Cost-effectiveness of the implantable cardioverter-defibrillator versus antiarrhythmic drugs in survivors of serious ventricular tachyarrhythmias: results of the Antiarrhythmics Versus Implantable Defibrillators (AVID) economic analysis substudy

Costs and quality-of-life effects of implantable cardioverter-defibrillators

Although the clinical efficacy of implantable cardioverter-defibrillators (ICDs) has been convincingly demonstrated in clinical trials, the impact of ICDs on health care costs and recipients' quality of life (QOL) is less certain. The existing medical research on the health care costs and QOL effects of ICDs was reviewed and summarized. Medline and the Institute for Scientific Information's Web of Knowledge were searched for publications reporting costs of care and QOL assessments of ICD recipients. Unpublished and non-peer-reviewed "gray" publications were excluded. Reports were included if they reported primary, original patient data that were collected after 1993, when nonthoracotomy defibrillators entered clinical practice. Two reviewers independently evaluated publications for relevance and quality, abstracted study data, and summarized the findings. Excessive heterogeneity among studies prevented formal meta-analysis, so a narrative synthesis was performed, and key themes were identified from the published research. There were limited published data on the costs of ICD care, especially for the primary prevention of sudden cardiac death. The published research on ICD QOL lacked large, multicenter, longitudinal studies. Many ICD QOL studies were performed in small numbers of patients at single centers. Initial ICD implantation costs ranged (in 2006 United States dollars) from $28,500 to $55,200, with annual follow-up costs ranging from $4,800 to $17,000. QOL was higher for ICD recipients than for patients treated with antiarrhythmic drugs, but there was a substantial prevalence of anxiety, depression, and "loss of control" in ICD recipients, particularly in those who had received ICD shocks. In conclusion, ICD implantation remains costly but may be becoming less expensive over time, and ICD recipients' QOL is significantly affected by their devices.

Cost-effectiveness of surgery plus radiotherapy versus radiotherapy alone for metastatic epidural spinal cord compression

PURPOSE

A recent randomized clinical trial has demonstrated that direct decompressive surgery plus radiotherapy was superior to radiotherapy alone for the treatment of metastatic epidural spinal cord compression. The current study compared the cost-effectiveness of the two approaches.

METHODS AND MATERIALS

In the original clinical trial, clinical effectiveness was measured by ambulation and survival time until death. In this study, an incremental cost-effectiveness analysis was performed from a societal perspective. Costs related to treatment and posttreatment care were estimated and extended to the lifetime of the cohort. Weibull regression was applied to extrapolate outcomes in the presence of censored clinical effectiveness data.

RESULTS

From a societal perspective, the baseline incremental cost-effectiveness ratio (ICER) was found to be $60 per additional day of ambulation (all costs in 2003 Canadian dollars). Using probabilistic sensitivity analysis, 50% of all generated ICERs were lower than $57, and 95% were lower than $242 per additional day of ambulation. This analysis had a 95% CI of -$72.74 to 309.44, meaning that this intervention ranged from a financial savings of $72.74 to a cost of $309.44 per additional day of ambulation. Using survival as the measure of effectiveness resulted in an ICER of $30,940 per life-year gained.

CONCLUSIONS

We found strong evidence that treatment of metastatic epidural spinal cord compression with surgery in addition to radiotherapy is cost-effective both in terms of cost per additional day of ambulation, and cost per life-year gained.

What is the appropriate outcome for studies of treatments for out-of-hospital cardiac arrest?

BACKGROUND

A good outcome following out-of-hospital medical care for cardiac arrest is survival to hospital discharge. Because a large number of patients are required to detect a minimum clinically important difference in survival, an intermediate outcome such as hospital admittance is commonly used. For an intermediate outcome to be a useful surrogate, the survival rate conditional on achieving the intermediate outcome should not depend upon the field treatment. If so, an advantage of the intermediate outcome may be a smaller sample size. However, recent trials demonstrate that survival conditional on admittance may depend upon the field treatment. Even if the resources are available to power a study for survival, is survival the right outcome? For example, no increase in survival and a large increase in admittance could be considered a bad result, as it represents a substantial waste of resources. Similarly no increase in mortality and a decrease in admittance should be considered a good result, as it represents a substantial cost savings without any sacrifice of life. Both admittance and survival are important outcomes and need to be considered jointly, that is, as a bivariate outcome.

METHODS

Cost-effectiveness concepts are used to distinguish between a good and bad (bivariate) outcome. Simulations are conducted to compare the impact of the univariate and the bivariate outcomes in a variety of trial scenarios. A table of sample sizes is computed for the bivariate outcome across a range of trial scenarios.

RESULTS

The bivariate outcome outperforms both univariate outcomes for most alternatives. The required sample size for the joint outcome of admittance and survival may be substantially, over 50%, less than that for the survival outcome alone.

CONCLUSION

Use of the bivariate outcome could provide more informed decision making about resuscitation strategies and at less cost then the current gold standard of hospital survival.

Implantable or external defibrillators for individuals at increased risk of cardiac arrest: where cost-effectiveness hits fiscal reality

OBJECTIVES

Implantable cardioverter defibrillators (ICDs) are highly effective at preventing cardiac arrest, but their availability is limited by high cost. Automated external defibrillators (AEDs) are likely to be less effective, but also less expensive. We used decision analysis to evaluate the clinical and economic trade-offs of AEDs, ICDs, and emergency medical services equipped with defibrillators (EMS-D) for reducing cardiac arrest mortality.

METHODS

A Markov model was developed to compare the cost-effectiveness of three strategies in adults meeting entry criteria for the MADIT II Trial: strategy 1, individuals experiencing cardiac arrest are treated by EMS-D; strategy 2, individuals experiencing cardiac arrest are treated with an in-home AED; and strategy 3, individuals receive a prophylactic ICD. The model was then used to quantify the aggregate societal benefit of these three strategies under the conditions of a constrained federal budget.

RESULTS

Compared with EMS-D, in-home AEDs produced a gain of 0.05 quality-adjusted life-years (QALYs) at an incremental cost of $5225 ($104,500 per QALY), while ICDs produced a gain of 0.90 QALYs at a cost of $114,660 ($127,400 per QALY). For every $1 million spent on defibrillators, 1.7 additional QALYs are produced by purchasing AEDs (9.6 QALYs/$million) instead of ICDs (7.9 QALYs/$million). Results were most sensitive to defibrillator complication rates and effectiveness, defibrillator cost, and adults' risk of cardiac arrest.

CONCLUSIONS

Both AEDs and ICDs reduce cardiac arrest mortality, but AEDs are significantly less expensive and less effective. If financial constraints were to lead to rationing of defibrillators, it might be preferable to provide more people with a less effective and less expensive intervention (in-home AEDs) instead of providing fewer people with a more effective and more costly intervention (ICDs).

Cost-Effectiveness of Defibrillator Therapy or Amiodarone in Chronic Stable Heart Failure

Background— In the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT), implantable cardioverter-defibrillator (ICD) therapy significantly reduced all-cause mortality rates compared with medical therapy alone in patients with stable, moderately symptomatic heart failure, whereas amiodarone had no benefit on mortality rates. We examined long-term economic implications of these results.

Methods and Results— Medical costs were estimated by using hospital billing data and the Medicare Fee Schedule. Our base case cost-effectiveness analysis used empirical clinical and cost data to estimate the lifetime incremental cost of saving an extra life-year with ICD therapy relative to medical therapy alone. At 5 years, the amiodarone arm had a survival rate equivalent to that of the placebo arm and higher costs than the placebo arm. For ICD relative to medical therapy alone, the base case lifetime cost-effectiveness and cost-utility ratios (discounted at 3%) were $38 389 per life-year saved (LYS) and $41 530 per quality-adjusted LYS, respectively. A cost-effectiveness ratio <$100 000 was obtained in 99% of 1000 bootstrap repetitions. The cost-effectiveness ratio was sensitive to the amount of extrapolation beyond the empirical 5-year trial data: $127 503 per LYS at 5 years, $88 657 per LYS at 8 years, and $58 510 per LYS at 12 years. Because of a significant interaction between ICD treatment and New York Heart Association class, the cost-effectiveness ratio was $29 872 per LYS for class II, whereas there was incremental cost but no incremental benefit in class III.

Conclusions— Prophylactic use of single-lead, shock-only ICD therapy is economically attractive in patients with stable, moderately symptomatic heart failure with an ejection fraction ≤35%, particularly those in NYHA class II, as long as the benefits of ICD therapy observed in the SCD-HeFT persist for at least 8 years.

Cost-Effectiveness of a Microvolt T-Wave Alternans Screening Strategy for Implantable Cardioverter-Defibrillator Placement in the MADIT-II–Eligible Population

OBJECTIVES

This study was designed to compare the cost-effectiveness of implantable cardioverter-defibrillator (ICD) placement with and without risk stratification with microvolt T-wave alternans (MTWA) testing in the MADIT-II (Second Multicenter Automatic Defibrillator Implantation Trial) eligible population.

BACKGROUND

Implantable cardioverter-defibrillators have been shown to prevent mortality in the MADIT-II population. Microvolt T-wave alternans testing has been shown to be effective in risk stratifying MADIT-II-eligible patients.

METHODS

On the basis of published data, cost-effectiveness of three therapeutic strategies in MADIT-II-eligible patients was assessed using a Markov model: 1) ICD placement in all; 2) ICD placement in patients testing MTWA non-negative;, and 3) medical management. Outcomes of expected cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness were determined for patient lifetime.

RESULTS

Under base-case assumptions, providing ICDs only to those who test MTWA non-negative produced a gain of 1.14 QALYs at an incremental cost of 55,700 dollars when compared to medical therapy, resulting in an incremental cost-effectiveness ratio (ICER) of 48,700 dollars/QALY. When compared with a MTWA risk-stratification strategy, placing ICDs in all patients resulted in an ICER of 88,700 dollars/QALY. Most (83%) of the potential benefit was achieved by implanting ICDs in the 67% of patients who tested MTWA non-negative. Results were most sensitive to the effectiveness of MTWA as a risk-stratification tool, MTWA negative screen rate, cost and efficacy of ICD therapy, and patient risk for arrhythmic death.

CONCLUSIONS

Risk stratification with MTWA testing in MADIT-II-eligible patients improves the cost-effectiveness of ICDs. Implanting defibrillators in all MADIT-II-eligible patients, however, is not cost-effective, with one-third of patients deriving little additional benefit at great expense.

Implantable cardioverter-defibrillators for secondary prevention: is it worth it in the elderly?

Aging is associated with structural alterations in the heart that predispose the elderly to life-threatening ventricular arrhythmias. The majority of sudden cardiac deaths occur in people aged 65 and older. As the proportion of elderly in our population continues to grow, a greater number of elderly patients with malignant ventricular arrhythmias will require appropriate medical management. Clinical outcome trials have demonstrated that implantable cardioverter-defibrillators (ICDs) improve overall survival compared with pharmacologic therapy when used for the secondary prevention of cardiac arrest. Despite proven efficacy, physicians may be reluctant to implant a defibrillator in an older patient. This review summarizes the data pertaining to the use of defibrillators for secondary prevention in the elderly. ICD use for secondary prevention reduces all-cause mortality and appears to be economically advantageous in an older patient population. Currently, there is no convincing data to suggest that ICD therapy should be withheld from a patient based on age alone.

The Cost Effectiveness of Implantable Cardioverter-Defibrillators

OBJECTIVES

We sought to evaluate the cost implications of the implantable cardioverter-defibrillator (ICD), using utilization, cost, and survival data from the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II.

BACKGROUND

This trial showed that prophylactic implantation of a defibrillator reduces the rate of mortality in patients who experienced a previous myocardial infarction and low left ventricular ejection fraction. Given the size of the eligible population, the cost effectiveness of the ICD has substantial implications.

METHODS

Our research comprises the cost-effectiveness component of the randomized controlled trial, MADIT-II, based on utilization, cost, and survival information from 1,095 U.S. patients who were assigned randomly to receive an ICD or conventional medical care. Utilization data were converted to costs using a variety of national and hospital-specific data. The incremental cost-effectiveness ratio (iCER) was calculated as the difference in discounted costs divided by the difference in discounted life expectancy within 3.5 years. Secondary analyses included projections of survival (using three alternative assumptions), corresponding cost assumptions, and the resulting cost-effectiveness ratios until 12 years after randomization.

RESULTS

During the 3.5-year period of the study, the average survival gain for the defibrillator arm was 0.167 years (2 months), the additional costs were 39,200 dollars, and the iCER was 235,000 dollars per year-of-life saved. In three alternative projections to 12 years, this ratio ranged from 78,600 dollars to 114,000 dollars.

CONCLUSIONS

The estimated cost per life-year saved by the ICD in the MADIT-II study is relatively high at 3.5 years but is projected to be substantially lower over the course of longer time horizons.

Evaluation of eplerenone in the subgroup of EPHESUS patients with baseline left ventricular ejection fraction ≤30%

AIMS

Because of the prognostic importance of LV dysfunction following an AMI and the increasing use of electrical and/or mechanical interventions in patients with LV systolic dysfunction, this retrospective analysis of EPHESUS patients with LVEF <or=30% at baseline was conducted to determine the value of eplerenone in this setting.

METHODS AND RESULTS

In EPHESUS, 6,632 patients with LVEF <or=40% and clinical heart failure (HF) post-AMI who were receiving standard therapy were randomized to eplerenone 25 mg/day titrated to 50 mg/day or placebo for a mean follow-up of 16 months. Treatment with eplerenone in the subgroup of patients with LVEF <or=30% (N=2106) resulted in relative risk reductions of 21% versus placebo in both all-cause mortality (P=0.012) and cardiovascular (CV) mortality/CV hospitalization (P=0.001), and 23% for CV mortality (P=0.008). The relative risk of sudden cardiac death (SCD) was reduced 33% (P=0.01) and HF mortality/HF hospitalization was reduced 25% (P=0.005) with eplerenone compared with placebo. Within 30 days of randomization, eplerenone resulted in relative risk reductions of 43% for all-cause mortality (P=0.002), 29% for CV mortality/CV hospitalization (P=0.006), and 58% for SCD (P=0.008).

CONCLUSIONS

Treatment with eplerenone plus standard therapy in patients with post-AMI HF and LVEF <or=30% provided significant incremental benefits in reducing both early and late mortality and morbidity.

Characteristics of heart beat intervals and prediction of death

OBJECTIVE

To assess the value for improving risk stratification of measures, unadjusted and adjusted for heart rate, of heart rate variability (HRV) and heart rate turbulence (HRT) based on 2- to 24-h ambulatory electrocardiographic recordings; and to relate this to the decision to use an implantable cardiac defibrillator (ICD) and the attendant consequences on effectiveness and cost-effectiveness.

BACKGROUND

Risk stratification for high risk or low risk of lethal ventricular arrhythmic events, and hence for a decision about defibrillator implant, most commonly utilizes the left ventricular ejection fraction (LVEF). Electrocardiographic (ECG) approaches include 24-h ambulatory ECG recordings, with counts of ventricular premature contractions (VPCs), measures of heart rate variability (HRV), and heart rate turbulence (HRT). HRT has two components: turbulence onset (TO) and turbulence slope (TS).

METHODS AND RESULTS

We evaluated the qualifying ambulatory ECG recordings from 744 patients in the active treatment arms of the Cardiac Arrhythmia Suppression Trial (CAST). Beat characteristics, VPC counts, normal-to-normal beat intervals, and time-domain measures of HRV and HRT were calculated. Tachograms were rescaled to a heart rate of 75 and the resulting "normalized" measures evaluated as risk predictors for death, compared to unnormalized measures. Measures based on 2-h ECGs were also evaluated as risk predictors. The most powerful univariate predictor of survival was the normalized turbulence slope. The best multivariate prediction model had six components: history of angina, hypertension, diabetes, and absence of post-myocardial infarction revascularization, the log of LVEF, normalized TS, HR, and an interaction term of HR and normalized TS. Gains in effectiveness from use of this model cost between $0 and $4000 per year of life saved.

CONCLUSIONS

Turbulence slope substantially exceeded other ECG-based measures in improving prediction of subsequent death in models which included LVEF, and other clinical parameters. Use of this model would improve the effectiveness and cost-effectiveness of the ICD.

Cost-effectiveness of in-home automated external defibrillators for individuals at increased risk of sudden cardiac death

BACKGROUND/OBJECTIVE

In-home automated external defibrillators (AEDs) are increasingly recommended as a means for improving survival of cardiac arrests that occur at home. The current study was conducted to explore the relationship between individuals' risk of cardiac arrest and cost-effectiveness of in-home AED deployment.

DESIGN

Markov decision model employing a societal perspective.

PATIENTS

Four hypothetical cohorts of American adults 60 years of age at progressively greater risk for sudden cardiac death (SCD): 1) all adults (annual probability of SCD 0.4%); 2) adults with multiple SCD risk factors (probability 2%); 3) adults with previous myocardial infarction (probability 4%); and 4) adults with ischemic cardiomyopathy unable to receive an implantable defibrillator (probability 6%).

INTERVENTION

Strategy 1: individuals suffering an in-home cardiac arrest were treated with emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals suffering an in-home cardiac arrest received initial treatment with an in-home AED, followed by EMS.

RESULTS

Assuming cardiac arrest survival rates of 15% with EMS-D and 30% with AEDs, the cost per quality-adjusted life-year gained (QALY) of providing in-home AEDs to all adults 60 years of age is 216,000 dollars. Costs of providing in-home AEDs to adults with multiple risk factors (2% probability of SCD), previous myocardial infarction (4% probability), and ischemic cardiomyopathy (6% probability) are 132,000 dollars, 104,000 dollars, and 88,000 dollars, respectively.

CONCLUSIONS

The cost-effectiveness of in-home AEDs is intimately linked to individuals' risk of SCD. However, providing in-home AEDs to all adults over age 60 appears relatively expensive.

Cost-effectiveness of dual-chamber pacing compared with ventricular pacing for sinus node dysfunction

BACKGROUND

Compared with single-chamber ventricular pacing, dual-chamber pacing can reduce adverse events and, as a result, improve quality of life in patients paced for sick sinus syndrome. It is not clear, however, how these benefits compare with the increased cost of dual-chamber pacemakers.

METHODS AND RESULTS

We used 4-year data from a 2010-patient, randomized trial to estimate the incremental cost-effectiveness of dual-chamber pacing compared with ventricular pacing and then projected these findings over the patients' lifetimes by using a Markov model that was calibrated to the first 5 years of in-trial data. To assess the stability of the findings, we performed 1000 bootstrap analyses and multiple sensitivity analyses. During the first 4 years of the trial, dual-chamber pacemakers increased quality-adjusted life expectancy by 0.013 year per subject at an incremental cost-effectiveness ratio of 53,000 dollars per quality-adjusted year of life gained. Over a lifetime, dual-chamber pacing was projected to increase quality-adjusted life expectancy by 0.14 year with an incremental cost-effectiveness ratio of approximately 6800 dollars per quality-adjusted year of life gained. In bootstrap analyses, dual-chamber pacing was cost-effective in 91.9% of simulations at a threshold of 50,000 dollars per quality-adjusted year of life and in 93.2% of simulations at a threshold of 100,000 dollars. Its cost-effectiveness ratio was also below this threshold in numerous sensitivity analyses that varied key estimates.

CONCLUSIONS

For patients with sick sinus syndrome requiring pacing, dual-chamber pacing increases quality-adjusted life expectancy at a cost that is generally considered acceptable.

Cost-effectiveness of training unselected laypersons in cardiopulmonary resuscitation and defibrillation

PURPOSE

The cost-effectiveness of cardiopulmonary resuscitation (CPR) and defibrillation training for laypersons unselected for risk of encountering cases of cardiac arrest is not known. We compared the costs and health benefits of alternative resuscitation training strategies for adults without professional first-responder duties who are at average risk of encountering cases of out-of-hospital cardiac arrest.

METHODS

We constructed a cost-effectiveness analytic model. Data on cardiac arrest epidemiology and the effectiveness of CPR/defibrillation training were obtained from the medical literature. Instructional costs were determined from a survey of training programs. Downstream cardiac arrest survivor quality-adjusted life expectancy and long-term health care costs were derived from prior studies. We compared three strategies for training unselected laypersons: CPR/defibrillation training alone, training combined with home defibrillator purchase, and no training. The main outcome measures were total instructional costs for trainees combined with health care costs for additional cardiac arrest survivors, and quality-adjusted survival for additional patients resuscitated by trainees.

RESULTS

CPR/defibrillation training yielded 2.7 quality-adjusted hours of life at a cost of 62 US dollars per trainee (202,400 US dollars per quality-adjusted life-year [QALY] gained). Training laypersons in CPR/defibrillation with subsequent defibrillator purchase cost 2,489,700 US dollars per QALY. In contrast, CPR/defibrillation training cost less than 75,000 US dollars per QALY if trainees lived with persons older than 75 years or with persons who had cardiac disease, or if total training costs were less than 10 US dollars.

CONCLUSION

Training unselected laypersons in CPR/defibrillation is costly compared with other public health initiatives. Conversely, training laypersons selected by occupation, low training costs, or having high-risk household companions is substantially more efficient.

Update on implantable cardioverter defibrillator trials

Many randomized trials of implantable cardioverter defibrillator (ICD) therapy versus medical treatment for the prevention of death in survivors of cardiac arrest or in patients at high risk of sudden cardiac death (SCD) have been reported. ICD therapy has been consistently efficacious in preventing SCD. ICD therapy has generally favorably impacted total mortality, but this has depended upon the control group's risk for arrhythmic and nonarrhythmic mortality. In these trials, predictors of sudden or total mortality better than ventricular dysfunction have not emerged. This review summarizes the randomized ICDs trials and the impact ICDs have on SCD prevention.

Sudden cardiac death

Sudden cardiac death (SCD) due to ventricular tachyarrhythmias is a leading cause of death in the United States. This phenomenon is associated with coronary artery disease, valvular heart disease, nonischemic cardiomyopathies, congenital heart disease, primary electrical abnormalities, autonomic nervous system abnormalities, and other less common disorders. Evaluation and management of patients at risk for SCD (primary prevention) and of patients who have survived at least 1 episode of SCD (secondary prevention) have evolved in recent years because clinical trials have shown consistent benefit from implantation of cardioverter-defibrillators in appropriately selected patients. An evidence-based approach to primary and secondary prevention of SCD is presented.

Lower Observed Versus Expected (Based on U.S. Age and Gender Specific Rates) Survival in Patients Treated for Near-Fatal Ventricular Arrhythmias

Implantable cardioverter defibrillators (ICDs) have improved survival for patients with ventricular fibrillation (VF) or sustained vertricular tachycardia (VT). However, the survival of these patients compared to the general population has not been assessed. Observed survival rates for patients randomized to either antiarrhythmic drug therapy (mainly amiodarone) arm or ICD arm were compared to expected rates, calculated using age and sex-specific survival rates derived from the 1989-1991 US population life tables and applied to the age and sex distribution of patients in each arm. Consistent with the results of the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial, patients randomized to receive ICDs experienced significantly higher survival than those in the drug arm; however, both groups experienced significantly lower survival than expected using age and gender matched U.S. survival rates. Within arms, the difference between the observed and expected rates increased over 3 years of follow-up from 7.7% to 15.3% for the ICD arm, and from 14.6% to 26.4% for the drug arm. These results quantify the improvements in survival that can be expected for VF or VT patients using drug or ICD therapies and underscore the need for continued research into methods for further improving the overall level of health of these patients.

The patient with an implantable cardioverter defibrillator

Electrophysiologic technology developed over the past 20 years has improved the life expectancy of patients who have survived sudden cardiac death events. Use of an implantable cardioverter defibrillator (ICD) continues to increase as more indications for the device are researched. Patients with ICDs will be cared for in the postanesthesia care unit following cardiac and noncardiac surgery and require PACU nurses to be knowledgeable about this advanced and changing technology as well as provide for emotional and psychological needs.

Cost-effectiveness of the implantable cardioverter defibrillator: a review of current evidence

INTRODUCTION

Implantable cardioverter defibrillator (ICD) therapy is indicated for patients at risk for sudden cardiac death (SCD) due to ventricular tachycardia (VT) or ventricular fibrillation (VF). The high relative cost of therapy with the ICD versus antiarrhythmic drugs has raised questions regarding its cost-effectiveness. To address these questions, we review the literature on ICD cost-effectiveness.

METHODS AND RESULTS

MEDLINE and other databases were searched for articles published since 1980 reporting original data on the cost-effectiveness of ICD versus drug therapy for patients at risk for SCD. Data on costs and life-years were abstracted and studies grouped into decision analysis models and trial-based analyses. Cost-effectiveness ratios were inflated to 2002 US dollars. Thirteen economic studies were included in this review: 6 decision-analytic models, 4 economic analysis alongside randomized controlled trials, and 1 observational study. Two additional studies evaluated the cost-effectiveness of ICDs stratified by mortality risk. Studies varied in time horizon, and in all but one study ICD therapy was more costly than drug therapy. Early models assumed larger survival benefits than were observed in subsequent trials; therefore, ICDs appeared to be more cost-effective (i.e., US dollars 28000-US dollars 60000 per life-year gained). Three large clinical trial-based studies estimated that the cost per life-year gained was between US dollars 30181 and US dollars 185000. Stratified analyses show that patients at higher risk for mortality due to structural heart disease (e.g., left ventricular ejection fraction <35%) benefit more from ICD therapy, resulting in lower cost-effectiveness ratios.

CONCLUSION

ICD therapy continues to evolve with changing methods of implantation and improving technology. Current evidence suggests that ICDs may be a cost-effective option in patients at high risk for VT/VF. The cost-effectiveness of ICD therapy for primary and secondary prevention of SCD depends upon patient characteristics that influence their prior risk of mortality. Further research on patient selection criteria and the measurement of health-related quality of life is required.

Resynchronization therapy is an important advance in the management of congestive heart failure: view of an antagonist

The antagonist portion of the debate acknowledges that cardiac resynchronization therapy (CRT) is an important advance in the management of congestive heart failure, but the eligible treatment population currently is small relative to the whole. The impact of CRT on mortality without an implantable cardioverter defibrillator (ICD) probably is not significant, although a beneficial effect on morbidity associated with heart failure has clearly been achieved. The costs of CRT are not negligible. The morbidity and mortality of the procedure to implant these devices must be considered in future trial design.

Cost-effectiveness of automated external defibrillator deployment in selected public locations

OBJECTIVE

The American Heart Association (AHA) recommends an automated external defibrillator (AED) be considered for a specific location if there is at least a 20% annual probability the device will be used. We sought to evaluate the cost-effectiveness of the AHA recommendation and of AED deployment in selected public locations with known cardiac arrest rates.

DESIGN

Markov Decision Model employing a societal perspective.

SETTING

Selected public locations in the United States.

PATIENTS

A simulated cohort of the American public.

INTERVENTION

Strategy 1: individuals experiencing cardiac arrest were treated by emergency medical services equipped with AEDs (EMS-D). Strategy 2: individuals were treated with AEDs deployed as part of a public access defibrillation program. Strategies differed only in the initial availability of an AED and its impact on cardiac arrest survival.

RESULTS

Under the base-case assumption that a deployed AED will be used on 1 cardiac arrest every 5 years (20% annual probability of AED use), the cost per quality-adjusted life year (QALY) gained is $30,000 for AED deployment compared with EMS-D care. AED deployment costs less than $50,000 per QALY gained provided that the annual probability of AED use is 12% or greater. Monte Carlo simulation conducted while holding the annual probability of AED use at 20% demonstrated that 87% of the trials had a cost-effectiveness ratio of less than $50,000 per QALY.

CONCLUSIONS

AED deployment is likely to be cost-effective across a range of public locations. The current AHA guidelines are overly restrictive. Limited expansion of these programs can be justified on clinical and economic grounds.

The impact of including passive benefits in cost-effectiveness analysis: the case of automated external defibrillators on commercial aircraft

OBJECTIVE

Traditional cost-utility analysis assumes that all benefits from health-related interventions are captured by the quality-adjusted life-years (QALYs) gained by the few individuals whose outcome is improved by the intervention. However, it is possible that many individuals who do not directly benefit from an intervention receive utility, and therefore QALYs, because of the passive benefit (aka sense of security) provided by the existence of the intervention. The objective of this study was to evaluate the impact that varying quantities of passive benefit have on the cost-effectiveness of airline defibrillator programs.

METHODS

A decision analytic model with Markov processes was constructed to evaluate the cost-effectiveness of defibrillator deployment on domestic commercial passenger aircraft over 1 year. Airline passengers were assigned small incremental utility gains (.001-.01) during an estimated 3-hour flight to evaluate the impact of passive benefit on overall cost-effectiveness.

RESULTS

In the base case analysis with no allowance for passive benefit, the cost-effectiveness of airline automated external defibrillator deployment was US dollars 34000 per QALY gained. If 1% of all passengers received utility gain of.01, the cost-effectiveness declined to US dollars 30000. Cost-effectiveness was enhanced when the quantity of passive benefit was raised or the percentage of individuals receiving passive benefit increased.

CONCLUSIONS

Automated external defibrillator deployment on passenger aircraft is likely to be cost-effective. If a small percentage of airline passengers receive incremental utility gains from passive benefit of automated external defibrillator availability, the impact on overall cost-effectiveness may be substantial. Further research should attempt to clarify the magnitude and percentage of patients who receive passive benefit.

[The impact of the Multicenter Automatic Defibrillator Implantation Trial II in a university hospital--do all patients with myocardial infarction and reduced left ventricular function need an implantable cardioverter-defibrillator?]

BACKGROUND AND OBJECTIVES

Patients with coronary artery disease (CAD) and severely compromised left ventricular ejection fraction are at high risk to die from sudden cardiac death. The Multicenter Automatic Defibrillator implantation Trial II (MADIT II) shows a significant benefit of a cardioverter-defibrillator (ICD) therapy compared to standard treatment alone in this selected group of patients. The objective of the present study was to investigate the number of patients who will fulfil the MADIT II criteria and are candidates for prophylactic ICD implantation.

METHODS AND MATERIAL

From January to December 2001 a total of 2653 patients underwent coronary angiography at our institution due to angina pectoris, positive exercise stress testing, pathological SPECT myocardial perfusion images, suspected dilated cardiomyopathy or ventricular arrhythmias. According to the MADIT II inclusion criteria patients with significant coronary artery disease (diameter stenosis > 50%), ejection fraction < 0.31% and previous myocardial infarction were included. Exclusion criteria were acute coronary syndromes, patients with ventricular tachyarrhythmias or an existing indication for ICD therapy, and patients with coronary artery bypass graft surgery or percutaneous transluminal coronary angioplasty within the past or following three months.

RESULTS

Out of 2653 patients 185 (7%) had an ejection fraction less than 0.31, 149 (5.6%) showed significant coronary artery stenosis and 70 (2.6%) patients fulfilled the MADIT II criteria. The mean age of these patients was 68 +/- 9 years, the left ventricular ejection fraction 24 +/- 6. In 37 patients an ICD system was implanted according to the existing guidelines. 70 patients met the MADIT II inclusion criteria, resulting in an increase of 189% of ICD implantations per year.

CONCLUSION

2.6% out of 2653 patients who were referred to coronary angiography fulfilled the criteria of MADIT II. The expanding indication for ICD therapy will result in an annual increase of 70 (189%) prophylactic ICD implantations in our study population.

Cost effectiveness of implantable cardioverter defibrillator therapy versus drug therapy for patients at high risk of sudden cardiac death

The implantable cardioverter defibrillator (ICD) is a therapy for patients at risk of sudden cardiac death due to ventricular tachycardia (VT) or ventricular fibrillation (VF). But the apparent high cost of ICD therapy relative to antiarrhythmic drugs such as amiodarone has raised questions about the cost effectiveness of ICD therapy versus drug therapy. To inform this debate we reviewed the literature on ICD cost effectiveness. An electronic and manual search was conducted for articles published since 1980 reporting original data on the cost effectiveness of ICD versus drug therapy for patients at risk of VT/VF. Data on costs and life-years gained were abstracted and studies were grouped into those that used decision-analysis models and those that were trial-based analyses. Cost-effectiveness ratios were inflated to 2001 US dollars. Nine studies were included in the review; five studies were modelling studies and four were part of randomised trials of ICD therapy. Studies varied in time horizon, but all except one indicated that ICD therapy was more costly than drug therapy. Early decision models assumed larger survival benefits than those observed in subsequent trials and therefore had attractive incremental cost-effectiveness ratios in the range of dollars US 27000 to dollars US 60000 per life-year gained. Trial-based studies, with the exception of one small trial, indicated cost per life-year gained in the range dollars US 44000 to dollars US 144000. Stratified analysis shows clearly that patients with a greater risk of mortality due to structural heart disease (e.g. left ventricular ejection fraction < or =35%) benefit more from ICD therapy and therefore have a more attractive cost effectiveness ratio than patients at lower risk. ICD therapy is still evolving over time with implant costs declining and device technology improving. Current evidence is that, in selected patients who are at high risk of VT/VF, ICD therapy can be a cost-effective option. Future research should focus on (i) patient selection to optimise benefits for available resources; and (ii) more comprehensive outcome measures to include health-related quality of life.