Cost-Effectiveness of Percutaneous Coronary Intervention Versus Bypass Surgery for Patients With Left Main Disease: Results From the EXCEL Trial

BACKGROUND

The EXCEL trial (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) demonstrated in patients with left main coronary artery disease, no significant difference between coronary artery bypass graft surgery (CABG) and percutaneous coronary intervention (PCI) with everolimus-eluting stents for the composite end point of death, stroke, or myocardial infarction at 5 years. However, all-cause mortality at 5 years was higher with PCI. Long-term cost-effectiveness of these 2 strategies has heretofore not been evaluated.

METHODS

From 2010 to 2014, 1905 patients with left main coronary artery disease were randomized to CABG (n=957) or PCI (n=948). Costs ($2019) were assessed over 5 years using resource-based costing and Medicare reimbursement rates. Health utilities were assessed using the EuroQOL 5-dimension questionnaire. Five-year EXCEL data in combination with US lifetables were used to develop a Markov model to evaluate lifetime cost-effectiveness. An incremental cost-effectiveness ratio <$50 000 per quality-adjusted life year (QALY) gained was considered highly cost-effective.

RESULTS

Index revascularization procedure costs were $4,850/patient higher with CABG, and total costs for the index hospitalization were $17 610/patient higher with CABG ($32 297 versus $19 687, P<0.001). Cumulative 5-year costs were $20 449/patient higher with CABG. CABG was projected to increase lifetime costs by $21 551 while increasing quality-adjusted life expectancy by 0.49 QALYs, yielding an incremental cost-effectiveness ratio of $44 235/QALY. In a post hoc sensitivity analysis using mortality hazard ratios from a meta-analysis of all randomized CABG versus PCI in left main disease trials, the gain associated with CABG was 0.08 to 0.14 QALYs, resulting in an incremental cost-effectiveness ratio of $139 775 to $232 710/QALY gained.

CONCLUSIONS

Based on data from the EXCEL trial, CABG is an economically attractive revascularization strategy compared with PCI over a lifetime horizon for patients with significant left main coronary artery disease. However, this conclusion is sensitive to the long-term mortality rates with the 2 strategies, and CABG is no longer highly cost-effective when substituting the pooled treatment effect from the 4 major PCI versus CABG trials for left main disease.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT01205776.

Two-year PAD-related health care costs in patients undergoing lower extremity endovascular revascularization: results from the LIBERTY 360° trial

BACKGROUND

Multiple studies have demonstrated the high economic burden related to the management of lower extremity peripheral artery disease (PAD). This is the first study to examine long-term PAD-related costs among unselected patients undergoing endovascular intervention, and to investigate how clinical and anatomic factors impact cost outcomes over time.

METHODS AND RESULTS

We performed a prospective health economic study alongside the LIBERTY 360° trial (ClinicalTrials.gov; identifier NCT01855412) - a prospective, multi-center study evaluating the long-term outcomes of endovascular revascularization to treat claudication or critical limb ischemia. Costs (2018) were calculated using a combination of standard "bottom-up" cost accounting methods (for index procedures), itemized hospital charges and department level cost-to-charge ratios (for non-procedural hospital resources), national Medicare Severity-Diagnosis Related Group-specific average reimbursements (for follow-up hospitalizations) and Medicare payments (for outpatient/chronic care). Methods for the analysis of censored cost data were used to adjust cost estimates for patients with incomplete follow-up. Independent predictors of cumulative 2-year costs were explored using generalized linear models. A total of 1,189 patients were included (500 Rutherford 2-3, 589 Rutherford 4-5, 100 Rutherford 6). Mean total costs associated with the index procedure hospitalization increased with Rutherford classification ($10,304, $11,418, and $19,403 for Rutherford 2-3, 4-5, and 6, respectively; p < 0.01 in all pairwise comparisons). Mean total 2-year follow-up costs were $11,416, $24,846, and $25,720 for Rutherford 2-3, 4-5, and 6, respectively (p < 0.001 comparing Rutherford 2-3 to the other 2 groups; p = 0.09 comparing Rutherford 4-5 and Rutherford 6). Key predictors of higher cumulative 2-year costs included female sex, pedal lesion location, severe lesion calcification, the presence of one or more chronic total occlusions, the number of wounds present on the target limb at baseline, and Rutherford classification.

CONCLUSIONS

Among patients with symptomatic lower extremity PAD undergoing endovascular revascularization, initial treatment costs and total 2-year costs vary significantly according to clinical and lesion-level characteristics, as well as symptom burden.

Cardiovascular- and Bleeding-Related Hospitalization Rates With Edoxaban Versus Warfarin in Patients With Atrial Fibrillation Based on Results of the ENGAGE AF–TIMI 48 Trial

Background

The ENGAGE AF–TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation–Thrombolysis in Myocardial Infarction 48) demonstrated noninferiority of once-daily 60 mg (30 mg dose-reduced) edoxaban compared with warfarin for prevention of stroke/systemic embolism in patients with atrial fibrillation. No previous analysis has explored the impact of treatment with edoxaban versus warfarin on rates of hospitalizations.

Methods

Detailed healthcare resource utilization data from ENGAGE AF–TIMI 48 for the 14 024 randomized patients who received at least one dose of study drug were used to compare the rates of bleeding- and cardiovascular-related hospitalizations for edoxaban versus warfarin. Hospitalization rates were calculated for each treatment group, and relative rates were estimated using Poisson regression. The influence of patient characteristics on the impact of edoxaban versus warfarin was evaluated through the inclusion of interaction terms.

Results

The overall rate of cardiovascular- or bleeding-related hospitalization was significantly lower for edoxaban than warfarin (relative rate [RR], 0.91 [95% CI, 0.85–0.97], P =0.003). Rates of hospitalizations for cardiovascular reasons (RR, 0.91 [95% CI, 0.85–0.97], P =0.004), stroke (RR, 0.80 [95% CI, 0.72–0.88], P <0.0001), and for each stroke subtype (ischemic: RR, 0.89 [95% CI, 0.81–0.99], P =0.03; hemorrhagic: RR, 0.60 [95% CI, 0.54–0.68], P <0.0001) were also lower for edoxaban. Notably, significantly greater reductions with edoxaban versus warfarin were seen for ischemic stroke–related hospitalizations in vitamin K antagonist naive patients and patients with CHADS 2 scores 4 to 6, previous stroke or transient ischemic attack, age ≥75, and no previous coronary artery disease. For nonstroke bleeding–related hospitalizations, greater reductions with edoxaban were seen in vitamin K antagonist naive patients, patients with CHADS 2 scores 4 to 6, and patients with moderate renal dysfunction.

Conclusions

Edoxaban 60 mg (30 mg dose-reduced) was associated with a significantly lower overall rate of cardiovascular- or bleeding-related hospitalization and significant reductions in the subcategories of cardiovascular-related, stroke-related, bleed-related, and nonstroke cardiovascular–related hospitalizations, when compared with warfarin. These results suggest the potential for cost offsets with edoxaban, with even greater reductions in higher-risk patients.

Registration:

URL: https://www.clinicaltrials.gov ; Unique identifier: NCT00781391

Cost-Effectiveness of Pharmacomechanical Catheter-Directed Thrombolysis Versus Standard Anticoagulation in Patients With Proximal Deep Vein Thrombosis: Results From the ATTRACT Trial

BACKGROUND

In patients with acute deep vein thrombosis (DVT), pharmacomechanical catheter-directed thrombolysis (PCDT) in conjunction with anticoagulation therapy is increasingly used with the goal of preventing postthrombotic syndrome. Long-term costs and cost-effectiveness of these 2 treatment strategies from the perspective of the US healthcare system have not been compared.

METHODS AND RESULTS

Between 2009 and 2014, the ATTRACT trial (Acute Venous Thrombosis: Thrombus Removal With Adjunctive Catheter-Directed Thrombolysis) randomized 692 patients with acute proximal DVT to PCDT plus anticoagulation (n=337) or standard treatment with anticoagulation alone (n=355). Costs (2017 US dollars) were assessed over a 24-month follow-up period using a combination of resource-based costing, hospital bills, Medicare reimbursement rates, and the Drug Topics Red Book. Health state utilities were obtained from the Short Form-36. In-trial results and US life tables were used to develop a Markov cohort model to evaluate lifetime cost-effectiveness. For the PCDT group, mean costs of the initial procedure were $13 600; per-patient costs associated with the index hospitalization were $21 509 for PCDT and $3877 for standard care (difference=$17 632; 95% CI, $16 117-$19 243). The 24-month difference in costs was $20 045 (95% CI, $16 093-$24 120). Utility scores increased significantly between baseline and 6 months for both groups, with no significant differences between groups at any follow-up time point. Projected differences in lifetime costs of $16 740 and quality-adjusted life years (QALYs) of 0.08, yield an incremental cost-effectiveness ratio for PCDT of $222 041/QALY gained. In probabilistic sensitivity analysis, the probability that PCDT would achieve a lifetime incremental cost-effectiveness ratio <$50 000/QALY or <$150 000/QALY was 1% and 25%, respectively. For iliofemoral DVT, QALY gains with PCDT were greater, yielding an incremental cost-effectiveness ratio of $137 526/QALY; for femoral-popliteal DVT, standard therapy was an economically dominant strategy.

CONCLUSIONS

With an incremental cost-effectiveness ratio >$200 000/QALY gained, PCDT is not an economically attractive treatment for proximal DVT. PCDT may be of intermediate value in patients with iliofemoral DVT. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00790335.

Cost-Effectiveness of Long-Term Ticagrelor in Patients With Prior Myocardial Infarction: Results From the PEGASUS-TIMI 54 Trial

BACKGROUND

In patients with a myocardial infarction (MI) 1 to 3 years earlier, treatment with ticagrelor + low-dose aspirin (ASA) reduces the risk of cardiovascular (CV) death, MI, or stroke compared with low-dose aspirin alone, but at an increased risk of major bleeding.

OBJECTIVES

The authors evaluated cost-effectiveness of ticagrelor + low-dose ASA in patients with prior MI within the prior 3 years.

METHODS

The authors performed a prospective economic substudy alongside the PEGASUS-TIMI 54 (Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin-Thrombolysis In Myocardial Infarction 54) trial, which randomized 21,162 patients to ASA alone, ticagrelor 60 mg twice daily + low-dose ASA, or ticagrelor 90 mg twice daily + low-dose ASA. Medical resource use data were collected over a median 33-month follow-up. Costs were assessed from the U.S. health care system perspective. In-trial data relating to survival, utility, and costs were combined with lifetime projections to evaluate lifetime cost-effectiveness of the Food and Drug Administration-approved lower-dose ticagrelor regimen (60 mg twice daily).

RESULTS

Hospitalization costs were similar for ticagrelor 60 mg and placebo ($2,262 vs. $2,333; 95% confidence interval for difference -$303 to $163; p = 0.54); after inclusion of a daily ticagrelor 60 mg cost of $10.52, total costs were higher for ticagrelor ($10,016 vs. $2,333; 95% CI: $7,441 to $7,930; p < 0.001). In-trial quality-adjusted life-years (QALYs) were similar (2.28 vs. 2.27; p = 0.34). Over a lifetime horizon, ticagrelor was associated with QALY gains of 0.078 and incremental costs of $7,435, yielding an incremental cost-effectiveness ratio (ICER) of $94,917/QALY gained. Several high-risk groups had more favorable ICERs, including patients with >1 prior MI, multivessel disease, diabetes, renal dysfunction (all with ICERs $50,000 to $70,000/QALY gained), patients age <75 years (ICER = $44,779/QALY gained), and patients with peripheral artery disease (ICER = $13,427/QALY gained).

CONCLUSIONS

For patients with a history of MI >1 year previously, long-term treatment with ticagrelor 60 mg + low-dose ASA yields a cost-effectiveness ratio suggesting intermediate value based on current guidelines. Ticagrelor appears to provide higher value for patients in several recognized high-risk subgroups. (Prevention of Cardiovascular Events [e.g., Death From Heart or Vascular Disease, Heart Attack, or Stroke] in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin [PEGASUS]; NCT01225562).

Impact of Ezetimibe on the Rate of Cardiovascular-Related Hospitalizations and Associated Costs Among Patients With a Recent Acute Coronary Syndrome

Background—

Ezetimibe, when added to simvastatin therapy, reduces cardiovascular events after recent acute coronary syndrome. However, the impact of ezetimibe on cardiovascular-related hospitalizations and associated costs is unknown.

Methods and Results—

We used patient-level data from the IMPROVE-IT (Improved Reduction of Outcomes: Vytorin Efficacy International Trial) to examine the impact of simvastatin–ezetimibe versus simvastatin–placebo on cardiovascular-related hospitalizations and related costs (excluding drug costs) over 7 years follow-up. Medicare Severity–Diagnosis Related Groups were assigned to all cardiovascular hospitalizations. Hospital costs were estimated using Medicare reimbursement rates for 2013. Associated physician costs were estimated as a percentage of hospital costs. The impact of treatment assignment on hospitalization rates and costs was estimated using Poisson and linear regression, respectively. There was a significantly lower cardiovascular hospitalization rate with ezetimibe compared with placebo (risk ratio, 0.95; 95% confidence interval, 0.90–0.99; P =0.031), mainly attributable to fewer hospitalizations for percutaneous coronary intervention, angina, and stroke. Consequently, cardiovascular-related hospitalization costs over 7 years were $453 per patient lower with ezetimibe (95% confidence interval, −$38 to −$869; P =0.030). Although all prespecified subgroups had lower cost with ezetimibe therapy, patients with diabetes mellitus, patients aged ≥75 years, and patients at higher predicted risk for recurrent ischemic events had even greater cost offsets.

Conclusions—

Addition of ezetimibe to statin therapy in patients with a recent acute coronary syndrome leads to reductions in cardiovascular-related hospitalizations and associated costs, with the greatest cost offsets in high-risk patients. These cost reductions may completely offset the cost of the drug once ezetimibe becomes generic, and may lead to cost savings from the perspective of the healthcare system, if treatment with ezetimibe is targeted to high-risk patients.

Clinical Trial Registration—

URL: https://www.clinicaltrials.gov . Unique Identifier: NCT00202878

Economic Outcomes of Bioresorbable Vascular Scaffolds Versus Everolimus-Eluting Stents in Patients Undergoing Percutaneous Coronary Intervention: 1-Year Results From the ABSORB III Trial

OBJECTIVES

The purpose of this study was to evaluate the economic impact of the Absorb bioresorbable vascular scaffold compared with the Xience everolimus-eluting stent in patients undergoing percutaneous coronary intervention.

BACKGROUND

The ABSORB III trial (Everolimus-Eluting Bioresorbable Scaffolds for Coronary Artery Disease) demonstrated that the Absorb scaffold was noninferior to the Xience stent with respect to target lesion failure at 1 year. Whether health care costs differ between the Absorb scaffold and the Xience stent is unknown.

METHODS

We performed a prospective health economic study alongside the ABSORB III trial, in which patients undergoing percutaneous coronary intervention for stable or unstable angina were randomized to receive the Absorb scaffold (n = 1,322) or Xience stent (n = 686). Resource use data were collected through 1 year of follow-up. Costs were assessed using resource-based accounting (for procedures), MedPAR data (for other index hospitalization costs), and Medicare reimbursements (for follow-up costs and physician fees).

RESULTS

Initial procedural costs were higher with the Absorb scaffold than the Xience stent ($6,316 ± 1,892 vs. $6,103 ± 1,895; p = 0.02), driven mainly by greater balloon catheter use and the higher cost of the scaffold in the Absorb group. Nonetheless, index hospitalization costs ($15,035 ± 2,992 for Absorb vs. $14,903 ± 3,449 for Xience; p = 0.37) and total 1-year costs ($17,848 ± 6,110 for Absorb vs. $17,498 ± 7,411 for Xience; p = 0.29) were similar between the 2 groups.

CONCLUSIONS

Although initial procedural costs were higher with the Absorb scaffold, there were no differences in total 1-year health care costs between the 2 cohorts. Longer term follow-up is needed to determine whether meaningful cost savings emerge after scaffold resorption. (A Clinical Evaluation of Absorb™ BVS, the Everolimus-Eluting Bioresorbable Vascular Scaffold in the Treatment of Subjects With de Novo Native Coronary Artery Lesions; NCT01751906).

Cost-effectiveness of percutaneous coronary intervention with drug eluting stents versus bypass surgery for patients with diabetes mellitus and multivessel coronary artery disease: results from the FREEDOM trial

BACKGROUND

Studies from the balloon angioplasty and bare metal stent eras have demonstrated that coronary artery bypass grafting (CABG) is cost-effective compared with percutaneous coronary intervention (PCI) for patients undergoing multivessel coronary revascularization-particularly among patients with complex coronary artery disease or diabetes mellitus. Whether these results apply in the drug-eluting stent (DES) era is unknown.

METHODS AND RESULTS

Between 2005 and 2010, 1900 patients with diabetes mellitus and multivessel coronary artery disease were randomized to PCI with DES (DES-PCI; n=953) or CABG (n=947). Costs were assessed from the perspective of the U.S. health care system. Health state utilities were assessed using the EuroQOL 5 dimension 3 level questionnaire. A patient-level microsimulation model based on U.S. life-tables and in-trial results was used to estimate lifetime cost-effectiveness. Although initial procedural costs were lower for CABG, total costs for the index hospitalization were $8622 higher per patient. Over the next 5 years, follow-up costs were higher with PCI, owing to more frequent repeat revascularization and higher outpatient medication costs. Nonetheless, cumulative 5-year costs remained $3641 higher per patient with CABG. Although there were only modest gains in survival with CABG during the trial period, when the in-trial results were extended to a lifetime horizon, CABG was projected to be economically attractive relative to DES-PCI, with substantial gains in both life expectancy and quality-adjusted life expectancy and incremental cost-effectiveness ratios <$10 000 per life-year or quality-adjusted life-year gained across a broad range of assumptions regarding the effect of CABG on post-trial survival and costs.

CONCLUSIONS

Despite higher initial costs, CABG is a highly cost-effective revascularization strategy compared with DES-PCI for patients with diabetes mellitus and multivessel coronary artery disease.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinical-trials.gov. Unique identifier: NCT00086450.

Use of drug-eluting stents as a function of predicted benefit: clinical and economic implications of current practice

BACKGROUND

Benefits of drug-eluting stents (DES) in percutaneous coronary intervention (PCI) are greatest in those at the highest risk of target-vessel revascularization (TVR). Drug-eluting stents cost more than bare-metal stents (BMS) and necessitate prolonged dual antiplatelet therapy (DAPT), which increases costs, bleeding risk, and risk of complications if DAPT is prematurely discontinued. Our objective was to assess whether DES are preferentially used in patients with higher predicted TVR risk and to estimate if lower use of DES in low-TVR-risk patients would be more cost-effective than the existing DES use pattern.

METHODS

We analyzed more than 1.5 million PCI procedures in the National Cardiovascular Data Registry (NCDR) CathPCI registry from 2004 through 2010 and estimated 1-year TVR risk with BMS using a validated model. We examined the association between TVR risk and DES use and the cost-effectiveness of lower DES use in low-TVR-risk patients (50% less DES use among patients with <10% TVR risk) compared with existing DES use.

RESULTS

There was marked variation in physicians' use of DES (range 2%-100%). Use of DES was high across all predicted TVR risk categories (73.9% in TVR risk <10%; 78.0% in TVR risk 10%-20%; and 83.2% in TVR risk >20%), with a modest relationship between TVR risk and DES use (relative risk, 1.005 per 1% increase in TVR risk [95% CI, 1.005-1.006]). Reducing DES use by 50% in low-TVR-risk patients was projected to lower US health care costs by $205 million per year while increasing the overall TVR event rate by 0.5% (95% CI, 0.49%-0.51%) in absolute terms.

CONCLUSIONS

Use of DES in the United States varies widely among physicians, with only a modest correlation to patients' risk of restenosis. Less DES use among patients with low risk of restenosis has the potential for significant cost savings for the US health care system while minimally increasing restenosis events.

Cost-effectiveness of everolimus- versus paclitaxel-eluting stents for patients undergoing percutaneous coronary revascularization (from the SPIRIT-IV Trial)

Although several drug-eluting stents (DESs) have been shown to be economically attractive compared to bare-metal stents in patients at moderate to high risk of restenosis, little is known about the cost-effectiveness of alternative DES designs, especially second-generation DESs. We therefore performed an economic substudy alongside the SPIRIT-IV trial, in which 3,687 patients undergoing single or multivessel percutaneous coronary intervention were randomized to receive second-generation everolimus-eluting stents (EESs; n = 2,458) or first-generation paclitaxel-eluting stents (PESs; n = 1,229). Costs through 2 years of follow-up were assessed from the perspective of the United States health care system. The primary cost-effectiveness end point was the incremental cost-effectiveness ratio assessed as cost per quality-adjusted life year gained. Over a 2-year period, use of EESs versus PESs led to a trend toward decreased overall repeat revascularization procedures (14.2 vs 16.2 per 100 subjects, p = 0.20) driven by a significant decrease in the number of target vessel revascularization procedures (8.2 vs 11.0 per 100 subjects, p = 0.02) but also a slight increase in the number of nontarget vessel revascularization procedures (6.0 vs 5.1 per 100 subjects, p = 0.37). Follow-up cardiovascular costs were decreased by $273/patient in the EES group (95% confidence interval for difference 1,048 less to 502 more, p = 0.49). Formal cost-effectiveness analysis based on these results demonstrated that the probability that EES was an economically attractive strategy (incremental cost-effectiveness ratio <$50,000/quality-adjusted life year gained) was 85.7%. These findings demonstrate that in patients undergoing percutaneous coronary intervention with DESs, use of EESs is economically attractive compared to PESs with improved clinical outcomes and lower overall medical care costs at 2 years.

Cost-Effectiveness of Transcatheter Aortic Valve Replacement Compared With Standard Care Among Inoperable Patients With Severe Aortic Stenosis

Background—

In patients with severe aortic stenosis who cannot have surgery, transcatheter aortic valve replacement (TAVR) has been shown to improve survival and quality of life compared with standard therapy, but the costs and cost-effectiveness of this strategy are not yet known.

Methods and Results—

The PARTNER trial randomized patients with symptomatic, severe aortic stenosis who were not candidates for surgery to TAVR (n=179) or standard therapy (n=179). Empirical data regarding survival, quality of life, medical resource use, and hospital costs were collected during the trial and used to project life expectancy, quality-adjusted life expectancy, and lifetime medical care costs to estimate the incremental cost-effectiveness of TAVR from a US perspective. For patients treated with TAVR, mean costs for the initial procedure and hospitalization were $42 806 and $78 542, respectively. Follow-up costs through 12 months were lower with TAVR ($29 289 versus $53 621) because of reduced hospitalization rates, but cumulative 1-year costs remained higher ($106 076 versus $53 621). We projected that over a patient's lifetime, TAVR would increase discounted life expectancy by 1.6 years (1.3 quality-adjusted life-years) at an incremental cost of $79 837. The incremental cost-effectiveness ratio for TAVR was thus estimated at $50 200 per year of life gained or $61 889 per quality-adjusted life-year gained. These results were stable across a broad range of uncertainty and sensitivity analyses.

Conclusions—

For patients with severe aortic stenosis who are not candidates for surgery, TAVR increases life expectancy at an incremental cost per life-year gained well within accepted values for commonly used cardiovascular technologies.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00530894.

Abstract P20: One-Year Hospitalization Costs Associated with Carotid Stenting Versus Endarterectomy: Results from the CREST Trial

Background: The CREST trial demonstrated that for patients at standard risk of surgical complications, there was no significant difference in the primary composite outcome of periprocedural death, MI, or stroke, or late ipsilateral stroke between carotid artery stenting (CAS) and carotid endarterectomy (CEA), although CAS had a higher rate of stroke, and CEA had a higher rate of MI. The economic implications of these two strategies are unknown.

Methods: We performed a prospective health economic study alongside the CREST trial. Costs were assessed from the perspective of the US health care system in 2008 dollars using a combination of resource-based and event-based methods. Costs for carotid revascularization procedures were based on measured resource use and unit costs derived from a sample of study hospitals. Non-procedural costs for these hospitalizations were estimated using hospital billing data (charges) and cost-center-specific cost-to-charge-ratios. Costs for follow-up events were estimated using national average DRG reimbursements. The primary analysis was based on a modified intention-to-treat population for which the assigned procedure was attempted (n=1212 CAS; 1193 CEA).

Results: CAS was associated with higher total procedural costs (Δ=$675, see Table), driven mainly by higher costs for disposable supplies. Length of stay was shorter for CAS, with associated reductions in non-procedural hospital costs (Δ = -$436). Total cost for the index hospitalization remained slightly higher for CAS (Δ=$239) with similar differences at 1 year.

Conclusions: For patients at standard risk of surgical complications, total 1-year costs are slightly higher for CAS vs. CEA, driven largely by higher initial procedural costs. Cost-utility analysis will be performed to determine whether differences in quality of life observed in CREST render CAS an economically attractive strategy.

CAS (n= 1212) CEA (n=1193) Δ CAS - CEA (95% CI via bootstrap) Index Procedure Costs, $     Excluding MD Fees 6782 ± 1412 5743 ± 1370 1039 (926, 1148)     MD Fees 1114 ± 240 1478 ± 108 -364 (-379, -349)     Total 7896 ± 1551 7221 ± 1450 675 (555, 800) Index Hospital Stay 7159 ± 5108 7595 ± 7482 -436 (-951, -59) TOTAL Index Hosp Costs 15055 ± 5539 14816 ± 7709 239 (-302, 778) Index Hosp LOS (days)     ICU LOS 0.7 ± 1.1 0.8 ± 1.4 -0.1 (-0.24, -0.04)     Non-ICU LOS 1.9 ± 3.2 2.2 ± 4.1 -0.2 (-0.55, 0.06) TOTAL LOS 2.6 ± 3.3 3.0 ± 4.5 -0.4 (-0.7, -0.06) 1-year Rehosp Costs:     Repeat Revasc - CAS 295 ± 2097 273 ± 2126 -21 (-142, 201)     Repeat Revasc - CEA 287 ± 2088 477 ± 2510 -190 (-371, -11)     Ipsilateral Stroke 556 ± 3273 384 ± 2580 172 (-75, 402)     TIA 48 ± 520 33 ± 487 16 (-25, 56)     Death 63 ± 846 45 ± 779 18 (-49, 85) TOTAL Rehosp costs 1321 ± 4827 1293± 4502 28 (-334, 396) TOTAL 1-year costs 16375 ± 7730 16108 ± 9030 267 (-366, 961)