Do Guidelines Make a Difference? SCCT Session Probes Impact and Equity

BOSTON, MA—Do guidelines actually make a difference? If so, to whom?

Those questions were posed during a special session at the recent 2023 Society of Cardiovascular Computed Tomography (SCCT) meeting held here addressing whether these standards are having a meaningful impact on practice and, if they are, how their implementation can be improved to ensure equitable care across the population.

Martha Gulati, MD (Cedars Sinai Medical Center, Los Angeles, CA), president of the American Society for Preventive Cardiology and chair of the 2021 US chest pain guidelines, defended the role of guidelines, saying that they’ve clearly improved cardiovascular care. “If we didn’t have guidelines, hearsay would be the way people practice medicine, and in my experience, it’s never a way that we should be practicing in modern medicine,” she told TCTMD.

The documents provide a way to distill the results of trials demonstrating which treatments are most effective for improving outcomes and create recommendations, she said, noting that cardiology is very evidence-based. “I guess this is why I hold our community a bit to the fire, because we are so evidence-based that we should be doing right by people,” Gulati said, alluding to continuing disparities in care, which persist despite some improvements over time.

Assessing the Impact

Jonathan Weir-McCall, MBChB, PhD (University of Cambridge, England), was tasked with giving a talk on whether guidelines actually make a difference, and he started off by noting that he is a member of the SCCT guideline committee.

When it comes to the question of whether guidelines actually make a difference, “the evidence isn’t strong,” he said, pointing to a 2021 analysis of the uptake of the US cholesterol treatment guidelines, which showed only a small increase in the proportion of patients receiving statins 2 years after their release. “So, not the most resounding success for the support of the utility of guidelines.”

But he spent most his presentation tackling the question with a focus on the UK chest pain guidelines from the National Institute for Health and Care Excellence (NICE). First published in 2010, they were updated in 2016, giving more prominence to coronary CT angiography (CCTA) for diagnosis due to high sensitivity and specificity compared with other modalities. But the real driving force, Weir-McCall said, was the cost-effectiveness of the test.

In an analysis published earlier this year, Weir-McCall and his colleagues explored the impact of the release of the NICE guidelines in the UK, assessing trends in CAD imaging and their relationships with healthcare outcomes and cost. The analysis appeared to show an impact, with about a 4% increase in cardiac imaging overall but a 25% increase in use of CT during the study period spanning from 2012 to 2018. The growth in CT, as well as in invasive angiography, was greater than what would have been projected without the release of the guidelines, Weir-McCall said.

To evaluate the potential impact of the NICE document on patient outcomes, the investigators mapped the growth of CT in different parts of the UK and compared it with changes in CV mortality. “What essentially we found was that areas that showed greater growth in cardiac CT, greater response to the guidelines, saw more rapid falls in their cardiovascular mortality,” he said.

Weir-McCall acknowledged correlation doesn’t establish causation, but said that because the SCOT-HEART trial did show a chest pain workup involving CCTA reduced CV endpoints compared with standard care, “this does help support the argument of causation rather than simple correlation.”

Yes, Guidelines Matter

Asked in a broader sense about the real influence of guidelines, Stephan Achenbach, MD (University of Erlangen, Germany), a past president of the European Society of Cardiology who served as the first president of the SCCT from 2005 to 2007, told TCTMD that guidelines influence practice by providing a “channel of communication.”

Released on a regular schedule over the years, “the guidelines are an important wheel that is turning to make sure that there’s a constant update of information in the community,” he said. “I think this is where guidelines make a big difference, because they provide a reason to reflect on how to treat a certain patient in a certain situation.”

There are debates about how often the documents should be updated and how detailed they should be, but “they have been working well considering the balance of how much effort goes into producing it and how frequently a clinician can consume new information about what should be done.”

Biases Affecting Women, Underrepresented Groups

Gulati agreed that guidelines are important, but in her talk, she looked at the lingering disparities that see women receiving substandard care compared with men, gaps that could also be applied to members of underrepresented groups. These gaps have narrowed, but “while the disparities continue, I will not be satisfied,” she told TCTMD.

She said a pet peeve of hers is when women are relegated to a section of various guidelines for special populations, often found deeper within documents, despite women making up more than 50% of the US population. That’s something that was purposefully avoided in the chest pain guidelines, which present issues relevant to women up top in the main messages and throughout the document.

If we didn’t have guidelines, hearsay would be the way people practice medicine. Martha Gulati

Addressing why it’s significant that guidelines are applied differently in women than in men, Gulati pointed to mortality after acute MI, which, according to the latest statistics from the American Heart Association, remains higher in women at both 1 year and 5 years. This outcome difference may be partially related to how the standards are applied and might represent a difference in response to medications and interventions, she said.

Generally, guidelines do not advise treating women less aggressively, though there is a lot of evidence, particularly in the area of acute MI, showing that that is indeed the case. Women are less likely undergo catheterization or PCI, their door-to-balloon times are longer, they’re less likely to receive fibrinolytic therapy (with longer door-to-needle times), and they’re less likely to receive guideline-directed medical therapies either acutely or at discharge. In addition to a higher risk of mortality after acute MI, women are also more likely to be readmitted.

“There is some bias in our care for women compared to men despite the fact that our guidelines really don’t say to treat women differently,” Gulati said, who noted that these types of disparities also are seen in other settings, including CV prevention, heart failure, valvular heart disease, and atrial fibrillation.

How to Apply Guidelines More Equitably

As to how guidelines can be applied equally to all segments of the population, Achenbach pointed to two main factors that will play a role: education and reimbursement. The need for payment in particular will drive physician behavior, he indicated, because “nobody can afford to lose money practicing, so if something is not reimbursed of course it will severely impact whether it’s being done or not.” He added that it’s important to “make sure that there is no incentive to not treat optimally by the reimbursement structure that is out there.”

After Gulati’s presentation, Achenbach asked her about the conflict he perceives between calls to treat women and men equally and the acknowledgement that there are some biological differences between the sexes that could impact treatment decisions.

Of course we want to apply guidelines or good data with the same level of scrutiny in treating men and women, but women are different from men. Stephan Achenbach

To TCTMD, he gave an example from his perspective as an interventional cardiologist: on average, women have smaller coronary arteries than do men, which means PCI complication rates are higher and operators might need to be more selective when placing stents.

“Of course we want to apply guidelines or good data with the same level of scrutiny in treating men and women, but women are different from men and maybe we need specific recommendations on what to do . . . that differentiates a woman from a man in certain cases,” Achenbach said.

Indeed, women are not the same as men, and when there is evidence of differences in response to treatments, guidelines should reflect that, Gulati said. The problem, she highlighted, is that women and other individuals from diverse populations are understudied, often underdiagnosed, and undertreated. So, she said, “if we don’t have that data [about differences between sexes] and if that’s not spelled out in our guidelines, we shouldn’t be withholding treatment.”

To encourage guidelines to have an equitable impact on care, universal healthcare would be a good starting point, Gulati said. But something that could be put in place right now might include integration of artificial intelligence into electronic medical record systems to prompt clinicians to deliver recommended treatments, she said.

Moreover, physicians now and in the future should be trained to recognize and overcome biases in the care of patients, whether that’s related to sex or race/ethnicity. “We need to know why we do things differently and how can we change that,” Gulati said.

Other key efforts she highlighted are the tracking of metrics at the hospital and national levels to maintain accountability and identify areas for improvement; additional implementation research to study efforts to enhance the impact of guidelines; and vigilance when it comes to ensuring that study participants are representative of the broader population.

“When we continue to allow there to be underrepresentation of people in our clinical trials, not representing the people that are suffering from the diseases, it also makes it very hard,” Gulati said, noting that in the early days of statin use, some clinicians balked at giving the medications to women because they were not well represented in the trials. “We need to be very proactive in planning our future research. It’s not just about saying there needs to be equity in research. There actually has to be accountability.”

Despite these continuing challenges, “I do think guidelines make us as a cardiology community better,” Gulati stressed. “That’s why we spend so much time and effort making the guidelines. We know the value that it’s bringing our community and our patients.”

Still, she added, “I hope we become more critical of our guidelines and also figure out when our guidelines are good but not being applied equally [and] point that out in our guidelines and try to see where implementation research has actually helped us improve the care of both men and women. Our goal is to help both.”