Elective Versus Ruptured Abdominal Aortic Aneurysm Repair: A 1-Year Cost-Effectiveness Analysis

Polygenic Risk Score Informed Clinical Model for Improving Abdominal Aortic Aneurysm Screening

BACKGROUND

Abdominal aortic aneurysm (AAA) is a complex disease with environmental and genetic risk factors. Polygenic risk scores (PRSs) based on disease-specific risk-associated single nucleotide variants (SNVs) have demonstrated effectiveness in stratifying individual-level disease risk for cardiovascular diseases. This prospective cohort study assessed associations of PRS of AAA (PRSAAA) with risk of incident AAA, analyzed the effectiveness of a combined clinical-genetic risk model, and explored the clinical utility of the model in identifying high-risk individuals for AAA screening.

METHODS

PRSAAA was calculated using 911,440 SNVs and PRS of coronary artery disease was calculated using 2,324,683 SNVs derived from mixed ancestry genome-wide association studies. The UK Biobank was used as the study cohort. All individuals with complete genetic data available and no diagnosis of AAA at the time of recruitment were included in the analysis and followed prospectively to assess for incident AAA. A PRS-informed clinical model, Prob-AAA, was developed using clinically significant variables and PRSAAA.

RESULTS

Four hundred eighty-one thousand one hundred 5 individuals were included in the analysis with 2,668 incident AAA cases. Incident AAA increased from 0.30 to 0.93% between the lowest and highest decile of PRSAAA; similarly, severe AAA, requiring surgery and/or presenting with rupture, increased from 23 to 39% of incident AAA cases across deciles. PRSAAA was a predictor of incident AAA diagnosis (hazard ratio 2.06 [1.70-2.48]) independent of other clinical risk factors including male sex, older age, and smoking history. Prob-AAA was an independent predictor of incident AAA (hazard ratio 1.92 [1.69-2.20]), and identified 9.6% of cases of incident AAA compared to only 4.2% by PRSAAA. Current screening guidelines captured 5.7% of the overall cohort, with an incident AAA rate of approximately 3.2%. Among males not included by current guidelines, Prob-AAA identified an additional cohort, approximately 2% of the overall cohort, with a similar rate of incident AAA.

CONCLUSIONS

Prob-AAA, a PRS-informed clinical model for AAA, improved upon the predictive power of current, clinical risk factor-informed, screening guidelines for AAA.

Short-term Mortality and Postoperative Complications of Abdominal Aortic Aneurysm Repair in Obese versus Non-obese Patients

Background

Obesity is a risk factor not only for abdominal aortic aneurysm (AAA) but also for complications after vascular surgery. This study was to determine the effect of obesity on short-term mortality and post-intervention complications after AAA repair.

Methods

A systematic review and meta-analysis were performed. A systematic search was performed in PubMed; the articles describing the differences in post-intervention complications after open or endovascular repair of an AAA between obese and non-obese patients were selected. The primary outcome was short-term mortality defined as in-hospital mortality or mortality within 30 days after AAA repair. The secondary outcomes were cardiac complications, pulmonary failure, renal failure, and wound infections. The meta-analysis was performed using OpenMeta.

Results

Four articles were included in the meta-analysis; these articles included 35,989 patients of which 10,917 (30.3%) were obese. The meta-analysis showed no significant differences for short-term mortality (odds ratio [OR], 0.85; 95% confidence interval [CI], 0.69-1.04). Also, no significant difference was found in pulmonary failure (OR, 1.09; 95% CI, 0.85-1.42). However, obese patients were less likely to suffer from cardiac complications (OR, 0.73; 95% CI, 0.55-0.96). Nevertheless, there was a significantly higher risk of renal failure (OR, 1.16; 95% CI, 1.05-1.30) and wound infections (OR, 1.92; 95% CI, 1.55-2.38) in obese patients.

Conclusion

Obesity is not a risk factor for short-term mortality after AAA repair compared to non-obesity. Moreover, obese patients suffer less from cardiac complications than non-obese patients.

Predictors of adverse outcomes and cost after surgical management for idiopathic normal pressure hydrocephalus: Analyses from a national database

INTRODUCTION

We utilized a national administrative database to investigate drivers of immediate adverse economic and hospital outcomes, including non-routine discharge, prolonged length of stay (LOS), and admission costs among patients undergoing surgery for idiopathic normal pressure hydrocephalus (iNPH).

METHODS

The National Inpatient Sample (NIS) was queried from 2007 to 2017 for patients aged ≥60 with a diagnosis code for iNPH undergoing surgery. Multivariable logistic-regression models and Wald χ2 were used to identify drivers of non-routine discharge, prolonged length of stay (LOS) (>75th percentile) and higher admission costs (>90th percentile).

RESULTS

A total of 13,363 patients with iNPH undergoing surgical management were identified. The most common comorbidity reported in the cohort was a cardiovascular pathology (56.9 %, n = 7,787), followed by urinary pathology (37.2 %, n = 5,084), osteoarthritis (7.8 %, n = 1,071), Alzheimer's disease (4.6 %, n = 626) and cerebrovascular pathology (4.2 %, n = 569). The most frequently employed procedure was ventriculo-peritoneal (VP) shunt placement (65.6 %, n = 8,942) of which 89.8 % (n = 8,027) were performed open and 10.2 % (n = 915) laparoscopically. This was followed by lumbo-peritoneal (LP) shunting (15.5 %, n = 2,115), lumbar puncture alone (screened, serial CSF removal) (14.8 %, n = 2,013), endoscopic third ventriculostomy (ETV) (2%, n = 274), ventriculo-atrial (VA) shunt (0.95 %, n = 130) and ventriculo-pleural (Vpleural) shunt (0.46 %, n = 64). The median (IQR) LOS was 3 days (2-5), the rate of non-routine discharge was 37.3 % and median (IQR) cost was $11,230 ($7,735-15,590). On multivariable-analysis, emergent-admission (OR 2.91), older age (76-90: OR 1.55; 90+: OR 2.66), VP shunt (open: OR 3.09; laparoscopic: OR 2.32), ETV (OR 3.16), VA/VPleural shunt (OR 2.73) and hospital admission in Northeast-region compared to Midwest (OR 1.27) were found to be associated with increased risk of non-routine discharge. Some of the highly significant associated factors for prolonged LOS included emergent-admission (OR 11.34), ETV (OR 10.92), VA/VPleural shunt (OR 7.79) and open VP shunt (OR 8.24). For increased admission costs, some of the highly associated factors included VA/VPleural shunt (OR 18.48), laparoscopic VP shunt (OR 9.92), open VP shunt (OR 12.72) and ETV (OR 9.34). Predictor importance analysis revealed emergent admission, number of diagnosis codes (comorbidities) open VP shunt, hospital region, age] and revision or removal of shunt to be the most important drivers of these outcomes.

CONCLUSION

Analyses from a national database indicate that among patients with iNPH, an emergent-admission may be the most significant risk-factor of adverse economic outcomes and higher costs.

The subsequent course of disability in older persons discharged to a skilled nursing facility after an acute hospitalization

OBJECTIVES

To evaluate the association between the type of acute hospitalization and subsequent course of disability in older persons discharged to a skilled nursing facility (SNF).

DESIGN

Longitudinal study of 754 community-living persons aged 70 or older.

PARTICIPANTS

The analytical sample included 365 participants who had one or more admissions to a SNF after an acute hospitalization (n=520 index admissions).

MEASUREMENTS

Information on hospitalizations, SNF admissions, and disability was ascertained over 15years. The primary and secondary outcomes were disability burden and recovery of pre-hospital function, respectively, assessed monthly over a 6-month period. Index admissions were classified into four mutually exclusive groups based on the type of hospitalization: elective major surgery, non-elective major surgery, critical illness, and other.

RESULTS

Disability worsened considerably after hospitalization for each of the four groups. Relative to elective major surgery, the disability burden over 6months was significantly greater for non-elective major surgery, critical illness, and other hospitalizations, with adjusted rate ratios (RRs) of 1.37 (95% CI 1.19 to 1.59), 1.37 (95% CI 1.19 to 1.58), and 1.29 (95% CI 1.14 to 1.47), respectively. Overall, recovery to pre-hospital function was observed in only 132 (25.4%) admissions. Relative to elective major surgery, the likelihood of recovering pre-hospital function was considerably lower for each of the three other groups. The results were consistent for basic, instrumental and mobility activities.

CONCLUSION

Among older persons discharged to a SNF after an acute hospitalization, the functional course over 6months was generally poor, with recovery to pre-hospital function observed in only one out of every four cases. Relative to elective major surgery, functional outcomes were worse for non-elective major surgery, critical illness, and other hospitalizations.

Incremental Cost of Emergency Versus Elective Surgery

OBJECTIVE

To determine hospital costs and the adjusted risk of death associated with emergent versus elective surgery.

BACKGROUND

Emergency surgery has a higher cost and worse outcomes compared with elective surgery. However, no national estimates of the excess burden of emergency surgery exist.

METHODS

Nationwide Inpatient Sample (NIS) data from 2001 to 2010 were analyzed. Patients aged 18 years or older who underwent abdominal aortic aneurysm repair, coronary artery bypass graft, or colon resection for neoplasm were included. Using generalized linear models with propensity scores, cost differences for emergent versus elective admission were calculated for each procedure. Multivariable logistic regression was performed to investigate the adjusted odds of mortality comparing elective and emergent cases. Discharge-level weights were applied to analyses.

RESULTS

A total of 621,925 patients, representing a weighted population of 3,057,443, were included. The adjusted mean cost difference for emergent versus elective care was $8741.22 (30% increase) for abdominal aortic aneurysm repair, $5309.78 (17% increase) for coronary artery bypass graft, and $7813.53 (53% increase) for colon resection. If 10% of the weighted estimates of emergency procedures had been performed electively, the cost benefit would have been nearly $1 billion, at $996,169,160 (95% confidence interval [CI], $985,505,565-$1,006,834,104). Elective surgery patients had significantly lower adjusted odds of mortality for all procedures.

CONCLUSIONS

Even a modest reduction in the proportion of emergent procedures for 3 conditions is estimated to save nearly $1 billion over 10 years. Preventing emergency surgery through improved care coordination and screening offers a tremendous opportunity to save lives and decrease costs.

The role of cost-effectiveness for vascular surgery service provision in the United Kingdom

OBJECTIVE

The cost of health care is increasingly becoming an international issue, with many health care systems requiring evaluation of cost when agreeing to fund health care. In the United Kingdom (UK), for example, the National Institute for Health and Care Excellence highlights the importance of using cost-effectiveness analyses to facilitate the effective use of resources. This study evaluates the use of cost-effectiveness analyses and the provision of vascular surgery.

METHODS

A systematic review of published literature was performed. UK-based studies assessing cost-effectiveness or cost-utility of superficial venous interventions, abdominal aortic aneurysm (AAA) repair, and carotid endarterectomy (CEA) were included. All included studies were quality assessed to determine the overall strength of UK economic evidence for each intervention.

RESULTS

Four superficial venous, six AAA, and two CEA studies met the inclusion criteria. After quality assessment, the UK evidence supporting the cost-effectiveness of superficial venous intervention was graded strong. The economic evidence for asymptomatic and symptomatic CEA was graded limited and insufficient, respectively, owing to a paucity of UK literature in this field. There was strong UK economic evidence affirming that endovascular aneurysm repair (EVAR) is unlikely to be a cost-effective alternative to open repair.

CONCLUSIONS

There is strong economic evidence for symptomatic superficial venous intervention. However, funding for varicose vein treatments remains controversial. Future economic analyses are required for symptomatic and asymptomatic CEA to better advise national policy. Despite strong economic evidence, current UK guidance is for EVAR over open repair in the elective setting, with the majority of elective AAA repairs being EVAR.

Novel biomarkers of abdominal aortic aneurysm disease: identifying gaps and dispelling misperceptions

Abdominal aortic aneurysm (AAA) is a prevalent and potentially life-threatening disease. Early detection by screening programs and subsequent surveillance has been shown to be effective at reducing the risk of mortality due to aneurysm rupture. The aim of this review is to summarize the developments in the literature concerning the latest biomarkers (from 2008 to date) and their potential screening and therapeutic values. Our search included human studies in English and found numerous novel biomarkers under research, which were categorized in 6 groups. Most of these studies are either experimental or hampered by their low numbers of patients. We concluded that currently no specific laboratory markers allow screeing for the disease and monitoring its progression or the results of treatment. Further studies and studies in larger patient groups are required in order to validate biomarkers as cost-effective tools in the AAA disease.

Cost-effectiveness of intensive smoking cessation therapy among patients with small abdominal aortic aneurysms

INTRODUCTION

Smoking cessation is one of the few available strategies to decrease the risk for expansion and rupture of small abdominal aortic aneurysms (AAAs). The cost-effectiveness of an intensive smoking cessation therapy in patients with small AAAs identified at screening was evaluated.

METHODS

A Markov cohort simulation model was used to compare an 8-week smoking cessation intervention with adjuvant pharmacotherapy and annual revisits vs nonintervention among 65-year-old male smokers with a small AAA identified at screening. The smoking cessation rate was tested in one-way sensitivity analyses in the intervention group (range, 22%-57%) and in the nonintervention group (range, 3%-30%). Literature data on the effect of smoking on AAA expansion and rupture was factored into the model.

RESULTS

The intervention was cost-effective in all tested scenarios and sensitivity analyses. The smoking cessation intervention was cost-effective due to a decreased need for AAA repair and decreased rupture rate even when disregarding the positive effects of smoking cessation on long-term survival. The incremental cost/effectiveness ratio reached the willingness-to-pay threshold value of €25,000 per life-year gained when assuming an intervention cost of > €3250 or an effect of ≤ 1% difference in long-term smoking cessation between the intervention and nonintervention groups. Smoking cessation resulted in a relative risk reduction for elective AAA repair by 9% and for rupture by 38% over 10 years of follow-up.

CONCLUSIONS

An adequate smoking cessation intervention in patients with small AAAs identified at screening can cost-effectively increase long-term survival and decrease the need for AAA repair.

Simple adaptation of current abdominal aortic aneurysm screening programs may address all-cause cardiovascular mortality: prospective observational cohort study

BACKGROUND

Population screening for abdominal aortic aneurysm (AAA) can be cost-justified by its impact on the incidence of emergency presentations with rupture. The objective of this prospective, cohort study was to determine whether the proposed framework can be further evolved to address all-cause cardiovascular mortality in the community by integrating full risk factor assessment.

METHODS

Male volunteers aged >60 years attending for AAA screening by ultrasound also underwent full cardiovascular assessment via physician-administered health questionnaire, sphygmomanometry, anthromorphometry, and fasting phlebotomy for lipid and glucose profiling. Framingham and SCORE project evaluations were used to calculate 10-year risk of ischemic heart disease and all-cause fatal cardiovascular disease, respectively.

RESULTS

A total of 481 men were screened, and 23 (4.8%) had an AAA detected (22% of which were >4 cm). Obesity, smoking, hypertension, impaired glucose metabolism, and hypercholesterolemia were notably frequent in those without an AAA. Mean 10-year cardiovascular risk in the population without AAA (6.89 and 6.74 by SCORE and Framingham estimations, respectively) was similar to those with AAA (7.78 and 7.04, respectively). Supplementary screening increased total costs by 2.5%. Reserving concomitant atherosclerotic testing for those with elevated systolic blood pressure at presentation allowed identification of 96%/95% of those with Framingham/SCORE risks >10%, respectively, thus saving 162 (33%) individuals from additional investigation and conserving the cost increment to 1.8% overall.

CONCLUSION

The proven framework of population sifting for AAA provides a unique opportunity to also confront latent cardiovascular malady. Sphygmomanometry during ultrasonographic screening for AAA seems both cost-effective and readily incorporated within the current paradigm.

Aneurismas toracoabdominais rotos

OBJETIVO: Avaliar os dados pré, intra e pós-operatórios dos aneurismas toracoabdominais rotos operados no Hospital de Clínicas da Universidade Estadual de Campinas. MÉTODOS: Estudo retrospectivo de cinco pacientes submetidos à correção de aneurisma toracoabdominal roto no Hospital de Clínicas da Universidade Estadual de Campinas, entre setembro de 2000 e abril de 2004. Todos os pacientes apresentavam aneurisma toracoabdominal tipo IV roto, sendo que quatro estavam estáveis hemodinamicamente. Três pacientes foram operados com o simples pinçamento da aorta supracelíaca e infusão de soro fisiológico a 4 ºC nas artérias renais; um paciente evoluiu para óbito no intra-operatório antes da abertura do aneurisma; e um paciente foi operado utilizando-se perfusão de sangue oxigenado nas artérias viscerais. RESULTADOS: Dos cinco pacientes operados, dois foram a óbito (40%). Um deles apresentava instabilidade hemodinâmica e faleceu no intra-operatório; o outro faleceu no 26º dia pós-operatório com insuficiência de múltiplos órgãos. Todos os três sobreviventes evoluíram bem, sem seqüelas. Entre os pacientes que chegaram ao centro cirúrgico estáveis hemodinamicamente, a mortalidade foi de 25%. CONCLUSÕES: Pacientes com aneurisma toracoabdominal tipo IV roto, com estabilidade hemodinâmica, alcançam resultados cirúrgicos satisfatórios, semelhantes aos aneurismas rotos infra-renais.