Economics and Outcomes of Coronary Stenting
Economics and Outcomes of Coronary Stenting
In recent years, coronary stenting has become increasingly popular and the most common form of percutaneous coronary intervention. Several clinical trials have demonstrated lower rates of restenosis, and similarly low rates of death or myocardial infarction (MI), after angioplasty with coronary stents than with balloon angioplasty. At the time of these trials (early 1990s), however, coronary stenting was more costly, even at follow-up, than balloon angioplasty. Since these trials were conducted, there have been numerous improvements in stent technology, deployment, and anti-platelet therapy, resulting in better outcomes, less bleeding, and essentially no need for full anti-coagulation after the procedure. Coronary stent implantation has now become so dominant that it is no longer possible to contemplate a randomized trial of balloon angioplasty versus stenting, except for special categories of patients.
The theme of coronary stenting's wide applicability is developed further in this issue of the Journal by Ikeda et al. The authors of this study have developed a cost-effectiveness simulation comparing coronary stenting to balloon angioplasty.
Based on surveys in Japan, the authors find lower in-hospital and follow-up event rates with stenting than with balloon angioplasty. Lower event rates were suggested for death, Q wave MI, and additional revascularization procedures. In addition, the authors suggest that although in-hospital costs would be higher with stents than with balloon angioplasty, by 1 year the additional resource use after balloon angioplasty would make it more expensive than coronary stenting. In this situation, where clinical outcome is better with stenting than with angioplasty and stenting costs less, then stenting would be said to dominate balloon angioplasty.
One form of therapy dominating another is a very attractive situation, as one could make the case to place stents whenever possible. However, before making such a decision, either when considering the care of an individual patient or for public policy making purposes, it is necessary to fully critique this position. The first area of concern is internal validity. The authors make it clear that the study is a simulation and not directly based on clinical trial data. As noted above, a clinical trial to consider the cost-effectiveness of coronary stenting compared to coronary angioplasty is probably no longer possible. In this regard, some readers may find the relative clinical merits of stenting compared to balloon angioplasty, as presented in this study, to be somewhat optimistic. However, the costs cannot be independently verified, which is often a concern in cost studies and, thus, can only be taken as a given. Despite these concerns, the overall thrust that stenting dominates balloon angioplasty seems quite reasonable.
If we are to accept that stenting dominates balloon angioplasty, as defined in the study by Ikeda et al., how generalizable are these findings? Can the findings of this study be expanded to all groups of patients? For some patients, coronary stent placement may be technically difficult. In some groups of patients, such as in patients with blockages in small vessels, there are less data and there may be less advantage to coronary stenting. In vein grafts, there are some randomized trial data concerning stenting, but the evidence is relatively meager. In addition, for specialized groups such as vein graft procedures, the estimation of event rates in the study by Ikeda et al. are likely to be low for both stents and balloon angioplasty.
The next area to consider is the applicability of this paper outside of Japan. The authors are quite careful about this issue and make no special claims. While dominance of stenting over coronary angioplasty may seem likely in North America, Europe, and elsewhere, it cannot be adequately supported by data at the present time.
Although Ikeda et al. make no broad-based claims about the relative importance of percutaneous coronary angioplasty versus other therapeutic strategies, this is certainly a serious issue. Trials from the 1980s to the early 1990s showed that for patients with multi-vessel disease, balloon angioplasty and coronary surgery had similar rates of death or MI, but that there was both better symptom control and lower additional revascularization rates with coronary surgery than with angioplasty. The BARI trial in particular showed that outcome was better with surgery than with angioplasty, in treated diabetics with multi-vessel disease. This has been supported in some but not all registry studies. Both the BARI trial and EAST showed that while in-hospital costs were higher with coronary surgery than with angioplasty, over time the costs were similar, due to additional revascularization needed after angioplasty. In the BARI trial, coronary surgery dominated angioplasty for diabetics. Currently, coronary stenting is being compared to coronary surgery in three randomized trials: ARTS, ERACI II, and SoS, and final results are expected. Hopefully, these studies will also cast a light on the issue of choice of revascularization in diabetics. There will be economic analyses with these trials. No trial comparing contemporary stent usage with coronary surgery has been conducted or is anticipated in the United States. While there have been several trials comparing balloon angioplasty to medical therapy, they have been in lower risk patients and have been relatively small studies. Coronary stenting will be compared to medical therapy in the much larger COURAGE trial, which is currently underway in the United States and Canada. BARI II has recently been funded and will readdress the issue of revascularization of diabetics.
A rather different point to consider in a cost-effectiveness analysis is the perspective of the study. The study by Ikeda et al. takes a societal perspective, which is appropriate. However, while coronary stenting may dominate balloon angioplasty from the point of view of society, society is made up of a series of stakeholders, not all of whom may agree on the point of view. A patient who only pays for medications may find stenting to be preferable to angioplasty from a clinical point of view, but may object to the high cost of outpatient, anti-platelet therapy. Payment plans may also influence the view of the data. Thus, a hospital that is paid by standard indemnity insurance may find that the lower repeat procedure rate cuts into revenue. Alternatively, a capitated health system may view stenting as a way to control costs by avoiding procedures.
In conclusion, one must consider how cost-effectiveness analyses are to be used. Such studies can be used as a stimulus for further thought and planning of additional research, to guide medical decision-making, and to inform and guide public policy. It would certainly seem to be premature, however, to assume that stents should be advocated over balloon angioplasty as public policy. It would also be premature to suggest that percent stent use could be a process measure indicator of the quality of care of patients undergoing percutaneous coronary intervention. Finally, it would seem premature for guidelines to suggest that stents should be used when possible, rather than balloons. Thus, it is reasonable to say that stents may dominate balloon angioplasty, but caution remains as the order of the day.
In recent years, coronary stenting has become increasingly popular and the most common form of percutaneous coronary intervention. Several clinical trials have demonstrated lower rates of restenosis, and similarly low rates of death or myocardial infarction (MI), after angioplasty with coronary stents than with balloon angioplasty. At the time of these trials (early 1990s), however, coronary stenting was more costly, even at follow-up, than balloon angioplasty. Since these trials were conducted, there have been numerous improvements in stent technology, deployment, and anti-platelet therapy, resulting in better outcomes, less bleeding, and essentially no need for full anti-coagulation after the procedure. Coronary stent implantation has now become so dominant that it is no longer possible to contemplate a randomized trial of balloon angioplasty versus stenting, except for special categories of patients.
The theme of coronary stenting's wide applicability is developed further in this issue of the Journal by Ikeda et al. The authors of this study have developed a cost-effectiveness simulation comparing coronary stenting to balloon angioplasty.
Based on surveys in Japan, the authors find lower in-hospital and follow-up event rates with stenting than with balloon angioplasty. Lower event rates were suggested for death, Q wave MI, and additional revascularization procedures. In addition, the authors suggest that although in-hospital costs would be higher with stents than with balloon angioplasty, by 1 year the additional resource use after balloon angioplasty would make it more expensive than coronary stenting. In this situation, where clinical outcome is better with stenting than with angioplasty and stenting costs less, then stenting would be said to dominate balloon angioplasty.
One form of therapy dominating another is a very attractive situation, as one could make the case to place stents whenever possible. However, before making such a decision, either when considering the care of an individual patient or for public policy making purposes, it is necessary to fully critique this position. The first area of concern is internal validity. The authors make it clear that the study is a simulation and not directly based on clinical trial data. As noted above, a clinical trial to consider the cost-effectiveness of coronary stenting compared to coronary angioplasty is probably no longer possible. In this regard, some readers may find the relative clinical merits of stenting compared to balloon angioplasty, as presented in this study, to be somewhat optimistic. However, the costs cannot be independently verified, which is often a concern in cost studies and, thus, can only be taken as a given. Despite these concerns, the overall thrust that stenting dominates balloon angioplasty seems quite reasonable.
If we are to accept that stenting dominates balloon angioplasty, as defined in the study by Ikeda et al., how generalizable are these findings? Can the findings of this study be expanded to all groups of patients? For some patients, coronary stent placement may be technically difficult. In some groups of patients, such as in patients with blockages in small vessels, there are less data and there may be less advantage to coronary stenting. In vein grafts, there are some randomized trial data concerning stenting, but the evidence is relatively meager. In addition, for specialized groups such as vein graft procedures, the estimation of event rates in the study by Ikeda et al. are likely to be low for both stents and balloon angioplasty.
The next area to consider is the applicability of this paper outside of Japan. The authors are quite careful about this issue and make no special claims. While dominance of stenting over coronary angioplasty may seem likely in North America, Europe, and elsewhere, it cannot be adequately supported by data at the present time.
Although Ikeda et al. make no broad-based claims about the relative importance of percutaneous coronary angioplasty versus other therapeutic strategies, this is certainly a serious issue. Trials from the 1980s to the early 1990s showed that for patients with multi-vessel disease, balloon angioplasty and coronary surgery had similar rates of death or MI, but that there was both better symptom control and lower additional revascularization rates with coronary surgery than with angioplasty. The BARI trial in particular showed that outcome was better with surgery than with angioplasty, in treated diabetics with multi-vessel disease. This has been supported in some but not all registry studies. Both the BARI trial and EAST showed that while in-hospital costs were higher with coronary surgery than with angioplasty, over time the costs were similar, due to additional revascularization needed after angioplasty. In the BARI trial, coronary surgery dominated angioplasty for diabetics. Currently, coronary stenting is being compared to coronary surgery in three randomized trials: ARTS, ERACI II, and SoS, and final results are expected. Hopefully, these studies will also cast a light on the issue of choice of revascularization in diabetics. There will be economic analyses with these trials. No trial comparing contemporary stent usage with coronary surgery has been conducted or is anticipated in the United States. While there have been several trials comparing balloon angioplasty to medical therapy, they have been in lower risk patients and have been relatively small studies. Coronary stenting will be compared to medical therapy in the much larger COURAGE trial, which is currently underway in the United States and Canada. BARI II has recently been funded and will readdress the issue of revascularization of diabetics.
A rather different point to consider in a cost-effectiveness analysis is the perspective of the study. The study by Ikeda et al. takes a societal perspective, which is appropriate. However, while coronary stenting may dominate balloon angioplasty from the point of view of society, society is made up of a series of stakeholders, not all of whom may agree on the point of view. A patient who only pays for medications may find stenting to be preferable to angioplasty from a clinical point of view, but may object to the high cost of outpatient, anti-platelet therapy. Payment plans may also influence the view of the data. Thus, a hospital that is paid by standard indemnity insurance may find that the lower repeat procedure rate cuts into revenue. Alternatively, a capitated health system may view stenting as a way to control costs by avoiding procedures.
In conclusion, one must consider how cost-effectiveness analyses are to be used. Such studies can be used as a stimulus for further thought and planning of additional research, to guide medical decision-making, and to inform and guide public policy. It would certainly seem to be premature, however, to assume that stents should be advocated over balloon angioplasty as public policy. It would also be premature to suggest that percent stent use could be a process measure indicator of the quality of care of patients undergoing percutaneous coronary intervention. Finally, it would seem premature for guidelines to suggest that stents should be used when possible, rather than balloons. Thus, it is reasonable to say that stents may dominate balloon angioplasty, but caution remains as the order of the day.
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