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

Cardiopulmonary resuscitation: what cost to cheat death?

OBJECTIVES

To review the various outcomes from cardiopulmonary resuscitation (CPR), the factors that influence these outcomes, the costs associated with CPR, and the application of cost-analyses to CPR.

DATA SOURCES

Data used to prepare this article were drawn from published articles and work in progress.

STUDY SELECTION

Articles were selected for their relevance to the subjects of CPR and cost-analysis by MEDLINE keyword search.

DATA EXTRACTION

The authors extracted all applicable data from the English literature.

DATA SYNTHESIS

Cost-analysis studies of CPR programs are limited by the high variation in resources consumed and attribution of cost to these resources. Furthermore, cost projections have not been adjusted to reflect patient-dependent variation in outcome. Variation in the patient's underlying condition, presenting cardiac rhythm, time to provision of definitive CPR, and effective perfusion all influence final outcome and, consequently, influence the cost-effectiveness of CPR programs. Based on cost data from previous studies, preliminary estimates of the cost-effectiveness of CPR programs for all 6-month survivors of a large international multicenter collaborative trial are $406,605.00 per life saved (range $344,314.00 to $966,759.00), and $225,892.00 per quality-adjusted-life-year (range $191,286.00 to $537,088.00).

CONCLUSIONS

Reported outcome from CPR has varied from reasonable rates of good recovery, including return to full employment to 100% mortality. Appropriate CPR is encouraged, but continued widespread application appears extremely expensive.

Cost-effectiveness of screening for asymptomatic carotid atherosclerotic disease

BACKGROUND AND PURPOSE

The value of screening for asymptomatic carotid stenosis has become an important issue with the recently reported beneficial effect of endarterectomy. The purpose of this study is to evaluate the cost-effectiveness of using Doppler ultrasound as a screening tool to select subjects for arteriography and subsequent surgery.

METHODS

A computer model was developed to simulate the cost-effectiveness of screening a cohort of 1000 men during a 20-year period. The primary outcome measure was incremental present-value dollar expenditures for screening and treatment per incremental present-value quality-adjusted life-year (QALY) saved. Estimates of disease prevalence and arteriographic and surgical complication rates were obtained from the literature. Probabilities of stroke and death with surgical and medical treatment were obtained from published clinical trials. Doppler ultrasound sensitivity and specificity were obtained through review of local experience. Estimates of costs were obtained from local Medicare reimbursement data.

RESULTS

A one-time screening program of a population with a high prevalence (20%) of > or = 60% stenosis cost $35130 per incremental QALY gained. Decreased surgical benefit or increased annual discount rate was detrimental, resulting in lost QALYs. Annual screening cost $457773 per incremental QALY gained. In a low-prevalence (4%) population, one-time screening cost $52588 per QALY gained, while annual screening was detrimental.

CONCLUSIONS

The cost-effectiveness of a one-time screening program for an asymptomatic population with a high prevalence of carotid stenosis may be cost-effective. Annual screening is detrimental. The most sensitive variables in this simulation model were long-term stroke risk reduction after surgery and annual discount rate for accumulated costs and QALYs.

Age and outcome with contemporary thrombolytic therapy. Results from the GUSTO-I trial. Global Utilization of Streptokinase and TPA for Occluded coronary arteries trial

BACKGROUND

Elderly patients with acute myocardial infarction have much to gain from reperfusion with thrombolytic therapy but are also at increased risk of adverse events. We examined outcomes according to age of patients receiving thrombolysis in an international trial.

METHODS AND RESULTS

Patients were randomized to streptokinase plus subcutaneous heparin, streptokinase plus intravenous heparin, accelerated tissue plasminogen activator (TPA) plus intravenous heparin, or streptokinase and TPA plus intravenous heparin. Clinical outcomes at 30 days (death, stroke, and nonfatal, disabling stroke) and 1-year mortality were summarized descriptively for patients aged < 65 (n = 24,708), 65 to 74 (n = 11,201), 75 to 85 (n = 4625), and > 85 years (n = 412) and assessed as continuous functions of age. Older patients had a higher-risk profile with regard to baseline clinical and angiographic characteristics. Mortality at 30 days increased markedly with age (3.0%, 9.5%, 19.6%, and 30.3% in the four groups, respectively), as did stroke, cardiogenic shock, bleeding, and reinfarction. Combined death or disabling stroke occurred less often with accelerated TPA in all but the oldest patients, who showed a weak trend toward a lower incidence with streptokinase plus subcutaneous heparin: odds ratio 1.13; 95% confidence interval 0.6, 2.1. Similarly, accelerated TPA treatment resulted in lower 1-year mortality in all but the oldest patients (47% TPA versus 40.3% streptokinase).

CONCLUSIONS

Lower mortality and greater net clinical benefit were seen with accelerated TPA in patients aged < or = 85 years. Because data are limited for patients aged > 85 years, the relative superiority of a given thrombolytic regimen cannot be determined. The interactions of stroke and mortality with newer thrombolytic strategies must be examined explicitly in older patients.

Initial cost of primary angioplasty for acute myocardial infarction

OBJECTIVES

We sought to evaluate the initial economic cost of primary angioplasty for acute myocardial infarction under varying assumptions about whether a cardiac catheterization laboratory exists, whether services are provided during night and weekend hours and how cardiovascular surgical backup is arranged.

BACKGROUND

Primary angioplasty for acute myocardial infarction has resulted in clinical outcomes superior or equal to those obtained with thrombolysis in recent studies, but its future implementation depends greatly on its cost and cost-effectiveness. There is a gap in knowledge about the true economic costs of this procedure, and understanding costs under a variety of hypothetic scenarios is important in planning whether and how the procedure should be offered to broad groups of patients.

METHODS

A generalizable spreadsheet model was constructed to calculate the cost of primary angioplasty at a single hospital with assumptions based on data from a large nonprofit health maintenance organization (Kaiser Permanente). The following baseline assumptions were made: 1) A total of 200 patients with myocardial infarction presented to the hospital each year; 2) primary angioplasty was offered for 10 years; 3) the hospital had a cardiac catheterization laboratory; 4) costs of night call for technical personnel and cardiovascular surgical backup were already covered. Other scenarios were modeled to represent different assumptions about existing resources.

RESULTS

Under the baseline assumptions, primary angioplasty cost $1,597/procedure. If night call for technical personnel were a new expense, the average cost would be > or = $3,206. If a new cardiac catheterization laboratory needed to be built, costs would range from $3,866 to $14,339/procedure, depending on how cardiovascular surgical backup was provided. Results were sensitive to assumptions about the annual volume of myocardial infarctions, the number of years the procedure was offered and the costs of labor, construction and equipment.

CONCLUSIONS

The initial cost of providing primary angioplasty for acute myocardial infarction varies greatly, depending on the setting in which it is provided. To provide information for clinical policy decisions, a cost-effectiveness model is needed that combines these initial costs with data on survival, quality of life and rates and costs of subsequent cardiac procedures.

Prognostic value of noninvasive risk stratification in younger and older patients referred for evaluation of suspected coronary artery disease

OBJECTIVES

The purpose of this investigation is to explore the relationship of patient gender and age on coronary artery disease diagnostic evaluation and to assess the impact of noninvasive testing results on coronary revascularization rates and cardiac event-free survival.

STUDY DESIGN

Retrospective observational cohort.

PARTICIPANTS

From a series of 5322 consecutively tested patients from a Midwestern university tertiary medical center, a hospital cohort of 1345 patients with clinically suspected coronary artery disease was enrolled from 1988 through 1989.

MEASUREMENTS AND RESULTS

Cardiac risk factor and symptom profiles were worse in women, whereas rates of positive test results were similar in both sexes. Multivariable-adjusted risk for follow-up diagnostic testing was 1.8 and 1.9 times greater, respectively, for men < or = and > 65 years of age than for women (P < .01). Younger women were 4.9 times (P = .001) more likely to experience a cardiac event than younger men, with no differences between younger and older women (relative risk = 1.1; P > .20). Overall cardiac event rates were 2.3, 7.4, 16.7, and 20.2% for young men, young women, older women, and older men, respectively. Initial screening was delayed 2 to 7 times longer for older and younger women compared with men (P < .001); the greatest delays were observed for younger women. Diagnostic follow-up and subsequent cost of total care from initial evaluation through 2 years of follow-up were higher for men than for women (P < .0001), with older women having the lowest rate of subsequent diagnostic and interventional follow-up. In the highest risk patients, subsequent utilization rates were 40 and 20% higher for younger and older men than for similarly aged women. In particular, diabetics were less likely to undergo follow-up diagnostic testing and revascularization (67% younger women).

CONCLUSIONS

Age appears to significantly and differently influence decisions regarding noninvasive and invasive medical service utilization in men and women and may partially account for variable outcomes in this and previous gender-based comparisons.

One-year results from the Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO-I) trial. GUSTO-I Investigators

BACKGROUND

In the randomized Global Utilization of t-PA and Streptokinase for Occluded Coronary Arteries (GUSTO-I) trial, 41021 patients received one of four thrombolytic regimens. Patients treated with accelerated tissue plasminogen activator (TPA) had a lower 30-day mortality rate (6.3%) than those treated with the other regimens (7.3%, combined streptokinase groups).

METHODS AND RESULTS

Each patient who was alive at 30 days was sent a return postcard to ascertain vital status at 1 year. If the postcard was not returned, the patient (or an alternate specified at randomization) was contacted by telephone. A locator service was used in the United States for patients who could not be located by these methods. Final follow-up was 96% worldwide. One-year mortality rates remained in favor of accelerated TPA (9.1%) over streptokinase with subcutaneous heparin (10.1%, P = .011) and streptokinase with intravenous heparin (10.1%, P = .009). Combination therapy had an intermediate 1-year mortality (9.9%); this outcome was statistically indistinguishable from that with streptokinase (P = .47) but was marginally different from that with accelerated TPA (P = .05).

CONCLUSIONS

The 1-year results demonstrated a saving of 10 lives per 1000 patients treated with accelerated TPA versus streptokinase and subcutaneous or intravenous heparin. Combination thrombolytic therapy had an intermediate benefit but offered no advantage over accelerated TPA treatment alone.

Implications of the GUSTO trial for thrombolytic therapy

This article discusses the impact of previous clinical observations on the development of the GUSTO-I protocol, particularly the absence of a survival benefit of alteplase (rt-PA) over streptokinase in the GISSI-2/International Study Group and ISIS-3 trials in spite of a higher efficacy for clot lysis. The demonstrated superiority of front-loaded alteplase in this large trial is translated into useful guidelines for the practising clinician. Risk-benefit analysis indicates that, in general, this thrombolytic regimen is most indicated in patients presenting with large amounts of jeopardized ischaemic myocardium in the absence of a particularly increased risk of haemorrhagic stroke. Finally, the impact of this study for future development in the field of acute coronary syndromes is evaluated, more specifically for the design of new trials with new fibrinolytic and antithrombotic agents. These include mutants of alteplase, staphylokinase, direct antithrombins and inhibitors of the glycoprotein IIb/IIIa platelet receptor.

An emergency department-based protocol for rapidly ruling out myocardial ischemia reduces hospital time and expense: results of a randomized study (ROMIO)

OBJECTIVES

We tested the hypothesis that an emergency department-based protocol for rapidly ruling out myocardial ischemia would reduce hospital time and expense but maintain diagnostic accuracy.

BACKGROUND

Patients with a missed diagnosis of myocardial infarction have a high mortality rate; however, providing routine hospital care to low risk patients may not be time- or cost-effective.

METHODS

One hundred low risk patients were entered into the study and randomized either to an emergency department-based rapid rule-out protocol (n = 50) or to routine hospital care (n = 50). Patients receiving routine care were managed by their attending physicians. The rapid protocol included serum enzyme testing at 0, 3, 6 and 9h, serial electrocardiograms with continuous ST segment monitoring and, if results were negative, a predischarge graded exercise test. Study patients were also compared with 160 historical control subjects.

RESULTS

Myocardial infarction or unstable angina occurred in 6% of patients within 30 days; no diagnoses were missed. By intention to treat analysis (n = 50 in each group), the hospital stay was shorter and charges were lower with the rapid protocol than with routine care (p = 0.001). Among patients in whom ischemia was ruled out, those assigned to the rapid protocol had a shorter hospital stay (median 11.9 vs. 22.8 h, p = 0.0001) and lower initial ($893 vs $1,349, p = 0.0001) and 30-day ($898 vs. $1,522, p = 0.0001) hospital charges than did patients given routine care. In historical control subjects, the hospital stay was longer (median 34.5 h, p = 0.001 vs. either group) and charges greater (median $2,063, p = 0.001, vs rapid protocol, p = 0.02, vs. routine care group).

CONCLUSIONS

In low risk patients who present to the emergency department with chest pain, the rapid protocol ruled out myocardial infarction and unstable angina more quickly and cost-effectively than did routine hospital care.

Pharmacologic profile of survivors of acute myocardial infarction at United States academic hospitals

Optimal drug therapy for patients with acute myocardial infarction (AMI) is well described in the medical literature. However, data on the actual pharmacologic management of patients surviving AMI at academic hospitals is unavailable. The purpose of this study was to document treatment profiles in 500 patients surviving AMI at 12 academic hospitals in the United States. These profiles were compared with established guidelines and were evaluated for trends. Overall, thrombolytics (streptokinase > or = tissue-type plasminogen activator) were administered in 29% of the patients, with a greater proportion of patients receiving beta-blockers than calcium channel antagonists in the initial 72 hours (61% vs 40%; p < 0.005) and at discharge (51% vs 35%; p < 0.005). Further, women were less likely than men to receive thrombolytic therapy (odds ratio [OR] = 0.61; confidence interval [CI], 0.54 to 0.69) or beta-blocker therapy within the first 72 hours (OR = 0.61; CI, 0.55 to 0.67) or at hospital discharge (OR = 0.53; CI, 0.48 to 0.58). Overall, improvements could still be made in the number of patients who receive thrombolytic and acute and chronic beta-blocker therapies after AMI, particularly in women. Changes in treatment profiles may be a reflection of the publication of large clinical trials.

Primary angioplasty and thrombolysis for acute myocardial infarction: an evidence summary

Coronary angioplasty is being increasingly used as the primary treatment for patients with acute myocardial infarction, but controversy remains over its potential adoption in preference to thrombolysis as standard care. This report summarizes the published evidence on health outcomes after primary angioplasty compared with thrombolysis or no intervention for patients with acute myocardial infarction. The data tables presented provide the scientific groundwork to assist physicians and other policy-makers in deciding which interventions to provide for broad populations of patients.

The FDA and regulation of cost-effectiveness claims

The Food and Drug Administration (FDA) has issued draft guidelines that would require more rigorous standards for making pharmacoeconomic claims. This paper critiques the guidelines and explores the objectives of market regulation for health-related cost and effectiveness information on pharmaceutical products. It argues that the FDA should proceed with caution and flexibility. In particular, regulations should recognize the potential usefulness of pharmacoeconomic information in helping health care decisionmakers make better-informed choices. They also should acknowledge the enhanced ability of those using the information to evaluate pharmacoeconomic studies and the degree to which the various players in the market can impose their own regulatory discipline.

Costs and effects of enalapril therapy in patients with symptomatic heart failure: an economic analysis of the Studies of Left Ventricular Dysfunction (SOLVD) Treatment Trial

The clinical results of the Studies of Left Ventricular Dysfunction (SOLVD) Treatment Trial have been published previously, but no evaluation of cost-effectiveness based on the primary data has been reported. The authors used a decision analytic model based on primary data from SOLVD to estimate years of survival (overall, by New York Heart Association Class, and quality-adjusted) and to estimate costs of nonfatal hospitalizations, ambulatory care, therapy with enalapril, and deaths. Clinical and resource utilization data were derived from participants in SOLVD, and cost data were derived from the United States. Therapy with enalapril during the approximate 48-month follow-up period in SOLVD resulted in a gain of 0.16 year of life and savings of dollars 718. During the patient's lifetime, a survival benefit of 0.40 year, a cost per year of life saved of dollars 80, and a cost per quality-adjusted life year of dollars 115 with the use of enalapril were projected. The results indicated a net savings and gain in life expectancy during the SOLVD treatment trial. The lifetime projection suggests that therapy with angiotensin-converting enzyme inhibitors, such as enalapril, is extremely attractive when compared with many commonly used interventions in patients with cardiovascular disease or heart failure.

Clinical and economic lessons from studies of coronary thrombolysis

The era of coronary reperfusion in acute coronary care was made possible by the recognition that acute myocardial infarction is usually due to a ruptured atherosclerotic plaque with associated thrombosis. If the infarct artery becomes occluded, a typical electrocardiographic picture is produced and a wave-front of myocardial necrosis ensues. Reperfusion during the early postinfarction hours can halt this process and preserve myocardial function. Pooled analysis of data in almost 60,000 patients has shown that thrombolysis saves lives relative to no reperfusion therapy. Streptokinase has been the standard thrombolytic agent, but recent data from the GUSTO trial show that tissue plasminogen activator (t-PA) given in an accelerated dosing regimen saves one extra patient per hundred treated. The mechanism of benefit of t-PA is improved early and complete restoration of blood flow down the infarct artery. Economic analysis of the GUSTO data shows that t-PA is an "economically attractive" therapeutic technology with a cost-effectiveness ratio of approximately $33,000 per life-year added relative to streptokinase therapy. Because of the growth of managed care and other cost-containment forces, expensive new medical technologies will increasingly need to demonstrate that they produce extra medical benefits in appropriate measure for their extra costs.

Cost-effectiveness of captopril therapy after myocardial infarction

OBJECTIVES

This study sought to assess the cost-effectiveness of captopril therapy for survivors of myocardial infarction.

BACKGROUND

The recent randomized, controlled Survival and Ventricular Enlargement (SAVE) trial showed that captopril therapy improves survival in survivors of myocardial infarction with an ejection fraction < or = 40%. The present ancillary study was designed to determine how the costs required to achieve this increase in survival compared with those of other medical interventions.

METHODS

We developed a decision-analytic model to assess the cost-effectiveness of captopril therapy in 50- to 80-year old survivors of myocardial infarction with an ejection fraction < or = 40%. Data on costs, utilities (health-related quality of life weights) and 4-year survival were obtained directly from the SAVE trial, and long-term survival was estimated using a Markov model. In one set of analyses, we assumed that the survival benefit associated with captopril therapy would persist beyond 4 years (persistent-benefit analyses), whereas in another set we assumed that captopril therapy incurred costs but no survival benefit beyond 4 years (limited-benefit analyses).

RESULTS

In the limited-benefit analyses, the incremental cost-effectiveness of captopril therapy ranged from $3,600/quality-adjusted life-year for 80-year old patients to $60,800/quality-adjusted life-year for 50-year old patients. In the persistent-benefit analyses, incremental cost-effectiveness ratios ranged from $3,700 to $10,400/quality-adjusted life-year, depending on age. The outcome was generally not sensitive to changes in estimates of variables when they were varied individually over wide ranges. In a "worst-case" analysis, incremental cost-effectiveness ratios for captopril therapy remained favorable ($8,700 to $29,200/quality-adjusted life-year) for 60- to 80-year old patients but were higher ($217,600/quality-adjusted life-year) for 50-year old patients.

CONCLUSIONS

We conclude that the cost-effectiveness of captopril therapy for 50- to 80-year old survivors of myocardial infarction with a low ejection fraction compares favorably with other interventions for survivors of myocardial infarction.