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M A Hlatky

Publications and source records attributed to M A Hlatky.

At least 19 recordsLinked to original sources
PubMed1995

A meta-analysis of randomized trials comparing coronary artery bypass grafting with percutaneous transluminal coronary angioplasty in multivessel coronary artery disease.

We performed a meta-analysis of randomized trials that compared percutaneous transluminal coronary angioplasty (PTCA) with coronary artery bypass graft (CABG) surgery in patients with multivessel coronary artery disease. The outcomes of death, combined death, and nonfatal myocardial infarction (MI), repeat revascularization, and freedom from angina were analyzed. The overall risk of death and nonfatal MI was not different over a follow-up of 1 to 3 years (CABG:PTCA odds ratio [OR] 1.03, 95% confidence interval 0.81 to 1.32, p = 0.81). Patients randomized to CABG tended to have a higher risk of death or MI in the early, periprocedural period (OR 1.33, p = 0.091), but a lower risk in subsequent follow-up (OR 0.74, p = 0.093). CABG patients were much less likely to undergo another revascularization procedure (p < 0.00001), and were more likely to be angina free (OR 1.57, p < 0.00001). Thus, CABG and PTCA patients have similar overall risks of death and nonfatal MI at 1 to 3 years of follow-up, but relative risk differences in mortality of up to 25% cannot be excluded. CABG patients have significantly less angina and less repeat revascularization than PTCA patients.

Angioplasty, Balloon, Coronary↗
PubMed1995

Job strain and the prevalence and outcome of coronary artery disease.

BACKGROUND: It has been hypothesized that jobs that have both high psychological demands and low decision latitude ("job strain") can lead to coronary disease. The objective of this study was to test whether job strain was correlated with the presence of coronary disease at angiography or with long-term outcome in patients with angiographic coronary disease. METHODS AND RESULTS: Employed patients under the age of 65 years undergoing diagnostic coronary angiography completed a self-administered questionnaire about their job duties and work environment. Job strain was measured by the method of Karasek. Patients were separated into three groups, based on extent of coronary disease: significant disease (> or = 75% stenosis), insignificant disease (> 0% but < 75% stenosis), and normal coronary arteries. Statistical analyses were performed using logistic regression and the Cox proportional hazards model. The 1489 patients enrolled had a median age of 52 years; 76% were male and 88% were white. By design, all patients were employed, 60% in white-collar jobs and only 16% in jobs requiring heavy labor. Traditional cardiac risk factors were most prevalent in the 922 patients with significant coronary artery disease, at intermediate levels in the 204 patients with insignificant disease, and least prevalent in the 363 patients with normal coronary arteries (all P < .01). Job strain was actually more common in patients with normal coronary arteries (35%) than in patients with insignificant (26%) or significant disease (25%, P < .002). In a multivariate analysis, job strain was not significantly correlated with the presence of coronary disease. Job strain was not correlated with angina frequency at the time of angiography. Job strain was not a predictor of cardiac events (cardiac death or nonfatal myocardial infarction) during follow-up. CONCLUSIONS: Job strain was not correlated with the prevalence or severity of coronary artery disease in a cohort of patients undergoing coronary angiography. The outcome of patients with angiographically defined coronary disease was not affected by the level of job strain as measured by the method of Karasek.

Adult↗
PubMed1995

The role of coronary angiography and coronary revascularization before noncardiac vascular surgery.

OBJECTIVE: To determine whether preoperative coronary angiography and revascularization improve short-term outcomes in patients undergoing noncardiac vascular surgery. DESIGN: Decision analysis. PATIENTS: Patients undergoing elective vascular surgery who had either no angina or mild angina and a positive dipyridamole-thallium scan result. INTERVENTIONS: Three strategies were compared. The first strategy was to proceed directly to vascular surgery. The second was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to cancel vascular surgery in patients with severe inoperable coronary artery disease (CAD). The third was to perform coronary angiography, followed by selective coronary revascularization, before proceeding to vascular surgery and to perform vascular surgery in patients with inoperable CAD. MAIN OUTCOME MEASURES: Mortality, nonfatal myocardial infarction, stroke, uncorrected vascular disease, and cost. All outcomes were assessed within 3 months. RESULTS: Proceeding directly to vascular surgery led to lower morbidity and cost in the base case analysis. The coronary angiography strategy led to higher mortality if vascular surgery would proceed in patients with inoperable CAD, but led to slightly lower mortality if vascular surgery were canceled in patients with inoperable CAD. The coronary angiography strategy also led to lower mortality when vascular surgery was particularly risky. CONCLUSIONS: Decision analysis indicates vascular surgery without preoperative coronary angiography generally leads to better outcomes. Preoperative coronary angiography should be reserved for patients whose estimated mortality from vascular surgery is substantially higher than average.

Coronary Angiography↗
PubMed1995

Cost effectiveness of thrombolytic therapy with tissue plasminogen activator as compared with streptokinase for acute myocardial infarction.

BACKGROUND: Patients with acute myocardial infarction who were treated with accelerated tissue plasminogen activator (t-PA) (given over a period of 1 1/2 hours rather than the conventional 3 hours, and with two thirds of the dose given in the first 30 minutes) had a 30-day mortality that was 15 percent lower than that of patients treated with streptokinase in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) study. This was equivalent to an absolute decrease of 1 percent in 30-day mortality. We sought to assess whether the use of t-PA, as compared with streptokinase, is cost effective. METHODS: Our primary, or base-case, analysis of cost effectiveness used data from the GUSTO study and life expectancy projected on the basis of the records of survivors of myocardial infarction in the Duke Cardiovascular Disease Database. In the primary analysis, we assumed that there were no additional treatment costs due to the use of t-PA after the first year and that the comparative survival benefit of t-PA was still evident one year after enrollment. RESULTS: One year after enrollment, patients who received t-PA had both higher costs ($2,845) and a higher survival rate (an increase of 1.1 percent, or 11 per 1000 patients treated) than streptokinase-treated patients. On the basis of the projected life expectancy of each treatment group, the incremental cost-effectiveness ratio--with both future costs and benefits discounted at 5 percent per year--was $32,678 per year of life saved. The use of t-PA was least cost effective in younger patients and most cost effective in older patients. At all ages, the use of t-PA in patients with anterior infarctions yielded more favorable cost-effectiveness values. In our secondary analyses, the cost-effectiveness values were most sensitive to a lowering of the projected long-term survival benefits of t-PA and to moderate or greater increases in the projected medical costs for patients in the t-PA group after the first year. In contrast, our results were not sensitive to even very unfavorable assumptions about the additional costs associated with the higher rate of disabling stroke that was noted in patients treated with t-PA in the GUSTO study. CONCLUSIONS: The cost effectiveness of treatment with accelerated t-PA rather than streptokinase compares favorably with that of other therapies whose added medical benefit for dollars spent is judged by society to be worthwhile.

Adult↗
PubMed1995

Initial functional and economic status of patients with multivessel coronary artery disease randomized in the Bypass Angioplasty Revascularization Investigation (BARI).

Randomized trials of coronary angioplasty and bypass surgery have hypothesized that these procedures will have equivalent long-term rates of death and myocardial infarction. Functional status, quality of life, employment, and healthcare cost will therefore be critical measures of the efficacy of these alternative revascularization procedures. Patients at 7 sites in the Bypass Angioplasty Revascularization Investigation (BARI) were enrolled in an ancillary Study of Economics and Quality of Life (SEQOL). Physical function was assessed by the Duke Activity Status Index and emotional status by the Mental Health Inventory. Employment patterns and health care utilization were also measured at study entry and at 3-month intervals in follow-up. The 934 patients enrolled in SEQOL were similar to the 895 remaining BARI randomized patients. Most patients (63%) aged < or = 64 years were working, and almost all working patients (96%) intended to return to work. Patients aged > or = 65 years had lower household incomes but better health insurance coverage. Overall health ratings were significantly correlated with both physical and emotional status (p < 0.001). Patients enrolled in SEQOL are representative of the overall BARI population. Data collected in SEQOL will provide a detailed picture of the physical, emotional, and economic well-being after coronary angioplasty and bypass surgery.

Angioplasty, Balloon, Coronary↗
PubMed1995

Cost of initial therapy in the Electrophysiological Study Versus ECG Monitoring trial (ESVEM).

BACKGROUND: Patients randomized to either serial electrophysiological testing (EPS) or serial Holter monitoring (HM) to guide antiarrhythmic therapy for life-threatening ventricular arrhythmias had equivalent rates of mortality and arrhythmia recurrence in the ESVEM study. This report analyzes the effects of EPS, HM, and clinical factors on the charges for initial evaluation and management of patients with life-threatening ventricular arrhythmias. METHODS AND RESULTS: Ten of 14 clinical centers participating in ESVEM provided bills from the initial hospitalization for randomized patients. Predictors of charges (1991 dollars) were analyzed by linear regression after logarithmic transformation. Initial hospital charge data were obtained for 286 patients randomized in ESVEM (88% of patients eligible for this substudy, 59% of all ESVEM patients). Patients with charge data were somewhat more likely to be older, to be female, and to have failed previous antiarrhythmic drug therapy at study entry and were less likely to have a drug predicted effective after randomization. Mean overall hospital charges were $35,986 (SD, $32,628) with a median of $24,532 (interquartile range, $16,126 to $43,593). Prerandomization patient characteristics generally had insignificant effects on charges, with the exception of presentation with resuscitated sudden death (28% increase in charges, P = .01) and heart failure (26% increase in charges, P = .02). Patients randomized to EPS had higher mean charges for evaluation ($42,002 versus $29,970, P = .0015) as well as more drug trials (3.0 versus 2.1, P = .0001) and a longer hospital stay (19.6 versus 13.9 days, P = .0007). In a multivariate regression model, failure to find an effective drug (P = .0001), the number of drug trials (P = .0001), and resuscitated sudden death as the presenting arrhythmia (P = .0001) were the only independent predictors of higher initial charges. CONCLUSIONS: (1) Initial hospital charges are significantly higher for EPS-guided than HM-guided therapy. (2) The higher charges for EPS-guided therapy were due to a greater number of drug trials and a lower probability of finding an effective drug. (3) Failure to find an effective drug, a larger number of drug trials, and a history of resuscitated sudden death independently predict higher charges.

Aged↗
PubMed1995

Differences in the treatment of myocardial infarction between the United States and Canada. A survey of physicians in the GUSTO trial.

Treatment of acute myocardial infarction differs between the United States and Canada, but the reasons for these practice pattern differences remain elusive. To investigate whether physician beliefs and access to procedures account for these differences in the treatment of acute myocardial infarction, a random sample of physicians involved in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries trial in the United States (n = 332) and Canada (n = 200) was surveyed. We found that American physicians recommend coronary angiography after uncomplicated infarction significantly more (median: 7 versus 3 of 11 possible indications, P = 0.0001). Coronary angiography, angioplasty, and bypass surgery were available in-hospital to more American than Canadian physicians (77% versus 41%), and the reported waiting period for cardiac procedures in a stable patient was longer in Canada (angiography: 28 versus 1.5 days; angioplasty: 30 versus 2 days; bypass surgery: 84 versus 3 days, all P < 0.001). More American than Canadian physicians were cardiologists (88% versus 74%), and more were interventional cardiologists (61% versus 26%). American physicians more highly rated the importance of patient requests, malpractice, and insurance coverage, whereas Canadians more highly rated availability of cardiac procedures as influencing clinical decisions. After statistical adjustment for these factors, however, Americans remained significantly more likely to recommend coronary angiography.

Adult↗
PubMed1994

Use of medical resources and quality of life after acute myocardial infarction in Canada and the United States.

BACKGROUND: Much attention has been directed to the use of medical resources and to patients' outcomes in Canada as compared with the United States. We compared U.S. and Canadian patients with respect to their use of medical resources and their quality of life during the year after acute myocardial infarction. METHODS: A total of 2600 U.S. and 400 Canadian patients were randomly selected from the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) trial. Base-line data from their initial hospitalizations were analyzed, and the patients were then interviewed by telephone 30 days, 6 months, and 1 year after myocardial infarction to determine their use of medical care and quality of life. RESULTS: The Canadian patients typically stayed in the hospital one day longer (P = 0.009) than the U.S. patients but had a much lower rate of cardiac catheterization (25 percent vs. 72 percent, P < 0.001), coronary angioplasty (11 percent vs. 29 percent, P < 0.001), and coronary bypass surgery (3 percent vs. 14 percent, P < 0.001). At one year 24 percent of the Canadian and 53 percent of the U.S. patients had undergone angioplasty or bypass surgery at least once (P < 0.001). The Canadian had more visits to physicians during the follow-up year (P < 0.001), but fewer visits to specialists (P < 0.001). At 30 days, functional status was equivalent in the patients from the two countries. However, after one year the U.S. patients had substantially more improvement than the Canadian patients (P < 0.001). The prevalence of chest pain and dyspnea at one year was higher among the Canadian patients (34 percent vs. 21 percent and 45 percent vs. 29 percent, respectively; P < 0.001). CONCLUSIONS: The Canadian patients had more cardiac symptoms and worse functional status one year after acute myocardial infarction than the U.S. patients. The Canadian patients also underwent fewer invasive cardiac procedures and had fewer visits to specialist physicians. These results suggest, but do not prove, that the more aggressive pattern of care in the United States may have been responsible for the better quality of life.

Aged↗
PubMed1992

Identification of patients with coronary disease at high risk for loss of employment. A prospective validation study.

BACKGROUND: Work disability is common in patients with coronary artery disease and adversely affects both economic well-being and quality of life. The purpose of this study was to construct a model to predict premature departure from the work force of patients with coronary disease and to validate this model prospectively in an independent cohort of patients. METHODS AND RESULTS: We enrolled 1,252 coronary disease patients referred for diagnostic cardiac catheterization who were less than age 65, employed, and without prior coronary angioplasty or coronary bypass surgery. Medical, functional, psychological, economic, and job-related variables were measured at the time of baseline diagnostic cardiac catheterization, and all patients were followed for 1 year. Three hundred twelve patients underwent percutaneous transluminal coronary angioplasty (PTCA) within 60 days of catheterization, and 449 had coronary artery bypass graft surgery (CABG) within 60 days of catheterization. The remaining 491 patients were treated with initial medical therapy. Logistic regression was used to develop a multivariable model for predicting 1-year work status in the training sample patients (872 patients enrolled between March 1986 and February 1989). This model was then validated in the independent prospective test sample (380 patients enrolled between March 1989 and June 1990). Eight factors were independent predictors of departure from the work force: lower initial functional status (as assessed by the Duke Activity Status Index), followed by older age, black race, presence of congestive heart failure, lower education level, presence of extracardiac vascular disease, poorer psychological status, and lower job classification. Standard clinical variables provided only 20% of the total predictive information available from the model about follow-up work outcomes, whereas functional measures provided 27%, and demographic and socioeconomic measures provided 45%. In the test sample, the area under the receiver operating characteristic curve for the model predictions was 0.74, compared with 0.80 in the training sample, and model predictions agreed well with observed prevalences of return to work. After adjustment for baseline imbalances, there was no significant difference in 1-year return-to-work rates among the patients receiving initial PTCA or CABG therapy versus initial medical therapy. CONCLUSIONS: Patients with coronary disease who are at high risk for premature departure from the work force can be accurately identified from a combination of medical and nonmedical risk factors. The model developed in this study provides a tool to identify patients at high risk for premature loss from the work force. Such patients may benefit from special multidimensional intervention programs designed to preserve work status. Our data show that revascularization with either PTCA or CABG is not, by itself, sufficient to accomplish this goal.

Angioplasty, Balloon, Coronary↗
PubMed1991

Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease.

BACKGROUND: The treadmill exercise test identifies patients with different degrees of risk of death from cardiovascular events. We devised a prognostic score, based on the results of treadmill exercise testing, that accurately predicts outcome among inpatients referred for cardiac catheterization. This study was designed to determine whether this score could also accurately predict prognosis in unselected outpatients. METHODS: We prospectively studied 613 consecutive outpatients with suspected coronary disease who were referred for exercise testing between 1983 and 1985. Follow-up was 98 percent complete at four years. The treadmill score was calculated as follows: duration of exercise in minutes--(5 x the maximal ST-segment deviation during or after exercise, in millimeters)--(4 x the treadmill angina index). The numerical treadmill angina index was 0 for no angina, 1 for nonlimiting angina, and 2 for exercise-limiting angina. Treadmill scores ranged from -25 (indicating the highest risk) to +15 (indicating the lowest risk). RESULTS: Predicted outcomes for the outpatients, based on their treadmill scores, agreed closely with the observed outcomes. The score accurately separated patients who subsequently died from those who lived for four years (area under the receiver-operating-characteristic curve = 0.849). The treadmill score was a better discriminator than the clinical data and was even more useful for outpatients than it had been for inpatients. Approximately two thirds of the outpatients had treadmill scores indicating low risk (greater than or equal to +5), reflecting longer exercise times and little or no ST-segment deviation, and their four-year survival rate was 99 percent (average annual mortality rate, 0.25 percent). Four percent of the outpatients had scores indicating high risk (less than -10), reflecting shorter exercise times and more severe ST-segment deviation; their four-year survival rate was 79 percent (average annual mortality rate, 5 percent). CONCLUSIONS: The treadmill score is a useful and valid tool that can help clinicians determine prognosis and decide whether to refer outpatients with suspected coronary disease for cardiac catheterization. In this study, it was a better predictor of outcome than the clinical assessment.

Adult↗
PubMed1991

Digoxin Immune Fab therapy in the management of digitalis intoxication: safety and efficacy results of an observational surveillance study.

An observational surveillance study was conducted to monitor the safety and effectiveness of treatment with Digoxin Immune Fab (Ovine) (Digibind) in patients with digitalis intoxication. Before April 1986, a relatively limited number of patients received treatment with digoxin-specific Fab fragments through a multicenter clinical trial. Beginning with commercial availability in July 1986, this study sought additional, voluntarily reported clinical data pertaining to treatment through a 3 week follow-up. The study included 717 adults who received Digoxin Immune Fab (Ovine). Most patients were greater than or equal to 70 years old and developed toxicity during maintenance dosing with digoxin. Fifty percent of patients were reported to have a complete response to treatment, 24% a partial response and 12% no response. The response for 14% of patients was not reported or reported as uncertain. Six patients (0.8%, 95% confidence interval 0.3% to 1.8%) had an allergic reaction to digoxin-specific antibody fragments. Three of the six had a history of allergy to antibiotic drugs. Twenty patients (2.8%, 95% confidence interval 1.7% to 4.3%) developed recrudescent toxicity. Risk of recrudescent toxicity increased sixfold when less than 50% of the estimated dose of antibody was administered. A total of 215 patients experienced posttreatment adverse events. The events for 163 patients (76%) were judged to result from manifestations of underlying disease and thus considered unrelated to Fab treatment. Digoxin-specific antibody fragments were generally well tolerated and clinically effective in patients judged by treating physicians to have potentially life-threatening digitalis intoxication.

Adolescent↗
PubMed1991

Complete atrioventricular block complicating inferior wall acute myocardial infarction treated with reperfusion therapy. TAMI Study Group.

Previous studies report larger myocardial infarcts and increased in-hospital mortality rates in patients with inferior wall acute myocardial infarction (AMI) and complete atrioventricular block (AV), but the clinical implications of these complications in patients treated with reperfusion therapy have not been addressed. The clinical course of 373 patients--50 (13%) of whom developed complete AV block--admitted with inferior wall AMI and given thrombolytic therapy within 6 hours of symptom onset was studied. Acute patency rates of the infarct artery after thrombolytic therapy were similar in patients with or without AV block. Ventricular function measured at baseline and before discharge in patients with complete AV block showed a decrement in median ejection fraction (-3.5 vs -0.4%, p = 0.03) and in median regional wall motion (-0.14 vs +0.24 standard deviations/chord, p = 0.05). The reocclusion rate was higher in patients with complete AV block (29 vs 16%, p = 0.03). Patients with complete AV block had more episodes of ventricular fibrillation or tachycardia (36 vs 14%, p less than 0.001), sustained hypotension (36 vs 10%, p less than 0.001), pulmonary edema (12 vs 4%, p = 0.02) and a higher in-hospital mortality rate (20 vs 4%, p less than 0.001), although the mortality rate after hospital discharge was identical (2%) in the 2 groups. Multivariable logistic regression analysis revealed that complete AV block was a strong independent predictor of in-hospital mortality (p = 0.0006). Thus, despite initial successful reperfusion, patients with inferior wall AMI and complete AV block have higher rates of in-hospital complications and mortality.

Aged↗
PubMed1991

Using databases to evaluate therapy.

Clinical and administrative databases are increasingly used for clinical research. Descriptive studies and analyses of prognostic factors are established research uses of databases, but using them to compare therapies remains controversial. Such comparisons may be possible when a validated model of prognosis can account for the effect of clinically recognized variables on outcome. Models meeting these criteria have been developed using the Duke Cardiovascular Disease Database. They were applied to compare medical therapy to surgical therapy for coronary artery disease. Predictions from these models agreed well with the results of the three major randomized trials of bypass surgery versus medical therapy. These findings indicate that when data is reliable and understanding of factors affecting prognosis is good, researchers can use statistical techniques to minimize the bias due to non-random treatment assignment. Carefully performed analyses of observational clinical data can complement and extend randomized studies.

Coronary Disease↗
PubMed1991

Estimating the likelihood of severe coronary artery disease.

PURPOSE: To determine which clinical characteristics obtained by a physician during an initial clinical examination are important for estimating the likelihood of severe coronary artery disease, and to determine whether estimates based on these characteristics remain valid when applied prospectively and in different patient groups. PATIENTS AND METHODS: We examined clinical characteristics predictive of severe disease in 6,435 consecutive symptomatic patients referred for suspected coronary artery disease between 1969 and 1983. RESULTS: Eleven of 23 characteristics were important for estimating the likelihood of severe coronary artery disease. A model using these characteristics accurately estimated the likelihood of severe disease in an independent sample of 2,342 patients referred since 1983. The model also accurately estimated the prevalence of severe disease in large series of patients reported in the literature. CONCLUSIONS: These findings suggest that the clinician's initial evaluation can identify patients at high or low risk of anatomically severe coronary artery disease. Cost-conscious quality care is encouraged by identifying patients at higher risk for severe coronary artery disease who are most likely to benefit from further evaluation.

Adult↗