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Biomedical subjects

Daniel B Mark

Publications and source records attributed to Daniel B Mark.

At least 55 records · Page 3Linked to original sources
PubMed2004

Impact of different patterns of invasive care on quality of life outcomes in patients with non-ST elevation acute coronary syndrome: results from the GUSTO-IIb Canada-United States substudy.

BACKGROUND: Comparing American and Canadian practice patterns and outcomes offers a natural experiment to examine the relative benefits of aggressive versus conservative management of coronary artery disease. In a prospective substudy of the Global Use of Strategies to Open Occluded Coronary Arteries IIb (GUSTO-IIb) trial, differences in the management of non-ST elevation acute coronary syndrome, and the associated impact on quality of life (QOL) outcomes, were examined in the two countries. METHODS AND RESULTS: The patient population, selected randomly from the parent trial population, comprised 390 Canadian and 1122 American patients for whom both baseline and one-year data were available. Validated instruments were used to assess QOL, including the Duke Activity Status Index (DASI) and scales from the SF-36 questionnaire. At baseline, American patients had significantly higher cardiac catheterization rates (83% versus 45%), percutaneous coronary intervention rates (39% versus 24%) and coronary bypass surgery rates (19% versus 12%) than did Canadian patients, respectively. However, at one year, Canadian coronary bypass surgery rates were at par with those in the United States (24% versus 26%, respectively). At baseline, the mean DASI score was 24.6 among Canadian patients and 23.4 among American patients (P=0.14). At one year, neither cohort reported any significant change in functional scores and there was no intercountry difference in DASI scores, even after accounting for baseline risk. Canadian patients had significantly worse mental health scores than American patients at baseline (mean score 71.6 versus 75.4, respectively; P=0.02), but by one year, Canadian patients had better scores (mean score 80.1 versus 76.2, respectively; P=0.01). After adjusting for baseline characteristics, Canadian patients continued to report better mental health status scores than did American patients (4 points higher, P<0.01). When asked to rate their health state on a scale from 0 to 100, both cohorts reported similar values at baseline. However, after adjusting for baseline characteristics, American patients' perception of their health state was better than that reported by Canadians (3 points higher, P<0.01). CONCLUSION: Despite higher rates of invasive procedures in the American cohort, one-year QOL outcomes in the cohort were similar to those in the more conservatively managed Canadian cohort. These results suggest that routine cardiac catheterization and increased procedure use may be associated with diminishing marginal returns with respect to improving QOL outcomes among patients with non-ST elevation acute coronary syndromes.

Aged↗
PubMed2003

Effect of smoking and sedentary behavior on the association between depressive symptoms and mortality from coronary heart disease.

It has been suggested that one of the mechanisms linking depression with elevated mortality risk is the association between depressive symptoms and other established coronary artery disease (CAD) risk factors, such as smoking and failure to exercise. The present study examined this hypothesis using repeated assessments of smoking and exercise from patients with CAD in whom depressive symptoms had been shown to predict decreased survival. Initially, associations between depressive symptoms and the risk factors of smoking and sedentary behavior were assessed. Next, patterns of smoking and sedentary behavior were examined as mediators and/or moderators of the association between depressive symptoms and mortality. Depressive symptoms were positively related to smoking (p <0.01) and sedentary behavior (p <0.01). Depressive symptoms, smoking, and sedentary behavior were independent predictors of mortality. Results indicated that smoking and/or sedentary behavior may partially mediate the relation between depressive symptoms and mortality. No evidence for moderation was found.

Age Distribution↗
PubMed2003

Depression as a risk factor for mortality after coronary artery bypass surgery.

BACKGROUND: Studies that have shown clinical depression to be a risk factor for cardiac events after coronary artery bypass graft (CABG) surgery have had small sample sizes, short follow-up, and have not had adequate power to assess mortality. We sought to assess whether depression is associated with an increased risk of mortality. METHODS: We assessed 817 patients undergoing CABG at Duke University Medical Center between May, 1989, and May, 2001. Patients completed the Center for Epidemiological Studies-Depression (CES-D) scale before surgery, 6 months after CABG, and were followed-up for up to 12 years. FINDINGS: In 817 patients there were 122 deaths (15%) in a mean follow-up of 5.2 years. 310 patients (38%) met the criterion for depression (CES-D > or =16): 213 (26%) for mild depression (CES-D 16-26) and 97 (12%) for moderate to severe depression (CES-D > or =27). Survival analyses, controlling for age, sex, number of grafts, diabetes, smoking, left ventricular ejection fraction, and previous myocardial infarction, showed that patients with moderate to severe depression at baseline (adjusted hazard ratio [HR] 2.4, [95% CI 1.4-4.0]; p=0.001) and mild or moderate to severe depression that persisted from baseline to 6 months (adjusted HR 2.2, [1.2-4.2]; p=0.015) had higher rates of death than did those with no depression. INTERPRETATION: Despite advances in surgical and medical management of patients after CABG, depression is an important independent predictor of death after CABG and should be carefully monitored and treated if necessary.

Cause of Death↗
PubMed2003

Poverty, process of care, and outcome in acute coronary syndromes.

OBJECTIVES: We sought to determine whether income-based disparities in care processes and outcome exist in patients with acute coronary syndromes. BACKGROUND: Using income proxies and limited clinical data, some observational studies have shown income disparities in outcome after acute myocardial infarction (MI). METHODS: Using annual household income from the economic substudy of the PURSUIT (Platelet Glycoprotein IIB/IIIA In Unstable Angina: Receptor Suppression Using Integrilin Therapy) trial, patients were grouped into low-, middle-, and high-income categories based on the U.S. Census Bureau definition of poverty. Logistic regression analysis was used to examine the association between income category and the use of cardiac procedures and the prescription of evidence-based medications at hospital discharge. Cox regression analysis was used to examine the hazard of 30-day and six-month death or recurrent MI across income categories, after adjusting for baseline characteristics. RESULTS: Low-income patients had more chronic medical conditions and were sicker at presentation. Among low-income patients, the use of some evidence-based medications and cardiac procedures was lower and the unadjusted rates of 30-day death and six-month death or MI was higher. After multivariable adjustment, there was no consistent pattern for disparity in care processes, but the trend for higher short and intermediate-term death or MI persisted for low-income patients. CONCLUSIONS: Income level is associated with a trend toward worse outcome among patients with acute coronary syndromes. The disparity in 30-day and six-month death or MI between low and high-income patients could not be readily explained by differences in in-hospital medical or invasive treatment, suggesting that the poor outcomes may be due to differences occurring after hospital discharge.

Acute Disease↗
PubMed2003

Development and validation of a simple model to predict severe coronary artery disease after myocardial infarction: potential impact on cardiac catheterization use in the United States and Canada.

BACKGROUND: Improved patient selection may optimize the efficiency of cardiac catheterization in both high- and low-rate regions. The purpose of this study was to develop and validate a clinical model for predicting high-risk coronary artery disease (CAD) after myocardial infarction (MI) and to examine the model's potential impact on the use rate of both US and Canadian catheterization practices. METHODS AND RESULTS: By the use of baseline clinical variables from 1122 patients in the angiographic substudy of the Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-1) trial, we developed a model that was predictive of severe CAD (left main or triple-vessel disease). The final model, which included prior MI, age, sex, hyperlipidemia, and decreased left ventricular ejection fraction (C-index = 0.70), was externally validated in 781 patients in the GUSTO IIb trial. Although the probability of severe CAD predicted 5-year survival, the frequency of catheterization in both Canada and the United States bore no relationship to severe CAD risk in the GUSTO-1 trial. By use of the model, we estimated that as much as 15% of US catheterizations from both GUSTO-1 and GUSTO IIb might have been avoided, without significantly compromising the number of patients with severe CAD who were identified (sensitivity = 0.94). By applying the model to Canadian practices, an additional 30 cases of severe CAD might have been identified per every 1000 catheterizations performed, without increasing the catheterization rate. CONCLUSIONS: The likelihood of severe CAD after ST-elevation MI may be predicted from simple baseline clinical variables. The use of a severe CAD predictive model to guide patient selection might enhance the cost-effectiveness of both aggressive and conservative catheterization practices.

Analysis of Variance↗
PubMed2003

Chronic kidney disease, mortality, and treatment strategies among patients with clinically significant coronary artery disease.

Cardiovascular disease is an important cause of mortality among patients with chronic kidney disease (CKD). This study describes associations between CKD, cardiac revascularization strategies, and mortality among patients with CKD and cardiovascular disease. All patients undergoing cardiac catheterization at Duke University Medical Center (1995 to 2000) with documented stenosis > or =75% of at least one coronary artery and available creatinine data were included. CKD was staged using creatinine clearance (CrCl) derived from the Cockcroft-Gault formula (normal, > or = 90 ml/min; mild, 60 to 89 ml/min; moderate, 30 to 59 ml/min; severe, 15 to 29 ml/min). Cox proportional-hazard regression estimated the relationship between clinical variables, including CrCl and percutaneous coronary artery intervention (PCI), coronary artery bypass grafting (CABG), medical management, and patient survival. There were 4584 patients included, and 24% had CrCl <60 ml/min. Each 10-ml/min decrement in CrCl was associated with an increase in mortality (hazard ratio, 1.14; P < 0.0001). CABG was associated with a survival benefit among patients with both normal renal function and patients with CKD compared with medical management. In patients with normal renal function, CABG was not associated with survival benefit over PCI. However, in patients with CKD, CABG was associated with improved survival. PCI was associated with a survival benefit compared with medical management among patients with normal, mildly, and moderately impaired renal function. Among patients with severe CKD, PCI was not associated with improved survival. CABG is associated with greater mortality reduction than PCI in severe CKD.

Aged↗
PubMed2002

A national survey of provisions in clinical-trial agreements between medical schools and industry sponsors.

BACKGROUND: Concerned about threats to the integrity of clinical trials in a research environment increasingly controlled by private interests, the International Committee of Medical Journal Editors (ICMJE) has issued revised guidelines for investigators' participation in the study design, access to data, and control over publication. It is unclear whether research conducted at academic institutions adheres to these new standards. METHODS: From November 2001 through January 2002, we interviewed officials at U.S. medical schools about provisions in their institutions' agreements with industry sponsors of multicenter clinical trials. A subgroup of the respondents were also asked about coordinating-center agreements for such trials. RESULTS: Of the 122 medical schools that are members of the Association of American Medical Colleges, 108 participated in the survey. The median number of site-level agreements executed per institution in the previous year was 103 (interquartile range, 50 to 210). Scores for compliance with a wide range of provisions--from ensuring that authors of reports on multicenter trials have access to all trial data (1 percent [interquartile range, 0 to 21]) to addressing the plan for data collection and monitoring (10 percent [interquartile range, 1 to 50])--demonstrated limited adherence to the standards embodied in the new ICMJE guidelines. Scores for coordinating-center agreements were somewhat higher for most survey items. CONCLUSIONS: Academic institutions routinely engage in industry-sponsored research that fails to adhere to ICMJE guidelines regarding trial design, access to data, and publication rights. Our findings suggest that a reevaluation of the process of contracting for clinical research is urgently needed.

Clinical Trials as Topic↗