Extent and sources of geographic variation in Medicare end-stage renal disease expenditures

Geographic variations in practices and expenditures have been widely documented, leading to concerns that care in some regions is clinically suboptimal and/or economically inefficient. Our objectives are to determine the extent and sources of geographic variation in Medicare expenditures per patient with end-stage renal disease (ESRD) per year. The study population included all patients with ESRD with Medicare as primary payer during 1997 (n = 284,670). Medicare expenditures were summarized at the hospital referral region (HRR) level. Using regression analysis, we estimated the relationship between expenditures and demographics, case mix, dialysis provider characteristics, distribution of patients across renal replacement therapy modalities, standardized hospitalization ratios, and healthcare wages. Spending per patient-year varied threefold across HRRs, ranging from $17,791 to $59,025 (mean, $38,966 +/- $6,774 [SD]). The regression equation explained 80% of this variation. Although several demographic and case-mix indicators that have been related to spending at the individual level were statistically significant predictors of spending at the HRR level, they did not show enough geographic variation to explain a large fraction of spending variation. Rather, patient distributions across renal replacement modalities, hospitalization patterns, and healthcare wages were the most powerful predictors of spending. Compared with Medicare generally, both the mean and SD of ESRD expenditures were approximately seven times larger. The substantial geographic variability in expenditures for patients with ESRD indicates the potential for improving efficiency and quality of care. Interventions designed to increase transplantation rates, ensure access to peritoneal dialysis, and reduce hospitalization appear most promising.

The use of volume standards in health services

The ways in which volume standards are implemented by health services organizations are not clear. Therefore, the authors sought to evaluate the extent of use of volume standards, the purposes for which such standards were developed, and the sources of the standards in a sample of health services organizations. The authors found that volume standards were used widely by accrediting organizations, professional societies, and hospitals in their sample, but almost never by health maintenance organizations. Volume standards were used for ensuring adequate experience among residents, providing guidelines to residency programs, and privileging and credentialing physicians. Expert consensus appeared to be the usual source of volume standards.

Capital investment strategies in health care systems

Capital investment decisions are among the most important decisions made by firms. They determine the firm's capacity for providing services and commit the firm's cash for an extended period of time. Interviews with chief financial officers of leading health care systems reveal capital investment strategies that generally follow the recommendations of modern finance theory. Still, there is substantial variation in capital budgeting techniques, methods of risk adjustment, and the importance of qualitative considerations in investment decision making. There is also variation in delegation of investment decision making to operating units and methods of performance evaluation. Health care systems face the same challenges as other organizations in developing and implementing capital investment strategies that use consistent methods for evaluation of projects that have inconsistent aims and outcomes.

Cash management in health care systems

Cash is one of the most precious assets held by health systems. This article presents results of discussions on cash management and investment policies at a dozen major not-for-profit health systems. Health system data indicate that cash holdings have increased dramatically since 1993, mostly due to investment earnings. Discussions with chief financial officers of these health systems reveal that cash holdings are significant, that decisions about cash balances are strategic, and that most systems aim to increase cash balances to levels that permit access to capital markets on more favorable terms.

Financial management in leading health care systems

To understand better the financial management practices and strategies of modern health care organizations, we conducted interviews with chief financial officers (CFOs) of several leading health care systems. In this introduction, we present an overview of the project and summary responses on corporate financial structures and strategic challenges facing CFOs.

Sources of project financing in health care systems

Through discussions with chief financial officers of leading health care systems, insights are offered on preferences for project financing and development efforts. Data from these same systems provide at least anecdotal evidence in support of pecking-order theory.

Capital structure strategy in health care systems

The capital structures (the relative use of debt and equity to support assets) of leading health care systems are viewed as a strategic component of their financial plans. While not-for-profit hospitals as a group have maintained nearly constant levels of debt over the past decade, investor-owned hospitals and a group of leading health care systems have reduced their relative use of debt. Chief financial officers indicated that in addition to reducing debt because of less favorable reimbursement incentives, there was a focus on maintaining high bond ratings. Debt levels have not been reduced as sharply in these health care systems as they have in investor-owned hospitals, in part due to the use of debt to support investments in financial markets. Because these health care systems do not have easy access to equity, high bond ratings and solid investment earnings are central to their capital structure policies of preserving access to debt markets.

Changes in functional health status of older women with heart disease: evaluation of a program based on self-regulation

OBJECTIVES

This study involving 570 women aged 60 years or older with heart disease, assessed the effects of a disease management program on physical functioning, symptom experience, and psychosocial status.

METHODS

Women were randomly assigned to control or program groups. Six to eight women met weekly with a health educator and peer leader over 4 weeks to learn self-regulation skills with physical activity as the focus. Evaluative data were collected through telephone interviews, physical assessments, and medical records at baseline and 4 and 12 months post baseline.

RESULTS

At 12 months, compared with controls, program women were less symptomatic (p < .01), scored better on the physical dimension of the Sickness Impact Profile (SIP; p < 0.05), had improved ambulation as measured by the 6-minute walk (p < 0.01), and lost more body weight (p < .001). No differences related to psychosocial factors as measured by the SIP were noted.

CONCLUSION

A self-regulation-based program that was provided to older women with heart disease and that focused on physical activity and disease management problems salient to them, improved their physical functioning and symptom experience. Psychosocial benefit was not evident and may be a result of measurement error or due to insufficient program time spent on psychosocial aspects of functioning.

Prosthetic above-knee femoropopliteal bypass grafting: five-year results of a randomized trial

PURPOSE

This trial was designed to identify factors affecting patency rates of primary prosthetic above-knee femoropopliteal bypass grafts at 5 years.

METHODS

A multi-institutional, prospective trial randomized 240 patients to compare patency rates of Gore-tex and Hemashield above-knee femoropopliteal bypass grafts at 5 years. Univariate comparisons of patency between levels of each prognostic variable were made with the Kaplan-Meier method. Variables that had a univariate P value less than.25 or those known to be important were submitted to a Cox regression analysis.

RESULTS

The patient survival rate at 5 years was 59.4%. There were no differences in primary or secondary patency rates at 5 years between the two graft materials (primary, 45% vs 43% and secondary, 68% vs 68%). The risk for graft occlusion was significantly increased for patients younger than 65 years (2.1; P =.001) and for grafts with a diameter less than 7 mm (1.65; P =.0219). Variables with no apparent independent effect on patency rates were smoking status, runoff, diabetes mellitus, sex, presenting symptoms, and postoperative treatment with aspirin or Coumadin. Noninvasive test results were not predictive of subsequent graft function.

CONCLUSION

Although the type of prosthetic used for above-knee femoropopliteal bypass grafts does not affect 5-year patency rates, age and graft size do influence results. These factors should be considered before a prosthetic bypass grafting procedure. Furthermore, these data should serve as a contemporary standard, with which evolving and conventional procedures can be compared.

Private and public ownership in outpatient substance abuse treatment: do we have a two-tiered system?

As investor-owned organizations increase their presence in the mental health care sector, questions emerge regarding the effects of ownership type on service delivery. One important question is whether ownership is related to patient access to care for persons requiring treatment for substance abuse problems. Using data from a 1995 national survey of outpatient substance abuse treatment units, the authors investigate whether there are differences in measures of patient access to care among investor-owned, not-for-profit, and public provider organizations. Results indicate investor-owned units cater to and serve a clientele that differs from that of not-for-profit and public units, suggesting the presence of a two-tiered system of substance abuse treatment.

Steal syndrome complicating hemodialysis access procedures: can it be predicted?

The development of steal syndrome distal to an arteriovenous fistula (AVF) created for hemodialysis access remains a significant clinical problem. This study was undertaken to determine the role of intraoperative noninvasive testing in the prediction and management of steal syndrome following arteriovenous fistula creation. First, in order to determine a threshold digital/brachial index (DBI) for patients at risk for steal syndrome, we performed a retrospective review of patients who had had the DBI measured and who developed symptoms (steal syndrome) following AVF creation. This was followed by a prospective evaluation of the ability of the DBI to predict which patients undergoing AVF surgery would develop steal syndrome. A DBI of <0.6 identifies a patient at risk for steal syndrome. Intraoperative DBI cannot be used to predict which patient will develop steal syndrome; however, if revision is indicated, the DBI should be increased to >0.6. Failure to accomplish this puts the patient at risk for continued steal syndrome.

Subfascial perforator vein ablation: comparison of open versus endoscopic techniques

PURPOSE

To compare the outcomes and complications of open (OSPS) versus endoscopic subfascial perforator surgery (SEPS) for treatment of chronic venous insufficiency.

METHODS

Data were retrospectively collected on 25 patients who underwent 27 SEPSs from February 1996 to August 1997 and from 22 patients who underwent 29 OSPSs between March 1978 and May 1993. Outcomes were evaluated for postoperative complications, ulcer healing, recurrence, and venous dysfunction scores on the last follow-up for the SEPS group and at 1-year follow-up for the OSPS group.

RESULTS

The 2 groups were similar in age, sex, history of previous venous surgery, healed or active ulcers, etiology, deep venous incompetency, pathophysiology, and venous refill times. Eighteen (90%) of 20 active ulcers in the SEPS group healed with recurrences in 5 (28%) limbs at 7.5 +/- 5.4-month follow-up. All 19 ulcers in the OSPS group healed, with recurrences in 13 (68%) limbs at 35 +/- 35-month follow-up. Clinical venous dysfunction scores showed significant improvement following SEPS (10.0 +/- 3.6 to 5.4 +/- 4.1, p < 0.001) and OSPS (10.0 +/- 3.2 to 6.7 +/- 3.6, p < 0.001) with no significant difference between groups. Both groups also had significant improvement in anatomical and disability scores. There was no postoperative mortality in either group. The OSPS group had significantly more wound complications (45%) than the SEPS group (7%) (p < 0.005). The hospital stay and readmission rate for wound problems were also higher in the OSPS group.

CONCLUSIONS

The early outcome showed equal improvement in clinical venous dysfunction scores in the 2 groups, but with significantly fewer complications in the SEPS group. Although the long-term durability of the endoscopic approach has not been determined, the short-term results would favor SEPS for treatment of severe venous insufficiency when perforator incompetence is a significant component.

What do we want and what do we get from not-for-profit hospitals?

The tax exemption for not-for-profit hospitals has been subject to many recent challenges, in part related to concerns over whether these hospitals provide sufficient levels of community benefits to merit tax exemption. Computing the value of community benefits for California hospitals as the sum of uncompensated care, education and research, net income, money-losing services, and price discounts from for-profit hospitals reveals that 20 to 80 percent of hospitals would have met various recommended community benefits standards. There is a clear need for hospitals and their communities to establish dialogues on what levels of community benefits are appropriate.

Financial and organizational determinants of hospital diversification into subacute care

OBJECTIVE

To examine the financial, market, and organizational determinants of hospital diversification into subacute inpatient care by acute care hospitals in order to guide hospital managers in undertaking such diversification efforts.

STUDY SETTING

All nongovernment, general, acute care, community hospitals that were operating during the years 1985 through 1991 (3,986 hospitals in total).

DATA SOURCES

Cross-sectional, time-series data were drawn from the American Hospital Association's (AHA) Annual Survey of Hospitals, the Health Care Financing Administration's (HCFA) Medicare Cost Reports, a latitude and longitude listing for all community hospital addresses, and the Area Resource File (ARF) published in 1992, which provides county level environmental variables.

STUDY DESIGN

The study is longitudinal, enabling the specification of temporal patterns in conversion, causal inferences, and the treatment of right-censoring problems. The unit of analysis is the individual hospital.

KEY FINDINGS

Significant differences were found in the average level of subacute care offered by investor-owned versus tax-exempt hospitals. After controlling for selection bias, financial performance, risk, size, occupancy, and other variables, IO hospitals offered 31.3 percent less subacute care than did NFP hospitals. Financial performance and risk are predictors of IO hospitals' diversification into subacute care, but not of NFP hospitals' activities in this market. Resource availability appears to expedite expansion into subacute care for both types of hospitals.

CONCLUSIONS

Investment criteria and strategy differ between investor-owned and tax-exempt hospitals.

Managed care and technical efficiency in outpatient substance abuse treatment units

This article examines (1) the extent to which managed care participation is associated with technical efficiency in outpatient substance abuse treatment (OSAT) organizations and (2) the contributions of specific managed care practices as well as other organizational, financial, and environmental attributes to technical efficiency in these organizations. Data are from a nationally representative sample survey of OSAT organizations conducted in 1995. Technical efficiency is modeled using data envelopment analysis. Overall, there were few significant associations between managed care dimensions and technical efficiency in outpatient treatment organizations. Only one managed care oversight procedure, the imposition of sanctions by managed care firms, was significantly associated with relative efficiency of these provider organizations. However, several organizational factors were associated with the relative level of efficiency including hospital affiliation, mental health center affiliation, JCAHO accreditation, receipt of lump sum revenues, methadone treatment modality, percentage clients unemployed, and percentage clients who abuse multiple drugs.

A comparison of surgery for neurogenic thoracic outlet syndrome between laborers and nonlaborers

OBJECTIVE

To determine factors of outcome following surgical intervention for neurologic thoracic outlet syndrome (NTOS).

METHODS

In a retrospective study of patients surgically treated for NTOS, outcome was evaluated by postoperative symptoms and the ability of patients to return to work.

RESULTS

Good, fair, and poor results were obtained in 26 (48%), 21 (39%), and 7 (13%) patients, respectively. The best predictor of a good outcome was occupation. Nonlaborers were more likely to have good outcome (21 of 32, 66%) when compared with laborers (5 of 22, 23%; P = 0.0025). Only 6 of 20 (30%) laborers were able to return to their original occupation compared with 17 of 26 (65%) nonlaborers (P = 0.036).

CONCLUSIONS

Laborers with NTOS are less likely to have a good result from surgical intervention, are unlikely to return to their original occupation, and may require retraining for a non-labor-intensive occupation if they cannot return to their original work.

Long-term outcome after early infrainguinal graft failure

PURPOSE

To determine the long-term outcome and prognostic factors after early infrainguinal graft failure (< 30 days).

METHODS

Retrospective analysis of limb salvage data, patency data, and prognostic risk factors in 112 new infrainguinal bypass grafts from 1985 to 1995 that occluded within 30 days of operation.

RESULT

Thirty-six femoropopliteal and 76 femorotibial/femoropedal arterial bypass ("index") procedures were performed for rest pain (50%), tissue loss (31%), or disabling claudication (19%). In 103 patients, an immediate additional revascularization ("takeback") procedure was performed at the time of early graft failure. Life table analysis of the takeback procedures for threatened limbs (n = 84) revealed limb salvage rates of 74%, 54%, 40%, and 31% at 1 month, 1 year, 3 years, and 5 years, respectively. The 1-month limb salvage rate (threatened limbs) was 12% (1 of 8) in patients who were not taken back for revascularization and 33% (4 of 12) in patients who had undergone more than one takeback procedure within 30 days. The secondary graft patency rates for the takeback procedures (n = 103) were 70%, 37%, 27%, and 23% at 1 month, 1 year, 3 years, and 5 years, respectively. Univariate and life table analysis revealed that patients who were given anticoagulation medication after the index procedure (before graft thrombosis) or patients who had undergone previous ipsilateral leg revascularization had significantly lower rates of limb salvage and graft patency (p < 0.05). The limb salvage rate was also significantly worse in patients who had single-vessel runoff compared with those who had multiple-vessel runoff (p < 0.01). Thrombectomy and revision or complete graft replacement had a better secondary patency rate than thrombectomy alone (p < 0.05). Autogenous vein grafts had better outcome than polytetrafluoroethylene-containing grafts, but statistical significance was not achieved. No significant differences in limb salvage or graft patency rates were found between femoropopliteal versus femorotibial/femoropedal bypass grafting, age, gender, previous inflow surgery, diabetes, hypertension, smoking, or cardiac, renal, or pulmonary disease.

CONCLUSION

The long-term limb salvage and graft patency rates after takeback revascularization procedures for early graft failure are poor. Despite poor outcome, a single takeback procedure appears warranted in all patients. Multiple takeback procedures, however, do not appear to be justified, especially in patients who are given anticoagulation medication after the index bypass procedure, repeat leg bypass procedures, or if there is no potential for graft revision.

Blunt injury of the abdominal aorta: a review

Injury to the abdominal aorta after blunt trauma occurs much less frequently than injury to the thoracic aorta. Although presentations vary, common themes continue to emerge with each patient. Within a 6-month period, our trauma unit diagnosed and treated two cases of blunt abdominal aortic trauma. Both patients were restrained passengers in motor vehicle crashes with resultant abdominal aortic injuries and demonstrated some of the most common associated injuries. Our two cases bring the number found in the literature to 62 and demonstrate the need for rapid recognition and treatment of this potentially lethal injury. This article is a comprehensive review of the management of abdominal aortic injury from blunt trauma.

Prosthetic above-knee femoropopliteal bypass grafting: results of a multicenter randomized prospective trial. Above-Knee Femoropopliteal Study Group

PURPOSE

There are excellent arguments in favor of the preferential use of prosthetic grafts above the knee for the treatment of infrainguinal occlusive disease. This approach has been popularized on the basis of the seemingly acceptable results when using polytetrafluoroethylene (PTFE). However, in many centers, knitted Dacron polyester has been used in these patients, and there are several studies that show equivalent and, in some, superior results with Dacron when compared with PTFE. The purpose of this study was to examine these results in a definitive way.

METHODS

A randomized prospective trial in eight clinical academic centers in the United States and Canada was initiated in 1991. Two hundred forty-four patients eligible for such a study, by virtue of criteria extant in each institution at the time, were centrally randomized. They underwent placement of either a knitted Dacron polyester graft impregnated with collagen or a thin-wall expanded reenforced PTFE graft to the above-knee popliteal artery, usually from the common femoral artery. They were frequently observed by protocol for as long as 5 years by a physical examination noninvasive hemodynamic study, including duplex scanning in many instances. Continuing patency was noted, as were other potential adverse outcome events. The data were analyzed by the log-rank test for cumulative patency and expressed as Kaplan-Meier curves. Data were further analyzed with a Cox proportional hazards model.

RESULTS

There were no differences in graft groups in demographic or comorbid factors. The procedural mortality rate was zero, and the morbidity rate was low (6.5%). The long-term patient survival rate was excellent (77% at 3 years). At the end of these years, no statistical significance in primary or secondary patency rates was observed between the two grafts (primary patency rate, 62% +/- 14.4% for Dacron; 57% +/- 15.5% for PTFE). No unexpected adverse outcomes on limb status were noted. Patency rates in both graft groups were inferior in patients who received small grafts (5 to 6 mm vs 7 to 8 mm; hazards ratio, 4.15) and younger (<65 years) smoking patients.

CONCLUSIONS

The fact that these two prosthetic grafts performed in equivalent fashion in a controlled, well-conducted prospective study is not surprising in spite of the previous work that suggested differences. If the preferential use of synthetic bypass grafts above the knee is to be used, it should be restricted to older nonsmokers with favorable anatomy. In that instance, the choice of graft material will depend on handling characteristics and cost. Above-knee prostheses should be only selectively used in younger, smoking patients, and graft size should be carefully considered in patients who undergo this operation.

A new technique for hemodialysis access surgery: use of the pneumatic tourniquet

The purpose of this study was to determine whether tourniquet occlusion could be safely used on the upper extremity for vascular control during hemodialysis access surgery. The hospital and outpatient records of 44 patients undergoing 105 hemodialysis access procedures were retrospectively reviewed. In 48 procedures tourniquet occlusion was used for vascular control, whereas in 57 procedures vascular clamps were used. In those procedures in which the tourniquet was used, the mean tourniquet time was 30 minutes and the mean tourniquet pressure was 242 mm Hg. The operative time was significantly less in the tourniquet group as compared to the clamp group (72.5 minutes vs. 84 minutes, respectively; p = 0.029). There was no statistically significant difference in the incidence of nerve injury, bleeding, hematoma, vascular steal, infection, or swelling between the two groups. There were no complications related specifically to the use of the tourniquet. There was no difference in primary patency in comparing the tourniquet control group with the clamp control group (p > 0.5). The use of a pneumatic tourniquet for vascular control during hemodialysis access surgery allows for a faster, technically easier operation with no increase in the complication rate and no effect on primary patency.

Philanthropy and hospital financing

OBJECTIVE

This study explores the relationships among donations to not-for-profit hospitals, the returns provided by these hospitals, and fund-raising efforts. It tests a model of hospital behavior and addresses an earlier debate regarding the supply price of donations.

DATA SOURCES

The main data source is the California Office of Statewide Health Planning data tapes of hospital financial disclosure reports for fiscal years 1980/1981 through 1986/1987. Complete data were available for 160 hospitals.

STUDY DESIGN

Three structural equations (donations, returns, and fund-raising) are estimated as a system using a fixed-effects, pooled cross-section, time-series least squares regression.

PRINCIPAL FINDINGS

Estimation results reveal the expected positive relation between donations and returns. The reverse relation between returns and donations is insignificant. The estimated effect of fund-raising on donations is insignificantly different from zero, and the effect of donations on fund-raising is negative. Fund-raising and returns are negatively associated with one another.

CONCLUSION

The empirical results presented here suggest a positive donations-returns relations and are consistent with a positive supply price for donations. Hospitals appear to view a trade-off between providing returns and soliciting donations, but donors do not respond equally to these two activities. Attempts to increase free cash flow through expansion of community returns or fund-raising activity, at least in the short run, are not likely to be highly successful financing strategies for many hospitals.

Fundraising, government grants and donations to nonprofit hospital charities

Using 1982-1987 tax return data from California hospital charities, this paper investigates the relationship between fundraising expenditures, government grants and donations, during a time in which significant changes were being made in the system of hospital reimbursement. Empirical results suggest that while donations have been declining, charities have been efficient in their solicitation of donations. Results also suggest that government grants worked to reduce charitable contributions in the period before the institution of Medicare's Prospective Payment System. In more recent years, government grants have been associated with increases in donations to hospital charities.

Coexistent abdominal aortic aneurysm and renal carcinoma: management options

Renal carcinoma (RCA) presenting in association with abdominal aortic aneurysm (AAA) is extremely rare, with only sporadic case reports previously described. The management of six cases of AAA and concomitant RCA presenting to a single institution from March, 1991 through December, 1993 was reviewed and management options considered. AAAs ranged in size from 4.5-7.0 cm (mean, 5.6 cm). Three left renal carcinomas were resected via a retroperitoneal approach simultaneous to repair of the AAA. One right renal carcinoma was resected in combination with repair of an AAA through a transperitoneal approach. The fifth case was managed by left nephrectomy, followed by interval aneurysmectomy, and the sixth case was managed by nonsurgical methods because of the presence of widely metastatic disease. Renal malignancies included five renal cell carcinomas and one transitional cell carcinoma. Three patients remain free of disease 8-11 months postoperatively, and one patient had metastatic disease detected 19 months postoperatively. Two deaths have occurred; one due to a massive CVA 1 month following a combined aneurysmectomy and left nephrectomy, and a second due to unknown etiology in the patient managed non-surgically. No peripheral vascular or aortic graft related complications have occurred. The treatment of AAA and RCA should be governed by the size of the AAA, the location of the cancer, and the extent of malignant disease. Simultaneous resection is safe and effective in patients with coexistent AAA and renal cancer. Left sided tumors should be resected via a retroperitoneal approach that also provides excellent exposure for simultaneous AAA resection.(ABSTRACT TRUNCATED AT 250 WORDS)

Intraoperative iliac artery stents: combination with infra-inguinal revascularization procedures

Iliac artery percutaneous transluminal angioplasty (PTA) can effectively provide in-flow for subsequent distal vascular reconstruction. Iliac artery stents may improve the initial hemodynamics and long term patency of PTA, and thus may be well-suited for combined proximal PTA with distal bypass procedures. This report reviews our preliminary experience with iliac artery stenting in combination with infra-inguinal vascular reconstruction. Thirteen iliac artery stent procedures combined with simultaneous distal revascularization were performed in 11 patients. Ten procedures were performed for limb salvage, two for disabling claudication, and one before planned orthopedic surgery. Distal revascularization procedures included seven femoropopliteal, four femorotibial bypasses, one common femoral endarterectomy, and one thrombectomy of a femoropopliteal bypass. Stent placement was technically successful in all patients. Mean pre-operative ankle-brachial index (ABI) was 0.41 (+/- 0.28), which improved to 0.91 (+/- 0.18) post-operatively (P < 0.0001). Mean systolic iliac artery gradients across the lesions improved from 27.1 (+/- 9.8) mm Hg to 2.7 (+/- 3.4) mm Hg after stent placement (P < 0.0001). Mean follow-up is 5.8 months (range 1-12 months). Two femoropopliteal bypass grafts occluded in the follow-up period. One occlusion was caused by a mid-vein graft stenosis that was repaired with subsequent graft patency. The other graft occlusion occurred in a patient with rest pain who did not require a second bypass procedure, as the ABI increased from 0.3 to 0.7 following stent placement with resolution of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)