National study finds no support for highintensity statin treatment after AAA repair

Statin treatment after aortic repair is associated with improved long-term survival, while dose does not matter. This was the key message from a first-to-podium presentation delivered by Kevin Mani (Uppsala University, Uppsala, Sweden) at the 2023 Charing Cross (CX) International Symposium (25–27 April, London, UK). The CX audience showed their support for this conclusion, with 89% agreeing with the statement ‘Statins save lives’ during discussion time.

Mani began by underlining the fact that abdominal aortic aneurysm (AAA) is a cardiovascular disease that shares risk factors with atherosclerotic cardiovascular disease (ASCVD). According to the American Heart Association (AHA), the presenter detailed, AAA is in fact classified as one of the ASCVDs.

“AAA patients have a higher mortality than the general population due to cardiovascular disease,” Mani noted, adding that statin treatment is associated with improved survival in patients with ASCVD.

The presenter detailed that current European Society for Vascular Surgery (ESVS) guidelines on the management of abdominal aortoiliac artery aneurysms, published in 2019, suggest that patients with AAA should have blood pressure control, statins and antiplatelet therapy. “This is a class IIa recommendation with level b evidence,” the presenter specified, which he said indicates that “probably all patients” with AAA should have statin treatment.

The AHA guidelines, Mani highlighted, split statin treatment into high dose and moderate to low dose. “The suggestion is that patients with ASCVD including those with AAA should have high-dose statin treatment,” the presenter shared with the Kensington 1 audience. “However,” he said, “the evidence for what dose should be given to AAA patients is non-existent, and the vascular surgical guidelines do not recommend a specific dose for AAA patients.”

To address this gap in the literature, Mani and colleagues conducted a national study assessing the potential benefit of statin treatment in AAA patients and whether dose has an effect. The team used four national registries and then cross-matched these to identify all AAA repairs performed in Sweden between the years of 2006 and 2018, the presenter explained. The team then assessed statin treatment by combining patient data and the national prescribed drug registry, looking at outcomes in terms of death, cause of death and rehospitalisation, also using national registries.

Mani detailed that the researchers performed three analyses, the first looking at 90-day mortality for patients who had statin treatment preoperatively, the second assessing statin versus no statin treatment postoperatively, and the final one examining highdose versus low-to-moderate-dose statin treatment postoperatively, considering overall survival, aorticrelated survival and freedom from cardiovascular events. Propensity score matching was used to ensure that the groups were comparable in terms of baseline comorbidities and characteristics.

The presenter revealed that approximately 60% of the 11,000 patients who underwent AAA repair in the national study had statin treatment prior to undergoing repair. Postoperatively, he added, half of the patients had continuous statin treatment 80% of the time after the operation. In both instances, the rates were higher

Endurant stent graft proves efficacious and durable in ENGAGE 10-year data

A first-to-podium presentation at CX 2023 saw Hence Verhagen (Erasmus Medical Center, Rotterdam, The Netherlands) present unique 10-year data from the ENGAGE OUS registry on the Endurant abdominal aortic aneurysm (AAA) stent graft (Medtronic). “Ever since we started doing endovascular aneurysm repair (EVAR) about 30 years ago, there have been concerns about durability,” Verhagen stated at the opening of the talk. “What we have revealed is that the survival between open and endovascular patients is the same in the long term.”

VERHAGEN DIRECTED HIS audience’s attention to previous randomised controlled trials such as EVAR1 and DREAM, which “raise[d] concern” around durability. The latter in particular showed patients in its EVAR group had “many more secondary interventions after about four years”. He also said that, though there were some other studies with long-term data (≥10 years), many of these have “strict limitations”, leading to a “paucity of long-term data” with a large stenting sample size. The reason, he said, was the high mortality in such trials— meaning that, after 10 years, “there are not that many patients left […] You need a very large group to start off with to have survival and results after 10 years.”

Verhagen detailed among men compared to women.

Looking at perioperative mortality, Mani reported that this was the same in the group on statin treatment versus no statin treatment and was equal for the endovascular aneurysms repair (EVAR) and open repair cohorts, with an overall 90-day mortality of just under 3%.

The presenter also shared the finding that patients on statin treatment had an improved survival in the long term, and that overall survival was “significantly improved” in a propensity score-matched group of patients with or without continuous statin treatment after AAA repair. Aortic-related survival was improved with statin treatment, he stated, as was freedom from cardiovascular events, if the patients were on statin treatment.

Finally, the team assessed the highdose statin group versus the low-tomoderate-dose group. “There was no effect of the dose of statins, neither on overall survival nor on aortic-related survival or cardiovascular events,” he communicated. “These were equal, irrespective of dose.” that the registry included 1,260 patients from 79 sites in 30 countries. The patients initially enrolled only consented to five-year follow-up, however, which required a reconsent process for 10-year follow-up—with only 49 of the initial 79 centres agreeing. This, combined with patient refusals, reduced the total cohort for long-term results to around 390 patients. “Not surprisingly, these patients were a little younger than the original and had generally fewer comorbidities,” Verhagen added.

“In conclusion,” the presenter summarised, “statin treatment is beneficial in AAA patients with improved long-term survival, as well as improved freedom from aortic-related complications and cardiovascular events.” However, he added the caveat that there is no support in the study for high-intensity statin treatment after AAA repair, and that perioperative mortality was not affected by statin treatment.

In subsequent discussion, panellist Janet Powell (Imperial College London, London, UK) asked whether the study results are independent of lowdensity lipoprotein (LDL) cholesterol levels. Mani responded that the team does not have such data. However, he highlighted the fact that the AHA recommendation for high-dose statins for patients with AAA below the age of 75 is irrespective of their LDL levels. “Clearly, this is an area where we need to work more on how we achieve the adequate effect of statins by looking at LDL levels,” he remarked, considering future research in this space.

All-cause mortality up to 10 years was analysed, revealing a survival rate of about 42%. There was no steep decline after five years, something which also held for aneurysm-related mortality (around 5% of patients). Reinterventions, “the Achilles’ heel of EVAR,” were also not found to accelerate after five years’ follow-up, with around 70% of patients free from secondary interventions. Stratified into groups undergoing reintervention at 0–5 years and at 6–10 years, Verhagen and colleagues found “very, very few” type 3 endoleaks “in the first seven years or so”, he stated, “with a slight increase at 10 years”.

Patients with a type 1a endoleak, Verhagen noted, increased in number by 4.1% at 10 years. Of those, however, 40% “started off with wellknown risk factors”. Clinical events were also examined, with aneurysm rupture—“the ultimate failure”— occurring “very, very little”, increasing at a rate of 1.5% at 10 years.

The take-home message, Verhagen stated, was that these were “probably unique data” up to 10 years, and that they “confirm the long-term efficacy and the durability of the Endurant stent graft with these numbers of aneurysms and mortality”. He added that “lifelong surveillance is critical for EVAR patients”.