When Is Sick Too Sick for TAVR? Physicians Grapple With Identifying Futile Care

CHICAGO, IL—When is a patient too sick for transcatheter aortic valve replacement, and at what stage do comorbidities and the likelihood of a poor clinical outcome trump the need to treat symptomatic aortic stenosis?

Those were the questions a panel of experts grappled with at TVT 2016, with David Cohen, MD (St. Luke’s Mid America Heart Institute, Kansas City, MO), attempting to identify truly “futile” care. He said that when evaluating the potential clinical outcomes for patients considering TAVR, an improvement in quality of life is at least as important as improved survival.

“This is a tricky topic and challenging one, but I think one we all wrestle with every day, every week, as we’re trying to figure out which patients we really should not treat,” said Cohen. “If we look at the outcomes from the pivotal trials with very carefully selected patients and a lot of screening, at 6 months and 1 year, a substantial proportion of our patients are either dead or have a poor quality of life. I think we would all consider those outcomes we would want to avoid. The question is how to avoid this.”

In terms of general guidance, the US Food and Drug Administration (FDA) and the Centers for Medicare & Medicaid Services (CMS) specifically state that TAVR should not be offered to patients if it’s unlikely to positively affect their “quantity and quality of life. 

Cohen noted that from a societal perspective, a procedure should not be performed if the expected costs, including the downstream costs, could provide greater benefit if the money were spent elsewhere. From an economic perspective, he said, TAVR is not cost-effective if the patient is expected to live less than 3 years. At 3 years, the cost per quality-adjusted life-year (QALY) gained is approximately $50,000, which meets the US threshold for cost-effectiveness. In statistical models that exclude quality of life and focus solely on survival, however, the incremental cost-effective ratio is significantly higher—approximately $80,000 per QALY gained—and TAVR is no longer cost-effective compared with medical therapy.

Howard Herrmann, MD (Perelman School of Medicine at the University of Pennsylvania, Philadelphia), who chaired the session on difficult cases and challenging clinical scenarios, said interventional cardiologists frequently encounter patients in whom TAVR is unlikely to extend the duration of life but might have a positive impact on the quality of years left.

“I have patients referred now with a 1-year prognosis from CLL [chronic lymphocytic leukemia] or some other form of cancer, and the word we get from the oncologist is, ‘Well, they feel terrible, why not just do it? They’ll have gone home in a couple of days and feel better for their last year of life,’” said Herrmann. “How do we answer that? When do we do TAVR when we know it’s almost futile but we’re being asked to help them to feel better?”

Cohen said that if he is convinced the patient is highly symptomatic with severe aortic stenosis and is going to feel better with TAVR, he doesn’t object to performing the procedure. While the procedure isn’t inexpensive, it is safe when performed by experienced operators. This places the onus on physicians to understand if the patient truly has aortic stenosis and how much it is contributing to their symptoms, he said.

“Why should we deprive people of feeling better for their last year of life if we’re convinced they’re going to benefit?” said Cohen. In situations where they are uncertain about the extent to which aortic stenosis is contributing to their symptoms, Cohen said balloon valvuloplasty is an option and is something patients have found helpful.

No Single Risk Factor Identifies What’s Futile

During his presentation, Cohen said that from an individual patient perspective, there is no single risk factor sufficient to identify futility. For example, in an analysis of data from the Society of Thoracic Surgeons/American College of Cardiology (STS/ACC) TVT Registry, 1-year mortality rates ranged from 30% to 41% among high-risk patients, such as the very elderly (≥ 95 years), those with chronic obstructive pulmonary disease, those on dialysis, and those with left ventricular dysfunction. Still, the 1-year mortality rate among inoperable patients in the medical therapy arm of the PARTNER cohort B study was 50%, said Cohen.

“Every one of these individual groups does better than the PARTNER B control group, so it’s hard to say that any single risk factor is going to identify patients in whom TAVR is likely to be futile,” he said. Combinations of risk factors don’t fare much better, added Cohen, noting that even among patients with an STS-Predicted Risk of Mortality score 15% or higher, TAVR still confers a substantial survival benefit at 3 to 5 years.

Cohen, along with Suzanne Arnold, MD (St. Luke’s Mid America Heart Institute), has developed and published a risk calculator that estimates mortality and worsened/unimproved quality of life in the 6 months after TAVR. Using the score, which is known as the PARTNER “Poor Outcomes” risk calculator, 58.7% of high-risk patients and 73.0% of very-high-risk patients were likely to have died or have poor quality of life at 1 year.

An unsettled question is whether the calculator can truly identify what counts as futility. “If you told a patient who was miserable from their aortic stenosis that they had a 27% chance of being alive and having a good quality of life at 1 year, would they view that as futile?” asked Cohen. “I don’t know. I think we have to ask our patients that question. It isn’t necessarily futility and it isn’t necessarily for me, for you, or for anybody other than for the patient and their family to decide.” 

To TCTMD, Cohen said one of the challenges is conveying information from risk models to patients, particularly since the information is quantitative, which patients might not be skilled in interpreting. Secondly, he said the risk models have not yet identified a patient with excessively prohibitive risk—patients who are 90% to 95% likely to die or have worsened quality of life at 1 year. “We can certainly identify those in whom TAVR is likely to succeed,” he said. “We can identify patients in whom there is a higher chance it might work. But to get to the patient where there is a 90%-plus chance the outcome [will be] poor, we simply haven’t treated those patients so it’s not in our dataset.”

Martin Leon, MD (Columbia University Medical Center, New York, NY), said he believes the development of risk scores can make it easier to communicate information to patients, but “on an individual basis, in terms of making decisions, that’s where these tend to break down.” A variety of clinical factors, including sociological factors, affect the clinical decision-making process and these aren’t captured in the risk scores.

“Even though I encourage this kind of activity, I’m not sure on an individual patient basis it will add that much in terms of making the decision of TAVR versus surgery,” said Leon.

Cohen said that risk scores, in general, outperform clinicians for the assessment of risk, but he suspects physicians still factor in their own clinical impression about potential outcomes. He told TCTMD the goal when treating patients is to identify their priorities and to understand their reasons for wanting to undergo the procedure. “We try to give them the best council we can as to what the likelihood they’re going to improve is,” he said.