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Biomedical subjects

D B Mark

Publications and source records attributed to D B Mark.

At least 19 recordsLinked to original sources
PubMed2005

Relation between baseline risk and treatment decisions in non-ST elevation acute coronary syndromes: an examination of international practice patterns.

OBJECTIVES: To examine the interaction between ST segment depression on the baseline ECG and subsequent in-hospital revascularisation on six month mortality among patients with non-ST elevation acute coronary syndromes. To examine whether ST segment depression influenced clinical decision making and whether there was international variation in the use of cardiac procedures across ST segment depression categories. METHODS: 11 453 patients enrolled in GUSTO-IIB (global use of strategies to open occluded coronary arteries), PARAGON (platelet IIb/IIIa antagonism for the reduction of acute coronary syndrome events in a global organisation network) -A, and PARAGON-B were studied. Patients were categorised as having no ST segment depression, 1 mm ST segment depression in two contiguous leads, and ST segment depression > or = 2 mm in two contiguous leads. International practice across four geographic regions was examined: USA, Canada, Europe, and Australia/New Zealand. RESULTS: Revascularisation appeared to have no impact on survival among patients with no ST segment depression; however, revascularisation was associated with a significant survival benefit among patients with ST segment depression > or = 1 mm. There was an inverse relation between the extent of ST segment depression and the use of angiography as well as angioplasty (p < 0.01). However, patients with ST segment depression > or = 2 mm were more likely to undergo bypass surgery. The only significant trend of increasing use of revascularisation procedures with increasing ST segment depression was observed in the USA. CONCLUSIONS: International practice patterns in procedure use appear to be insensitive to the extent of ST segment depression. Major opportunities for more efficient delivery of care exist in all regions.

Acute Disease↗
PubMed2003

Time-based risk assessment after myocardial infarction. Implications for timing of discharge and applications to medical decision-making.

AIMS: We evaluated timing of adverse cardiac events after thrombolysis to guide length of stay after ST-segment elevation myocardial infarction. METHODS AND RESULTS: Kaplan-Meier survival curves described timing of major postinfarction complications in 41021 fibrinolytic-treated patients in GUSTO-I. Using model-fitting, these data were best explained by a mixed-exponential survival model: an acute curve describing most adverse events and a chronic curve describing a lower background rate. We replicated this strategy in 15059 fibrinolytic-treated patients in GUSTO-III. From the relation between time and events described by the model's acute curve in GUSTO-III, we proposed times for hospital discharge. The acute curve explained 97% of deaths and 68%-96% of various event composites. Of complications within 10 days, 90% of deaths and 70% of acute curve death, stroke, shock, heart failure, or reinfarction occurred by 24 h. By 2.7 days, 95% of deaths, stroke, shock, heart failure, or reinfarction occurred. Most major ventricular arrhythmias occurred within 24 h, after which the hazard curve was flat. CONCLUSIONS: Mixed-exponential survival modelling describes timing of post-infarction complications and supports discharge 4 days after uncomplicated infarction. Such time-based risk assessment could guide decision-making in other settings in which randomized studies are impractical.

Decision Making↗
PubMed2001

Report of the substudy assessing the impact of neurocognitive function on quality of life 5 years after cardiac surgery.

BACKGROUND AND PURPOSE: The importance of perioperative cognitive decline has long been debated. We recently demonstrated a significant correlation between perioperative cognitive decline and long-term cognitive dysfunction. Despite this association, some still question the importance of these changes in cognitive function to the quality of life of patients and their families. The purpose of our investigation was to determine the association between cognitive dysfunction and long-term quality of life after cardiac surgery. METHODS: After institutional review board approval and patient informed consent, 261 patients undergoing cardiac surgery with cardiopulmonary bypass were enrolled and followed for 5 years. Cognitive function was measured with a battery of tests at baseline, discharge, and 6 weeks and 5 years postoperatively. Quality of life was assessed with well-validated, standardized assessments at the 5-year end point. RESULTS: Our results demonstrate significant correlations between cognitive function and quality of life in patients after cardiac surgery. Lower 5-year overall cognitive function scores were associated with lower general health and a less productive working status. Multivariable logistic and linear regression controlling for age, sex, education, and diabetes confirmed this strong association in the majority of areas of quality of life. CONCLUSIONS: Five years after cardiac surgery, there is a strong relationship between neurocognitive functioning and quality of life. This has important social and financial implications for preoperative evaluation and postoperative care of patients undergoing cardiac surgery.

Age Distribution↗
PubMed2001

Using observational data to estimate prognosis: an example using a coronary artery disease registry.

With the proliferation of clinical data registries and the rising expense of clinical trials, observational data sources are increasingly providing evidence for clinical decision making. These data are viewed as complementary to randomized clinical trials (RCT). While not as rigorous a methodological design, observational studies yield important information about effectiveness of treatment, as compared with the efficacy results of RCTs. In addition, these studies often have the advantage of providing longer-term follow-up, beyond that of clinical trials. Hence, they are useful for assessing and comparing patients' long-term prognosis under different treatment strategies. For patients with coronary artery disease, many observational comparisons have focused on medical therapy versus interventional procedures. In addition to the well-studied problem of treatment selection bias (which is not the focus of the present study), three significant methodological problems must be addressed in the analysis of these data: (i) designation of the therapeutic arms in the presence of early deaths, withdrawals, and treatment cross-overs; (ii) identification of an equitable starting point for attributing survival time; (iii) site to site variability in short-term mortality. This paper discusses these issues and suggests strategies to deal with them. A proposed methodology is developed, applied and evaluated on a large observational database that has long-term follow-up on nearly 10 000 patients.

Analysis of Variance↗
PubMed2001

Longitudinal assessment of neurocognitive function after coronary-artery bypass surgery.

BACKGROUND: Cognitive decline complicates early recovery after coronary-artery bypass grafting (CABG) and may be evident in as many as three quarters of patients at the time of discharge from the hospital and a third of patients after six months. We sought to determine the course of cognitive change during the five years after CABG and the effect of perioperative decline on long-term cognitive function. METHODS: In 261 patients who underwent CABG, neurocognitive tests were performed preoperatively (at base line), before discharge, and six weeks, six months, and five years after CABG surgery. Decline in postoperative function was defined as a drop of 1 SD or more in the scores on tests of any one of four domains of cognitive function. (A reduction of 1 SD represents a decline in function of approximately 20 percent.) Overall neurocognitive status was assessed with a composite cognitive index score representing the sum of the scores for the individual domains. Factors predicting long-term cognitive decline were determined by multivariable logistic and linear regression. RESULTS: Among the patients studied, the incidence of cognitive decline was 53 percent at discharge, 36 percent at six weeks, 24 percent at six months, and 42 percent at five years. We investigated predictors of cognitive decline at five years and found that cognitive function at discharge was a significant predictor of long-term function (P<0.001). CONCLUSIONS: These results confirm the relatively high prevalence and persistence of cognitive decline after CABG and suggest a pattern of early improvement followed by a later decline that is predicted by the presence of early postoperative cognitive decline. Interventions to prevent or reduce short- and long-term cognitive decline after cardiac surgery are warranted.

Cardiopulmonary Bypass↗
PubMed2001

Outcomes of noncardiac surgery after coronary bypass surgery or coronary angioplasty in the Bypass Angioplasty Revascularization Investigation (BARI).

PURPOSE: Previous studies have shown that coronary artery bypass surgery reduces the risk of cardiac complications after noncardiac surgery. Whether coronary angioplasty provides equivalent protection is not known. SUBJECTS AND METHODS: Patients were randomly assigned to undergo cardiac artery bypass surgery or angioplasty as part of the Bypass Angioplasty Revascularization Investigation trial. All subsequent noncardiac surgeries during a mean (+/- SD) follow-up of 7.7 years were recorded among participants in the ancillary Study of Economics and Quality of Life. Rates of mortality and nonfatal myocardial infarction, length of stay, and hospital costs were compared by the original randomized assignment. RESULTS: A total of 501 patients had noncardiac surgery at a median of 29 months after their most recent coronary revascularization procedure. Mortality and nonfatal myocardial infarction within 30 days of the first noncardiac surgery occurred in 4 of the 250 of the surgery-assigned patients and in 4 of the 251 of the angioplasty-assigned patients (P = 1.0). There were no significant differences in the mean length of hospital stay (6.3 +/- 6.7 versus 6.2 +/- 6.8 days; P = 0.47) or hospital cost ($8,920 +/- $11,511 versus $7,785 +/- $7,643; P = 0.33) between the surgery and angioplasty groups. Similar results were obtained when subsequent noncardiac procedures were included in the analysis. CONCLUSION: Rates of myocardial infarction and death after noncardiac surgery are similarly low after contemporary bypass surgery or angioplasty in patients with multivessel coronary artery disease.

Aged↗
PubMed2001

Temperature during coronary artery bypass surgery affects quality of life.

BACKGROUND: The objective of this study was to examine the effects of temperature on a variety of indices of psychologic adjustment and quality of life. METHODS: A total of 209 patients randomly received normothermic (warm) or hypothermic (cold) conditions during coronary artery bypass surgery (CABS), and a number of physical, social, and psychologic measures were assessed before as well as 6 weeks and 6 months after CABS. RESULTS: Repeated measures analyses of covariance revealed significant temperature group main effects for anxiety (p = 0.008) and depression (p = 0.039), with the normothermic group obtaining lower anxiety and depression levels than the hypothermic group at both 6 weeks and 6 months after surgery. Additionally, among patients who entered the study with higher depression levels, those in the hypothermic group tended to have higher depression scores at follow-up compared with patients in the normothermic condition (p = 0.012). No temperature group differences were observed on other quality of life indices. CONCLUSIONS: The results of the present study indicate that hypothermic conditions during CABS are associated with higher levels of emotional distress after CABS than normothermic conditions, particularly for patients with greater stress to begin with.

Aged↗
PubMed2001

Risk stratification in patients with chest pain.

This article reviews the role of exercise testing in the assessment of patients with suspected coronary disease. To accomplish this, four major topics are considered: the general concept of risk stratification; the estimation of outcomes using data from the initial evaluation of the patient; diagnostic assessment with the exercise test; and prognostic assessment with the exercise test. This review focuses on the standard treadmill exercise test.

Chest Pain↗
PubMed2001

Personality and coping with a common stressor: cardiac catheterization.

The association between coping and personality was examined in a sample of 204 cardiac catheterization patients who were asked to evaluate the use of specific coping strategies used to deal with their cardiac catheterization. Personality, as measured by the NEO Five-Factor Inventory (FFI), was moderately correlated with coping measures. In multivariate analyses, after considering confounding factors, Neuroticism was positively and Extraversion was negatively related to avoidance coping and Neuroticism was negatively associated with counting one's blessings as a coping strategy. Personality was not related to either problem solving or seeking social support coping strategies for individuals experiencing a cardiac catheterization. However, important covariates were associated with coping strategies. Not being married was negatively correlated with use of seeking social support and not having a confidant was negatively related with seeking social support and positively with avoidance. These results suggest that there are specific relationships between personality and coping, but these relationships are, for the most part, moderate in persons coping with a cardiac catheterization, and that coping processes are associated with individual differences in available social resources.

Adaptation, Psychological↗
PubMed2001

Severity of renal vascular disease predicts mortality in patients undergoing coronary angiography.

BACKGROUND: Renal artery stenosis (RAS) is a relatively uncommon but potentially reversible cause of renal failure. In a previous report, we demonstrated that the presence of RAS is independently associated with mortality in a group of patients undergoing coronary angiography. Our current study expands on this cohort, investigating the effect of the severity of RAS on all-cause mortality. METHODS: A total of 3987 patients underwent abdominal aortography immediately following coronary angiography. For the purpose of survival analysis, significant RAS was defined as > or =75% narrowing in the luminal diameter. RESULTS: Significant RAS was present in 4.8% of patients studied and was bilateral in 0.8%. Factors associated with the presence of RAS included female gender, older age, hypertension, congestive heart failure, elevated serum creatinine, and congestive heart failure. The four-year unadjusted survivals for patients with and without significant RAS were 57 and 89%, respectively (P < 0.001). Using the Cox proportional hazards model, the factors independently associated with decreased survival were the presence of RAS, increased age, the severity of coronary artery disease, the presence of comorbid disease, reduced ejection fraction, symptoms of congestive cardiac failure, and the mode of treatment of coronary artery disease. In the multivariate model, the presence of RAS conferred a hazard ratio of 2.01 (95% CI, 1.51 to 2.67, P < 0.001). We demonstrated an incremental effect on mortality according to the severity of RAS at baseline. Four-year adjusted survival for patients with 50%, 75%, and > or =95% stenosis was 70%, 68%, and 48%, respectively. In addition, bilateral disease was associated with four-year survival of 47% as compared with 59% for patients with unilateral disease (P < 0.001). The impact of RAS on survival remained robust regardless of the manner of treatment of coronary artery disease [that is, medical, percutaneous transluminal coronary angioplasty (PTCA), or coronary artery bypass graft (CABG)]. CONCLUSIONS: In this patient population, the presence of RAS is a strong independent predictor of mortality. Increasing severity of RAS has an incremental effect on survival probability.

Aged↗
PubMed2001

Advanced coronary artery disease: Appropriate end points for trials of novel therapies.

BACKGROUND: The segment of patients with advanced coronary artery disease, or disease that is not amenable to conventional revascularization therapies, continues to grow. Because the natural history of these patients is less defined, the appropriate end points for trials of novel revascularization therapies involving patients with advanced coronary artery disease are not certain. METHODS AND RESULTS: The Mediators of Social Support Study (MOSS) prospectively followed up outcomes of long-term survival, quality of life, resource use, and costs for 1189 patients and compared outcomes of patients with advanced coronary artery disease with those of a reference group who underwent bypass surgery or angioplasty. CONCLUSIONS: Despite greater disease burden, cost, and mortality for patients with advanced coronary artery disease, a number of self-reported measures of general health status improved in a similar fashion to that of patients eligible for angioplasty or bypass surgery. These findings should inform the design of trials involving novel therapies, suggesting that angina status and mortality be included as primary end points in the consideration of efficacy. This work also suggests that additional studies of novel therapies involving larger sample sizes may be required to confidently characterize efficacy.

Cardiac Catheterization↗
PubMed2001

Prospective randomized trial of normothermic versus hypothermic cardiopulmonary bypass on cognitive function after coronary artery bypass graft surgery.

BACKGROUND: Despite significant advances in cardiopulmonary bypass (CPB) technology, surgical techniques, and anesthetic management, central nervous system complications occur in a large percentage of patients undergoing surgery requiring CPB. Many centers are switching to normothermic CPB because of shorter CPB and operating room times and improved myocardial protection. The authors hypothesized that, compared with normothermia, hypothermic CPB would result in superior neurologic and neurocognitive function after coronary artery bypass graft surgery. METHODS: Three hundred patients undergoing elective coronary artery bypass graft surgery were prospectively enrolled and randomly assigned to either normothermic (35.5-36.5 degrees C) or hypothermic (28-30 degrees C) CPB. A battery of neurocognitive tests was performed preoperatively and at 6 weeks after surgery. Four distinct cognitive domains were identified and standardized using factor analysis and were then compared on a continuous scale. RESULTS: Two hundred twenty-seven patients participated in 6-week follow-up testing. There were no differences in neurologic or neurocognitive outcomes between normothermic and hypothermic groups in multivariable models, adjusting for covariable effects of baseline cognitive function, age, and years of education, as well as interaction of these with temperature treatment. CONCLUSIONS: Hypothermic CPB does not provide additional central nervous system protection in adult cardiac surgical patients who were maintained at either 30 or 35 degrees C during CPB.

Anesthetics, Intravenous↗
PubMed2001

Assessing the clinical and economic burden of coronary artery disease: 1986-1998.

BACKGROUND: The acute phase of coronary artery disease (CAD) is dramatic and receives much attention because of its high mortality and associated treatment cost. However, the acute phase typically resolves within 30 days whereas CAD is a chronic disease, which most patients will live with for more than a decade. We compared the clinical and economic burden of CAD during the acute phase (first 30 days) with that in the postacute phase (31st day through 10 years). METHODS: We included acute coronary syndrome (ACS) patients with significant CAD receiving an initial cardiac catheterization at Duke University Medical Center between 1986 and 1997 with follow-up continuing through 1998. Inpatient medical costs were estimated from ACS clinical trial and economic study data. Costs were adjusted to 1997 values and discounted at 3% per annum. RESULTS: Our study included 9,876 ACS patients (5,557 with an acute myocardial infarction [MI] and 4,319 with unstable angina [UA]). Acute MI patients had higher 30-day mortality than UA patients (5.6% vs. 2.3%, P <0.001). In addition, acute MI and UA patients had significant 10-year unadjusted and adjusted survival differences (both P <0.001). For patients who survived to 30 days, there was no difference in 10-year survival between acute MI and UA patients before adjustment (P = 0.472). After adjustment, however, unstable angina patients who survived to 30 days had greater survival than myocardial infarction patients (P = 0.011). Mean 10-year discounted ACS inpatient medical costs were $45,253 ($23,510 acute phase and $21,819 postacute phase, P = 0.002). Ten year costs for unstable angina patients were $46,423 ($21,824 acute phase and $24,599 postacute phase, P = 0.003); ten year costs for myocardial infarction patients were $44,663 ($24,823 acute phase and $19,840 postacute phase, P <0.001). CONCLUSIONS: We found that the clinical and economic burden of CAD continues long after a patient's acute event has resolved and that postacute CAD cardiac event rates and inpatient medical costs may be higher than previously estimated. With much of all medical costs occurring in the postacute phase, the potential for effective secondary prevention therapies is substantial.

Aged↗
PubMed2000

Economic assessment of platelet glycoprotein IIb/IIIa receptor blockade with abciximab and low-dose heparin during percutaneous coronary revascularization: results from the EPILOG randomized trial. Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade.

BACKGROUND: In the EPILOG trial (Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade), abciximab administered with weight-adjusted heparin diminished the risk of ischemic complications within 30 days by 56% among patients undergoing percutaneous coronary revascularization, without increased bleeding complications. METHODS AND RESULTS: A prospective economic assessment was performed in the 2792 patients enrolled in EPILOG. Patients were randomized to receive placebo with standard-dose weight-adjusted heparin, abciximab with low-dose weight-adjusted heparin, or abciximab with standard-dose weight-adjusted heparin during percutaneous coronary intervention. Hospital billing data for the baseline hospitalization were collected for 2581 patients (92.4% of total) and imputed for the remainder, with physician fees estimated from the Medicare Fee Schedule. For the baseline hospitalization, medical costs (hospitalization and physician fees) averaged $9632 for the placebo arm compared with $8758 (P:=0.005) and $9092 (P:=0.176) for the abciximab with low-dose and standard-dose heparin arms, respectively. Inclusive of average drug cost ($1454 to $1457), the net incremental baseline cost of these 2 abciximab strategies was $583 with low-dose weight-adjusted heparin and $914 with standard-dose weight-adjusted heparin. During 6-month follow-up, average hospital costs were not significantly different in the 3 treatment groups; cumulative net incremental costs were $1236 and $1268 in the abciximab with low-dose and standard-dose heparin groups, respectively. CONCLUSIONS: Treatment with abciximab and low-dose, weight-adjusted heparin during percutaneous coronary revascularization reduces ischemic events and associated costs, thereby offsetting some of the cost of the drug. The suppression of bleeding complications associated with this agent by heparin dose reduction optimizes the economic attractiveness of this treatment strategy.

Abciximab↗
PubMed2000

Moderators of the effect of social support on depressive symptoms in cardiac patients.

Social support and depression have been shown to affect the prognosis of coronary patients, and social support has been found to influence depression in community and patient samples. We investigated the characteristics of coronary patients whose depressive symptomatology was most likely to improve with social support. We predicted that social support would be most beneficial for the most severely depressed, the old, the poor, the most severely ill, and those with poor functional status. Patients (n = 590) with documented coronary artery disease were assessed for depressive symptoms, social support, and functional status while in hospital. They were reassessed for depression 1 month later during a home visit. Depression scores were lower at follow-up (p = 0.001), and improvement was more marked among those reporting more support (p <0.001). The social support effect was strongest among those with high levels of depression at baseline (p <0.001) and those with lower income (p = 0.01). Unexpectedly, social support was more strongly associated with improvement in younger patients (p = 0.01). Social support did not interact with gender, disease severity, or functional status. These findings are partially consistent with the notion that social support is most effective for those who are most vulnerable and/or have few coping resources. These findings also have implications for the design and interpretation of psychosocial interventions.

Aged↗
PubMed2000

Use of resources, quality of life, and clinical outcomes in patients with and without new Q waves after thrombolytic therapy for acute myocardial infarction (from the GUSTO-I trial).

Previous reports indicate that patients who do not develop Q waves after thrombolytic therapy are a different population with a better long-term survival than those who do develop Q waves. However, the use of resources, quality of life, and health status of this population have not been fully evaluated. Using data from the Economics and Quality of Life subset of the Global Utilization of Streptokinase and tPA for Occluded Arteries study, we examined 30-day and 1-year mortality, use of resources, and quality-of-life measures among 1,830 of 3,000 patients with acute myocardial infarction and ST-segment elevation treated with thrombolytic therapy. At hospital discharge, 555 patients (30.2%) had not developed Q waves. These patients had lower mortality than patients with Q waves at 30 days (1.6% vs 4.5%, p <0.01) and at 1 year (4.7% vs 6.8%, p <0.04). Recurrent chest pain and dyspnea were similar at 30 days and 1 year. Patients without Q waves had significantly more angiography and trends toward higher readmission, revascularization, and use of calcium antagonists at 30 days. Angiography, revascularization, readmission, and quality of life were equivalent from 30 days to 1 year, with no sign of late instability. Logistic regression analysis showed an association between in-hospital revascularization and better survival and quality of life at 1 year. Conversely, there was no association between in-hospital use of calcium antagonists and outcome to explain the lower mortality in non-Q-wave patients. The absence of Q waves after thrombolytic therapy is a marker of success, implying better prognosis and equivalent quality of life, use of resources, and health status than for patients with Q-wave acute myocardial infarction and no sign of long-term unstable clinical course.

Aged↗
PubMed2000

Cost effectiveness of early discharge after uncomplicated acute myocardial infarction.

BACKGROUND: Reducing the length of hospitalizations can reduce short-term costs, but there are few data on the long-term clinical and economic consequences of early discharge. METHODS: Using data from the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-1) trial, we identified 22,361 patients with acute myocardial infarction who had an uncomplicated course for 72 hours after thrombolysis. Then, using a decision-analytic model, we examined the cost effectiveness of an additional day of hospitalization in this group. We defined incremental survival attributable to another day of monitored hospitalization, using Kaplan-Meier estimates to determine the rate of resuscitation after cardiac arrest between 72 and 96 hours. Lifetime survival curves for each group in the decision-analytic model were estimated from empirical one-year survival data from GUSTO-1. The costs of key hospital resources (e.g., room and monitoring) were derived from data in the GUSTO-1 cost-effectiveness analysis. RESULTS: Of the patients with an uncomplicated course within 72 hours after thrombolysis, 16 had ventricular arrhythmias during the next 24 hours; 13 of these patients (81 percent) survived for at least 24 hours. On average, another 0.006 year of life per patient could be saved by keeping patients with an uncomplicated course in the hospital another day. At a cost of $624 for hospital and physicians' services, extending the hospital stay by another day would cost $105,629 per year of life saved. In sensitivity analyses, it was found that a fourth day of hospitalization would be economically attractive only if its cost could be reduced by more than 50 percent or if a high-risk subgroup could be identified in which the estimated survival benefit would be doubled. CONCLUSIONS: Hospitalization of patients with uncomplicated myocardial infarction beyond three days after thrombolysis is economically unattractive by conventional standards.

Aged↗