Acute and long-term cost implications of coronary stenting

Coronary Stenting: Reflections on a 35-Year Journey

Stenting was introduced as a therapy for coronary artery disease 35 years ago, and is currently the most commonly performed minimally invasive procedure globally. Percutaneous coronary revascularization, initially with plain old balloon angioplasty and later with stenting, has dramatically affected the outcomes of acute myocardial infarction and acute coronary syndromes. Coronary stenting is probably the most intensively studied therapy in medicine on the basis of the number of randomized clinical trials for a broad range of indications. Continuous improvements in stent materials, design, and coatings concurrent with procedural innovations have truly been awe-inspiring. The story of stenting is replete with high points and some low points, such as the initial experience with stent thrombosis and restenosis, and the more recent disappointment with bioabsorbable scaffolds. History has shown rapid growth of stent use with expansion of indications followed by contraction of some uses in response to clinical trial evidence in support of bypass surgery or medical therapy. In this review we trace the constantly evolving story of the coronary stent from the earliest experience until the present time. Undoubtedly, future iterations of stent design and materials will continue to move the stent story forward.

How to perform electroanatomic mapping-guided cardiac resynchronization therapy using Carto 3 and ESI NavX three-dimensional mapping systems

AIMS 

To examine the feasibility and safety of a novel protocol for low fluoroscopy, electroanatomic mapping (EAM)-guided Cardiac resynchronization therapy with a defibrillator (CRT-D) implantation and using both EnSite NavX (St. Jude Medical, St. Paul, MN, USA) and Carto 3 (Biosense Webster, Irvine, CA, USA) mapping systems.

METHODS AND RESULTS

Twenty consecutive patients underwent CRT implantation using either a conventional fluoroscopic approach (CFA) or EAM-guided lead placement with Carto 3 and EnSite NavX mapping systems. We compared fluoroscopy and procedural times, radiopaque contrast dose, change in QRS duration pre- and post-procedure, and complications in all patients. Fluoroscopy time was 86% lower in the EAM group compared to the conventional group [mean 37.2 min (CFA) vs. 5.5 min (EAM), P = 0.00003]. There was no significant difference in total procedural time [mean 183 min (CFA) vs. 161 min (EAM), P = 0.33] but radiopaque contrast usage was lower in the EAM group [mean 16 mL (CFA) vs. 4 mL (EAM), P = 0.006]. Likewise, there was no significant change in QRS duration with BiV pacing between the groups [mean -13 (CFA) vs. -25 ms (EAM), P = 0.09].

CONCLUSION 

Electroanatomic mapping-guided lead placement using either Carto or ESI NavX mapping systems is a feasible alternative to conventional fluoroscopic methods for CRT-D implantation utilizing the protocol described in this study.

Cost-effectiveness modelling of percutaneous coronary interventions in stable coronary artery disease

The objective of this study is to develop a cost-effectiveness model comparing drug eluting stents (DES) vs bare metal stent (BMS) in patients suffering of stable coronary artery disease. Using a 2-years time horizon, two simulation models have been developed: BMS first line strategy and DES first line strategy. Direct medical costs were estimated considering ambulatory and hospital costs. The effectiveness endpoint was defined as treatment success, which is the absence of major adverse cardiac events. Probabilistic sensitivity analyses were carried out using 10000 Monte-Carlo simulations. DES appeared slightly more efficacious over 2 years (60% of success) when compared to BMS (58% of success). Total costs over 2 years were estimated at 9303 € for the DES and at 8926 € for bare metal stent. Hence, corresponding mean cost-effectiveness ratios showed slightly lower costs (P < 0.05) per success for the BMS strategy (15520 €/success), as compared to the DES strategy (15588 €/success). Incremental cost-effectiveness ratio is 18850 € for one additional percent of success. The sequential strategy including BMS as the first option appears to be slightly less efficacious but more cost-effective compared to the strategy including DES as first option. Future modelling approaches should confirm these results as further comparative data in stable coronary artery disease and long-term evidence become available.

Drug-eluting stents: from evidence to policy

Drug-eluting stents are a major breakthrough in cardiology, with the Cypher (Cordis Corporation) and Taxus (Boston Scientific) stents preventing 60-70% of repeat coronary revascularizations, compared with bare metal stents. Both evidence- and risk-based application of drug-eluting stents is expected to create relevant financial and equity problems to most public hospitals, as the cost of drug-eluting stents is over 1000 higher than traditional stents. In the perspective of third-party payers, drug-eluting stents are cost-effective revascularization strategies for a large portion of patients actually undergoing stenting. However, adequate guidelines and reimbursement strategies are still awaited in several countries.

Assessment of coronary artery stent patency and restenosis using 64-slice computed tomography

RATIONALE AND OBJECTIVES

Restenosis remains a major limitation of coronary catheter-based stent placement. Therefore, a reliable noninvasive diagnostic method for the evaluation of stented coronary arteries would be highly desirable. Our aim was to evaluate the diagnostic accuracy of high-resolution 64-slice computed tomography (64SCT) in a pilot study for the assessment of the lumen of coronary artery stents.

MATERIALS AND METHODS

Twenty-five patients underwent 64SCT of the coronary arteries and quantitative x-ray coronary angiography (QCA) after coronary artery stent placement. 64SCT coronary angiography was performed with the following parameters: spatial resolution = 0.4 x 0.4 x 0.4 mm; temporal resolution = 83-165 milliseconds; contrast agent = 80 mL at a flow rate of 5 mL/second; retrospective electrocardiogram gating. The 64SCT scans were evaluated for image quality and for the presence of significant in-stent and peri-stent (proximal and distal) stenoses. Determinations were made of the sensitivity, specificity, diagnostic accuracy, and positive and negative predictive values (PPV and NPV) of 64SCT for the detection or exclusion of stenoses.

RESULTS

A total of 46 stents were evaluated, of which 45 (98%) were of diagnostic image quality. Significant in-stent restenosis or occlusion was detected on QCA in 8/45 cases (>/=50% stenosis = 6; occlusion = 2). The sensitivity, specificity, accuracy, PPV, and NPV of 64SCT for the detection of significant in-stent disease was 75%, 92%, 89%, 67%, and 94%, respectively. Both occluded coronary artery stents were correctly identified. The sensitivity, specificity, and accuracy values of 64SCT for the detection of significant proximal peri-stent stenoses were 75%, 95%, and 93%, respectively, whereas the values for detection of significant distal peri-stent stenoses were 67%, 85%, and 84%, respectively.

CONCLUSION

The high spatial and temporal resolution of 64SCT may permit improved assessment of stent occlusion and peri-stent disease, although detection of in-stent stenosis remains difficult.

Provisional stenting for multivessel PCI

BACKGROUND

Bare stents reduce acute complications and repeat revascularization following percutaneous coronary intervention (PCI), but are costly and may lead to in-stent restenosis. It remains unclear whether stents should be universally implanted or whether provisional stenting mainly to suboptimal balloon dilatation results is an acceptable approach for multivessel PCI.

OBJECTIVE

To compare the long-term clinical restenosis and target lesion revascularization (TLR) of stented and non-stented coronary artery lesions in patients who had multivessel PCI.

METHODS

We performed retrospective analysis of matched data from 129 consecutive patients who underwent multivessel PCI (at least optimal balloon angioplasty to one coronary artery segment and balloon angioplasty plus stenting to another coronary artery in the same patient, all lesions are de novo native coronary artery lesions with vessel diameter >/=2.5 mm). The study endpoint was restenosis and repeat revascularization at one-year follow-up.

RESULTS

Baseline characteristics were similar in both groups. Low in-hospital MACE (3.1%). Acute myocardial infarction, emergency revascularization via either PCI or CABG was detected and angiographic success was achieved in 99.3% of lesions in both groups. The rate of clinically driven angiographic restenosis and TLR at one-year (follow-up 100%) was similar (17.1% versus 18.6%, P=0.871, and 13.9% versus 16.3%, P=0.728, for optimal balloon angioplasty versus provisional stenting.

CONCLUSIONS

The main findings from this study are that long-term angiographic restenosis and TLR was comparable for optimal balloon angioplasty and provisional stenting, suggesting that provisional stenting is an acceptable approach for multivessel PCI.

Randomized comparison of a titanium-nitride-oxide-coated stent with a stainless steel stent for coronary revascularization: the TiNOX trial

BACKGROUND

Stent coating with titanium-nitride-oxide has been shown to reduce neointimal hyperplasia in the porcine restenosis model. We designed a prospective, randomized, clinical study to investigate the safety and efficacy of titanium-nitride-oxide-coated stents compared with stainless steel stents.

METHODS AND RESULTS

Ninety-two patients with de novo lesions were randomly assigned to treatment with titanium-nitride-oxide-coated stents (n=45) or stainless steel stents of otherwise identical design (n=47; control). Baseline characteristics were similar in both groups. At 30 days, no stent thromboses or other adverse events had occurred in either group. Quantitative coronary angiography at 6 months revealed lower late loss (0.55+/-0.63 versus 0.90+/-0.76 mm, P=0.03) and percent diameter stenosis (26+/-17% versus 36+/-24%, P=0.04) in lesions treated with titanium-nitride oxide-coated than in control stents. Binary restenosis was reduced from 33% in the control group to 15% in the titanium-nitride oxide-coated stent group (P=0.07). Intravascular ultrasound studies at 6 months showed smaller neointimal volume in titanium-nitride-oxide-coated stents than in control stents (18+/-21 versus 48+/-28 mm3, P<0.0001). Major adverse cardiac events at 6 months were less frequent in titanium-nitride-oxide-coated stents than in control stent-treated patients (7% versus 27%, P=0.02), largely driven by a reduced need for target-lesion revascularization (7% versus 23%, P=0.07).

CONCLUSIONS

Revascularization with titanium-nitride-oxide-coated stents is safe and effective in patients with de novo native coronary artery lesions. Titanium-nitride-oxide-coated stents reduce restenosis and major adverse cardiac events compared with stainless steel stents of otherwise identical design.

Economic effects of prolonged clopidogrel therapy after percutaneous coronary intervention

OBJECTIVES

This study examined the incremental cost-effectiveness of extending clopidogrel therapy from one month to one year after percutaneous coronary intervention (PCI) in an unselected, heterogeneous patient population.

BACKGROUND

Clinical trials suggest that prolonging clopidogrel therapy for up to one year after PCI reduces downstream cardiac events. However, clopidogrel therapy is costly and may increase bleeding risk.

METHODS

Using decision analysis, we compared the outcomes and cost of prolonging clopidogrel treatment from one month to one year after PCI with the alternative strategy of discontinuing therapy one month after the procedure. Event rates were based on 3,976 PCI patients who were treated between January 1999 and December 2001 at the Duke Medical Center and received no more than one month of clopidogrel after the procedure. Baseline characteristics and event rates were obtained from Duke clinical information systems. The effect of prolonged clopidogrel therapy on event rates was based on the Clopidogrel for the Reduction of Events During Observation (CREDO) trial per-protocol data. Unit costs and the effect of myocardial infarction (MI) on life expectancy were based on published sources.

RESULTS

Extending clopidogrel therapy from one month to one year after PCI cost USD 879 per patient and reduced the risk of MI by 2.6%. Assuming MI decreases life expectancy by two years, prolonged therapy would cost USD 15,696 per year of life saved. Economic attractiveness of therapy varied with baseline risk, the effect of prolonged therapy on MI risk, and the price of clopidogrel.

CONCLUSIONS

Prolonging clopidogrel therapy for one year after PCI is economically attractive, particularly in high-risk patients.

Cost-effectiveness of fluvastatin following successful first percutaneous coronary intervention

BACKGROUND

In the LIPS (Lescol Intervention Prevention Study), fluvastatin 80 mg/day reduced the risk of major adverse cardiac events (MACE) by 22% versus placebo (p = 0.01) following successful first percutaneous coronary intervention (PCI) in patients with stable or unstable angina or silent ischemia. The cost-effectiveness of such therapy is unknown.

OBJECTIVE

To evaluate the cost-effectiveness of fluvastatin following successful first PCI from a US healthcare system perspective.

METHODS

We used a Markov model to estimate expected outcomes and costs of 2 alternative treatment strategies following successful first PCI in patients with stable or unstable angina or silent ischemia: (1) diet/lifestyle counseling plus immediate fluvastatin 80 mg/day; and (2) diet/lifestyle counseling only, with initiation of fluvastatin 80 mg/day following occurrence of future nonfatal MACE. The model was estimated with data from LIPS and other published sources. Cost-effectiveness was calculated as the ratio of the difference in expected medical-care costs to the expected difference in life-years (LYs) and quality-adjusted life-years (QALYs) alternatively.

RESULTS

Treatment with fluvastatin following successful first PCI was found to increase life expectancy by 0.78 years (QALYs 0.68). Cost-effectiveness of fluvastatin following successful first PCI is 13 505 dollars per LY (15 454 dollar per QALY) saved. Ratios are lower for patients with diabetes (9396 dollar per LY; 10 718 dollar per QALY) and those with multivessel disease (9662 dollar per LY; 11 076 dollar per QALY). Findings were robust with respect to changes in key model parameters and assumptions.

CONCLUSIONS

Fluvastatin therapy following PCI is cost-effective compared with other generally accepted medical interventions.

Clinical and economic outcomes of percutaneous coronary interventions in the elderly: an analysis of medicare claims data

BACKGROUND

Outcomes after percutaneous coronary intervention (PCI) have been documented extensively in clinical trials and single-center series, but few data exist on the clinical and economic outcomes after PCI in an unselected population.

METHODS AND RESULTS

We used the Medicare Standard Analytic File to identify all initial PCI procedures performed in 1998 among a random sample of 5% of all Medicare beneficiaries > or =65 years of age. These patients (n=9868) were followed up for 1 year after PCI to identify clinical outcomes, medical resource use, and costs. Between 1 month and 1 year after PCI, 16.9% of patients required > or =1 repeat revascularization procedures. Mean 1-year medical care costs increased 5-fold among patients with repeat revascularization compared with those without (26,186 dollars versus 5344 dollars; P<0.001). After adjustment for baseline differences, the independent cost of repeat revascularization was 19,074 dollars (95% CI, 18,440 to 19,707). Assuming from previous studies that 85% of repeat revascularization procedures over the first year of follow-up are attributable to restenosis, the estimated clinical restenosis rate was 14.4%, and the 1-year economic burden of restenosis to the healthcare system was 2747 dollars per initial PCI procedure.

CONCLUSIONS

Among unselected elderly patients undergoing PCI, repeat revascularization occurs in approximately 14% and increases 1-year healthcare costs by >19,000 dollars per occurrence. These findings have important implications for the cost-effectiveness of new treatments that substantially reduce restenosis.

Economic impact of drug-eluting stents on hospital systems: a disease-state model

BACKGROUND

Drug-eluting intracoronary stents decrease restenosis and later revascularization. The US Department of Health and Human Services (HHS), recognizing the financial and clinical impact of this technology, recently proposed accelerated reimbursement to hospitals.

METHODS AND RESULTS

A disease state-transition computer model simulated the clinical and economic consequences to hospitals of drug-eluting stents over 5 years. Model parameters combined information from a longitudinal clinical database, a hospital cost-accounting system, and a survey instrument. Simulations were repeated 1000 times for each set of parameters. With 85% of stent procedures shifted to drug-eluting stents in the first year of availability, the mean number of repeat revascularizations dropped by 60.4% at year 5. With no changes in reimbursement policy, a hospital with a catheterization laboratory volume of 3112 patients yearly converted from a 2.01 million dollars (M) annual profit to an 8.10 M dollars loss in the first year (95% CI 8.09 M dollars to 8.12 M dollars) and 8.7 M dollars annual losses in later years. This represented an overall change in cash flow of 55.71 M dollars (95% CI 55.66 M dollars to 55.76 M dollars) away from the hospital over 5 years. The incremental reimbursement proposed by HHS reduced this loss to 4.75 M dollars in the first year and to 5.6 M dollars annually thereafter. In sensitivity analyses, the conversion of patients from bypass surgery to drug-eluting stents was the largest driver of overall cash flow shifts.

CONCLUSIONS

Although Medicare has proposed to increase reimbursement to ease the impact of drug-eluting stents on hospitals, this increase will not totally offset the costs.

A polymer-based, paclitaxel-eluting stent in patients with coronary artery disease

BACKGROUND

Restenosis after coronary stenting necessitates repeated percutaneous or surgical revascularization procedures. The delivery of paclitaxel to the site of vascular injury may reduce the incidence of neointimal hyperplasia and restenosis.

METHODS

At 73 U.S. centers, we enrolled 1314 patients who were receiving a stent in a single, previously untreated coronary-artery stenosis (vessel diameter, 2.5 to 3.75 mm; lesion length, 10 to 28 mm) in a prospective, randomized, double-blind study. A total of 652 patients were randomly assigned to receive a bare-metal stent, and 662 to receive an identical-appearing, slow-release, polymer-based, paclitaxel-eluting stent. Angiographic follow-up was prespecified at nine months in 732 patients.

RESULTS

In terms of base-line characteristics, the two groups were well matched. Diabetes mellitus was present in 24.2 percent of patients; the mean reference-vessel diameter was 2.75 mm, and the mean lesion length was 13.4 mm. A mean of 1.08 stents (length, 21.8 mm) were implanted per patient. The rate of ischemia-driven target-vessel revascularization at nine months was reduced from 12.0 percent with the implantation of a bare-metal stent to 4.7 percent with the implantation of a paclitaxel-eluting stent (relative risk, 0.39; 95 percent confidence interval, 0.26 to 0.59; P<0.001). Target-lesion revascularization was required in 3.0 percent of the group that received a paclitaxel-eluting stent, as compared with 11.3 percent of the group that received a bare-metal stent (relative risk, 0.27; 95 percent confidence interval, 0.16 to 0.43; P<0.001). The rate of angiographic restenosis was reduced from 26.6 percent to 7.9 percent with the paclitaxel-eluting stent (relative risk, 0.30; 95 percent confidence interval, 0.19 to 0.46; P<0.001). The nine-month composite rates of death from cardiac causes or myocardial infarction (4.7 percent and 4.3 percent, respectively) and stent thrombosis (0.6 percent and 0.8 percent, respectively) were similar in the group that received a paclitaxel-eluting stent and the group that received a bare-metal stent.

CONCLUSIONS

As compared with bare-metal stents, the slow-release, polymer-based, paclitaxel-eluting stent is safe and markedly reduces the rates of clinical and angiographic restenosis at nine months.

Retroinfusion-supported stenting in high-risk patients for percutaneous intervention and bypass surgery: Results of the prospective randomized myoprotect I study

The objective of this study was to assess event-free survival and total treatment costs of retroinfusion-supported stenting in high-risk patients compared to bypass surgery. An increasing number of patients with main-stem and main-stem-equivalent stenosis are treated by stent implantation, which appears to be safe in the short-term follow-up. However, there is a lack of randomized studies comparing conventional bypass surgery with stent implantation, particularly in patients with high risk for both treatments. We here report on the 1-year results of a prospective randomized single-center study in patients with symptomatic main-stem and main-stem-equivalent lesions with substantially increased risk for bypass surgery. Patients where randomized to undergo either percutaneous transluminal coronary angioplasty/stent procedure (n = 23) or bypass surgery (n = 21). Patients randomized to stent implantation were supported by selective pressure-regulated retroinfusion of the anterior cardiac vein during ischemia. Patients of the stent group and the bypass group did not differ in baseline characteristics, including Parsonnet score and quality-of-life score. Twenty-eight-day mortality and 1-year mortality rate as well as quality-of-life scores were similar in both groups. Event-free survival after 1 year was higher in the bypass group (71.4% vs. 52.3%; P = 0.02) due to a lower target lesion revascularization rate. With regard to total treatment costs, however, the stent group compared favorably to the bypass group (9,346 +/- 807 vs. 26,874 +/- 3,985 euro), predominantly as a result of a shorter intensive care and hospital stay. In this first randomized study in high-risk patients for stent implantation and bypass surgery, patients with retroinfusion-supported stent implantation had a similar 1-year outcome and quality of life compared to patients with bypass surgery. Though in the stent group event-free survival was lower and target lesion revascularization rate was higher, retroinfusion-supported stent implantation was associated with substantially lower costs and might be considered as an alternative treatment option in this selected group of high-risk patients.

Impact of a practice guideline for patients with atrial fibrillation on medical resource utilization and costs

Health care resource utilization is high for patients presenting with acute atrial fibrillation (AF). The potential for treatment algorithms to safely reduce resource consumption in this setting has not been prospectively evaluated. We designed and implemented a practice guideline for the management of patients presenting to the emergency department (ED) with the primary diagnosis of AF, with emphasis on appropriate cardioversion, use of oral rate-controlling medications, and expedited referral to an outpatient AF clinic. We prospectively collected clinical and resource utilization data on all such patients for 14 months before and after institution of the guideline. Institution of the guideline was associated with a decreased rate of hospital admission (from 74% to 38%), with no differences in ED return visits or hospital readmission within 30 days. No strokes or deaths were observed. This large decrease in resource utilization during the intervention phase of the study translated to an average decrease in 30-day total direct health care costs of approximately $1,400 US dollars per patient. Our clinical and cost outcomes were minimally affected after statistical adjustment for baseline differences between study groups. We conclude that the implementation of our practice guideline was feasible, safe, and effective. Widespread adoption of such practices may have large financial implications for the health care system.

Long-term resource use and cost of percutaneous transluminal coronary angioplasty versus stenting in the elderly: a retrospective claims data analysis

OBJECTIVE

Although the benefits of coronary stenting have been demonstrated in several large clinical trials, controversy remains as to whether stenting results in long-term cost savings compared to percutaneous transluminal coronary angioplasty (PTCA). The objective of this study was to evaluate the resource use and cost (Medicare payment) of PTCA versus bare stent in actual practice over a 2-year period.

METHODS

The data for this study came from the 1996 through 1998 Standard Analytic Files that contain 5% of Medicare claims. The rates of repeat revascularization procedures and hospitalizations were reported at 1 and 2 years. Costs associated with inpatient admission, outpatient procedures, physician services, skilled nursing facility admissions, and home health-care services were included to perform a comprehensive assessment. Regression analysis was performed to test for cost differences controlling for case-mix variation between the patient groups.

RESULTS

The selection process yielded 3782 PTCA patients and 2690 stent patients for analysis. The rate of revascularization was 26.7% for the PTCA group and 22.2% for the stent group at 2 years. The mean total cost for the initial procedure was 13,724 dollars for PTCA and 15,021 dollars for stenting. At 2 years, the total cumulative cost was 32,654 dollars for the PTCA group and 32,102 dollars for the stent group, a difference that was not statistically significant.

CONCLUSION

Although the difference in the rate of repeat revascularization procedures between PTCA and stenting is not as large as those reported in clinical trials, bare stents are cost-neutral when compared to PTCA for the Medicare population.

A break-even price calculation for the use of sirolimus-eluting stents in angioplasty

BACKGROUND

One of the major complications of angioplasty is the early occurrence of restenosis requiring a repeat procedure. When bare-metal stents are used, clinical restenosis results in a repeat procedure in 10% to 15% of cases. Based on the results of an international, randomized clinical trial, the use of sirolimus-eluting stents reduces this risk.

OBJECTIVES

The aims of this study were to calculate the theoretical break-even price for sirolimus-eluting stents in France, the Netherlands, and the United States, and to determine the additional health care cost per patient.

METHODS

The break-even price was calculated by adding the savings resulting from a 15% decrease in the rate of clinical restenosis to the price of bare-metal stents. Costs were computed from the viewpoint of the health care system, exclusive of other societal costs.

RESULTS

The break-even prices were 1291 Euro to 1489 Euro in France, 2028 Euro in the Netherlands, and 2708 Euroin the United States (1.00 Euro = 1.00 US dollar in purchasing power parity). These results indicate that the commercial price of sirolimuseluting stents will increase hospital spending for patients undergoing angioplasty by 17% to 55% per patient.

CONCLUSION

This additional cost to the health care system should be discussed in view of possible productivity savings and improved quality of life for patients.

Cost implications of closure of atrial septal defect

We sought to evaluate the relative cost of surgical and device closure of atrial septal defect. Device closure for atrial septal defects is becoming an alternative to surgical closure. We examined the hospital-generated cost data in 13 patients who underwent surgical repair and 15 patients who underwent device closure of an atrial septal defects (ASD) or patent foramen ovale (PFO) during a prospective clinical trial of the device. The cost of device closure of ASD was 7,837 dollars less on average than surgical closure when the cost of the occlusion device was excluded (device closure cost 7,397 dollars +/- 2,822 dollars, surgical closure cost 15,234 dollars +/- 3,851 dollars; P < 0.001). When adjusted for a 5% failure rate of device closure, the cost savings was 7,076 dollars. Device closure of ASD results in substantial hospital-related cost savings that will be an important consideration once new devices are approved for clinical use.

The impact of statistical adjustment on economic profiles of interventional cardiologists

OBJECTIVES

The objective of this study was to identify preprocedure patient factors associated with percutaneous intervention costs and to examine the impact of these patient factors on economic profiles of interventional cardiologists.

BACKGROUND

There is increasing demand for information about comparative resource use patterns of interventional cardiologists. Economic provider profiles, however, often fail to account for patient characteristics.

METHODS

Data were obtained from Duke Medical Center cost and clinical information systems for 1,949 procedures performed by 13 providers between July 1, 1997, and December 31, 1998. Patient factors that influenced cost were identified using multiple regression analysis. After assessing interprovider variation in unadjusted cost, mixed linear models were used to examine how much cost variability was associated with the provider when patient characteristics were taken into account.

RESULTS

Total hospital costs averaged $15,643 (median, $13,809), $6,515 of which represented catheterization laboratory costs. Disease severity, acuity, comorbid illness and lesion type influenced total costs (R(2) = 38%), whereas catheterization costs were affected by lesion type and acuity (R(2) = 32%). Patient characteristics varied significantly among providers. Unadjusted total costs were weakly associated with provider, and this association disappeared after accounting for patient factors. The provider influence on catheterization costs persisted after adjusting for patient characteristics. Furthermore, the pattern of variation changed: the adjusted analysis identified three new outliers, and two providers lost their outlier status. Only one provider was consistently identified as an outlier in the unadjusted and adjusted analyses.

CONCLUSIONS

Economic profiles of interventional cardiologists may be misleading if they do not adequately adjust for patient characteristics before procedure.

A comparison of total hospital costs for percutaneous coronary intervention patients receiving abciximab versus tirofiban

The purpose of this study was to examine the total hospital costs associated with the receipt of abciximab versus tirofiban for percutaneous coronary intervention (PCI) patients. Hospital billing data for patients with a primary procedure of PCI was examined for the period of July 1998 to June 1999 from HCIA-Sach's Clinical Pathways Database. Data were analyzed for all patient discharges whose records indicated use of abciximab or tirofiban with a PCI. Results are reported for 3,967 patients. Multivariate analysis was used to control for a wide range of factors (GP IIb/IIIa selection, patient demographics, stent use, insurance type, health conditions, admission information, and hospital characteristics) that may influence the cost of hospitalization. A two-stage sample selection model was used to estimate total costs. The first stage of the analysis utilizes a probit regression to determine the factors associated with the likelihood of receiving abciximab versus tirofiban. The second stage of the analysis examines the factors associated with total hospital costs, while controlling for unobserved factors that may be correlated with the patient's likelihood of receiving abciximab. The mean unadjusted cost per hospitalization, including drug costs, was $10,762 (abciximab $10,813 and tirofiban $10,567). After controlling for high-risk indications and selection bias with the two-stage sample selection model, results indicate there was no significant difference in costs associated with the receipt of abciximab versus tirofiban. However, the results also indicate that the two-stage sample selection model may not be needed (lambda was not statistically significant) hence, the cost equation was reestimated using ordinary least-squares methodology (OLS). In the OLS analysis, receipt of abciximab versus tirofiban was associated with a significant reduction in costs ($470 reduction; P = 0.05). This study uses real-world data to examine the total hospital costs for PCI patients who receive abciximab versus tirofiban. Results of the two-stage sample selection model indicate there is no difference in total hospital costs (including drug costs) between abciximab- and tirofiban-treated patients. If the results of the OLS model are considered, a slight decrease in total hospital costs is observed in abciximab recipients. Cost-containment strategies that focus on component costs may not lead to intended overall cost savings.

Long term outcome and cost-effectiveness of stenting versus balloon angioplasty for acute myocardial infarction

OBJECTIVE

To investigate the long term clinical outcome and cost-effectiveness of stenting compared with balloon angioplasty in patients with acute myocardial infarction.

METHODS

Patients with acute myocardial infarction were randomly allocated to primary stenting (112) or balloon angioplasty (115). The primary end point was the cumulative first event rate of death, non-fatal reinfarction, or target vessel revascularisation. Secondary end points were restenosis at six months and the cost-effectiveness at follow up.

RESULTS

After 24 months, the combined clinical end point of death/reinfarction was 4% after stenting and 11% after balloon angioplasty (p = 0.04). Subsequent target vessel revascularisation was necessary in 15 patients (13%) after stenting and in 39 (34%) after balloon angioplasty (p < 0.001). The cumulative cardiac event-free survival rate was also higher after stenting (84% v 62%, p < 0.001). The angiographic restenosis rate after stenting was less than after balloon angioplasty (12% v 34%, p < 0.001). Despite the higher initial costs of stenting (Dfl 21 484 v Dfl 18 625, p < 0.001), the cumulative costs at 24 months were comparable with those of balloon angioplasty (Dfl 31 423 v Dfl 32 933, p = 0.83).

CONCLUSIONS

Compared with balloon angioplasty, primary stenting for acute myocardial infarction results in a better long term clinical outcome without increased cost.

Achieving optimal results with standard balloon angioplasty: can baseline and angiographic variables predict stent-like outcomes?

OBJECTIVES

To predict which patients might not require stent implantation, we identified clinical and angiographic characteristics associated with repeat revascularization after standard balloon angioplasty.

BACKGROUND

Stents reduce the risk of repeat revascularization but are costly and may lead to in-stent restenosis, which remains difficult to treat. Identification of patients at low risk for repeat revascularization may allow clinicians to reserve stents for patients most likely to benefit.

METHODS

Data from five interventional trials (5,146 patients) were pooled for analysis. We identified patients with optimal angiographic results (final diameter stenosis < or =30% and no dissection) after balloon angioplasty and determined the multivariable predictors of repeat revascularization.

RESULTS

Optimal angiographic results were achieved in 18% of patients after angioplasty. The repeat revascularization rate at six months was lower for patients with optimal results (20% vs. 26%, p < 0.001) but still higher than observed in stent trials. Independent predictors of repeat revascularization were female gender (odds ratio [OR] 1.67, p = 0.01), lesion length > or =10 mm (OR 1.62, p = 0.03) and proximal left anterior descending coronary artery lesions (OR 1.62, p = 0.03). For the 8% of patients with optimal angiographic results and none of these risk factors, the repeat revascularization and target vessel revascularization rates were 14% and 8% respectively, similar to rates after stent implantation. Cost analysis estimated that $78 million per year might be saved in the U.S. with a provisional stenting strategy using these criteria compared with elective stenting.

CONCLUSIONS

A combination of baseline characteristics and angiographic results can be used to identify a small group of patients at very low risk for repeat revascularization after balloon angioplasty. Provisional stenting for these low risk patients could substantially reduce costs without compromising clinical outcomes.

Medical costs of intravascular ultrasound optimization of stent deployment. Results of the multicenter randomized 'REStenosis after Intravascular ultrasound STenting' (RESIST) study

OBJECTIVE: Intravascular ultrasound (IVUS) can be used to optimize the deployment of stents. The aim of this study was to assess the acute and long-term medical costs of the use of IVUS through the results of the 'REStenosis after Intravascular ultrasound STenting' (RESIST) study. METHODS: One hundred and fifty-five patients were randomized to routine stent deployment with (n = 79) versus without (n = 76) IVUS guidance, with clinical follow-up over 18 months. The medical costs (hospitalization plus procedural costs) were calculated using a cost accounting system at the time of stent implantation and for all repeat lesion revascularizations. (At the time of writing the exchange rate was 1 Euro = 1 US dollar.) RESULTS: Because of the cost of IVUS catheters and the need for more balloons, acute procedural costs were 18% higher in the group with IVUS guidance (2934 +/- 670 Euros vs 2481 +/- 911 Euros). Clinical events (death, myocardial infarction, unstable angina or lesion revascularization) occurred in 28/76 (37%) in the group without IVUS, versus 20/79 (25%) (OR = 1.7; 95%CI = [0.82; 3.63]) in the group with IVUS. There was a higher number of revascularization procedures in the control group (31 in the control group vs 20 in the IVUS group). The cumulative medical costs at 18 months were only slightly higher in the IVUS group (4535 +/- 2020 Euros vs 4679 +/- 1471 Euros in the IVUS group), as the higher acute costs in the group with IVUS guidance were partially offset by the lower cost for revascularization procedures. Sensitivity analysis using variations of the unit costs as well as variations in the number of revascularization procedures and length of hospital stay showed that the overcost remained in a range between 1% and 7.6%. CONCLUSIONS: Over 18 months of followup, despite higher acute costs, IVUS optimization of stent deployment did not considerably increase the medical costs.

A randomized trial comparing stenting with balloon angioplasty in small vessels in patients with symptomatic coronary artery disease. ISAR-SMART Study Investigators. Intracoronary Stenting or Angioplasty for Restenosis Reduction in Small Arteries

BACKGROUND

More than 30% of the lesions currently treated with interventional approaches are situated in vessels smaller in size than those representing an established indication for stenting. The objective of this randomized trial was to assess whether compared with PTCA, stenting of small coronary vessels is associated with a reduction of restenosis.

METHODS AND RESULTS

Patients with symptomatic coronary artery disease with lesions situated in native coronary vessels between 2 and 2.8 mm in size were randomly assigned to be treated with either stenting (n=204) or PTCA (n=200). Adjunct therapy consisted of abciximab, ticlopidine, and aspirin. Repeat angiography at 6-month follow-up was performed in 83% of the patients. The primary end point of the study was the incidence of angiographic restenosis (>/=50% diameter stenosis) at follow-up; adverse clinical events, such as death, myocardial infarction, stroke, or target vessel revascularization, were assessed as secondary end points. After 7 months, there were no significant differences in the infarct-free survival rates between the 2 study groups: 96.6% for stent patients, and 97.0% for PTCA patients (P:=0. 80). Target vessel revascularization was needed in 20.1% of the stent patients and 16.5% of the PTCA patients (P:=0.35). The primary end point of angiographic restenosis was found in 35.7% of the stent patients and 37.4% of the PTCA patients (P:=0.74). The net lumen gain observed at follow-up was identical (0.76+/-0.78 in the stent group versus 0.76+/-0.63 mm in the PTCA group, P:=0.93).

CONCLUSIONS

Stenting and PTCA are associated with equally favorable results when used for treating lesions in small coronary vessels.

Provisional stenting strategies: systematic overview and implications for clinical decision-making

Coronary stents reduce the rates of abrupt closure, emergency coronary artery bypass graft surgery and restenosis, but do not prevent myocardial infarction or death at six months. The financial burden of increased stent use and the difficulty in managing in-stent restenosis have provided the impetus to develop provisional stenting strategies. Patients at low risk for restenosis after balloon angioplasty may not derive additional benefit from stent implantation and may be successfully managed with percutaneous transluminal coronary angioplasty (PTCA) alone. Numerous patient, lesion and procedural predictors of restenosis have been identified. Postprocedural assessment using quantitative coronary angiography, intravascular ultrasound (IVUS), coronary flow velocity reserve (CVR) or fractional flow reserve (FFR) may further enhance the ability to predict adverse outcomes after PTCA. Several studies have been performed to investigate the feasibility of provisional stenting strategies using various modalities to identify low risk patients who could be managed with PTCA alone. An optimal or "stent-like" angiographic result after PTCA is associated with favorable clinical outcomes. Preliminary results of studies using IVUS or CVR to guide provisional stenting appear promising. Angiography alone may be inadequate to identify truly low risk patients and may need to be combined with clinical factors, assessment of recoil, IVUS or physiologic indexes. Strategies that avoid unnecessary stenting in even a small proportion of patients may have large impacts on health care costs. Provisional stenting may potentially reduce costs and rates of in-stent restenosis without compromising the quality of health care delivery.

Impact of patient characteristics, complications, and facility volume on the costs and time of cardiac catheterization and coronary angioplasty in 70 catheterization laboratories

Although over 1 million procedures are performed in cardiac catheterization laboratories (CCLs) annually, little comparative data exist on costs or resource use in these settings. In this study, data from 70 CCLs were used to profile CCL times and total direct costs for 2 high-volume procedures: left heart catheterization (LHC) and percutaneous transluminal coronary angioplasty (PTCA) with or without stent placement. In total, 70,677 consecutive patient examinations for a 12-month period from January 1, 1998 to December 31, 1998 were analyzed. For LHC mean total direct costs averaged $306, whereas for PTCA catheterization laboratory costs averaged $3,172. The average total times for these procedures were 63 and 108 minutes, respectively. Seventy-two percent of the PTCA patients underwent coronary stenting with an associated incremental cost of $1,244. By multivariate linear regression, baseline patient characteristics such as age, gender, and clinical factors had little impact on total time and total costs. The major determinants of CCL time and cost were procedural factors (e.g., number and type of interventions) and in-lab complications, including profound hypotension, abrupt vessel closure, and emergency bypass surgery. Using facility procedure volume as a proxy for potential economies of scale, we found no relation between CCL volume and total direct CCL costs. There did appear to be a significant inverse relation between facility volume and total procedural time with CCLs that performed the highest volumes of LHC and PTCA procedures saving an average of 5 to 9 minutes per procedure. These findings may be useful in defining specific time and cost benchmarks for these commonly performed procedures and serve to underscore the critical role of reducing complications in both quality improvement and cost-saving efforts.

Update on the interaction between aspirin and angiotensin-converting enzyme inhibitors

We summarized recent published literature regarding the significance of an interaction between aspirin and angiotensin-converting enzyme (ACE) inhibitors in patients with various cardiovascular diseases. A MEDLINE search (January 1998-July 1999) was performed and abstracts from the 1999 American College of Cardiology and 1998 American Heart Association annual scientific sessions were reviewed to identify pertinent studies. Material for discussion was identified through a MEDLINE search from January 1996-July 1999 and through cited references. The results of several studies added to our understanding of the clinical ramifications of an aspirin-ACE inhibitor interaction, but also introduced questions. These studies are largely contradictory, but do reiterate the possibility of an interaction, if only in certain subsets of patients. Low dosages (< or = 100 mg/day) of aspirin appear to be safer in this regard than higher dosages. The frequency and severity of the interaction and possible predisposing factors await future research.

The use of patient mix-adjusted control charts to compare in-hospital costs of care

We introduce a technique for patient mix-adjusting x charts and compared differences between unadjusted and patient mix-adjusted results. Our data came from coronary artery bypass graft (CABG) surgery patients at Baptist Medical Center, Oklahoma City, Oklahoma. We first developed an unadjusted x control chart to compare monthly changes in CABG surgery costs and then used a published model to patient mix-adjust our x control chart information. Before adjustment, the average log costs for three of ten months were outside the 90% control limit lines, and there was a trend toward increasing costs. After adjustment, two months had average costs outside the 90% lower control limit lines, and the trend toward increasing costs had been explained by differences in patient acuity.

Outpatient coronary stenting: femoral approach with vascular sealing

Miniaturized devices and pressures for increased patient convenience and lowered cost have shortened length of stay for coronary interventions. A cohort of 60 patients was recruited to assess the feasibility of outpatient stenting with vascular sealing. Patients with stable and unstable angina or myocardial infarction > 24 hours were considered for this strategy. Mean time to hemostasis, ambulation and discharge were 6.1, 256 and 296 minutes, respectively, for the 6F group, and 11.0, 351 and 489 minutes for the 7 to 8F group. No acute procedural complications occurred, and there were no ischemic complications at 24 hours or 1 month. There was 1 pseudoaneurysm requiring surgical correction, but no other access site requiring treatment. The cost saved using the 6F approach is estimated at $478 and using the 8F approach, $437. Outpatient stenting using vascular sealing is feasible and safe, and may lead to significant nationwide cost reductions in the range of $40,000,000 yearly.