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Applying a Cost-Effectiveness Methodology to Angina

Cath Lab Digest talks with David J. Cohen, MD, MSc, Professor of Medicine,
University of Missouri-Kansas City, and Director of Cardiovascular Research,
Saint Luke’s Mid America Heart Institute, Kansas City, Missouri.

Disclosure: Dr. David J. Cohen reports consulting income from Abbott Vascular and Medtronic, and research grant support from Abbott Vascular, Medtronic, and Boston Scientific.

Dr. David J. Cohen can be contacted at dcohen@saint-lukes.org.

What is the importance of a cost-effective methodology in healthcare?

For the past 20 years, I have been working in the area of cost-effectiveness in cardiovascular disease, focusing on interventional procedures in particular. We are trying to understand the relationship between the costs of a treatment and the benefits that it provides.

We want to understand what those tradeoffs might be, and what the value is of different treatments relative to other ways of spending that money. We don’t have an infinite amount of money to spend on healthcare and it is imperative that we spend our money wisely, as a healthcare system and as a country. Cost-effectiveness analysis is one technique that we can use to provide some guidance as to how best to invest our resources.

Do you think the Affordable Care Act (ACA) has encouraged this approach?

Over time, it will. As healthcare in the United States moves to an accountable care organization (ACO) model, doctors and healthcare providers of all sorts have more incentive to understand the long-term health consequences of the treatments they choose, because they are capitated. They only have a certain amount of money to spend and spending that money wisely becomes crucial.

Culturally, it now seems more acceptable to at least talk about the costs of care than in the past.

Well, it is acceptable to talk about it. But right now in the United States, we still don’t have a standardized approach to incorporating these insights into our guidelines or into our treatment patterns. When that starts to happen, as has already happened in most countries in Europe, you will start to see more concern. Ultimately, there are ways to eliminate waste from the system. There are ways to identify treatments where you are spending money and getting no value whatsoever. However, some cost effectiveness analyses will identify treatments that provide only marginal benefits for significant money spent, and those types of results can be tricky to interpret, because it ultimately means denying some patients care that might be beneficial, but provides a very small amount of benefit. When that starts to happen, there will be more backlash. Cost-effectiveness analysis is really about making transparent things that we often don’t discuss.

Can you describe how angina is viewed from a clinical and a cost effectiveness perspective?

Angina is a condition that has been recognized for many years. Typically we think of angina as being due to obstructed coronary arteries, and an imbalance of oxygen delivery and oxygen demand. But angina really is a syndrome of chest pain. Ultimately, this term refers to patients with coronary disease who have symptoms that may be related to coronary ischemia. Patients can have chest pain and occluded coronary arteries, and their chest pain can be coming from something completely other than myocardial ischemia, but we don’t have great abilities to distinguish its origin. When we discuss angina in a setting of clinical trials or research, it generally means chest pain syndromes that are not clearly arising from something other than the heart. Whether the pain is truly cardiac in origin may not make much of a difference. If the patient thinks their pain is coming from the heart, it is going to impair them, affect their quality of life, and there are going to be costs. There are many causes of angina, but research done over the last several decades has made it very clear that angina has an important impact on patients’ quality of life. It limits the activities they do, it limits their enjoyment and fulfillment in their daily lives, and it also has an economic burden. So angina is a double-edged sword. It affects both the patient and the healthcare system.

If patients have angina that is resistant to optimal medical therapy, should they receive revascularization?

In patients resistant to drug therapy, who are on several antianginal medications and continue to have angina, revascularization provides benefit. This scenario was probably studied best in the COURAGE trial. This trial showed that angina relief was better with revascularization compared to optimal medical therapy. It didn’t even focus on the patients who had the most refractory of angina. It was just any type of angina. As a result of COURAGE and other trials, our guidelines recognize and clearly indicate that it is appropriate to perform revascularization, whether by percutaneous coronary intervention or bypass surgery, in patients with significant angina despite good medical therapy.

What questions still remain regarding the treatment of angina?

There are many open questions. One is, does treatment of patients with angina and relief of ischemia lead to improved long-term outcomes, meaning improved survival, lower rates of heart attack, and lower rates of “hard” events? We know that revascularization improves health status and quality of life, but we don’t know if that leads to improvement in survival or reductions in rates of myocardial infarction. There are some observational data from the literature that suggest this might be the case, but these need to be substantiated by high-quality randomized trials. There is a very large, ongoing trial called ISCHEMIA, supported by the National Institutes of Health, that is randomizing about 8,000 patients with significant myocardial ischemia to invasive therapy with catheterization and revascularization as appropriate, versus continued optimal medical therapy. The ISCHEMIA trial will take several more years to complete recruitment, and several more years after that for follow-up. It should provide a more definitive answer on the benefits of revascularization versus medical therapy, especially with respect to the harder endpoints.

How wide would you cast a net when looking at the costs of angina? It can affect the healthcare system, but also if a patient can’t go to work, that’s productivity lost for the overall economy.

There are many perspectives that one can consider in evaluating the costs of angina. If patients are substantially disabled from angina and are not productive, then that also has an impact on society beyond the healthcare system. When we analyze these effects, we always have to make a decision of where we are going to draw the box around the costs to study. In most of our work, we tend to stop at the healthcare system, because we are really focused on organizations like Medicare or managed care organizations, which are peripherally concerned with work productivity, but are mainly concerned with their own costs.

Do the American College of Cardiology/American Heart Association (ACC/AHA) guidelines say anything about angina from an economic standpoint?

The guidelines say nothing about the economics of angina, but the ACC/AHA recently put forth a policy that will allow them to evaluate and make statements about value with respect to different treatments and therapies. However, that policy has just come out, and has not yet been formally accounted for in any of the current guidelines.

How might a bioabsorbable stent affect the healthcare system from a cost-effectiveness standpoint?

That is a complicated question. First of all, we have to determine whether bioabsorbable stents actually do affect angina. That is a hypothesis that has been raised by some looking at observational, historically controlled data. It is an interesting hypothesis. Very recently, the randomized data from the ABSORB II trial were presented at TCT. This was a small, mechanistic study, and the occurrence of angina was not a planned analysis in the study, but a post hoc analysis. The analysis did suggest that there were lower rates of angina or recurrent chest pain in the patients that were treated with the bioresorbable vascular scaffold (BVS, Abbott Vascular) compared with the standard drug-eluting stent over the first year follow-up. That observation has raised many questions, because it is hard to understand what mechanism could be responsible for the reduction in angina. All the benefits related to the BVS were thought to occur several years after the implant, when the BVS actually resorbs, not in the first few months. There is certainly an amount of healthy skepticism on the part of the clinical and academic community about whether this is a real finding or whether this is an artifact or a fluke, but it is a hypothesis that is certainly worth testing. The economic impact is clear. We have published studies over the years looking at healthcare resource utilization for patients who have angina versus those who do not. Angina leads to a great deal of diagnostic testing, it leads to hospitalizations, it leads to revascularization procedures, whether appropriate or not, and all of those things add cost to the healthcare system. If we did have a treatment where we could prove, in a rigorous fashion, that use of the BVS would reduce the frequency of recurrent angina, its use would clearly have economic benefits downstream by reducing follow-up costs in these patients. The first step, of course, is defining if the reduction in angina with a BVS is real.

The ABSORB II results certainly have brought renewed attention to the problem of angina.

It has helped to enhance our focus. Clinicians have paid lip service to angina for many, many years, but really, they didn’t focus on it. We have good tools to measure angina, such as the Seattle Angina questionnaire, which is a valid, easy-to-administer tool. One of the ideas when it was first developed was to use the results like a vital sign. Patients who come into a cardiology office could fill out the questionnaire while sitting in the waiting area. The results would then be presented to the clinician, who can use it as a barometer to see if the patient is doing well, and then if they are not, to use the questionnaire to try and understand what might have changed. Perhaps the patient needs their medications adjusted or perhaps they need to be considered for revascularization. However, the Seattle Angina questionnaire hasn’t caught on in the clinical community, and I think there are many different reasons for that. When we do administer formal instruments like the Seattle questionnaire to patients who are coming back after revascularization procedures, clinicians are often surprised to see how many patients do report some degree of persistent angina. We tend to think, oh, (my patient) is doing fine, and minimize things. Using these kinds of tools to highlight patients with residual symptoms could be valuable in this way. The fact that the ABSORB II trial has shown some tantalizing results with respect to angina is an eye-opener for the community and hopefully, it will lead to some more attention to this problem.


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