio, 3.34; 95% confidence interval, 1.84 to 6.20; P less than .0001). CONCLUSIONS: Low levels of social and economic resources identify an important high-risk group among medically treated patients with coronary artery disease, independent of important medical prognostic factors. Additional study will be required to see if interventions to increase these resources improve prognosis.

Cardiac Catheterization↗