Echocardiographic risk stratification for early surgery with endocarditis: a cost-effectiveness analysis.

BACKGROUND: Despite widespread acceptance of echocardiography for diagnosis of infective endocarditis, few investigators have evaluated its utility as a risk-stratification tool to aid therapeutic decision-making. METHODS: A decision tree and Markov analysis model were constructed using published and institutional data to estimate the cost-effectiveness of an echocardiographic risk-stratification strategy for infective endocarditis. The models compared surgery for high-risk patients based on clinical factors ("standard care") and surgery for high-risk patients based on echocardiographic findings ("echocardiography-guided"). RESULTS: The cost per patient for standard care and echocardiography-guided strategies was $47,766 and $53,669, respectively. The expected quality-adjusted life years (QALY) for standard care and echocardiography-guided strategies were 5.86 years and 6.10 years, respectively. Compared with standard care, the echocardiography-guided strategy cost an additional $23,867 per QALY saved. In one-way sensitivity analyses, the incremental cost of this strategy remained <$50,000/QALY across a broad range of scenarios. Baseline stroke risk had the greatest effect on cost-effectiveness. For populations with stroke risk less than 3.65%, the echocardiography-guided strategy was not cost-attractive (ICER >$50,000/QALY). At stroke risk between 3.65% and 14%, the ICER for the echocardiography-guided strategy was attractive (<$50,000 /QALY). The echocardiography-guided strategy became economically dominant at any baseline stroke risk greater than 18.3%. CONCLUSION: Echo-guided risk stratification for early surgery in patients with large vegetations is a cost-attractive treatment strategy for IE, as it improves outcome for an incremental cost <$50,000/QALY.

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.

Post-myocardial infarction risk stratification in elderly patients.

BACKGROUND: The purpose of this study was to examine the use of post-myocardial infarction (MI) risk stratification in the elderly. Although expert panels have recommended risk stratification after MI, limited data are available on whether patients actually undergo suggested testing. In particular, concern has been raised that the elderly, who are at high risk for recurrent ischemia and short-term death, are not referred as often as younger patients for post-MI testing. METHODS: We studied the records of 192,311 Medicare patients (age > or = 65 years) admitted with MI between January 1992 and November 1992. By combining Medicare part A and part B data, we created a longitudinal record of patient care within 60 days of an MI admission. We describe the pattern of post-MI testing for ischemia and left ventricular function and outcomes as a function of patient age. RESULTS: Patients > or = 75 years of age were significantly less likely than patients 65 to 74 years of age to have either cardiac catheterization (17% vs 43%) or any test for coronary artery disease severity (24% vs 53%). They were also less likely to have a test of left ventricular function (61% vs 76%). Even after adjustment for baseline characteristics, older patients remained less likely than younger patients to have an assessment of coronary artery disease severity (odds ratio, 0.44) or left ventricular function (odds ratio, 0.65). CONCLUSIONS: Post-MI risk stratification declines with age and falls short of recommendations in our nation's elderly. This lack of testing may result in lost opportunities for therapeutic interventions in this high-risk group.

Association between selective serotonin-reuptake inhibitor therapy and heart valve regurgitation.

The identification of an association between fenfluramines and valvular disease has raised the possibility of a similar association between another class of medications that increases local levels of serotonin, the selective serotonin-reuptake inhibitors (SSRIs). The objective of this study was to examine the association between heart valve regurgitation and treatment with SSRIs. We examined 5,437 consecutive patients who underwent echocardiography. Patients with a similar likelihood of SSRI treatment were identified by propensity models. The prevalence of regurgitation according to treatment was compared after adjusting for clinical characteristics associated with regurgitation. We also blindly reinterpreted a subset of 2,000 echocardiograms to identify characteristics associated with fenfluramine-associated valvular heart disease such as posterior mitral leaflet restriction. Among 5,437 consecutively hospitalized patients, we identified 292 who had taken SSRIs before admission. Patients taking SSRIs tended to be younger, female, Caucasian, unmarried, and more likely to have psychiatric illness and hypertension (p < or = 0.05). The overall prevalence of regurgitation meeting Food and Drug Administration criteria (at least moderate mitral regurgitation or mild aortic regurgitation) was 30%, with no significant difference in prevalence between those receiving SSRIs (26.7%) and controls (30.4%) (p = 0.19). The association remained negative when comparing SSRI-treated patients to controls with similar characteristics. Furthermore, the prevalence of features described in conjunction with fenfluramine exposure, such as posterior mitral leaflet restriction, was not higher in SSRI-treated patients. Among a large consecutive cohort of patients, the prevalence of mitral and aortic regurgitation in patients taking SSRIs was not different from that of controls, suggesting that SSRIs are not associated with valvular disease.

The progression of fenfluramine-associated valvular heart disease assessed by echocardiography.

BACKGROUND: An association between the dietary suppressants fenfluramine and dexfenfluramine and valvular heart disease was first described in patients from North Dakota and Minnesota in 1997. Limited data are available on the natural history of this valvulopathy after discontinuation of drug therapy. OBJECTIVE: To follow the progression of fenfluramine-associated valvular heart disease after discontinuation of therapy by using serial echocardiography. DESIGN: Retrospective cohort study. SETTING: Regional medical center in Fargo, North Dakota. PATIENTS: 50 patients with previous exposure to fenfluramines who had at least mild mitral regurgitation or aortic regurgitation after exposure to fenfluramines on serial echocardiography between December 1994 and February 1999 (96% were female, mean body mass index was 36.6 kg/m(2), and mean duration of drug exposure was 447 days). MEASUREMENTS: Serial echocardiograms were reviewed by two echocardiographers who were blinded to the order of image acquisition. The severity of valvular regurgitation and presence or absence of valve leaflet restriction were assessed. RESULTS: As described in the initial report, significant valvular disease on initial postexposure echocardiography was common in this cohort; 38 patients (76%) had at least mild mitral regurgitation and 43 patients (86%) had at least mild aortic regurgitation. On serial echocardiograms obtained an average of 356 days apart, mitral regurgitation improved by at least one grade in 17 patients (P = 0.001) and aortic regurgitation improved by at least one grade in 19 patients (P = 0.004). Nineteen and 22 patients, respectively, experienced no change in severity of mitral and aortic regurgitation. Two patients in each group experienced worsening of regurgitation by at least one grade. Results were similar for tricuspid (P = 0.002) and pulmonic (P = 0.012) regurgitation. CONCLUSION: On serial echocardiography, fenfluramine-associated valvular regurgitation improved or remained stable in most patients after therapy ended. Worsening of valvular regurgitation was uncommon. The potential for stabilization or regression of valvular regurgitation should be taken into account when counseling patients and considering the need for and timing of valve surgery.

Evaluating the potential 'economic attractiveness' of new therapies in patients with non-ST elevation acute coronary syndrome.

OBJECTIVE: To evaluate the relationship between how much a new cardiovascular therapy improves clinical outcomes over current therapies and how much more it can cost while still remaining 'economically attractive'. DESIGN: We developed a decision model to predict the 6-month cumulative cost savings and increased life expectancy that could be associated with new therapies for patients with non-ST elevation acute coronary syndrome. SETTING: This modelling study used outcome and cost data from US sources. METHODS: Event probabilities at 30 days and 6 months were estimated from US patients with non-ST elevation in the Global Use of Strategies to Open Occluded Coronary Arteries in Acute Coronary Syndromes (GUSTO) IIb trial; cost estimates were derived from patients enrolled in the Economics and Quality of Life substudy of this trial. Patient life expectancy estimates were calculated using survival estimates for similar patients treated at Duke University Medical Center. RESULTS: We found that new therapies costing up to $US2000 per episode that reduce 6-month mortality by 0.5%, death and nonfatal myocardial infarction (MI) by 1%, or death, nonfatal MI and revascularisation by 3%, may be cost effective by current standards. When new therapies costing up to $US1000 per episode reduce the absolute rate of death, nonfatal MI and revascularisation at 6 months by 6.5% or more, they may be cost saving. CONCLUSION: Our analysis suggests that economic constraints should not inhibit the development of effective new therapies.

Fenfluramine and phentermine and cardiovascular findings: effect of treatment duration on prevalence of valve abnormalities.

BACKGROUND: The combination of fenfluramine and phentermine was a widely used obesity treatment before the withdrawal of fenfluramine for an association with heart valve regurgitation. The prevalence and clinical significance of regurgitation among patients treated with these medications has yet to be fully established. METHODS AND RESULTS: To evaluate the potential association between the duration of treatment and the prevalence of heart valve abnormalities, we examined 1163 patients who had taken fenfluramine-phentermine and 672 control patients who had not taken the drug combination within 5 years. Mild or greater aortic regurgitation was present in 8.8% of treated patients and 3.6% of control patients (P<0.001). Moderate or greater mitral regurgitation was present in 2.6% of treated patients and 1.5% of control patients (P=0.18). The adjusted odds ratio compared with controls of aortic regurgitation of mild or greater severity increased according to duration of treatment: 90 to 180 days, 1.5 (P=0.23); 181 to 360 days, 2.4 (P=0.002); 361 to 720 days, 4.6 (P<0.001); >720 days, 6.2 (P<0.001). CONCLUSIONS: This is the largest study to demonstrate a relation between the length of treatment with fenfluramine-phentermine and the prevalence of valvular abnormalities. These findings suggest that valvular abnormalities in patients who took fenfluramine-phentermine primarily involve those who had taken these medications for >6 months and predominantly results in mild aortic regurgitation. The valve regurgitation identified by this study was not accompanied by significant differences in cardiovascular symptoms nor physical findings other than a higher prevalence of heart murmurs.

Calcium channel blockers and mortality in elderly patients with myocardial infarction.

BACKGROUND: Although calcium channel blockers are a useful therapy in relieving angina, lowering blood pressure, and slowing conduction of atrial fibrillation, growing evidence has cast doubt on their safety in patients with coronary disease. OBJECTIVE: To examine the association between calcium channel blocker therapy at hospital discharge and mortality in a population-based sample of elderly patients hospitalized with acute myocardial infarction. DESIGN: Retrospective cohort study using data from medical charts and administrative files. SETTING: All acute care hospitals in 46 states. PATIENTS: All Medicare patients with a principal diagnosis of acute myocardial infarction consecutively discharged from the hospital alive during 8-month periods between 1994 and 1995 (N = 141,041). MAIN OUTCOME MEASURE: Mortality at 30 days and 1 year. RESULTS: Calcium channel blockers were widely prescribed at hospital discharge to elderly patients with myocardial infarction between 1994 and 1995 (n = 51,921), the most commonly prescribed being diltiazem (n = 21,175), nifedipine (n = 12,670), amlodipine (n = 11,683), and verapamil (n = 3639). After adjusting for illness severity and concomitant medication use, patients who were prescribed calcium channel blockers at hospital discharge did not have increased risk for 30-day or 1-year mortality, with the exception of the few (n = 116) treated with bepridil. Bepridil differs from other calcium channel blockers because of its tendency to prolong repolarization, and its association with proarrhythmic effects in elderly patients. CONCLUSION: We did not identify a mortality risk in a large consecutive sample of elderly patients with myocardial infarction, which supports the need for additional prospective trials examining calcium channel blocker therapy for ischemic heart disease.

Cost-effectiveness of transesophageal echocardiography to determine the duration of therapy for intravascular catheter-associated Staphylococcus aureus bacteremia.

BACKGROUND: The appropriate duration of therapy for catheter-associated Staphylococcus aureus bacteremia is controversial. Conventional practice dictates that all patients receive prolonged courses of intravenous antibiotics. Some clinicians recommend abbreviated therapeutic courses, but an alternate approach involves prospectively identifying patients for whom abbreviated therapy is appropriate. OBJECTIVE: To determine the cost-effectiveness of transesophageal echocardiography (TEE) in establishing duration of therapy for catheter-associated S. aureus bacteremia. DESIGN: Cost-effectiveness analysis. DATA SOURCES: MEDLINE search of literature; clinical data from patients with S. aureus bacteremia (n = 196) and patients with endocarditis (n = 60); and costs obtained from the study institution, regional home health agency, and national estimates of professional and technical fees. TARGET POPULATION: Patients with catheter-associated S. aureus bacteremia on native heart valves without intravenous drug use or clinically apparent metastatic infection, immunosuppression, or indwelling prosthetic devices. TIME HORIZON: Patient lifetime. PERSPECTIVE: Societal. INTERVENTIONS: Antibiotic treatment based on TEE results compared with 2- or 4-week empirical therapy. OUTCOME MEASURES: Quality-adjusted life expectancy, costs, and incremental cost-effectiveness ratios. RESULTS OF BASE-CASE ANALYSIS: Compared with empirical short-course therapy, the TEE strategy cost $4938 per quality-adjusted life-year (QALY) gained. The effectiveness of the TEE strategy and the effectiveness of the long-course strategy were sufficiently similar that the additional cost of empirical long-course therapy ($1,667,971 per QALY) was higher than that which society usually considers cost-effective. RESULTS OF SENSITIVITY ANALYSES: In a four-way sensitivity analysis (endocarditis prevalence, TEE cost, short-course relapse rate, and TEE specificity), compared with empirical short-course therapy, the TEE strategy results ranged from cost savings to $155,624 per QALY. CONCLUSION: Within the limitations of existing empirical data, this study suggests that for patients with clinically uncomplicated catheter-associated S. aureus bacteremia, the use of TEE to determine therapy duration is a cost-effective alternative to 2- or 4-week empirical therapy.

The challenge of health care delivery to the elderly patient with cardiovascular disease. Demographic, epidemiologic, fiscal, and health policy implications.

Old age as our society is experiencing it is a new phenomenon. Never before in history have societies of developed countries enjoyed such longevity of life. In the next several decades the United States will face an unparalleled increase in the absolute number of elderly persons in our population. How will health care professionals, policy-makers, and society in general face the mammoth task of providing quality cardiovascular care for the elderly in an environment of limited financial resources? This article discusses the demographic, fiscal, and health policy implications of our aging society with particular emphasis on existing and anticipated impediments to the delivery of cardiovascular care to this rapidly expanding segment of our population.

The effects of New York's bypass surgery provider profiling on access to care and patient outcomes in the elderly.

OBJECTIVE: The aim of this study was to examine the effects of provider profiling on bypass surgery access and outcomes in elderly patients in New York. BACKGROUND: Since 1989, New York (NY) has compiled provider-specific bypass surgery mortality reports. While some have proposed that "provider profiling" has led to lower surgical mortality rates, critics have suggested that such programs lower in-state procedural access (increasing out-of-state transfers) without improving patient outcomes. METHODS: Using national Medicare data, we examined trends in the percentages of NY residents aged 65 years or older receiving out-of-state bypass surgery between 1987 and 1992 (before and after program initiation). We also examined in-state procedure use among elderly myocardial infarction patients during this period. Finally, we compared trends in surgical outcomes in NY Medicare patients with those for the rest of the nation. RESULTS: Between 1987 and 1992, the percentage of NY residents receiving bypass out-of-state actually declined (from 12.5% to 11.3%, p < 0.01 for trend). An elderly patient's likelihood for bypass following myocardial infarction in NY increased significantly since the program's initiation. Between 1987 and 1992, unadjusted 30-day mortality rates following bypass declined by 33% in NY Medicare patients compared with a 19% decline nationwide (p < 0.001). As a result of this improvement, NY had the lowest risk-adjusted bypass mortality rate of any state in 1992. CONCLUSIONS: We found no evidence that NY's provider profiling limited procedure access in NY's elderly or increased out-of-state transfers. Despite an increasing preoperative risk profile, procedural outcomes in NY improved significantly faster than the national average.

Treatment of hyperlipidemia by specialists versus generalists as secondary prevention of coronary artery disease.

Patients with known coronary disease and low-density lipoprotein >130 mg/dl who are followed by cardiologists after myocardial infarction are more than twice as likely to receive a cholesterol-lowering agent than patients followed by general internists.