Bispectral index and electroencephalographic entropy in patients undergoing aortocoronary bypass grafting

BACKGROUND AND OBJECTIVE

This study was conducted to compare bispectral index, state entropy and response entropy in patients undergoing coronary artery bypass grafting.

METHODS

In 66 patients, anaesthesia was maintained at two different levels using bispectral index. Doses of sufentanil and midazolam were adjusted to achieve a bispectral index in the range of 45-55 in 33 patients (BIS 50 group) and 35-44 in another 33 patients (BIS 40 group). Simultaneously, state entropy and response entropy were recorded.

RESULTS

The targeted values of bispectral index were achieved in both groups and the bispectral index values differed significantly during whole anaesthesia. Median response entropy and state entropy fell to 19-26 during anaesthesia in both groups. Response entropy and state entropy values in the two groups differed significantly only after induction of anaesthesia and did not differ during further anaesthesia. There was no explicit intraoperative recall in both groups. Patients in Group BIS 40 received significantly (P<0.05) more sufentanil than the BIS 50 group (704+/-181 microg vs. 490+/-107 microg, respectively) and midazolam (18.5+/-6.1 mg vs. 15.6+/-3.8 mg, respectively). After cardiopulmonary bypass, significantly (P<0.05) more patients in Group BIS40 needed inotropic support with dobutamine (79%) than in the BIS50 group (52%). Time to extubation did not differ between the two groups.

CONCLUSION

In patients undergoing coronary artery bypass grafting, no relationship was found between bispectral index levels and state entropy and response entropy at two different stages of a sufentanil-midazolam anaesthesia. A bispectral index level of 45-55 reduced anaesthetic medications used and the need for inotropic support.

Is early too early? Effect of shorter stays after bypass surgery

BACKGROUND

Postoperative stays after coronary artery bypass graft surgery (CABG) decreased substantially in the 1990s. Although shorter stays offer clinical benefits, premature discharge could increase adverse events and offset initial savings. This study examined the effect of early discharge after CABG on readmission/death and cost within 60 days of discharge home. Variability in hospitals' tendencies for early discharge and adverse outcomes was also explored.

METHODS

Analyses were based on clinical and claims data for 55,889 New York CABG patients discharged home 1995 to 1998. Early discharge was defined as a postoperative stay below the 15th percentile for patients with similar risk. The likelihood of early discharge and its effect on readmission/death were examined using hierarchical logistic regression, accounting for patient risk and within-hospital correlation. The correlation between early discharge and adverse outcomes at the hospital level was assessed. The effect of early discharge on subsequent inpatient, outpatient, skilled nursing, and home health costs was examined in the Medicare subset.

RESULTS

Overall, 17% of patients were discharged early, with increasing prevalence over time. The tendency to discharge early varied widely among hospitals (2% to 42% of patients). We found no association between hospitals' tendencies for early discharge and adverse outcomes. Lower postdischarge costs among patients discharged early (mean = 3,491 dollars versus 5,246 dollars for typical stays) resulted in average cumulative savings of 6,309 dollars.

CONCLUSIONS

Patients selected for earlier discharge after CABG did not have increased adverse event rates or higher costs. Variation among hospitals in early discharge suggests that more efficient patient management could be achieved at some hospitals.

U.S. Trends In CABG Hospital Volume: The Effect Of Adding Cardiac Surgery Programs

Hospital coronary artery bypass graft (CABG) volume is inversely related to mortality--with low-volume hospitals having the highest mortality. Medicare data (1992-2003) show that the number of CABG procedures increased from 158,000 in 1992 to a peak of 190,000 in 1996 and then fell to 152,000 in 2003, while the number of hospitals performing CABG increased steadily. Predictably, the proportion of CABG procedures performed at low-volume hospitals increased, and the proportion in high-volume hospitals declined. An unintended consequence of starting new cardiac surgery programs is declining CABG hospital volume--a side effect that might increase mortality.

The impact of age on outcomes after coronary artery bypass surgery versus stent-assisted percutaneous coronary intervention: one-year results from the Stent or Surgery (SoS) trial

BACKGROUND

Relative outcomes of coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI) may differ between younger and older patients. There are no data comparing the age-related CABG versus PCI outcomes in the stent era.

METHODS

The SoS trial compared CABG (n = 500) and stent-assisted PCI (n = 488). The impact of treatment assignment on 1-year outcomes was evaluated by age < or = 65 years (n = 295, CABG; n = 298, PCI) and > 65 years (n = 205, CABG; n = 190, PCI).

RESULTS

One-year procedural outcomes were similar between treatment groups regardless of age, with the exception of more repeat revascularizations after PCI (age < or = 65, 16.1% vs 4.8%; age > 65, 19.5% vs 3.4%; both P < .001). Six and 12-month Seattle Angina Questionnaire scores improved from baseline in both age and treatment groups. However, CABG was associated with greater improvement in physical limitation, angina frequency, and quality of life in younger patients at 6 and 12 months (12-month difference in improvement between CABG and PCI: 5.6, 4.8, and 3.9 points for 3 domains), whereas in the elderly a significant benefit of CABG observed at 6 months did not persist at 12 months (12-month difference: 0.9, 1.9, and 1.4). One-year costs were significantly higher after CABG regardless of age.

CONCLUSIONS

Although PCI and CABG result in similar rates in clinical outcomes irrespective of age, younger patients reported more health status benefits from CABG as compared with PCI, whereas in older patients the 2 approaches resulted in similar 1-year health status benefits.

Small Rural Hospitals and High-Risk Operations: How Would Regionalization Affect Surgical Volume and Hospital Revenue?

BACKGROUND

Because higher hospital procedure volume is associated with better outcomes for many high-risk procedures, regionalization to higher-volume hospitals has been proposed as a way to improve quality of surgical care. The potential impact of such policies on small rural hospital volume and revenue is unknown.

STUDY DESIGN

We identified all hospitalizations in small rural hospitals (less than 50 beds) in New York State from 1998 to 2001 that included an ICD-9 procedure code for 1 of 9 procedures for which there is a documented volume-outcomes association: abdominal aortic aneurysm repair, aortic-valve replacement, carotid endarterectomy, colectomy, coronary artery bypass, cystectomy, esophagectomy, pancreatectomy, or pulmonary resection. Revenue from these procedures was estimated using gross charges and payor-specific reimbursement rates. We then compared these estimates with total hospital inpatient revenue for each rural hospital.

RESULTS

We identified 14 small rural hospitals where at least one of the nine procedures was performed. All included hospitalizations for colectomy. Aortic aneurysm repairs, cystectomies, and pancreatectomies were performed in three hospitals; carotid endarterectomy in two; and esophagectomy in one. In no hospitals were cardiac procedures or pulmonary resections performed. Estimated average contribution to hospital net revenue for all 9 procedures was approximately 2%, nearly all attributable to colectomy.

CONCLUSIONS

If all aortic aneurysm repairs, major cardiothoracic procedures, carotid endarterectomies, cystectomies, and pancreatectomies in New York State were regionalized to higher-volume hospitals, no small rural hospitals would experience substantial impact in terms of rural hospital procedure volume and revenue. Even regionalization of colectomy would have a small impact on inpatient volume and revenue.

Economic considerations in managing patients with chronic stable angina

OBJECTIVE

To quantify the economic burden of chronic stable angina in the United States, characterize recent trends in the use of coronary revascularization, and compare the clinical outcomes and long-term costs of percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG), and medical management in patients with stable angina.

SUMMARY

The direct and indirect costs of stable angina are measured in tens of billions of dollars in the United States, with hospitalization contributing a large amount to the costs. The use of coronary revascularization, particularly PCI and insertion of coronary stents, has increased dramatically in recent years. The long-term costs of PCI and CABG are similar and high. Revascularization is sometimes used without an adequate trial of medical management, despite higher costs and a lack of evidence of long-term clinical benefits from revascularization.

CONCLUSION

Chronic stable angina is a costly condition. Medical management should be used before considering costly revascularization, unless medical management is contraindicated.

Cost-Effectiveness of Coronary Artery Bypass Grafts Versus Percutaneous Coronary Intervention for Revascularization of High-Risk Patients

BACKGROUND

A Department of Veterans Affairs Cooperative Study randomized high-risk patients with medically refractory myocardial ischemia, a group largely excluded from previous trials, to urgent revascularization with either percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). The present study examined the cost-effectiveness of PCI versus CABG for these high-risk patients.

METHODS AND RESULTS

Of 454 patients at 16 Department of Veterans Affairs medical centers, 445 were available for the economic analysis (218 PCI and 227 CABG patients). Total costs were assessed at 3 and 5 years from the third-party payer's perspective, and effectiveness was measured by survival. After 3 years, average total costs were 63,896 dollars for PCI versus 84,364 dollars for CABG patients, a difference of 20,468 dollars (95% confidence interval [CI] 13,918 dollars to 27,569 dollars). CIs were estimated by bootstrapping. Survival at 3 years was 0.82 for PCI versus 0.79 for CABG patients (P=0.34). Precision of the cost-effectiveness estimates were assessed by bootstrapping. PCI was less costly and more effective at 3 years in 92.6% of the bootstrap replications. After 5 years, average total costs were 81,790 dollars for PCI versus 100,522 dollars for CABG patients, a difference of 18,732 dollars (95% CI 9873 dollars to 27,831 dollars), whereas survival at 5 years was 0.75 for PCI patients versus 0.70 for CABG patients (P=0.21). At 5 years, PCI remained less costly and more effective in 89.4% of the bootstrap replications.

CONCLUSIONS

PCI was less costly and at least as effective for the urgent revascularization of medically refractory, high-risk patients over 5 years.

Demonstration project claims 1 billion dollars in potential savings

Savings would be realized if 76% of patients received most of quality measures. Numbers may be conservative, since participants had higher than average quality care. Premier offering P4P readiness program on the Internet free of charge.

[Cost-effectiveness of clopidogrel vs. aspirin treatment in high-risk acute coronary syndrome patients in Denmark]

INTRODUCTION

The aim of this study was to estimate the cost-effectiveness of clopidogrel versus aspirin (ASA) in Denmark in the secondary prevention of cardiovascular events in three high-risk CAPRIE populations: (1) patients with a history of coronary artery bypass grafting, (2) patients with a history of ischemic events and (3) patients with multiple vascular territory involvement. Additionally, the cost-effectiveness of clopidogrel versus no treatment in ASA-intolerant patients was estimated.

MATERIALS AND METHODS

Clinical, epidemiological and cost data (Danish estimates) were combined in a Markov model. Estimates of transition probabilities were derived from post hoc analyses of the CAPRIE database.

RESULTS

Cost-effectiveness (CE) ratios ranged from 25,445 Danish kroner per LYG (life year gained) in patients with a history of CABG to 55,503 Danish kroner per LYG in patients with multiple vascular territory involvement. The estimated cost-effectiveness ratio of clopidogrel in ASA-intolerant patients was significantly lower (3,093 Danish kroner per LYG). Sensitivity analyses showed that the order of magnitude of these CE ratios is unaffected by changes in model assumptions.

CONCLUSION

In a Danish setting, clopidogrel may be considered a cost-effective treatment alternative to ASA for the secondary prevention of cardiovascular events in high-risk populations. Clopidogrel is also an effective and cost-effective treatment for ASA-intolerant patients.

Cost Effective Endoscopic Radial Artery Harvesting

Radial artery harvesting has been routinely performed by endoscopy. We present a reduced cost technique using a reusable retractor and thermal welding shears. The combination of reusable and disposable tools allows patients to benefit from endoscopic radial artery harvesting with decreased morbidity and favorable cosmetic results.

Economic evaluation of alternative strategies to treat patients with diabetes mellitus and coronary artery disease

Diabetes mellitus and coronary artery disease (CAD) commonly coexist, and thus effective, cost-effective management strategies are needed. Intensive management of diabetes has been shown to increase medical costs while yielding better outcomes, with an acceptable cost-effectiveness ratio of <50,000 dollars per life-year added. On the basis of clinical trial findings in the 1970s and 1980s, coronary bypass surgery was cost-effective compared with medical therapy in the treatment of extensive CAD. Few trials have compared angioplasty with medical therapy, and its cost-effectiveness is not well established. The economic outcomes of contemporary coronary revascularization, especially angioplasty, compared with contemporary medical therapy must be evaluated. The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial will collect extensive economic data and examine the cost-effectiveness of alternative strategies to manage diabetes and CAD in patients with both disorders.

Cost, quality, and risk: measuring and stopping the hidden costs of coronary artery bypass graft surgery

PURPOSE

Blood conservation programs have been successfully implemented in hospitals in which an overarching commitment to the reduction of the number of blood transfusions existed. This review will describe the rationale and some of the considerations involved in starting such a program.

SUMMARY

Management of a hospital's blood supply is a high pressure area dominated by a resource shortage, increasing costs, a medical community that has been trained to use transfusion, public awareness and concern, and to a lesser extent an increasing body of evidence suggesting that transfusions are often deleterious. The implementation of new techniques and protocols to conserve blood during surgery can be facilitated if a physician champion addresses the medical staff and the hospital administrators clear political and budgetary issues. With a team approach and an understanding of the clinical and economic evidence supporting less blood use, many of the hurdles can be overcome.

CONCLUSION

Blood conservation programs offer a solution to the multiple problems that surround blood use. When successfully implemented, such initiatives reduce safety concerns, hospital spending, and the dependency of hospitals on the national blood supply and improve clinical outcomes and patient satisfaction.

Routine delivery of myoblasts during coronary artery bypass surgery: why not?

Skeletal myoblast transplantation has now entered the clinical arena as a potential means of restoring function to scarred myocardium. While the current experience derived from phase I trials suggests that cell implantation during coronary artery bypass operations is a straightforward and safe procedure, routine use of myoblast transplantation would certainly be premature. Two major issues have not yet been addressed: firstly, the risk-benefit ratio needs to be assessed, specifically whether the potential proarrhythmic risk associated with myoblast transplantation is supported by the results of an ongoing large, randomized study, and if so, whether this risk is offset by a benefit in terms of improvement of left ventricular function and patient outcome. Secondly, this putative benefit will then have to be weighed against the financial burden inherent to this type of procedure, to assess whether the cost-effectiveness ratio is favorably shifted and supports the expanded indication of myoblast transplantation during coronary artery revascularization in patients with severe ischemic heart failure.

Making a Business Case for Quality by Regional Information Sharing Involving Cardiothoracic Surgery

A consortium of cardiac surgeons, nurses, and administrators in Virginia has developed a clinical/financial database to identify sites with best outcomes and replicate best practices statewide. The financial value of quality improvements is estimated from the incremental savings gained by reducing postoperative complications. The group studied 7,417 coronary artery bypass graft cases in 2003-2004. The average costs of atrial fibrillation, stroke, mediastinitis, renal failure, reoperation for bleeding, and prolonged use of ventilation were measured using charge data and ratios of costs-to-charges. Costs ranged from 18,093 US dollars to 28,136 US dollars in eight hospitals. Lower-cost hospitals had lower standardized mortality ratios. Average total costs were 19,049 US dollars for cases with no complications. Cases with postoperative atrial fibrillation were 21,415 US dollars, an incremental cost of 2,366 US dollars (p<0.0001), and reached 54,671 US dollars for mediastinitis (deep sternal wound infections) and 57,360 US dollars for renal failure. Overall, 16.1% of 5,230 coronary artery bypass graft patients developed atrial fibrillation in 2003. Incidence ranged from <5% to nearly 30% across 14 hospitals. Reducing the incidence of complications by small fractions can yield significant savings. Paying for performance may lead to more comparative analysis, peer-to-peer collaboration, and new approaches to quality improvement and efficiency measurement.

Proliferation of Cardiac Technology in Canada

Background— Critics remain skeptical about the long-term sustainability of Medicare in Canada because of the proliferation of health technology and escalating expenditures. The objective of this study was to examine the temporal trends in the utilization and costs of cardiovascular technologies for the evaluation and/or management of patients with ischemic heart disease in Canada.

Methods and Results— This repeated cross-sectional population-based study of Ontario residents examined the temporal trends in the utilization and costs associated with echocardiography, stress (imaging and nonimaging) testing, coronary angiography, percutaneous coronary intervention (PCI), and bypass surgery between 1992 and 2001. Annual costs increased by nearly 2-fold over the 10-year study period and cumulatively accounted for more than $2.8 billion (Canadian) in expenditures. The proliferation in use of cardiac testing/interventions over time outstripped both demographic shifts and changes in the prevalence of coronary artery disease. Annual increases were widespread for all procedures ( P <0.001) and ranged from 2% per year for nonimaging stress tests to 12% per year for PCI, after adjustment for age and sex. Generally, utilization rates were higher among the elderly, males, and those of low socioeconomic status. With few exceptions, annual increases in the utilization rates of cardiac tests and procedures were disproportionately higher among the elderly and women, but they were similar across socioeconomic subgroups. Increases in utilization appeared to reflect referrals toward higher-risk populations.

Conclusions— Although definitive conclusions about the appropriateness of temporal patterns cannot be ascertained, the proliferation of cardiac testing challenges the sustainability of Medicare in Canada, especially given uncertainty as to whether the accompanying incremental rise in total expenditures translates into significant outcome benefits in the population.

Hospital integration and vertical consolidation: an analysis of acquisitions in New York State

While prior studies tend to view hospital integration through the lens of horizontal consolidation, I provide an analysis of its vertical aspects. I examine the effect of hospital acquisitions in New York State on the distribution of market share for major cardiac procedures across providers in target markets. I find evidence of benefits to acquirers via business stealing, with the resulting redistribution of volume across providers having small effects, if any, on total welfare with respect to cardiac care. The results of this analysis -- along with similar assessments for other services -- can be incorporated into future studies of hospital consolidation.

J-SAP Study 1-2: Outcomes of Patients With Stable High-Risk Coronary Artery Disease Receiving Medical-Preceding Therapy in Japan A Comparison With CABG-Preceding Therapy

BACKGROUND

Stable coronary artery disease (CAD) is classified into 2 types: high-risk (ie, 3-vessel disease, left main trunk lesions, or ostial lesions of the left anterior descending (LAD)) and low-risk (1- or 2-vessel disease other than ostial lesions of the LAD). Generally, the former is treated with coronary artery bypass grafting-preceding therapy (CABG), but not medical-preceding therapy (Medical); however, this is based on evidence from 30 years ago or more and does not reflect the recent progression of Medical and CABG. In addition, a randomized study has not been performed in Japan.

METHODS AND RESULTS

In high-risk CAD, the long-term outcomes of 77 Medical patients and age-, sex-, coronary-lesion-, symptom- and risk-factor-matched 99 CABG patients were surveyed over 3 years (mean: 3.4 years) starting in 2000 at 37 nationwide hospitals. The incidences of cardiac death and cardiac death+non-fatal acute coronary syndrome (9.1% and 11.7% in Medical, and 2.0% and 3.0% in CABG, respectively) were significantly higher and the improvement in clinical symptoms was significantly lower in Medical than CABG.

CONCLUSIONS

CABG is recommended in patients with high-risk CAD from the view of long-term prognosis; however, it should be remembered that the long-term outcome in Medical has considerably improved.

Coronary artery bypass graft surgery: do women cost more?

BACKGROUND

Coronary artery bypass graft surgery (CABG) in women has been associated with worse clinical outcomes than CABG in men. However, little is known about the impact of sex on the cost of CABG.

OBJECTIVE

To examine the impact of sex on hospital course and the cost of CABG.

METHODS

Hospital course and cost were examined among 2880 female and 9137 male patients from four Canadian and five American hospitals. Data were obtained from a resource and cost accounting system used by each of the nine hospitals.

RESULTS

Among the 12,017 patients who underwent CABG, 24% (n=2880) were women and 76% (n=9137) were men. Women had a significantly longer length of stay (LOS) than did men (10.3+/-0.2 days and 8.9+/-0.08 days, respectively; P<0.0001) and a significantly higher in-hospital mortality than did men (2.6% and 1.5%, respectively; P<0.0001). The total unadjusted cost was higher for women than for men both in Canada (US$11,200+/-268 and US$10,143+/-139, respectively; P<0.0001) and the United States (US$22,715+/-509 and US$19,906+/-269, respectively; P<0.0001). After adjusting for age and comorbid conditions, female sex was associated with a 10% increase in LOS (P<0.0001), a 97% increase in mortality (P=0.0006) and a 7% increase in overall cost (P<0.0001).

CONCLUSION

Compared with men, women undergoing CABG had a modestly increased LOS and a higher mortality. Total in-hospital cost was higher for women in each of the nine hospitals studied. Compared with other clinical variables, female sex is a relatively minor determinant of cost. Nevertheless, because of the expected increase in the number of women undergoing CABG in the future, this increased cost may translate into an important economic burden.

A comparison of self-selectivity corrections in economic evaluations and outcomes research

OBJECTIVE

Two alternative selectivity correction methods have been widely applied in the health economics literature: the sample selection model (SSM) and the multipart model (MPM). The difference between these two approaches results from their initial assumptions about the distribution of error terms. Because the distributional assumptions cannot be theoretically verified, the usefulness of the methods can only be evaluated by real world comparison. This article reviews and empirically tests the two alternative selectivity correction methods to give a reality-based evaluation.

METHODS

Using a randomized sample of patients as the "gold standard," the SSM and MPM are applied to a nonrandomized sample of patients with an identical set of dependent and independent variables. By comparing the actual estimates of the two methods, we evaluate the robustness of the two approaches.

RESULTS

The results show that neither method is empirically robust in replicating the results of the randomized trial. There is no consistent pattern in the coefficients from either selectivity-correction method for replicating the coefficients in the randomized sample.

CONCLUSIONS

Researchers should be cautious in applying these correction methods, and any conclusions based on these approaches may need to be qualified.