Cost-effectiveness Considerations in Routine and Complex Percutaneous Coronary Intervention
When broadly considering the cost impact of treatment strategies in patients with CAD, multiple therapeutic comparisons are of clinical and fiscal relevance. The first set of considerations relates to medical management versus revascularization in the setting of stable CAD. The next relates to mode of revascularization, surgical versus percutaneous, with the additional matter of routine versus selective use of DES in the latter group. In the interest of brevity, we will focus on cost-effectiveness of various revascularization strategies as it relates to patients with complex disease. While it is beyond the scope of this article to explore economic modeling in detail, it bears mention that variability and complexity of cost modeling methodology, differences in individual costs within the US healthcare system and across countries, and local trends in the practice of IC have all contributed to the lack of uniformity in conclusions regarding the cost-effectiveness of various revascularization strategies.34
Since commercial approval in the US in 2003, use of DES has grown, peaking in late 2005 at nearly 90 % and since settling into its current usage rate in over two-thirds of PCI procedures.35 Numerous randomized and non-randomized comparisons of BMS versus DES in PCI have been conducted and have uniformly found a reduction in target vessel revascularization (TVR) without significant reduction in death or myocardial infarction.36,37 Available economic analyses have not, however, uniformly upheld the cost-effectiveness of DES use in contemporary PCI. As noted, given the lack of mortality benefit with DES, the economic case to be made in favor of DES usage rests primarily with the ratio of incremental cost of these devices over BMS to enhanced quality of life (QoL) for patients who enjoy greater freedom from repeat revascularization following DES implant.38 Groeneveld et al. conducted a systematic review of the published literature on costs and QoL metrics associated with DES versus BMS use, incorporating eight QOL and four cost publications.38 In this analysis, patients receiving DES had $1,600 to $3,200 higher initial costs with the 1-year total cost differential dropping to $200 to $1,200. Wide variability in the relative rates of restenosis between BMS and DES in the studies included drove the large observed range in cost per revascularization avoided ($1,800–$36,900). Although all included studies were in agreement that restenosis negatively affects QOL, routine use of DES to avoid restenosis was found unlikely to be cost-effective. In another systematic review of DES cost-effectiveness, Ligthart and colleagues similarly found wide variability in the reported cost-effectiveness of DES that the authors concluded was influenced by the quality of the studies analyzed, source of study funding, and the country in which the studies were conducted.34 Ryan et al. have suggested however that DES usage would be economically favorable if used selectively in patients at moderate to high risk of BMS restenosis with sensitivity analyses demonstrating an acceptable cost-effectiveness ratio of < $10,000 per repeat revascularization avoided if the expected BMS TVR rate in a given population exceeded 11 % and cost savings if the BMS TVR rate exceeded 19 %.39 As noted, use of FFR guidance in single or multivessel PCI with implantation of second-generation DES in the FAME-2 trial yielded substantial reductions in the ischemic composite endpoint over optimal medical therapy (4.3 % in the PCI group and 12.7 % in the medical therapy group, hazard ratio [HR] with PCI 0.32; 95 % confidence interval [CI] 0.19 to 0.53; p<0.001).32 An economic analysis of these data found that while initial costs of drug-eluting stent PCI performed in the setting of FFR <0.80 were significantly higher compared with FFR followed by optimal medical therapy ($9,927 versus $3,900; p<0.001), the observed $6,027 difference decreased over the study’s 1-year follow-up to $2,883 (p<0.001), offset by the cost of subsequent revascularization procedures in the medical therapy arm. The incremental cost-effectiveness ratio (ICER) of PCI guided by an abnormal FFR in FAME-2 was $36,000 per quality-adjusted life year (QALY), an economically favorable value as it is below the standard willingness to pay threshold of $50,000 per QALY.40 Taken together, these data indicate that cost-containment strategies in PCI should include objective assessment of functional significance to guide lesion selection and estimation of restenosis/revascularization risks to help guide the use of DES versus BMS along with strategies to minimize the number of stents implanted and experience-based choices regarding adjunctive device use.
Relevant to the economics of complex PCI, a few recent studies have re-examined the age-old controversy of CABG versus drug-eluting stent PCI in multivessel CAD. As mentioned above, the SYNTAX trial randomly assigned 1,800 patients with multivessel or unprotected LMCA disease to CABG surgery versus PCI with paclitaxel-eluting DES. Twelvemonth rates of major adverse cardiac or cerebrovascular events were significantly higher in the PCI group (17.8 % versus 12.4 % for CABG; p=0.002), primarily due to an increased rate of repeat revascularization (13.5 % versus 5.9 %; p<0.001) with no difference in all-cause mortality, thus failing to demonstrate non-inferiority between the two treatment arms.15 However, when outcomes were stratified by tertiles of SYNTAX score there was noted to be an interaction between the SYNTAX score and treatment allocation with comparable MACE rates between PCI and CABG in those subjects with low (0–22) or intermediate (23–32) scores. A formal cost-effectiveness analysis conducted by Cohen et al. based on the SYNTAX data found that in the overall study population total costs for the index procedure and hospitalization were $5,693/patient higher in the CABG group, but follow-up costs $2,282/patient higher in the PCI group (driven primarily by the need for repeat TVR), thus economically favoring PCI at 1 year despite high resource utilization for PCI (average 4.5 DES per procedure; range 0–14 DES).41 Although PCI was deemed to be the economically dominant strategy in the primary analysis, disease complexity as quantified by tertiles of SYNTAX score once again served as an interaction term. The 1-year cost savings with PCI diminished from $6,154/patient among patients with low SYNTAX scores to $3,889/patient in patients with intermediate SYNTAX scores to $466/patient in patients with high SYNTAX scores. A similar interaction was also found in terms of disease complexity and qualityadjusted life expectancy with CABG strongly favored in patients with the highest SYNTAX scores. In 1,900 patients with diabetes randomized to drug-eluting stent PCI versus CABG in the Future Revascularization Evaluation in Patients with Diabetes Mellitus: Optimal Management of Multivessel Disease (FREEDOM), total 5-year costs were similarly $3,641 higher per CABG patient. However, when the trial data were projected over a lifetime survival horizon, CABG posted significant gains in quality-adjusted life expectancy relative to PCI.42 Careful assessment of up-front costs, anticipated intermediate- and long-term outcomes, and the need for repeat procedures and hospitalization must therefore accompany technical planning of revascularization in patients with complex multivessel CAD.
Percutaneous chronic total occlusion (CTO) revascularization is another sector of contemporary interventional practice that has recently seen renewed interest and utilization driven by advances in technology as well as the development of hybrid percutaneous treatment algorithms.43 Limited data exist regarding cost-effectiveness of percutaneous revascularization of CTOs versus medical management and, at the time of writing, no formal cost-modeling versus CABG exists although the presence of one or more CTOs is often cited as the primary reason for CABG referral.44 Gada et al. used a decision-analytic model to evaluate the morbidity and costs associated with CTO PCI versus optimal medical therapy in patients with Canadian Cardiovascular Society class III–IV angina.45 Assuming a reference case mean age of 60 years and CTO PCI success rate of 67.9 % and 5 years of simulated follow-up, along with literature-defined assumptions regarding procedural probabilities, costs, and outcomes, CTO PCI was more costly than optimal medical therapy ($31,512 versus $27,805), but resulted in greater QALYs (2.38 versus 1.99), thus resulting in an economically favorable ICER of $9,505 per QALY. As experience grows with use of the hybrid CTO algorithm as well as with current strategies for tackling bifurcation lesions with conventional DES or with dedicated bifurcation stent systems available outside the US, additional cost modeling data addressing these complex PCI subsets will hopefully be forthcoming.46