No evidence to deny vascular intervention based on frailty score alone, despite association with poor outcomes

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A systematic review and meta-analysis has found that frailty is an independent risk factor in vascular surgery patients, but there is no evidence to deny intervention in any patient based on frailty score alone. This was the main conclusion delivered by John Houghton (University of Leicester, Leicester, UK) in a scientific prize session at the European Society for Vascular Surgery annual meeting (ESVS; 24–27 September, Hamburg, Germany). On 22 October, the paper was published online in the Annals of Surgery.

In the study, Houghton et al sought to investigate the methods used to assess frailty and sarcopenia in vascular surgery patients, and associations with patient factors such as lifestyle, demographics and comorbidities as well as with outcomes.

“Frailty is complex and multifactorial. It is a distinct health state, which is defined as an increased vulnerability to poor recovery from a stressor,” Houghton told the session. “Frail patients are at increased risk of poor outcomes such a loss of independence and death from even a minor stressor. Sarcopenia is defined as a progressive loss of skeletal muscle strength coupled with a reduction in quantity or quality of skeletal muscle. And it has been extensively reported in the surgical literature as a surrogate for frailty but predominantly using CT [computed tomography] alone to define sarcopenia.”

The research team deployed a standard systematic review methodology, searching multiple databases with independent reviewers screening articles and extracting data. They deliberately took a broad view, Houghton said, including all vascular surgery pathologies, and patients both undergoing and not undergoing a procedure, in the meta-analysis “only if they reported patient factors and/or outcomes for frail and non-frail vascular surgery patients separately”.

Some 53 studies were included in the systematic review, with 29 of them having used the frailty assessment. “The majority of the frailty tools used have not been well validated in the general population of older adults,” Houghton explained. “Only nine studies used a well-validated tool such as the Clinical Frailty Scale. Twenty-five studies reported sarcopenia, the vast majority of which used CT alone. None of these measures have been well validated in the general population of older adults.

“We included 18 studies in the meta-analysis, representing data from nearly 63,000 patients. We assessed risk of bias using the Robins-E tool. Two-thirds of studies were at a serious risk of bias.”

In terms of association of age with frailty, the researcher performed a sub-group analysis, grouping studies by the way that they assessed frailty: “Either a well-validated tool, an unvalidated tool or by sarcopenia alone,” said Houghton, with “all sub-groups [showing] an association with age frailty, and in the pooled analysis frail patients were on average four years older than non-frail vascular surgery patients.”

Other patient factors associated with frailty that were identified included lower body mass index, female sex and respiratory disease. The research team also discovered an inverse association with smoking, said Houghton, likely “because these patients were younger, with predominantly smoking-related vascular surgery disease and therefore less frail.”

Also of note, Houghton added: “There is no association with a number of comorbidities that have been shown to be associated with frailty in a general population of older adults. And this is likely to be because the burden of comorbidity in vascular surgery patients is much higher.”

In terms of association with outcome, the researchers found that frailty was independently associated with post-op complications, 30-day mortality and long-term mortality. “Interestingly though, sarcopenia alone was not associated with any outcome in any of the individual meta-analyses that we performed,” said Houghton.

Houghton identified several limitations to the team’s work, including what he called the “significant heterogeneity” of studies included in the review and meta-analysis, as well as the “generally relatively poor” quality of the studies included, which he said came with a high risk of bias.

“I would argue that we should only be using well-validated frailty tools that are validated in a general population of older adults, used by geriatricians and experts in frailty such as the Fried criteria, Edmonton Frail Scale and Clinical Frailty Scale,” Houghton concluded. “And I would also argue that clinical utility of sarcopenia using CT alone is highly questionable. There may well be a role for assessing sarcopenia in vascular surgery patients using functional assessments such as grip strength.”


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