Predicting longevity in patients who may be candidates for aortic repair is challenging. This, coupled with a high and unchanging long-term postoperative mortality rate, begs the question: are patients living long enough to benefit from aortic repair?
Bijan Modarai (King’s College London and Guy’s and St Thomas’ NHS Foundation Trust, London, UK) set out and addressed this conundrum at the 27th European Vascular Course (EVC; 3–5 March, Maastricht, The Netherlands). He argued that a lack of evidence for predicting longevity—a key factor in deciding whether a patient should undergo aortic aneurysm repair—necessitates a future move towards precision medicine and personalised treatment to avoid operating on patients unnecessarily.
“Our assessment of patients has got better, but we still get surprised,” was Modarai’s opening message, sharing with the EVC audience three cases to illustrate his point that predicting longevity remains challenging and uncertain.
Despite showing two examples of aortic patients living longer than anticipated, Modarai highlighted that the totality of the data shows the opposite trend—a high long-term mortality rate. “When you go out to three to five years, there is a significant mortality rate associated with patients who have had an aneurysm repair,” he said, highlighting a 30–50% all-cause mortality rate at five years. “It’s evident that fixing the aneurysm is only one part of what we need to do for our patients.”
Against this backdrop, Modarai then turned his attention to cardiovascular risk factors and malignant transformation, specifically aortic stiffness and aneurysm sac biology, and how both could be managed better.
Regarding aortic stiffness, Modarai outlined some research on the topic: “When you place a stiff stent into the aorta, you change its compliance immediately. That has ramifications for perfusion of organs, particularly for the heart, and there is quite good evidence to show that pulse wave velocity—an indication of increased aortic stiffness—is a cardiovascular risk marker.” He then showed data illustrating that patients with high pulse wave velocity have poor cardiovascular outcomes. “Is that having an impact on our patients after endovascular aneurysm repair [EVAR]?” he asked. While there are currently few data on the topic, Modarai believes this is a “rich area for research”.
The presenter also spoke on whether radiation influences malignant transformation, referring in this part of his talk to the late results of the EVAR trial. “When you get out to beyond eight years,” he said, “there is a signal for higher malignancy rate in the EVAR group compared to the open group.” He also shared the outcomes of some exploratory work showing fourfold higher numbers of dicentric chromosomes in EVAR patients compared to those in a control group. “Dicentric chromosomes are a marker of genomic instability, caused by radiation damage, and may be a reason why there are more malignancies in this group, but there’s more we need to understand,” he said.
This led Modarai to make one of the key points of his talk. “The guidelines tell us you’ve got to predict longevity in patients when you decide which way to go, but I’m not sure there’s a lot of evidence or robust risk scoring to allow that,” he said.
With risk scoring not available, Modarai outlined how he and his team approach things now. “We’ve made our multidisciplinary meeting structure a lot more inclusive in the past five years,” he said, noting that it now includes a POPS (perioperative medicine for older people having surgery) team. He referred to two colleagues who run this service at Guy’s and St Thomas’ and have “transformed perioperative assessment and treatment of our patients”. He explained that they see just about all of the aortic patients at the hospital prior to surgery and report on what they think about frailty and other health factors. “They’re rolling out this service across the UK now with an NIHR [National Institute for Health and Care Research]-funded trial to find out what difference it makes,” Modarai informed the EVC audience.
Despite initiatives such as this, Modarai stressed that “we’ve still got a long way to go in predicting longevity”.
Moving in the right direction
“We need to have a precision approach to how we manage these patients,” Modarai emphasised. “There’s a lot of heterogeneity in the aortic group that we deal with and there is a lack of predictability. It’s all about developing these precision measures and personalised treatment of each patient using multimodal data.”
In terms of progress, Modarai believes “we’re starting to move in that direction”. He referenced a paper showing the use of advanced artificial intelligence (AI)-powered neural multi-task logistic regression techniques to perform patient-specific estimation of survival after elective aneurysm treatment. “These kinds of algorithms are more likely to capture complex, non-linear discrepancies between patients and I’m sure that in the next five years this is the direction that we’ll be moving in,” he said.
He also stressed the importance of AI in the future of precision medicine, opining that “we need to get on this wave early”.
“We’re still operating on too many patients with aortic aneurysms, I’m convinced of that,” Modarai said in his concluding remarks. “And when you put in a certain number of stent grafts and the enthusiasm plateaus, I think you’re more likely to admit that.”
Modarai also advised colleagues to “beware of endovascular heroics in patients who aren’t durable”.
The importance of multidisciplinary working was another of Modarai’s take-home messages. “I think medical collaboration and having an open mind about hearing from our medical colleagues is important,” he commented.
Sharing a forward-looking statement on what’s next for the treatment of aortic patients, Modarai opined: “I think a precision-medicine approach will be the future.”
