‘Considerable’ Aortic Stenosis Burden in UK Begs Money and a Plan
The NHS will need to invest heavily to treat a disease, one not modifiable with primary prevention, that’s growing in scope.
A new study is shedding some light on the growing number of people with severe aortic stenosis (AS) in the United Kingdom, with researchers reporting that there is a large burden of disease. The majority of these patients would benefit from surgery or transcatheter aortic valve intervention, they conclude.
The new data also hint at challenges the National Health Service (NHS) will face to meet the demand.
“The magnitude of the estimated prevalence is considerable,” senior author Huon Gray, MD (Emeritus National Clinical Director of Heart Disease, NHS), told TCTMD. “If we were to treat every patient who is symptomatic, which is roughly two-thirds of the 300,000 people with severe aortic stenosis in the UK, that constitutes quite a significant healthcare challenge. And the one-third who are asymptomatic, or at least don't report symptoms or have unrecognized symptoms, their prognosis will be poor if they don't get access to [clinical] investigation and possible treatment.”
Published this week in Open Heart, the primary goal of the study was to estimate how many people in the UK might need evidence-based treatment for severe AS. The NHS, said Gray, has come to view valvular disease as a burgeoning problem: the NHS Long Term Plan, which was published in 2019, emphasized that heart valve disease had been relatively underrecognized.
“The long-term plan covers the whole of the NHS, so it was only a very small component, but nevertheless, for the first time, it raised the profile of heart valve disease,” said Gray. “One of the motivations for this study, as far as I was concerned, was that we didn't understand the scale of the problem. What we really wanted to know, ideally within an NHS context, was the size of the problem: that being just how prevalent severe aortic stenosis is in the UK.”
The purpose of the report was not to criticize the NHS, said Gray, because the relative underrecognition of severe AS, and its growing burden, is a problem shared by healthcare systems the world over.
Scope of the Problem
Based on data from the UK Office of National Statistics, there were 66 million people living in the UK in 2019, of whom 20.1 million were 55 years or older. Based on previous studies, the researchers determined that the overall prevalence of severe AS was 1.48%, or 291,448 men and women. Of these, they estimated that 68.3%, or 199,059 people, would be symptomatic and require treatment with conservative medical therapy, surgery, or TAVI. The researchers suggest that more than 115,000 might be immediately eligible for surgery while 51,000 would benefit from TAVI.
Gray stressed that their report is based on estimates only and that a population-based, epidemiological study of prevalence, which would include assessment through routine screening, would provide more-accurate information. What is not debatable, Gray said, is the poor prognosis of these patients.
“Something in the order of 50% of people with severe aortic stenosis who are untreated die within 2 years and about 95% within 5 years,” said Gray. “There is, I think, a poor awareness generally about the potential severity of the condition and the potential benefits and advantages of being more proactive about trying to find people who have severe aortic stenosis and other forms of severe valve disease.”
Gray acknowledged that the growing burden of severe AS represents a challenge to healthcare systems around the world, including the NHS. In terms of low-cost interventions, Gray said there are ongoing efforts to establish “breathlessness” clinics and community diagnostic hubs with echocardiography to detect more patients with valve disease. There are also charities, such as the Heart Valve Voice and the British Heart Foundation, raising awareness about the signs, symptoms, and potential treatments.
“But, if you were to say to me, we’re going to double the number of patients who have aortic valve surgery or transcatheter aortic valve intervention, that would have a cost consequence absolutely,” said Gray. “There is the cost of purchasing valves and so forth, but the challenge is workforce related. I don't think the NHS, or any other country, has enough specialist staff, and services simply to say, next year, we're going to do double what we've done this year. It will require investment and will require a long-term plan as to how we get closer to everybody being correctly identified and treated. That's going to take time. It's not something that will be achieved overnight.”
Surveillance and Prevention
Gregory Roth, MD, MPH (University of Washington, Seattle), who has previously studied the global and regional burden of aortic and mitral valve diseases, said the estimated prevalence of severe AS in the UK is compatible with previously published data, including the OxVALVE study, as well as their own research. Like Gray, the current studies suggest a wave of patients will require treatment in the coming years.
“Calcific aortic valve disease is likely to become an increasingly large problem for health systems,” said Roth. “People are living longer and the population of people at older ages is growing. And despite all of the success we’ve had in treating other atherosclerotic cardiovascular diseases, we currently don’t have a therapy that modifies the natural history of calcific aortic valve disease.”
While the process of calcification looks similar to processes seen in other vessels, statin therapy, blood-pressure control, and even lifestyle modification have not proven to be effective strategies for slowing or preventing aortic-valve calcification.
“In other diseases, we can talk about primary prevention but not for this one,” said Roth. “Understanding what the health system needs to be prepared to do—in terms of effective therapies, like TAVI or surgery—is really important.”
Finding interventions that can modify the progression of calcific aortic valve disease is an important area of research, Roth said. Identifying patients sooner will also allow physicians and researchers to start thinking “what it will take” to prevent valve degeneration. Long-term, a prevention strategy would be ideal. Until one is available, though, physicians need to be increasingly thorough in their surveillance, he said.
“That doesn’t mean we should be looking in every adult for this disease, but in some ways, we already do that,” said Roth. “We listen with a stethoscope to every patient when they come in for their primary care checkup. . . . I do think we need to think about how we make sure we’re detecting everyone in the population, since it turns out that TAVI is a really effective intervention for most people.”
Strange GA, Stewart S, Curzen N, et al. Uncovering the treatable burden of severe aortic stenosis in the UK. Open Heart 2021;Epub ahead of print.
- Gray and Roth report no conflicts of interest.