Incidence of cardiovascular events and death after open or endovascular repair of abdominal aortic aneurysm in the randomized EVAR trial 1

Impact of isolated type 2 endoleak on subsequent cardiovascular events and mortality

OBJECTIVE

Assess subsequent cardiovascular events and all-cause mortality in patients with intact AAA treated by EVAR according to the existence of isolated EL2 at 1 year after EVAR implantation.

METHODS

This retrospective, single-centre study included patients treated with EVAR between 2010 and 2017 in the vascular surgery department of the University Hospital of Lyon with a infrarenal AAA > 50 mm. The baseline clinical characteristics collected just before EVAR were retrieved from electronic patient records of our institution. AAA characteristics, procedure and the one-year post-operative CTA were reported. Study endpoints, major adverse cardiovascular events (MACE), major adverse lower extremity events (MALE) and all-cause mortality, were recorded during follow-up. Patients were divided into 2 groups according to the presence of isolated EL2 (EL2 +) or absence (EL2 -) of any endoleak on CTA at 1 year. MACE, MALE and all-cause mortality were compared between both groups.

RESULTS

During the study period, 589 patients were treated by endovascular surgery and 207 were included. According to the CTA results at 1 year, 60 patients (29%) were included in the EL2 + group, and 147 patients (71%) in the EL2 - group. A total of 109 patients (53%) experienced a MACE or MALE; significantly fewer patients in the EL2 + than in the EL2 - group did so (p = .009). There were 47 patients (23%) who experienced at least one MALE, and the frequency was significantly lower in the EL2 + group (p = .017).

CONCLUSION

Patients with AAA treated by EVAR who did not develop EL2 at one year, were at higher risk of MALE during follow-up. This might be explained by more frequent symptomatic LEPAD at baseline in this group. These patients therefore require a closer follow-up and strict control of cardiovascular risk factors to prevent cardiovascular morbi-mortality.

Using machine learning to predict outcomes following open abdominal aortic aneurysm repair

OBJECTIVE

Prediction of outcomes following open abdominal aortic aneurysm (AAA) repair remains challenging with a lack of widely used tools to guide perioperative management. We developed machine learning (ML) algorithms that predict outcomes following open AAA repair.

METHODS

The Vascular Quality Initiative (VQI) database was used to identify patients who underwent elective open AAA repair between 2003 and 2023. Input features included 52 preoperative demographic/clinical variables. All available preoperative variables from VQI were used to maximize predictive performance. The primary outcome was in-hospital major adverse cardiovascular event (MACE; composite of myocardial infarction, stroke, or death). Secondary outcomes were individual components of the primary outcome, other in-hospital complications, and 1-year mortality and any reintervention. We split our data into training (70%) and test (30%) sets. Using 10-fold cross-validation, six ML models were trained using preoperative features (Extreme Gradient Boosting [XGBoost], random forest, Naïve Bayes classifier, support vector machine, artificial neural network, and logistic regression). The primary model evaluation metric was area under the receiver operating characteristic curve (AUROC). Model robustness was evaluated with calibration plot and Brier score. The top 10 predictive features in our final model were determined based on variable importance scores. Performance was assessed on subgroups based on age, sex, race, ethnicity, rurality, median area deprivation index, proximal clamp site, prior aortic surgery, and concomitant procedures.

RESULTS

Overall, 12,027 patients were included. The primary outcome of in-hospital MACE occurred in 630 patients (5.2%). Compared with patients without a primary outcome, those who developed in-hospital MACE were older with more comorbidities, demonstrated poorer functional status, had more complex aneurysms, and were more likely to require concomitant procedures. Our best performing prediction model for in-hospital MACE was XGBoost, achieving an AUROC of 0.93 (95% confidence interval, 0.92-0.94). Comparatively, logistic regression had an AUROC of 0.71 (95% confidence interval, 0.70-0.73). For secondary outcomes, XGBoost achieved AUROCs between 0.84 and 0.94. The calibration plot showed good agreement between predicted and observed event probabilities with a Brier score of 0.05. These findings highlight the excellent predictive performance of the XGBoost model. The top three predictive features in our algorithm for in-hospital MACE following open AAA repair were: (1) coronary artery disease; (2) American Society of Anesthesiologists classification; and (3) proximal clamp site. Model performance remained robust on all subgroup analyses.

CONCLUSIONS

Open AAA repair outcomes can be accurately predicted using preoperative data with our ML models, which perform better than logistic regression. Our automated algorithms can help guide risk-mitigation strategies for patients being considered for open AAA repair to improve outcomes.

Long-Term Outcomes of Open Versus Endovascular Treatment for Abdominal Aortic Aneurysm: Systematic Review and Meta-Analysis With Reconstructed Time-to-Event Data

BACKGROUND

The advent of endovascular techniques has revolutionized the care of patients with uncomplicated abdominal aortic aneurysms. This analysis compares the overall survival and the freedom from reintervention rate between open surgical repair (OSR) and endovascular repair (EVAR) in patients undergoing elective abdominal aortic aneurysm (AAA) repair.

METHODS

PubMed, Scopus, and Cochrane databases were searched for studies including patients who underwent either OSR or EVAR for uncomplicated AAA. All randomized controlled trials and propensity-score-matched cohort studies reporting on the outcomes of interest were considered eligible for inclusion. The systematic search of the literature was performed by 2 independent investigators in accordance with the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. We conducted 1-stage and 2-stage meta-analyses with Kaplan-Meier-derived time-to-event data and meta-analysis with a random-effects model.

RESULTS

Thirteen studies met our eligibility criteria, incorporating 13 409 and 13 450 patients in the OSR and EVAR arms, respectively. Patients who underwent open repair had improved overall survival rates compared with those who underwent EVAR (hazard ratio [HR]=0.93, 95% confidence interval [CI]=0.88-0.98, p=0.004) during a mean follow-up of 53.8 (SD=29.8) months and this was validated by the 2-stage meta-analysis (HR=0.89, 95% CI=0.8-0.99, p=0.03, I2=62.25%). Splitting timepoint analysis suggested that EVAR offers better survival outcome compared with OSR in the first 11 months following elective intervention (HR=1.37, 95% CI=1.22-1.54, p<0.0001), while OSR offers a significant survival advantage after the 11-month timepoint and up to 180 months (HR=0.84, 95% CI=0.8-0.89, p<0.0001). Similarly, freedom from reintervention was found to be significantly better in EVAR patients (HR=1.28, 95% CI=1.14-1.44, p<0.0001) within the first 30 days. After the first month postrepair, however, OSR demonstrated higher freedom-from-reintervention rates compared with EVAR that remained significant for up to 168 months during follow-up (HR=0.73, 95% CI=0.66-0.79, p<0.0001).

CONCLUSIONS

Despite the first-year survival advantage of EVAR in patients undergoing elective AAA repair, OSR was associated with a late survival benefit and decreased risk for reintervention in long-term follow-up.

CLINICAL IMPACT

Open surgical repair for uncomplicated abdominal aortic aneurysm offers better long-term outcomes in terms of survival and freedom from reintervention rate compared to the endovascular approach but in the first year it carries a higher risk of mortality. The novelty of our study lies that instead of comparing study-level effect estimates, we analyzed reconstructed individual patient-level data. This offered us the opportunity to perform our analyses with mathematically robust and flexible survival models, which was proved to be crucial since there was evidence of different hazard over time. Our findings underline the need for additional investigation to clarify the significance of open surgical repair when compared to the latest endovascular devices and techniques within the evolving era of minimally invasive procedures.

Mortality analysis of endovascular aneurysm sealing versus endovascular aneurysm repair

BACKGROUND

Endovascular aneurysm sealing (EVAS), using the Nellix endovascular aneurysm sealing system, has been associated with high reintervention and migration rates. However, prior reports have suggested that EVAS might be related to a lower all-cause mortality compared with endovascular aneurysm repair (EVAR). In the present study, we examined the 5-year all-cause mortality trends after EVAS and EVAR.

METHODS

We compared the 333 EVAS patients in the EVAS-1 Nellix U.S. investigational device exemption trial with 16,497 infrarenal EVAR controls from the Vascular Quality Initiative, treated between 2014 and 2016, after applying the exclusion criteria from the investigational device exemption trial (ie, hemodialysis, creatinine >2.0 mg/dL, rupture). As a secondary analysis, we stratified the patients by aneurysm diameter (<5.5 cm and ≥5.5 cm). We calculated propensity scores after adjusting for demographics, comorbidities, and anatomic characteristics and applied inverse probability weighting to compare the risk-adjusted long-term mortality using Kaplan-Meier and Cox regression analyses.

RESULTS

After weighting, the EVAS group had experienced similar 5-year mortality compared with the controls from the Vascular Quality Initiative (EVAS vs EVAR, 18% vs 14%; hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.71-1.7; P = .70). The subgroup analysis demonstrated that for patients with an aneurysm diameter of <5.5 cm, EVAS was associated with higher 5-year mortality compared with EVAR (19% vs 11%; HR, 2.4; 95% CI, 1.7-4.7; P = .013). In patients with an aneurysm diameter of ≥5.5 cm, EVAS was associated with lower mortality within the first 2 years (2-year mortality: HR, 0.29; 95% CI, 0.13-0.62; P = .002). However, compared with EVAR, EVAS was associated with higher mortality between 2 and 5 years (HR, 1.9; 95% CI, 1.2-3.0; P = .005), with no mortality difference at 5 years (18% vs 17%; HR, 0.82; 95% CI, 0.4-1.4; P = .46).

CONCLUSIONS

Within the overall population, EVAS was associated with similar 5-year mortality compared with EVAR. EVAS was associated with higher mortality for those with small aneurysms (<5.5 cm). For those with larger aneurysms (≥5.5 cm), EVAS was initially associated with lower mortality within the first 2 years, although this advantage was lost thereafter, with higher mortality after 2 years. Future studies are required to evaluate the specific causes of death and to elucidate the potential beneficial mechanism behind sac obliteration that leads to this potential initial survival benefit. This could help guide the development of future grafts with better proximal fixation and sealing that also incorporate sac obliteration.

Predictive factors for major adverse cardiac and cerebrovascular events in octogenarians after elective endovascular aneurysm repair

OBJECTIVES

The aim of this study was to identify risk factors of major adverse cardiac and cerebrovascular events (MACCE) in octogenarians who received elective endovascular aneurysm repair (EVAR).

METHODS

Consecutive patients aged ≥ 80 years undergoing elective EVAR from 2009 to 2020 were retrospectively evaluated. The primary outcome was long-term MACCE. All independent risk factors for outcomes were determined by multivariate logistic analysis or Cox regression analysis.

RESULTS

A total of 163 patients were enrolled in this study. The median age was 81 (interquartile range, IQR, 80-84) years and 85.9% (140/163) of them were male. MACCE happened in 2.5% (4/163) patients within 30 days. With median follow-up of 28 (IQR, 15-46) months, the incidence of long-term MACCE was 26.4% (43/163). Arrythmia was significantly associated with long-term MACCE (hazard ratio, HR = 2.64, 95% confidence interval, CI, 1.16-6.03, P = .021). Carotid artery disease was found a significant association with 2-year MACCE (odd ratio, OR = 6.50, 95% CI, 1.07-39.51, P = .042). Besides, we found that arrythmia and congestive heart failure (CHF) were predictors for overall survival (arrythmia, HR = 2.56, 95% CI, 1.05-6.28, P = .039; CHF, HR = 8.96, 95% CI, 2.12-37.79, P = .003).

CONCLUSIONS

EVAR in octogenarians had acceptable perioperative risk and long-term outcome. Considering high risk of 2-year MACCE, intervention strategy should be more cautious for patients with carotid artery disease. Octogenarians with arrythmia and CHF should receive stricter postoperative management in case of MACCE.

ANALYSIS OF SPIN IN VASCULAR SURGERY RANDOMIZED CONTROLLED TRIALS WITH NONSIGNIFICANT OUTCOMES

OBJECTIVES

Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS) for carotid stenosis (CS), and endovascular repair (EVAR) to open repair (OR) for abdominal aortic aneurysms (AAA).

METHODS

A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase three RCTs with nonsignificant primary outcomes comparing OR to EVAR or CEA to CAS were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs non-commercial) and (2) the publishing journal's impact factor.

RESULTS

Thirty-one of 355 articles captured were included for analysis. Spin was identified in nine abstracts (9/18) and 13 main texts (13/18) of AAA articles and seven abstracts (7/13) and ten main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the manuscript discussion section, with the most commonly employed strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (βOR = 0.96, 95% CI: 0.94 - 0.98, p < 0.01) while no significant association could be found with funding source (βOR = 1.33, 95% CI: 0.30-5.92, p = 0.71).

CONCLUSIONS

A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

Thresholds for abdominal aortic aneurysm repair in Canada and United States

BACKGROUND

Previous studies have demonstrated significant geographic variations in the management of abdominal aortic aneurysms (AAA) despite standard guidelines. Differences in patient selection, operative technique, and outcomes for AAA repair in Canada versus United States were assessed.

METHODS

The Vascular Quality Initiative was used to identify all patients who underwent elective endovascular or open AAA repair between 2010 and 2019 in Canada and the United States. Demographic, clinical, and procedural characteristics were recorded and differences between countries were assessed using independent t test and χ² test. The primary outcome was the percentage of AAA repaired below recommended diameter thresholds (men, <5.5 cm; women, <5.0 cm). The secondary outcomes were in-hospital and 1-year mortality rates. Associations between region and outcomes were assessed using univariate/multivariate logistic regression and Cox proportional hazards analysis.

RESULTS

There were 51,455 US patients and 1451 Canadian patients who underwent AAA repair in Vascular Quality Initiative sites during the study period. There was a higher proportion of endovascular repairs in the United States (83.7% vs 68.4%; odds ratio [OR], 2.38; 95% confidence interval [CI], 2.13-2.63; P < .001). US patients had more comorbidities, including hypertension, congestive heart failure, chronic kidney disease, and prior revascularization. The percentage of AAA repaired below recommended thresholds was significantly higher in the United States (38.8% vs 15.2%; OR, 3.57; 95% CI, 3.03-4.17; P < .001). This difference persisted after controlling for demographic, clinical, and procedural characteristics (adjusted OR, 3.57; 95% CI, 2.63-4.17; P < .001). Factors that predicted AAA repair below recommended thresholds were US region (adjusted OR, 3.57; 95% CI, 3.03-4.17), male sex (adjusted OR, 2.89; 95% CI, 2.72-3.07), and endovascular repair (adjusted OR, 2.08; 95% CI, 1.95-2.21). The in-hospital mortality rate was low (1.0% vs 0.8%) and the 1-year rate mortality was similar between countries (hazard ratio, 0.96; 95% CI, 0.70-1.31; P = .79).

CONCLUSIONS

There are significant variations in AAA management between Canada and the United States. A greater proportion of US patients underwent AAA repair below the recommended diameter thresholds. This finding is partly driven by a higher percentage of endovascular repairs. Despite these differences, the perioperative and 1-year mortality rates are similar. Future studies should investigate reasons for these variations and quality improvement projects are needed to standardize care.

Changes in Noninvasive Arterial Stiffness and Central Blood Pressure After Endovascular Abdominal Aneurysm Repair

Purpose:

To evaluate the impact of elective endovascular aneurysm repair (EVAR) on the carotid-femoral pulse wave velocity (cfPWV) and central pressure waveform, through 1-year follow-up.

Materials and Methods:

A tonometric device was used to measure cfPWV and estimate the central pressure waveform in 20 patients with an infrarenal abdominal aortic aneurysm scheduled for elective EVAR. The evaluated central hemodynamic parameters included the central pressures, the augmentation index (AIx), and the subendocardial viability ratio (SEVR). AIx quantifies the contribution of reflected wave to the central systolic pressure, whereas SEVR describes the myocardial perfusion relative to the cardiac workload. Measurements were performed before EVAR, at discharge, and 6 weeks and 1 year after EVAR.

Results:

CfPWV was increased at discharge (12.4±0.4 vs 11.3±0.5 m/s at baseline; p=0.005) and remained elevated over the course of 1-year follow-up (6 weeks: cfPWV = 12.2±0.5 m/s; 1 year: cfPWV = 12.2±0.7 m/s, p<0.05). After an initial drop in systolic central pressure at discharge, all the central pressures increased thereafter up to 1 year, without significant differences compared with baseline. The same was observed for the AIx and SEVR.

Conclusion:

Endovascular aortic aneurysm repair caused an increase in pulse wave velocity compared with baseline, which remained elevated through 1 year follow-up, which may be related to an increased cardiovascular risk. However, no differences in central pressure, augmentation index, and subendocardial viability ration were observed during follow-up.

Changes in Noninvasive Arterial Stiffness and Central Blood Pressure After Endovascular Abdominal Aneurysm Repair

PURPOSE

To evaluate the impact of elective endovascular aneurysm repair (EVAR) on the carotid-femoral pulse wave velocity (cfPWV) and central pressure waveform, through 1-year follow-up.

MATERIALS AND METHODS

A tonometric device was used to measure cfPWV and estimate the central pressure waveform in 20 patients with an infrarenal abdominal aortic aneurysm scheduled for elective EVAR. The evaluated central hemodynamic parameters included the central pressures, the augmentation index (AIx), and the subendocardial viability ratio (SEVR). AIx quantifies the contribution of reflected wave to the central systolic pressure, whereas SEVR describes the myocardial perfusion relative to the cardiac workload. Measurements were performed before EVAR, at discharge, and 6 weeks and 1 year after EVAR.

RESULTS

CfPWV was increased at discharge (12.4±0.4 vs 11.3±0.5 m/s at baseline; p=0.005) and remained elevated over the course of 1-year follow-up (6 weeks: cfPWV = 12.2±0.5 m/s; 1 year: cfPWV = 12.2±0.7 m/s, p<0.05). After an initial drop in systolic central pressure at discharge, all the central pressures increased thereafter up to 1 year, without significant differences compared with baseline. The same was observed for the AIx and SEVR.

CONCLUSION

Endovascular aortic aneurysm repair caused an increase in pulse wave velocity compared with baseline, which remained elevated through 1 year follow-up, which may be related to an increased cardiovascular risk. However, no differences in central pressure, augmentation index, and subendocardial viability ration were observed during follow-up.

Status of coronary disease and results from early endovascular aneurysm repair after preventive percutaneous coronary revascularization

BACKGROUND

The incidence of coronary artery disease (CAD) is high in patients with an aortic aneurysm but preoperative routine coronary angiography and preventive coronary revascularization are not recommended to reduce cardiac events in patients with severe CAD.

AIM

This study evaluated the safeness and efficacy of preventive percutaneous coronary intervention (PCI) in patients with severe CAD scheduled for endovascular aneurysm repair (EVAR).

METHODS

All patients with descending thoracic aneurysm (DTA) or abdominal aortic aneurysm (AAA) scheduled for EVAR underwent preliminary coronary angiography. Based on coronary angiography results, 917 patients (40.7%) had significant CAD and were treated by percutaneous coronary intervention (PCI; CAD group) and 1337 patients (59.3%) were without or with mild/moderate CAD and were considered as controls (no-CAD group). To evaluate the safeness and efficacy of preventive PCI in patients with severe CAD undergoing EVAR, groups were compared for hospital and 12-month cardiac adverse events.

RESULTS

CAD was present in 1210 patients (53.6%): significant in 917 patients (38%) and mild to moderate in 293 patients (5.3%). Hospital and 12-month cardiac events occurred in 15 (1.6%) and 13 (1.4%) CAD group patients and in 9 (0.7%) and 8 (0.4%) no-CAD group patients (p = .05 and p = .08), respectively. Hospital and 12-month cardiac deaths occurred in 3 (0.3%) and 2 (0.2%) CAD group patients and in 3 (0.2%) and 2 (0.2%) no-CAD group patients (p = .9 and p = .9), respectively.

CONCLUSION

The strategy to treat severe CAD preoperatively by PCI and early subsequent EVAR brings a similar outcome to that in patients without or with mild/moderate CAD.

Myocardial injury after non-cardiac surgery (MINS) in EVAR patients: a retrospective single-centered study

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) stands for myocardial injury due to ischemia that occurs during or within 30-days after non-cardiac surgery. Although MINS is known to be independently associated with 30-day mortality after intervention, little is described about the impact of MINS after vascular procedures, particularly after endovascular aneurysm repair (EVAR).

METHODS

This is an observational, retrospective, single-centered study. All patients underwent elective standard EVAR between January 2008 and June 2017, and them with at least one postoperative measurement of troponin I in the first 48 h after surgery, were retrospectively included. MINS was defined as the value exceeding the 99^th percentile of a normal reference population with a coefficient of variation <10%. Primary outcomes include the prevalence of MINS in this subset of EVAR patients, as well as its impact in mid-term all-cause mortality. As secondary aim, the preoperative predictors of MINS were also assessed.

RESULTS

One-hundred and thirty-six patients with postoperative troponin measurements were included (95.6% male; mean age 75.51years). MINS was diagnosed in 16.2% (N.=22) of the patients, and in 86.4% of the cases (N.=19) it was completely asymptomatic. Heart failure (31.8% vs. 10.5%, P=0.016), ASA Score ≥3 (95.5% vs. 67.5%, P=0.004), pre-operative (P=0.036) and postoperative (P=0.04) hemoglobin concentrations ≤12 g/dL were found to be significantly associated with MINS. Regarding remaining baseline characteristics, anesthesia and femoral access, no further differences were observed. Survival at 1, 3 and 5 years was 92% (95% CI: 4.6-6.9, standard error [SE] 0.023), 81% (95% CI: 5.6-7.6, SE=0.034) and 71% (95% CI: 6.9-8.7, SE=0.04), with two deaths reported at 30 days follow-up. MINS was found to be significantly associated with increased mid-term all-cause mortality after EVAR at 24 months follow-up (84.2±3.4% vs. 63.6±10.3%, P=0.001), with a 2.12-fold risk increase of death.

CONCLUSIONS

MINS is a common complication after EVAR and negatively impacts the mid-term prognosis of such interventions. In the majority of cases, it is asymptomatic and, therefore, not detectable unless routine postoperative troponin measurements are performed.

Aortobronchial fistula and Listeria endograft infection after repeated T/EVAR: a rare combination

Here we present a rare combination of aortobronchial fistula and Listeria endograft infection after repeat endovascular aortic repair. Device retention, debridement and negative pressure wound therapy, in combination with suppressive antimicrobial therapy, led to satisfactory control of infection until the patient died due to another complication. The combination of an aortobronchial fistula and Listeria endograft infection has never been described before. This present case should encourage and show clinicians the importance of an interdisciplinary approach in highly difficult clinical courses.

Endovascular Aneurysm Sealing is Associated with Higher Medium-Term Survival than Traditional EVAR

BACKGROUND

Endovascular aneurysm repair (EVAR) is the dominant treatment modality for abdominal aortic aneurysm (AAA). Periprocedural risks are low, and cardiovascular events are the principle determinants of long-term survival. Recently, the concept of endovascular aneurysm sealing (EVAS) has been introduced into clinical investigation. In previous cohort studies, EVAS has been associated with a lower all-cause mortality than expected despite device issues. We used a propensity weighted approach to investigate whether EVAS was associated with lower all-cause mortality after aneurysm repair.

METHODS

We compared 333 patients in the Nellix United States Investigational Device Exemption trial to 15,431 controls from the Vascular Quality Initiative between 2014 and 2016 after applying the exclusion criteria from the investigational device exemption (hemodialysis, creatinine > 2.0 mg/dL, or rupture). We calculated propensity scores and applied inverse probability weighting to compare risk adjusted medium-term survival using Kaplan-Meier and Cox regression.

RESULTS

After weighting, patients treated with the Nellix EVAS system experienced higher 3-year survival than controls from the Vascular Quality Initiative (93% vs. 88%, respectively). This corresponded to a 41% lower risk of mortality for EVAS compared with EVAR (HR 0.59 [0.38-0.92], P = 0.02). Subgroup analysis demonstrated that the association between EVAS and higher survival was strongest in the subgroup of patients with aneurysms over 5.5 cm (P for interaction < 0.001). In this subgroup, EVAS patients experienced half the rate of mortality as those patients treated with EVAR, with 3-year survival of 92% compared with 86% (HR 0.5 [0.3-0.9], P = 0.02).

CONCLUSIONS

In this select group of patients, EVAS was associated with higher medium-term survival than traditional EVAR. Although issues with the device have recently surfaced, this exploratory analysis shows that the concept of sac sealing may hold promise. Further study is needed to confirm this finding and determine whether EVAS is associated with lower rates of cardiovascular events.

Outcomes of Endovascular Repair for Abdominal Aortic Aneurysms: A Nationwide Survey in Japan

OBJECTIVE

To analyze data on patients treated with a bifurcated stent graft for abdominal aortic aneurysm (AAA).

BACKGROUND

The Japan Committee for Stentgraft Management (JACSM) was established in 2007 to manage the safety of endovascular aortic aneurysm repair (EVAR) in Japan. The JACSM registry includes detailed anatomical and clinical data of all patients who undergo stent graft insertion in Japan.

METHODS

Among 51,380 patients treated with bifurcated stent graft for AAA, we identified 38,008 eligible patients (excluding those with rupture or insufficient data). The analyzed factors included age, sex, comorbidities, AAA pathology and etiology, aneurysm and neck diameters, 7 anti-instructions for use (IFU) factors, and endoleaks at hospital discharge. The endpoints were death, adverse events, sac dilatation (≥5 mm), and reintervention.

RESULTS

The rates of intraoperative and in-hospital mortality were 0.08% and 1.07%, respectively. Infectious aneurysm and pseudo-aneurysm were associated with overall survival and reintervention. Older age, large aneurysm diameter, and all types of persistent endoleaks were strong predictors of adverse events, sac dilatation, and reintervention. Comorbid cerebrovascular disease, renal dysfunction, and respiratory disorders were also risk factors. In total, 47.6% of patients violated the IFU; among the anti-IFU factors assessed, poor access and severe neck calcification were strong risk factors for mortality, reintervention, and adverse events. The sac dilatation rate at 5 years was 23.3%.

CONCLUSIONS

Although the analysis included EVAR with poor anatomy, the perioperative mortality rate was acceptable compared with that in previous large population studies.

Factors associated with symptomatic postoperative myocardial infarction after endovascular aneurysm repair

OBJECTIVE

Endovascular aneurysm repair (EVAR) has now become the most common operation to treat abdominal aortic aneurysms (AAAs). One of the perceived benefits of EVAR over open AAA repair is reduced incidence of perioperative cardiac complications and mortality. The purpose of this study was to determine risk factors associated with postoperative myocardial infarction (POMI) in patients who have undergone EVAR.

METHODS

Data were obtained from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for the years 2012 to 2015 in the Participant Use Data File. All patients in the database who underwent EVAR during this time were identified. These patients were then divided into two groups: those with POMI and those without. Bivariate analysis was done for preoperative, intraoperative, and postoperative risk factors, followed by multivariable analysis to determine associations of independent variables with POMI. A risk prediction model for POMI was created to accurately predict incidence of POMI after EVAR.

RESULTS

A total of 7702 patients (81.3% male, 18.7% female) were identified who underwent EVAR from 2011 to 2015. Of these patients, 110 (1.4%) had POMI and 7592 (98.6%) did not. Several risk factors were related to an increased risk of POMI, including dependent functional health status, need for lower extremity revascularization, longer operation time, and ruptured AAA (P < .05, all).On multivariable analysis, the following factors were found to have significant associations with POMI: return to operating room (odds ratio [OR], 1.84; confidence interval [CI], 1.10-3.09; P = .020), ruptured AAA (OR, 1.87; CI, 1.18-2.95; P = .008), pneumonia (OR, 1.94; CI, 1.01-3.73; P = .048), age >80 years (compared with <70 years; OR, 2.30; CI, 1.36-3.86; P = .002), unplanned intubation (OR, 4.07; CI, 2.31-7.18; P < .001), and length of hospital stay >6 days (OR, 8.43; CI, 4.75-14.94; P < .001). The risk prediction model showed that in the presence of all these risk factors, the incidence of POMI was 58.3%. The incidence of cardiac arrest and death was significantly higher for patients with POMI compared with patients without POMI (cardiac arrest, 11.9% vs 1.3%; death, 10.2% vs 1.1%).

CONCLUSIONS

In patients who undergo EVAR, the risk of POMI is increased for those who are older, who present with a ruptured AAA, who have pneumonia, who have unplanned intubation, and who have prolonged hospital stay. Patients who suffer from POMI have higher risk of having cardiac arrest and death.

Reporting of Complications and Mortality in Relation to Risk Communication in Patients with an Abdominal Aortic Aneurysm: A Systematic Review

OBJECTIVES

High-quality reporting of surgical risks is necessary for evidence-based risk communication in clinical practice. Risk communication is defined as the process of discussing benefits and harms of treatment options with patients. This review addressed the current quality of reporting of complications and mortality in publications on abdominal aortic aneurysm treatment, with a focus on items relevant to risk communication.

DESIGN

A systematic review.

MATERIALS

Randomised clinical trials, comparative observational studies and registries from 2010 onwards were eligible if they reported complications and/or mortality in patients with an asymptomatic abdominal aortic aneurysms who received primary treatment.

METHODS

Quality of reporting was assessed by scoring items relevant to risk communication from the reporting standards of the Society for Vascular Surgery (SVS) and the Consolidated Standards of Reporting Trials (CONSORT) statement. Screening, quality assessment and data extraction were independently undertaken by two authors.

RESULTS

Forty-seven publications were included. Nine of 47 publications (19%) provided no definition of complications. In 14 of 47 publications (30%), it was unclear whether the number of adverse events or the number of patients with adverse events were presented. Absolute risk differences were provided in 1 of 32 publications (3.1%) that compared complications between two treatment options. Forty-six of 47 publications reported mortality, of which 42 reported overall mortality rates (91%). Absolute risk differences were given in 2 of the 31 publications (6.5%) that compared mortality between two treatment options.

CONCLUSIONS

The quality of reporting of complications and mortality following primary abdominal aortic aneurysm treatment varied considerably. Better adherence to the SVS reporting standards and the CONSORT statement, as well as stating absolute risk differences may improve the quality of reporting and facilitate evidence-based risk communication.

The most relevant unmet needs in endovascular management of descending thoracic aorta

Endovascular repair of descending thoracic aorta (DTA) is considered as first interventional option for most part of the aortic disorders. However, many unmet needs and issues are still limiting its applicability. One of the major limitations is related to the existing gaps in evidence. Clear and robust evidence is still needed in many aspects of the management of DTA pathologies. In numerous clinical scenarios, adequate trials are lacking. Besides those gaps in evidence, it is well recognized that thoracic endografting (TEVAR) is technically evolving in order to overcome technical and device-related complications and limitations. We can deploy endografts in any aortic segment: in the descending, in the ascending, in the arch, even preserving aortic branches. Nevertheless, from the pure technical point of view, current generations of endografts still need more development and improvement. Durability remains the major concern for any endovascular treatment, and thoracic endografting is not an exception. As Galenus said, the physician is only nature's assistant, thoracic endograft should also follow the natural anatomy instead of fighting against it. We will focus the following pages on the graft conformability and compliance, both related to durability and safety of thoracic endografting. We will review the current knowledge and concerns associated with the anatomical and hemodynamic modifications induced by the thoracic endograft strength, stiffness and straightness and their implications for the future thoracic endograft designs.

Comparison of major adverse event rates after elective endovascular aneurysm repair in New England using a novel measure of complication severity

OBJECTIVE

Major adverse event (MAE) rates are used as an outcome measure after surgical procedures. Although MAE rates summarize the occurrences of adverse events, they do not reflect differences in severity of these events. We propose that a measure of complication severity could provide a more accurate assessment about the quality of care. We aimed to analyze and to describe the regional variation in elective endovascular aneurysm repair (EVAR) MAE rates across centers in the Vascular Study Group of New England and to create an index for describing complication severity.

METHODS

Patients undergoing elective EVAR (n = 4731) at 30 Vascular Study Group of New England centers between 2003 and 2016 were studied. The MAE composite end point was defined as the occurrence of any of the following postoperative events: myocardial infarction, dysrhythmia, congestive heart failure, leg ischemia, renal insufficiency, bowel complication, reoperation, surgical site infection, stroke, respiratory complication, and no home discharge. An adjustment factor (complication severity index) was calculated as a ratio of length of stay for complicated to uncomplicated cases. Multivariate logistic regression was used to calculate predicted MAE rates. The observed and predicted MAE rates as well as complication severity index rates were compared among centers and across quintiles of center volume.

RESULTS

Observed MAE rates varied widely, ranging from 0% to 39%. Multivariate predictors of MAE included abdominal aortic aneurysm diameter >6 cm (odds ratio [OR], 2.1; 95% confidence interval [CI], 2.0-2.3), female sex (OR, 2.0; 95% CI, 1.8-2.2), chronic renal insufficiency (OR, 1.9; 95% CI, 1.7-2.1), age >75 years (OR, 1.9; 95% CI, 1.8-2.1), congestive heart failure (OR, 1.7; 95% CI, 1.5-1.9), chronic obstructive pulmonary disease (OR, 1.5; 95% CI, 1.4-1.6), diabetes (OR, 1.4; 95% CI, 1.1-1.7), positive stress test result (OR, 1.2; 95% CI, 1.1-1.4), preoperative beta blocker (OR, 1.2; 95% CI, 1.1-1.3), and no preoperative statin (OR, 1.2; 95% CI, 1.1-1.3). Predicted MAE rates had little variation (range, 21%-29%). In comparing observed MAE rates and complication severity, there was an inverse relation between the two, suggesting that although certain centers had a greater number of MAEs, the complications were less severe.

CONCLUSIONS

MAE rates after elective EVAR vary widely. However, centers with higher MAE rates tended to have less severe complications, suggesting that observed MAE rates may not be a good measure of outcomes assessment after elective EVARs.

Effects of Ischemic Preconditioning on Abdominal Aortic Aneurysm Repair: A Systematic Review and Meta-analysis

BACKGROUND

Ischemic preconditioning is an innate mechanism of cytoprotection against ischemia, with potential for end-organ protection. The primary goal of this study was to systematically review the literature to determine the effect of ischemic preconditioning on outcomes after open and endovascular abdominal aortic aneurysm (AAA) repair.

METHODS

The methodology followed the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. We included randomized clinical trials that evaluated the effect of remote ischemic preconditioning (RIPC) in reducing morbidity and mortality in patients undergoing open or endovascular AAA repair surgery. The primary outcomes were death, myocardial infarction, and renal impairment. Outcomes were addressed separately for open AAA repair and endovascular AAA repair (EVAR). Data were collected on patient characteristics, methodology, and preconditioning protocol for each trial.

RESULTS

Nine trials of ischemic preconditioning in aortic aneurysm surgery were included with a total of 599 patients; 336 patients were included in the open AAA repair meta-analysis, and 263 patients were included in the EVAR meta-analysis. For both open and endovascular repairs, ischemic preconditioning did not have a significant effect on death, myocardial infarction, or renal impairment requiring dialysis.

CONCLUSIONS

The randomized clinical trials investigating the effect of ischemic preconditioning on outcomes after open and endovascular AAA repair that have been completed to date have not been adequately powered to evaluate improvements in patient-important outcomes. The evidence is insufficient to support the use of ischemic preconditioning for AAA repair in clinical practice. The variability in treatment effect across studies may be explained by clinical and methodological heterogeneity.

Loco-regional versus general anaesthesia for elective endovascular aneurysm repair – results of a cohort study and a meta-analysis

Abstract. Background: The aim of this study was to investigate whether patients undergoing elective endovascular aneurysm repair (EVAR) with loco-regional anaesthetic techniques have better outcomes than those treated with general anaesthesia (GA). Patients and methods: We retrospectively evaluated outcomes of EVAR performed with regional anaesthesia (RA) or GA over a five-year period. Furthermore, we searched electronic bibliographic sources (MEDLINE, EMBASE, CINAHL, and CENTRAL) to identify studies comparing different anaesthetic methods in EVAR. We defined perioperative mortality and morbidity as well as length of hospital stay (LOS) as the primary outcome measures. Pooled effect estimates were calculated using fixed-effect or random-effects models. Results are reported as the odds ratio (OR) or mean difference (MD) and 95 % confidence interval (CI). Results: Three hundred and fifty-five patients underwent standard EVAR over the study period (RA, 215 patients; GA 140 patients). Patients in both groups had comparable baseline demographics and clinical characteristics. Perioperative mortality was significantly lower in the RA group (0.5 % vs. 4.3 %, P = 0.017). No difference was found in perioperative morbidity (P = 0.370), LOS (P = 0.146), postoperative destination (P = 0.799), reoperation (P = 0.355) or readmission within 30 days (P = 0.846). Meta-analysis of data on 15,472 patients from 15 observational studies found a significantly lower perioperative mortality (OR 0.70, 95 % CI 0.52–0.95, P = 0.02) and morbidity (OR 0.73, 95 % CI 0.55–0.96, P = 0.02) in patients treated with loco-regional anaesthetic techniques compared to those treated with GA. Our sub-group analysis demonstrated that both local anaesthesia (LA) (P = 0.003) and RA (P < 0.0001) were associated with a significantly shorter LOS compared to GA. Conclusions: Local and/or regional anaesthetic techniques may be advantageous over GA in elective EVAR, as indicated by reduced perioperative mortality and morbidity and a shorter hospital stay. Considering the current level of evidence, LA or RA should be considered in selected patients. Further clinical research is required to provide high level evidence on the optimal anaesthetic technique in EVAR.

The UK EndoVascular Aneurysm Repair (EVAR) randomised controlled trials: long-term follow-up and cost-effectiveness analysis

BACKGROUND

Short-term survival benefits of endovascular aneurysm repair (EVAR) compared with open repair (OR) of intact abdominal aortic aneurysms have been shown in randomised trials, but this early survival benefit is soon lost. Survival benefit of EVAR was unclear at follow-up to 10 years.

OBJECTIVE

To assess the long-term efficacy of EVAR against OR in patients deemed fit and suitable for both procedures (EVAR trial 1; EVAR-1); and against no intervention in patients unfit for OR (EVAR trial 2; EVAR-2). To appraise the long-term significance of type II endoleak and define criteria for intervention.

DESIGN

Two national, multicentre randomised controlled trials: EVAR-1 and EVAR-2.

SETTING

Patients were recruited from 37 hospitals in the UK between 1 September 1999 and 31 August 2004.

PARTICIPANTS

Men and women aged ≥ 60 years with an aneurysm of ≥ 5.5 cm (as identified by computed tomography scanning), anatomically suitable and fit for OR were randomly assigned 1 : 1 to either EVAR (n = 626) or OR (n = 626) in EVAR-1 using computer-generated sequences at the trial hub. Patients considered unfit were randomly assigned to EVAR (n = 197) or no intervention (n = 207) in EVAR-2. There was no blinding.

INTERVENTIONS

EVAR, OR or no intervention.

MAIN OUTCOME MEASURES

The primary end points were total and aneurysm-related mortality until mid-2015 for both trials. Secondary outcomes for EVAR-1 were reinterventions, costs and cost-effectiveness.

RESULTS

In EVAR-1, over a mean of 12.7 years (standard deviation 1.5 years; maximum 15.8 years), we recorded 9.3 deaths per 100 person-years in the EVAR group and 8.9 deaths per 100 person-years in the OR group [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 0.97 to 1.27; p = 0.14]. At 0-6 months after randomisation, patients in the EVAR group had a lower mortality (adjusted HR 0.61, 95% CI 0.37 to 1.02 for total mortality; HR 0.47, 95% CI 0.23 to 0.93 for aneurysm-related mortality; p = 0.031), but beyond 8 years of follow-up patients in the OR group had a significantly lower mortality (adjusted HR 1.25, 95% CI 1.00 to 1.56, p = 0.048 for total mortality; HR 5.82, 95% CI 1.64 to 20.65, p = 0.0064 for aneurysm-related mortality). The increased aneurysm-related mortality in the EVAR group after 8 years was mainly attributable to secondary aneurysm sac rupture, with increased cancer mortality also observed in the EVAR group. Overall, aneurysm reintervention rates were higher in the EVAR group than in the OR group, 4.1 and 1.7 per 100 person-years, respectively (p < 0.001), with reinterventions occurring throughout follow-up. The mean difference in costs over 14 years was £3798 (95% CI £2338 to £5258). Economic modelling based on the outcomes of the EVAR-1 trial showed that the cost per quality-adjusted life-year gained over the patient's lifetime exceeds conventional thresholds used in the UK. In EVAR-2, patients died at the same rate in both groups, but there was suggestion of lower aneurysm mortality in those who actually underwent EVAR. Type II endoleak itself is not associated with a higher rate of mortality.

LIMITATIONS

Devices used were implanted between 1999 and 2004. Newer devices might have better results. Later follow-up imaging declined, particularly for OR patients. Methodology to capture reinterventions changed mainly to record linkage through the Hospital Episode Statistics administrative data set from 2009.

CONCLUSIONS

EVAR has an early survival benefit but an inferior late survival benefit compared with OR, which needs to be addressed by lifelong surveillance of EVAR and reintervention if necessary. EVAR does not prolong life in patients unfit for OR. Type II endoleak alone is relatively benign.

FUTURE WORK

To find easier ways to monitor sac expansion to trigger timely reintervention.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN55703451.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and the results will be published in full in Health Technology Assessment; Vol. 22, No. 5. See the NIHR Journals Library website for further project information.

Surgical Versus Endovascular Aortic Aneurysm Repair: Evidence to Guide the Optimal Approach for the Individual Patient

The choice between an open surgical and an endovascular approach for abdominal aortic aneurysm (AAA) repair remains an individualized clinical decision. As the technology and applications of endovascular aortic aneurysm repair (EVAR) continue to evolve, so does the literature investigating its outcomes. Multiple high-quality, randomized controlled trials comparing EVAR to open surgical repair (OSR) have now been published with long-term follow-up. Experience with ruptured aneurysms and the use of complex endografts is growing as well. This review is an up-to-date compilation of pertinent clinical trials for practitioners placed in the context of individual patient considerations to guide the choice of an optimal approach to the management of AAAs.

Trends in Patient Safety of Intact Abdominal Aortic Aneurysm Repair: German Registry Data on 36,594 Procedures

OBJECTIVE/BACKGROUND

The study aim was to determine whether patient safety for non-ruptured abdominal aortic aneurysm (nrAAA) repair has changed between 1999 and 2010 in a large German cohort.

METHODS

The data source was the prospective quality assurance registry of the German Vascular Society from 1999 to 2010. Patient characteristics, surgical techniques (open aortic repair [OAR], endovascular aortic repair [EVAR]), procedural time and outcomes, including the length of hospital stay (LOS), were analysed using the Cochran-Armitage test for binary parameters and Spearman's correlation coefficient for quantitative parameters.

RESULTS

A total of 36,594 operations (23,037 OAR, 13,557 EVAR) for infrarenal nrAAA in 201 hospitals in Germany were investigated. Patients' mean age increased from 69.6 to 72.0 years (p < .001). The rate of patients with American Society of Anesthesiologists scores of 3 or 4 increased (p < .001). Use of EVAR increased (1999: 16.7%; 2010: 62.7%; p < .001), and since 2009, EVAR has been more frequently used than OAR. The overall in hospital mortality decreased from 3.1% in 1999 to 2.3% in 2010 (p < .001). There were no temporal trends for mortality rates for EVAR (p = .233) or OAR (p = .281) when considered separately. Cardiac (1999: 8.1%; 2010: 5.1%; p < .001) and pulmonary (1999: 7.8%; 2010: 4.8%; p < .001) complications decreased. The rate of post-operative renal failure increased (1999: 3.6%; 2010 4.1%; p = .017), without increasing the rate of patients needing dialysis (1999: 1.7%; 2010: 1.7%; p = .171). The median LOS decreased from 17 days in 1999 to 10 days in 2010 (p < .001).

CONCLUSION

This study shows significantly improved post-procedural in hospital outcomes and decreased use of resources for nrAAA repair. This trend can probably be attributed to the implementation of EVAR as a standard technique, but some trends could also possibly be explained by a change in the remuneration system. The main limitation of the registry is the lack of internal and external validation. However, in hospital patient safety for AAA repair seems to have improved significantly in the participating hospitals.

Pharmacological treatment of vascular risk factors for reducing mortality and cardiovascular events in patients with abdominal aortic aneurysm

BACKGROUND

Pharmacological prophylaxis has been proven to reduce the risk of cardiovascular events in individuals with atherosclerotic occlusive arterial disease. However, the role of prophylaxis in individuals with abdominal aortic aneurysm (AAA) remains unclear. Several studies have shown that despite successful repair, those people with AAA have a poorer rate of survival than healthy controls. People with AAA have an increased prevalence of coronary heart disease and risk of cardiovascular events. Despite this association, little is known about the effectiveness of pharmacological prophylaxis in reducing cardiovascular risk in people with AAA. This is an update of a Cochrane review first published in 2014.

OBJECTIVES

To determine the long-term effectiveness of antiplatelet, antihypertensive or lipid-lowering medication in reducing mortality and cardiovascular events in people with abdominal aortic aneurysm (AAA).

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist (CIS) searched the Cochrane Vascular Specialised Register (14 April 2016). In addition, the CIS searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2016, Issue 3) and trials registries (14 April 2016) and We also searched the reference lists of relevant articles.

SELECTION CRITERIA

Randomised controlled trials in which people with AAA were randomly allocated to one prophylactic treatment versus another, a different regimen of the same treatment, a placebo, or no treatment were eligible for inclusion in this review. Primary outcomes included all-cause mortality and cardiovascular mortality.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, and completed quality assessment and data extraction. We resolved any disagreements by discussion. Only one study met the inclusion criteria of the review, therefore we were unable to perform meta-analysis.

MAIN RESULTS

No new studies met the inclusion criteria for this update. We included one randomised controlled trial in the review. A subgroup of 227 participants with AAA received either metoprolol (N = 111) or placebo (N = 116). There was no clear evidence that metoprolol reduced all-cause mortality (odds ratio (OR) 0.17, 95% confidence interval (CI) 0.02 to 1.41), cardiovascular death (OR 0.20, 95% CI 0.02 to 1.76), AAA-related death (OR 1.05, 95% CI 0.06 to 16.92) or increased nonfatal cardiovascular events (OR 1.44, 95% CI 0.58 to 3.57) 30 days postoperatively. Furthermore, at six months postoperatively, estimated effects were compatible with benefit and harm for all-cause mortality (OR 0.71, 95% CI 0.26 to 1.95), cardiovascular death (OR 0.73, 95% CI 0.23 to 2.39) and nonfatal cardiovascular events (OR 1.41, 95% CI 0.59 to 3.35). Adverse drug effects were reported for the whole study population and were not available for the subgroup of participants with AAA. We considered the study to be at a generally low risk of bias. We downgraded the quality of the evidence for all outcomes to low. We downgraded the quality of evidence for imprecision as only one study with a small number of participants was available, the number of events was small and the result was consistent with benefit and harm.

AUTHORS' CONCLUSIONS

Due to the limited number of included trials, there is insufficient evidence to draw any conclusions about the effectiveness of cardiovascular prophylaxis in reducing mortality and cardiovascular events in people with AAA. Further good-quality randomised controlled trials that examine many types of prophylaxis with long-term follow-up are required before firm conclusions can be made.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

Daidzein attenuates abdominal aortic aneurysm through NF-κB, p38MAPK and TGF-β1 pathways

The current study focuses on the protection of daidzein on nerves, as daidzein was demonstrated to have a protective effect on neurons of the central nervous system in a glutamate excitotoxicity and oxygen/glucose deprivation model. However, the effect of daidzein on the abdominal aortic aneurysm (AAA) remains unclear. The angiotensin II-induced AAA mouse model was utilized in the present study to determine the effect of daidzein on AAA. The results demonstrated that daidzein significantly attenuated incidence of AAA, max aortic aneurysm and mortality in the angiotensin II‑induced AAA mice. Daidzein had an anti‑inflammatory effect by inhibiting tumor necrosis factor α (TNF-α), interleukin 1β (IL‑1β) and nuclear factor κB (NF‑κB) protein expression. In addition, daidzein strongly suppressed the gene expression of cyclooxygenase (COX)‑2, matrix metalloproteinase 2 (MMP‑2), tissue inhibitor of metalloproteinase 1 (TIMP-1), transforming growth factor β1 (TGF‑β1), and inhibited inducible nitric oxide synthase (iNOS) protein expression in angiotensin II‑induced AAA mice. It also inhibited phosphorylation of the p38 mitogen-activated protein kinase (MAPK) signaling pathway. These results demonstrate, to the best of our knowledge for the first time, that the anti‑inflammatory effects and inhibitory mechanism of daidzein attenuates AAA in angiotensin II‑induced mice. Daidzein contains strong anti‑inflammatory activity and affects various mechanism pathways including the NF‑κB, p38MAPK and TGF-β1 pathway.

Endovascular Aneurysm Repair Increases Aortic Arterial Stiffness When Compared to Open Repair of Abdominal Aortic Aneurysms

Objectives:

The initial survival advantage seen with endovascular aneurysm repair (EVAR) over open repair does not persist in the long term. Pulse wave velocity (PWV) is a measure of arterial stiffness, and increased PWV is an independent risk factor for increased cardiovascular morbidity and mortality. This prospective comparative pilot study examined the effect of implantation of an aortic graft on PWV in patients undergoing open or endovascular aortic aneurysm repair.

Patients and Methods:

Thirty-four patients (15 open and 19 EVAR) were recruited. Patient demographics were similar in both the groups. Pulse wave velocity was calculated for all patients preoperatively and postoperatively using a standardized technique on a Philips IU22 Vascular Ultrasound machine and the results compared.

Results:

An increase in mean PWV following EVAR was demonstrated. The mean postprocedure PWV of 9.7 (± 4.5) cm/sec detected in the open group was significantly lower than the elevated 12.2 (± 4.5) cm/sec detected in the EVAR group. The surgical group also demonstrated a mean decrease of 0.2 (± 4.9) cm/sec in PWV following open repair compared to a mean increase of 3.3 (± 3.7) cm/sec in the EVAR group.

Conclusion:

EVAR patients have a significantly higher postoperative PWV measurement than those undergoing open abdominal aortic aneurysm repair. Patients who have undergone EVAR may be at a higher risk of cardiovascular morbidity in the long term. A larger scale study with a longer prospective follow-up is required.

Quality of life from a randomized trial of open and endovascular repair for abdominal aortic aneurysm

Background

Long-term survival is similar after open or endovascular repair of abdominal aortic aneurysm. Few data exist on the effect of either procedure on long-term health-related quality of life (HRQoL) and health status.

Methods

Patients enrolled in a multicentre randomized clinical trial (DREAM trial; 2000–2003) in Europe of open repair versus endovascular repair (EVAR) of abdominal aortic aneurysm were asked to complete questionnaires on health status and HRQoL. HRQoL scores were assessed at baseline and at 13 time points thereafter, using generic tools, the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36®) and EuroQol 5D (EQ-5D™). Physical (PCS) and mental component summary scores were also calculated. Follow-up was 5 years.

Results

Some 332 of 351 patients enrolled in the trial returned questionnaires. More than 70 per cent of questionnaires were returned at each time point. Both surgical interventions had a short-term negative effect on HRQoL and health status. This was less severe in the EVAR group than in the open repair group. In the longer term the physical domains of SF-36® favoured open repair: mean difference in PCS score between open repair and EVAR −1·98 (95 per cent c.i. −3·56 to −0·41). EQ-5D™ descriptive and EQ-5D™ visual analogue scale scores for open repair were also superior to those for EVAR after the initial 6-week interval: mean difference −0·06 (−0·10 to −0·02) and −4·09 (−6·91 to −1·27) respectively.

Conclusion

In this study EVAR appeared to be associated with less severe disruption to HRQoL and health status in the short term. However, during longer-term follow-up to 5 years, patients receiving open repair appeared to have improved quality of life and health status.

Non-Invasive Pulse Wave Analysis in a Thrombus-Free Abdominal Aortic Aneurysm after Implantation of a Nitinol Aortic Endograft

Endovascular aneurysm repair has been associated with changes in arterial stiffness, as estimated by pulse wave velocity (PWV). This marker is influenced by the medical status of the patient, the elastic characteristics of the aneurysm wall, and the presence of intraluminal thrombus. Therefore, in order to delineate the influence of the endograft implantation in the early post-operative period, we conducted non-invasively pulse wave analysis in a male patient with an abdominal aortic aneurysm containing no intraluminal thrombus, unremarkable past medical history, and absence of peripheral arterial disease. The estimated parameters were the systolic and diastolic pressure calculated at the aortic level (central pressures), PWV, augmentation pressure (AP) and augmentation index (AI), pressure wave reflection magnitude (RM), and peripheral resistance. Central systolic and diastolic pressure decreased post-operatively. PWV showed subtle changes from 11.6 to 10.6 and 10.9 m/s at 1-week and 1-month, respectively. Accordingly, the AI decreased from 28 to 14% and continued to drop to 25%. The AP decreased gradually from 15 to 6 and 4 mmHg. The wave RM dropped from 68 to 52% at 1-month. Finally, the peripheral resistance dropped from 1.41 to 0.99 and 0.85 dyn × s × cm⁻⁵. Our example shows that the implantation of an aortic endograft can modify the pressure wave reflection over the aortic bifurcation without causing significant alterations in PWV.

Aspirin therapy is associated with less compact fibrin networks and enhanced fibrinolysis in patients with abdominal aortic aneurysm

OBJECTIVE

Thrombotic changes in fibrin networks contribute to increased cardiovascular risk in patients with abdominal aortic aneurysm (AAA). Given that aspirin modulates the fibrin network, we aimed to determine if aspirin therapy is associated with changes in ex-vivo fibrin clot characteristics in AAA patients and also conducted an exploratory analysis of 5-year mortality in these individuals.

METHODS

We recruited 145 male patients, divided into controls (aortic diameter < 3 cm, n = 49), AAA not taking aspirin (AAA-Asp, n = 50) and AAA on 75 mg day(-1) aspirin (AAA+Asp, n = 46), matched for aneurysm size. Characteristics of clots made from plasma and plasma-purified fibrinogen were investigated using turbidimetric analysis, permeation studies, and confocal and electron microscopy. Plasma fibrinogen, D-dimer and inflammatory marker levels were also measured.

RESULTS

Maximum absorbance (MA) of plasma clots from controls was lower than that of AAA patients not on aspirin (AAA-Asp) at 0.30 ± 0.01 and 0.38 ± 0.02 au, respectively (P = 0.002), whereas aspirin-treated subjects had MA similar to controls (0.31 ± 0.02 P = 0.9). Plasma clot lysis time displayed an identical pattern at 482 ± 15, 597 ± 24 and 517 ± 27 s for control, AAA-Asp and AAA+Asp (P = 0.001 and P = 0.8). The lysis time of clots made from purified fibrinogen of AAA-Asp was longer than that of AAA+Asp patients (756 ± 47 and 592 ± 52 s, respectively; P = 0.041). Permeation studies and confocal and electron microscopy showed increased clot density in AAA-Asp compared with the AAA+Asp group. Mortality in AAA-Asp and AAA+Asp was similar, despite increased cardiovascular risk in the latter group, and both exhibited higher mortality than controls.

CONCLUSION

Aspirin improves fibrin clot characteristics in patients with AAA, which may have important clinical implications.

Arterial Stiffness Alterations and Inflammatory Response Following Endovascular Aortic Repair: Based on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA)

Endovascular abdominal aortic aneurysm repair (EVAR) and thoracic aortic aneurysm repair (TEVAR) have been widely incorporated into clinical practice. However, changes in arterial stiffness and post-implantation syndrome after aortic endografting remain important issues under investigation. The aneurysm sac wall motion after successful EVAR and TEVAR reflects complex interactions between all the components of the excluded aneurysm, including true compliance of the aneurysm wall itself, intra-aneurysm sac pressure, remodeling of the thrombus, and mechanical characteristics of the endograft. Experimental and clinical studies have shown that aortic endografting results in increased arterial stiffness in animal models. It can be assumed that the alterations of aortic mechanical properties can have a direct impact on heart output. The long-term impact of these mechanical changes on cardiovascular outcomes and the potential effects of different endografts on hemodynamics are important issues under investigation. Post-implantation syndrome (PIS) is a systemic inflammatory response frequently observed after endovascular treatment of aortic pathologies. The main features of PIS include fever, leukocytosis, elevated C-reactive protein levels, and coagulation disturbances. Endograft design appears to influence this inflammatory response following aortic endografting; woven polyester endografts have been shown to be associated with greater inflammatory response compared to PTFE stent grafts. The purpose of this paper is to review the literature to elucidate arterial stiffness alterations and inflammatory response after EVAR and TEVAR and the impact of endograft design on aortic stiffness and the post-inflammatory response.

Complexity of persistent type II endoleak associated with sac expansion after endovascular abdominal aortic aneurysm repair

Type II endoleak after endovascular aortic aneurysm repair still remains the Achilles' heel of the treatment, the source of which regularly is difficult to identify and treat. We present a patient with a persistent type II endoleak associated with a continuous aneurysm sac expansion after endovascular aortic aneurysm repair for which many diagnostic modalities were used during his follow-up such as duplex scan, computed tomography angiography and magnetic resonance angiography. Attempts were undertaken to treat the source of endoleak including coil micro-embolisation of lumbar arteries and subsequent open ligation of the inferior mesenteric artery, but they failed to eliminate the endoleak. Finally, a middle sacral artery was identified as the source of the endoleak. At that time, the patient was subjected to surgery for sigmoid carcinoma, and simultaneously, a ligation of the sacral artery was undertaken which eventually eliminated the endoleak completely. This case highlights that type II endoleak may be evoked by various sources and there can be a great difficulty to identify these feeding vessels; thus, careful planning for its management is mandatory.

Current state in tracking and robotic navigation systems for application in endovascular aortic aneurysm repair

OBJECTIVE

This study reviewed the current developments in manual tracking and robotic navigation technologies for application in endovascular aortic aneurysm repair (EVAR).

METHODS

EMBASE and MEDLINE databases were searched for studies reporting manual tracking or robotic navigation systems that are able to manipulate endovascular surgical tools during abdominal or thoracic aortic aneurysm repair. Reports were grouped by the navigation systems and categorized into phantom, animal, and clinical studies. First, the general characteristics of each system were compared. Second, target registration error and deployment error were used to compare the accuracy of the tracking systems. Third, all systems were reviewed for fluoroscopy time (FT), radiation dose, and contrast volumes, if reported, in rigid and nonrigid studies. Fourth, vascular cannulation performance of the systems was compared, studying cannulation time, Imperial College Complex Cannulation Scoring Tool score, and the number of wall hits and catheter movements within rigid studies.

RESULTS

Of 721 articles and references found, 18 studies of four different navigation systems were included: the Aurora (Northern Digital, Waterloo, Ontario, Canada) tracking system, the StealthStation (Medtronic Inc, Minneapolis, Minn) tracking system, an ultrasound localization tracking system, and the Sensei (Hansen Medical, Mountain View, Calif) steerable remote-controlled robotic navigation system. The mean tracking accuracy averaged 1 mm for the three manual tracking systems measured in a rigid environment. An increase of target registration error reaching >3 mm was reported when measured in a nonrigid experimental environment or due to external distortion factors. Except within small-animal studies or case studies, no evidence was found on reduction of clinical outcome parameters, such as FT, radiation dose, and contrast volumes, within clinical EVAR. A comparison of vascular cannulation performance in rigid studies revealed that the Sensei robotic system might have an advantage during advanced cannulation compared with standard cannulation within complex cannulations tasks.

CONCLUSIONS

This review summarizes the current studies on manual tracking and robotic navigation systems for application in EVAR. The main focus of these systems is improving aortic vessel cannulation, required in complex EVAR, in which the robotic system with the improved steerability is favored over manual tracking systems or conventional cannulation. All reviewed tracking systems still require X-ray for anatomic imaging, stent graft deployment, and device registration. Although the current reviewed endovascular navigation systems have shown their potential in phantom and animal studies, clinical trials are too limited to conclude that these systems can improve EVAR outcomes or that they can systematically reduce FTs, radiation doses, and contrast volumes during (complex) EVAR.

Open versus Endovascular Repair of Abdominal Aortic Aneurysm in the Elective and Emergent Setting in a Pooled Population of 37,781 Patients: A Systematic Review and Meta-Analysis

Background. We evaluated the incidence of mortality and myocardial infarction (MI) in endovascular repair (EVAR) as compared to open aneurysm repair (OAR) in both elective and ruptured abdominal aortic aneurysm (AAA ) setting. Methods. We analyzed the rates of 30-day mortality, 30-day MI, and hospital length of stay (LOS) based on comparative observation and randomized control trials involving EVAR and OAR. Results. 41 trials compared EVAR to OAR with a total pooled population of 37,781 patients. Analysis of elective and ruptured AAA repair favored EVAR with respect to 30-day mortality with a pooled odds ratio of 0.19 (95% CI 0.17–0.20; I² = 88.9%; P < 0.001). There were a total of 1,835 30-day MI events reported in the EVAR group as compared to 2,483 events in the OAR group. The pooled odds ratio for elective AAA was 0.74 (95% CI 0.58–0.96; P = 0.02) in favor of EVAR. The average LOS was reduced by 296.75 hrs (95% CI 156.68–436.82 hrs; P < 0.001) in the EVAR population. Conclusions. EVAR has lower rates of 30-day mortality, 30-day MI, and LOS in both elective and ruptured AAA repair.

Long-term cost-effectiveness analysis of endovascular versus open repair for abdominal aortic aneurysm based on four randomized clinical trials

Background

A number of published economic evaluations of elective endovascular aneurysm repair (EVAR) versus open repair for abdominal aortic aneurysm (AAA) have come to differing conclusions about whether EVAR is cost-effective. This paper reviews the current evidence base and presents up-to-date cost-effectiveness analyses in the light of results of four randomized clinical trials: EVAR-1, DREAM, OVER and ACE.

Methods

Markov models were used to estimate lifetime costs from a UK perspective and quality-adjusted life-years (QALYs) based on the results of each of the four trials. The outcomes included in the model were: procedure costs, surveillance costs, reintervention costs, health-related quality of life, aneurysm-related mortality and other-cause mortality. Alternative scenarios about complications, reinterventions and deaths beyond the trial were explored.

Results

Models based on the results of the EVAR-1, DREAM or ACE trials did not find EVAR to be cost-effective at thresholds used in the UK (up to £30 000 per QALY). EVAR seemed cost-effective according to models based on the OVER trial. These results seemed robust to alternative model scenarios about events beyond the trial intervals.

Conclusion

These analyses did not find that EVAR is cost-effective compared with open repair in the long term in trials conducted in European centres. EVAR did appear to be cost-effective based on the OVER trial, conducted in the USA. Caution must be exercised when transferring the results of economic evaluations from one country to another.

Impact of hospital-acquired infection on long-term outcomes after endovascular and open abdominal aortic aneurysm repair

BACKGROUND

We hypothesized that infectious complications after open surgery (OPEN) and endovascular repair (EVAR) of nonruptured abdominal aortic aneurysms (AAAs) negatively affected long-term outcomes.

METHODS

Elective OPEN and EVAR cases were selected from 2005-2007 Medicare databases, and rates of postoperative infection, readmission, and longitudinal mortality were compared.

RESULTS

Forty thousand eight hundred ninety-two EVARs and 16,669 OPEN AAA repairs were evaluated. Patients with OPEN developed infection during and after the index hospitalization (12.8% and 4.9%, respectively) more often than those who had undergone EVAR (3.2% and 3.9%, respectively; P < 0.0001 for both). Patients with hospital-acquired infection compared to noninfectious ones were more likely to die during the index hospitalization (odds ratio [OR]: 3.7 [95% confidence interval {CI}: 3.22-4.30]) and within 30 days after discharge (OR: 3.6 [95% CI: 2.83-4.45]). They also were more likely to be readmitted to the hospital during 30 days after index discharge (OR: 1.8 [95% CI: 1.63-1.94]). Index infections associated with the greatest readmission were urinary tract infection after OPEN and sepsis after EVAR. Hospital-acquired infection significantly increased the duration of hospital stay (14.2 ± 13.2 vs 4.0 ± 4.4 days; P < 0.0001) and total hospital charges ($133,070 ± $136,100 vs $66,359 ± $45,186; P < 0.0001). The most common infections to develop 30 days after initial discharge were surgical site infection after EVAR (1.27%) and urinary tract infection after OPEN (1.38%).

CONCLUSION

Hospital-acquired infections had a dramatic effect by increasing hospital and 30-day mortality, readmission rates, and hospital resource use after AAA repair. Programs minimizing infectious complications may decrease future readmissions and mortality after AAA repair.

Endovascular repair of abdominal aortic aneurysm

BACKGROUND

An abnormal dilatation of the abdominal aorta is referred to as an abdominal aortic aneurysm (AAA). Due to the risk of rupture, surgical repair is offered electively to individuals with aneurysms greater than 5.5 cm in size. Traditionally, conventional open surgical repair (OSR) was considered the first choice approach. However, over the past two decades endovascular aneurysm repair (EVAR) has gained popularity as a treatment option. This article intends to review the role of EVAR in the management of elective AAA.

OBJECTIVES

To assess the effectiveness of EVAR versus conventional OSR in individuals with AAA considered fit for surgery, and EVAR versus best medical care in those considered unfit for surgery. This was determined by the effect on short, intermediate and long-term mortality, endograft related complications, re-intervention rates and major complications.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator (TSC) searched the Specialised Register (January 2013) and the Cochrane Central Register of Controlled Trials (CENTRAL) (2012, Issue 12). The TSC also searched trial databases for details of ongoing or unpublished studies.

SELECTION CRITERIA

Prospective randomised controlled trials (RCTs) comparing EVAR with OSR in individuals with AAA considered fit for surgery. and comparing EVAR with best medical care in individuals considered unfit for surgery. We excluded studies with inadequate data or using an inadequate randomisation technique.

DATA COLLECTION AND ANALYSIS

Three reviewers independently evaluated trials for appropriateness for inclusion and extracted data using pro forma designed by the Cochrane PVD Group. We assessed the quality of trials using The Cochrane Collaboration's 'Risk of bias' tool. We entered collected data in to Review Manager (version 5.2.3) for analysis. Where direct comparisons could be made, we determined odds ratios (OR). We tested studies for heterogeneity and, when present, we used a random-effects model; otherwise we used a fixed-effect model. We tabulated data that could not be collated.

MAIN RESULTS

Four high-quality trials comparing EVAR with OSR (n = 2790) and one high-quality trial comparing EVAR with no intervention (n = 404) fulfilled the inclusion criteria. In individuals considered fit for surgery, a pooled analysis, including 1362 individuals randomised to EVAR and 1361 randomised to OSR, found short-term mortality (including 30-day or inhospital mortality, excluding deaths prior to intervention) with EVAR to be significantly lower than with OSR (1.4% versus 4.2%, OR 0.33, 95% confidence interval (CI) 0.20 to 0.55; P < 0.0001). Using intention-to-treat analysis (ITT) there was no significant difference in mortality at intermediate follow-up (up to four years from randomisation), with 221 (15.8%) and 237 (17%) deaths in the EVAR (n = 1393) and OSR (n = 1390) groups, respectively (OR 0.92, 95% CI 0.75 to 1.12; P = 0.40). There was also no significant difference in long-term mortality (beyond four years), with 464 (37.3%) deaths in the EVAR and 470 (37.8%) deaths in the OSR group (OR 0.98, 95% CI 0.83 to 1.15; P = 0.78). Similarly, there was no significant difference in aneurysm-related mortality between groups, either at the intermediate- or long-term follow up.Studies showed that both EVAR and OSR were associated with similar incidences of cardiac deaths (OR 1.14, 95% CI 0.86 to 1.52; P = 0.36) and fatal stroke rate (OR 0.81, 95% CI 0.42 to 1.55; P = 0.52). The long-term reintervention rate was significantly higher in the EVAR group than in the OSR group (OR 1.98, 95% CI 1.12 to 3.51; P = 0.02; I(2) = 85%). Results of the reintervention analysis should be interpreted with caution due to significant heterogeneity. Operative complications, health-related quality of life and sexual dysfunction were generally comparable between the EVAR and OSR groups. However, there was a slightly higher incidence of pulmonary complications in the OSR group compared with the EVAR group (OR 0.36, 95% CI 0.17 to 0.75; P = 0.006).In individuals considered unfit for conventional OSR, the one included trial found no difference between the EVAR and no-intervention groups with regard to all-cause mortality at final follow up, with 21.0 deaths per 100 person-years in the EVAR group and 22.1 deaths per 100 person years in the no-intervention group (adjusted hazard ratio (HR) with EVAR 0.99, 95% CI 0.78 to 1.27; P = 0.97). Aneurysm-related deaths were, however, significantly higher in the no-intervention group than in the EVAR group (adjusted HR 0.53, 95% CI 0.32 to 0.89; P = 0.02). There was no difference in myocardial events (HR 1.07, 95% CI 0.60 to 1.91) between the groups in this study.

AUTHORS' CONCLUSIONS

In individuals considered fit for conventional surgery, EVAR was associated with lower short-term mortality than OSR. However, this benefit from EVAR did not persist at the intermediate- and long-term follow ups. Individuals undergoing EVAR had a higher reintervention rate than those undergoing OSR. Most of the reinterventions undertaken following EVAR, however, were catheter-based interventions associated with low mortality. Operative complications, health-related quality of life and sexual dysfunction were generally comparable between EVAR and OSR. However, there was a slightly higher incidence of pulmonary complications in the OSR group than in the EVAR group.In individuals considered unfit for open surgery, the results of a single trial found no overall short- or long-term benefits of EVAR over no intervention with regard to all-cause mortality, but individuals may differ and individual preferences should always be taken into account.

Pharmacological treatment of vascular risk factors for reducing mortality and cardiovascular events in patients with abdominal aortic aneurysm

BACKGROUND

Pharmacological prophylaxis has been proven to reduce the risk of cardiovascular events in patients with atherosclerotic occlusive arterial disease. However, the role of prophylaxis in patients with abdominal aortic aneurysm (AAA) remains unclear. Several studies have shown that despite successful repair, those with AAA have a poorer rate of survival than healthy controls. People with AAA have an increased prevalence of coronary heart disease and risk of cardiovascular events. Despite this association, little is known about the effectiveness of pharmacological prophylaxis in reducing cardiovascular risk in people with AAA.

OBJECTIVES

To determine the long-term effectiveness of antiplatelet, antihypertensive or lipid-lowering medication in reducing mortality and cardiovascular events in people with abdominal aortic aneurysm (AAA).

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched the Specialised Register (last searched April 2013) and CENTRAL (2013, Issue 3). Reference lists of relevant articles were also checked.

SELECTION CRITERIA

Randomised controlled trials in which people with AAA were randomly allocated to one prophylactic treatment versus another, a different regimen of the same treatment, a placebo, or no treatment were eligible for inclusion in this review. Primary outcomes included all-cause mortality and cardiovascular mortality.

DATA COLLECTION AND ANALYSIS

Selection of the studies, quality assessment and data extraction were completed independently by two review authors. Any disagreements were resolved by discussion. Only one study was included in the review, therefore meta-analysis could not be performed.

MAIN RESULTS

One randomised controlled study was included in the review. A subgroup of 227 patients with AAA received either metoprolol (N = 111) or placebo (N = 116). There was no clear evidence that metoprolol reduced all-cause mortality (odds ratio (OR) 0.17, 95% confidence interval (CI) 0.02 to 1.41), cardiovascular death (OR 0.20, 95% CI 0.02 to 1.76), AAA-related death (OR 1.05, 95% CI 0.06 to 16.92) or increased nonfatal cardiovascular events (OR 1.44, 95% CI 0.58 to 3.57) 30 days postoperatively. Furthermore, at six months postoperatively, estimated effects were compatible with benefit and harm for all-cause mortality (OR 0.71, 95% CI 0.26 to 1.95), cardiovascular death (OR 0.73, 95% CI 0.23 to 2.39) and nonfatal cardiovascular events (OR 1.41, 95% CI 0.59 to 3.35). Adverse drug effects were reported for the whole study population and were not available for the subgroup of participants with AAA. The study was deemed to be at a generally low risk of bias.

AUTHORS' CONCLUSIONS

Due to the limited number of trials, there is insufficient evidence to draw any conclusions about the effectiveness of cardiovascular prophylaxis in reducing mortality and cardiovascular events in people with AAA. Further good-quality randomised controlled trials examining many types of prophylaxis with long-term follow-up are required before firm conclusions can be made.