Effect of Diabetes on Long-term Mortality following Abdominal Aortic Aneurysm Repair: A Systemic Review and Meta-analysis

Risk Factors for Abdominal Aortic Aneurysm in Patients With Diabetes

OBJECTIVE

Although diabetes has been shown to be negatively associated with development of abdominal aortic aneurysm (AAA), patients with diabetes may still develop aneurysms. In this study we examined risk factors for development of AAA in patients with diabetes.

METHODS

Adults over 50 years with diabetes who underwent health screening between 2009 and 2012 were followed for incident AAA until December 31, 2019. Cox proportional hazard regression models were used to calculate multivariate hazard ratios (HR) and 95% confidence intervals (CI) for risk factors associated with AAA.

RESULTS

Among 1,913,066 participants (55.3% men), 6,996 AAA cases were identified during a mean follow-up of 7.7 years. Increased AAA risk was observed for age ≥ 65 years (HR 2.69, 95% CI 2.55-2.83), men (HR 1.81, 95% CI 1.69-1.94), smoking (ex-smoker ≥ 20 pack-years, HR 1.75, 95% CI 1.61-1.89; current smoker < 20 pack-years, HR 1.76, 95% CI 1.59-1.94; current smoker ≥ 20 pack-years, HR 2.40, 95% CI 2.23-2.59), abdominal obesity (HR 1.30, 95% CI 1.23-1.38), and comorbidities: hypertension (HR 1.63, 95% CI 1.53-1.73), dyslipidemia (HR 1.35, 95% CI 1.29-1.42), chronic kidney disease (HR 1.52, 95% CI 1.44-1.61), cardiovascular disease (HR 1.71, 95% CI 1.58-1.86). Heavy (HR 0.67, 95% CI 0.61-0.74) and mild alcohol consumption (HR 0.78, 95% CI 0.74-0.83), overweight (HR 0.87, 95% CI 0.81-0.93) and obesity (HR 0.81, 95% CI 0.75-0.87), longer diabetes duration (≥ 5 years: HR 0.74, 95% CI 0.70-0.78), and using ≥ 3 oral hypoglycemic agents (HR 0.84, 95% CI 0.79-0.90) were associated with decreased AAA risk, while insulin use was associated with a marginally increased risk (HR 1.09, 95% CI 1.00-1.18). Among the oral hypoglycemic agents, metformin (HR 0.95, 95% CI 0.90-1.00), thiazolidinedione (HR 0.87, 95% CI 0.79-0.97), and sulfonylurea (HR 0.88, 95% CI 0.83-0.93) were associated with decreased risk of AAA.

CONCLUSIONS

Although diabetes is associated with decreased AAA risk, those with comorbid cardiometabolic diseases, abdominal obesity, and smoking history should be aware of increased AAA risk. Further studies are warranted to verify the potential use of oral hypoglycemic agents for reducing AAA risk.

Association between diabetes status and long-term outcomes following open and endovascular repair of infrarenal abdominal aortic aneurysms

OBJECTIVE

Current literature reports conflicting findings regarding the effect of diabetes mellitus (DM) on outcomes of abdominal aortic aneurysm (AAA) repair. In this study we examined the effect of DM and its management on outcomes after open AAA repair (OAR) and endovascular AAA repair (EVAR).

METHODS

We identified all patients undergoing OAR or EVAR for infrarenal AAA between 2003 and 2018 in the Vascular Quality Initiative registry data linked with Medicare claims. We excluded patients with missing DM status. Patients were stratified by their preoperative DM status, and then further stratified by DM management: dietary, noninsulin antidiabetic medications (NIMs), or insulin. Outcomes of interest included 1-year aneurysm sac dynamics, 8-year aneurysm rupture, reintervention, and all-cause mortality. These outcomes were analyzed with the χ2 test, Kaplan-Meier methods, and multivariable Cox regression analyses.

RESULTS

We identified 34,021 EVAR patients and 4127 OAR patients, of whom 20% and 16% had DM, respectively. Of all DM patients, 22% were managed by dietary management, 59% by NIM, and 19% by insulin. After EVAR, DM patients were more likely to have stable sacs, whereas non-DM patients were more likely to have sac regression at 1 year. Compared with non-DM, DM was associated with a significantly lower risk for 8-year rupture in EVAR (EVAR hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.51-0.92). Compared with non-DM, NIM was associated with lower risk of rupture within 8-years for both EVAR and OAR (EVAR HR, 0.64; 95% CI, 0.44-0.94; OAR HR, 0.29; 95% CI, 0.41-0.80), whereas dietary control and insulin had a similar rupture risk compared with non-DM. However, compared with non-DM, DM was associated with a higher risk of 8-year all-cause mortality after EVAR and OAR (DM vs non-DM: EVAR HR, 1.17; 95% CI, 1.11-1.23; OAR HR, 1.16; 95% CI, 1.00-1.36). After further DM management substratification, compared with non-DM, management with NIM and insulin were associated with a higher 8-year mortality in EVAR and OAR (EVAR: NIM HR, 1.12; 95% CI, 1.05-1.20; insulin: HR, 1.40; 95% CI, 1.26-1.55; OAR: NIM HR, 1.27; 95% CI, 1.06-1.54; and insulin: HR, 1.57; 95% CI, 1.15-2.13). Finally, there was a similar risk of reintervention across the DM and non-DM populations for EVAR and OAR.

CONCLUSIONS

DM was associated with a lower adjusted risk of rupture after EVAR as well as OAR in patients managed with NIM. Nevertheless, just as in patients without AAA, preoperative DM was associated with a higher adjusted risk of all-cause mortality. Further study is needed to evaluate for differences in aneurysm-related mortality between DM and non-DM patients, and studies are planned to evaluate the independent effect of NIM on aneurysm-related outcomes.

Metformin Use and Long-term Outcomes Including Aneurysm Sac Dynamics Following EVAR for Infrarenal Abdominal Aortic Aneurysm: "A Retrospective Study"

PURPOSE

Metformin, widely used for the treatment of diabetes mellitus (DM), has shown potential for inhibiting abdominal aortic aneurysm (AAA) growth by reducing extracellular matrix remodeling and inflammation. However, its influence on clinical outcomes and aneurysm sac dynamics after endovascular aneurysm repair (EVAR) remains uncertain. This retrospective study aims to explore the effects of metformin on long-term outcomes following EVAR.

MATERIALS AND METHODS

Patients who underwent elective standard EVAR for infrarenal AAA at a single academic Dutch hospital from 2000 to 2022 were included. We collected baseline patient demographics, comorbid conditions, anatomical and operative characteristics, and 30-day postoperative events. Metformin use was defined as using it preceding EVAR. The primary outcome, the postoperative aneurysm sac volume over time, was investigated using linear mixed-effects modeling. The secondary outcomes, 8-year all-cause mortality and freedom from graft-related events, were evaluated using Kaplan-Meier methods.

RESULTS

We analyzed 685 patients, including 634 (93%) non-metformin users and 51 (7%) metformin users. The median follow-up period was similar (4.0 years [IQR=1.5, 6.5] vs 5.0 years [IQR=2.0, 8.0]; p=0.091). Patients on metformin had a preoperative aneurysm sac volume of 153 cc (IQR=114, 195) compared with 178 cc (IQR=133, 240) for non-metformin patients (p=0.054). At 30 days post-EVAR, metformin patients had a comparable mean aneurysm sac volume compared with non-metformin patients (metformin: -19.4 cc [95% confidence interval [CI]: -47.4, 8.5]; p=0.173). The effect of metformin on aneurysm growth over time was not significant (-3.9 cc/year; [95% CI: -22.7, 14.9]; p=0.685). Following risk-adjusted analysis, metformin use was associated with similar rates of all-cause mortality (metformin vs no metformin: 50% vs 44%; hazard ratio [HR]=1.11, 95% CI: 0.66, 1.88; p=0.688) and freedom from graft-related events (metformin vs no metformin: 63% vs 66%; HR=1.82, 95% CI: 0.98, 3.38; p=0.059).

CONCLUSION

Although metformin use may reduce preoperative AAA growth, it does not seem to influence overall/long-term post-EVAR AAA sac dynamics, all-cause mortality, or freedom from graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR. Further prospective studies are needed to investigate the mechanisms underlying the potential role of metformin in AAA management following EVAR.

CLINICAL IMPACT

There is currently no approved pharmacological treatment available to slow the abdominal aortic aneurysm (AAA) growth rate and reduce the related risk of rupture. In our retrospective analysis including 685 patients undergoing EVAR for infrarenal AAA, we found that metformin use was not associated with improved post-EVAR outcomes, such as a reduction of aneurysm sac volume over time, eight-year all-cause mortality, or freedom of graft-related events. These findings suggest that the potential protective effect of metformin on AAA may not be sustained after EVAR and underscore the need for ongoing research into this area.

The 5-Factor Modified Frailty Index is a Succinct yet Effective Predictor of Adverse Outcomes in Patients Undergoing Open Surgery for Abdominal Aortic Aneurysm

BACKGROUND

Frailty is an age-related, clinically recognizable state marked by increased susceptibility. The 5-item Modified Frailty Index (mFI-5) offers a concise assessment of frailty and has demonstrated its efficacy in various surgical fields. While the mFI-5 has been validated for endovascular aneurysm repair for abdominal aortic aneurysm (AAA), its applicability in open surgical repair (OSR) for AAA remains largely unexplored. This study sought to evaluate the utility of mFI-5 in predicting 30-day outcomes following OSR for AAA.

METHODS

Patients underwent OSR for AAA were identified in American College of Surgeons National Surgical Quality Improvement Program-targeted database from 2012 to 2021. Patients were stratified into 3 cohorts: mFI-5 score of 0 (control), 1, and 2+. Multivariable logistic regression was used to compare 30-day perioperative outcomes between frail patients and controls adjusting preoperative variables with P value <0.1.

RESULTS

Of the 5,249 patients who underwent OSR for AAA, 1,043 were controls, 2,938 had an mFI-5 score of 1 and 1,268 had an mFI-5 score of 2+. When compared to the control group, patients with an mFI-5 = 1 were more likely to have pulmonary events (adjusted odds ratio (aOR) = 1.452, P < 0.01), bleeding events (aOR = 1.33, P < 0.01), wound complications (aOR = 2.214, P < 0.01), ischemic colitis (aOR = 1.616, P = 0.01), and unplanned reoperation (aOR = 1.292, P = 0.04). Those with an mFI-5 = 2+ demonstrated higher risks of mortality (aOR = 1.709, P < 0.01), major adverse cardiovascular events (aOR = 1.347, P = 0.04), pulmonary events (aOR = 2.045, P < 0.01), renal dysfunction (aOR = 1.568, P < 0.01), sepsis (aOR = 1.587, P = 0.01), bleeding events (aOR = 1.429, P < 0.01), wound complications (aOR = 2.338, P < 0.01), ischemic colitis (aOR = 1.775, P = 0.01), unplanned reoperation (aOR = 1.445, P = 0.01), operation over 4 hours (aOR = 1.34, P < 0.01), length of stay over 7 days (aOR = 1.324, <0.01), discharge not to home (aOR = 1.547, P < 0.01), 30-day readmission (aOR = 1.657, P = 0.01).

CONCLUSIONS

The mFI-5 emerges as a succinct yet effective indicator of frailty for patients undergoing OSR for AAA. Especially, an mFI-5 score of 2+ is linked with increased 30-day mortality and complications. As such, mFI-5 can be used as a valuable screening tool for frailty in patients undergoing OSR for AAA.

Five Year Post-Endovascular Aneurysm Repair Aneurysm Sac Evolution in the GREAT Registry: an Insight in Diabetics Using Propensity Matched Controls

OBJECTIVE

To assess differences in the five year abdominal aortic aneurysm (AAA) sac regression rate after endovascular aneurysm repair (EVAR) in patients with and without diabetes mellitus (DM).

METHODS

An international prospective registry (Europe, USA, Brazil, Australia, and New Zealand) of patients treated with the GORE EXCLUDER endograft. All scheduled EVARs for infrarenal AAA between 2014 and 2016 with complete five year imaging follow up were included. Emergency procedures, ancillary proximal procedures, and inflammatory and infectious aetiologies were excluded. Descriptive and inferential statistics, and Cox proportional hazards survival models were used. A control group of patients without DM with similar age and comorbidities was selected using propensity scores, matched in a 1:2 scheme.

RESULTS

A total of 2 888 patients (86.1% male; mean age 73.5 ± 8 years) was included, of whom 545 (18.9%) had DM. Patients with DM had higher rates of hypertension (89.2% vs. 78.4%), dyslipidaemia (76.0% vs. 60.7%), coronary artery disease (52.3% vs. 37.9%), and chronic renal impairment (20.9% vs. 14.0%) (all p < .001). The mean pre-procedural AAA diameter was 58.1 ± 10 mm. Five years post-EVAR, the type 1A endoleak rate was 1.1% (0.6% DM vs. 1.2% non-DM), the endograft related re-intervention rate was 7.3% (6.2% vs. 7.6%), the major adverse cardiovascular event (MACE) rate was 1.4% (1.1% vs. 1.5%), and aortic related mortality rate was 1.0% (0.6% vs. 1.2%), without statistically significant differences between groups. The overall five year mortality rate was higher in diabetics (36.3% vs. 30.5%; hazard ratio [HR] 1.30, 95% confidence interval [CI] 1.07 - 1.58; p = .001). No statistically significant differences were found in sac regression rate (≥ 5 mm) between diabetics and non-diabetics 70.0% vs. 73.1%; HR 0.88, 95% CI 0.75-1.04; p = .131. These differences remained statistically non-significant after excluding patients performed out of instructions for use (p = .61) and patients with types 1, 2 or 3 endoleaks (p = .39).

CONCLUSION

The paradoxical relationship between DM and AAA does not appear to result in differences in post-EVAR sac regression rates. However, even when controlling for other comorbidities, patients with DM undergoing EVAR may have a higher five year mortality rate.

Sarcopenia defined by the psoas muscle mass or quality is associated with poor survival in patients with aortic aneurysm undergoing surgery: A meta-analysis

BACKGROUND

The impact of sarcopenia estimated by the skeletal muscle mass or quality on survival remains controversial in patients with aortic aneurysm. This meta-analysis aimed to assess the association between sarcopenia defined by the psoas muscle mass or quality and all-cause mortality in patients with aortic aneurysm.

METHODS

We comprehensively searched PubMed, Web of Science, and Embase databases until December 31, 2022. Studies investigating the association of CT-derived psoas muscle mass (psoas muscle area [PSA] and psoas muscle index [PMI]) or quality (lean PSA [LPSA]) with all-cause mortality in patients with aortic aneurysm undergoing surgery were included.

RESULTS

Eighteen studies reporting on 19 articles, enrolling 4767 patients were identified. A comparison of the bottom with the top psoas muscle mass, the pooled adjusted hazard ratios (HR) of all-cause mortality was 2.34 (95% confidence intervals [CI] 1.58-3.47). Low psoas muscle mass was associated with an increased risk of all-cause mortality when defined by the PSA (HR 2.01; 95% CI 1.42-2.75) or PMI (HR 2.37; 95% CI 1.24-4.55). Per 1 cm2 PMA increase conferred a 10% reduction in all-cause mortality. Patients with bottom LPMA had an increased risk of all-cause mortality (HR 3.27; 95% CI 1.90-5.60). Each 100 cm2 × HU LPMA increase conferred a 15% reduction in all-cause mortality.

CONCLUSIONS

Sarcopenia defined by the low psoas muscle mass or quality independently predicts all-cause mortality in patients with aortic aneurysm. However, the overall certainty of evidence for the categorical analysis of psoas muscle mass was downgraded by the presence of publication bias and significant heterogeneity.

Double-edged sword of diabetes mellitus for abdominal aortic aneurysm

INTRODUCTION

Diabetes mellitus (DM) has been proved to contribute to multiple comorbidities that are risk factors for abdominal aortic aneurysm (AAA). Remarkably, evidences from epidemiologic studies have demonstrated a negative association between the two disease states. On the other hand, hyperglycemic state was linked to post-operative morbidities following AAA repair. This review aims to provide a thorough picture on the double-edged nature of DM and major hypoglycemic medications on prevalence, growth rate and rupture of AAA, as well as DM-associated prognosis post AAA repair.

METHODS

We performed a comprehensive search in electronic databases to look for literatures demonstrating the association between DM and AAA. The primary focus of the literature search was on the impact of DM on the morbidity, enlargement and rupture rate, as well as post-operative complications of AAA. The role of antidiabetic medications was also explored.

RESULTS

Retrospective epidemiological studies and large database researches associated the presence of DM with decreased prevalence, slower expansion and limited rupture rate of AAA. Major hypoglycemic drugs exert similar protective effect as DM against AAA by targeting pathological hallmarks involved in AAA formation and progression, which were demonstrated predominantly by animal studies. Nevertheless, presence of DM or postoperative hyperglycemia was linked to poorer short-term and long-term prognosis, primarily due to greater risk of infection, longer duration of hospital stays and death.

CONCLUSION

While DM is a positive factor in the formation and progression of AAA, it is also associated with higher risk of negative outcomes following AAA repair. Concomitant use of antidiabetic medications may contribute to the protective mechanism of DM in AAA, but further studies are still warranted to explore their role following AAA repair.

Aneurysms and dissections - What is new in the literature of 2019/2020 - a European Society of Vascular Medicine annual review

More than 6,000 publications were found in PubMed concerning aneurysms and dissections, including those Epub ahead of print in 2019, printed in 2020. Among those publications 327 were selected and considered of particular interest.

Translational applications of glucose metabolism in abdominal aortic aneurysm

Even though diabetes mellitus is a major risk for cardiovascular events and atherosclerosis-related diseases, it is negatively associated with abdominal aortic aneurysm. The understanding of the mechanisms underlying this negative association could bring new insights to identify prognostic and therapeutic targets. Here we summarize current knowledge of the relationship between glycemic parameters and clinical outcomes of patients with abdominal aortic aneurysm. Translational applications of glucose-targeted approaches as well as their potential interest for clinical practice are discussed in this context.