Now showing items 1-20 of 38

    • Biomimetic Stents for Infra-inguinal Peripheral Arterial Disease: Systematic Review and Meta-Analysis

      Messender, Sarah; Pepper, Coral; Lopez-Pena, Gabriel; Saratzis, Athanasios (2023-11-04)
      Objective: Biomimetic stents are peripheral infra-inguinal self-expanding stents that mimic the anatomy of the vasculature and artery movement. They are indicated for use in infra-inguinal arteries. This research aimed to synthesise all current evidence on the use of biomimetic stents as adjuncts for endovascular treatment of infra-inguinal peripheral arterial disease (PAD), helping to guide clinical decision making. Data sources: MEDLINE, Embase, CINAHL and Cochrane databases. Review methods: Random effects meta-analysis following PRISMA guidelines (PROSPERO registration CRD42022385256). Study quality was assessed using the Joanna Briggs Institute critical appraisal tools checklist, and certainty assessment through the Grading of Recommendations, Assessment, Development and Evaluation (GRADE). Endpoints included primary patency, target lesion revascularisation, stent fracture, secondary patency, and mortality at 1 year. Results: In total, 37 studies were included in the meta-analysis (33 cohort studies, 2 case series, and 2 randomised controlled trials [RCTs]), representing 4 480 participants. Of these, 34 studies included data on Supera (81.5% of participants) and 3 studies reported data on BioMimics 3D (18.5% of participants) stents. The pooled primary patency rate of 33 studies at 1 year follow up was 81.4% (95% confidence interval [CI] 78.7 - 83.9%), and the pooled target lesion revascularisation rate of 18 studies at 1 year was 12.2% (95% CI 9.6 - 15.0%). The certainty of evidence outcome rating as qualified by GRADE was very low for both. Only one study reported a positive stent fracture rate at 1 year follow up of 0.4% with a certainty of evidence outcome of low. Conclusion: Using biomimetic stents for infra-inguinal PAD may be associated with acceptable 1 year primary patency and target lesion revascularisation rates, with near negligible 1 year stent fracture rate. Their use should be considered in those presenting with infra-inguinal PAD undergoing endovascular revascularisation. A RCT trial is necessary to determine their clinical and cost effectiveness.
    • The effect of hypercapnia on the directional sensitivity of dynamic cerebral autoregulation and the influence of age and sex

      Clough, Rebecca; Beishon, Lucy; Robinson, Thompson; Davies, Aaron; Minhas, Jatinder S (2023-09-25)
      The cerebral circulation responds differently to increases in mean arterial pressure (MAP), compared to reductions in MAP. We tested the hypothesis that this directional sensitivity is reduced by hypercapnia. Retrospective analysis of 104 healthy subjects (46 male (44%), age range 19-74 years), with five minute recordings of middle cerebral blood velocity (MCAv, transcranial Doppler), non-invasive MAP (Finometer) and end-tidal CO2 (capnography) at rest, during both poikilocapnia and hypercapnia (5% CO2 breathing in air) produced MCAv step responses allowing estimation of the classical Autoregulation Index (ARIORIG), and corresponding values for both positive (ARI+D) and negative (ARI-D) changes in MAP. Hypercapnia led to marked reductions in ARIORIG, ARI+D and ARI-D (p < 0.0001, all cases). Females had a lower value of ARIORIG compared to males (p = 0.030) at poikilocapnia (4.44 ± 1.74 vs 4.74 ± 1.48) and hypercapnia (2.44 ± 1.93 vs 3.33 ± 1.61). The strength of directional sensitivity (ARI+D-ARI-D) was not influenced by hypercapnia (p = 0.46), sex (p = 0.76) or age (p = 0.61). During poikilocapnia, ARI+D decreased with age in females (p = 0.027), but not in males. Directional sensitivity was not affected by hypercapnia, suggesting that its origins are more likely to be inherent to the mechanics of vascular smooth muscle than to myogenic pathways.
    • Intraoperative predictors of in-hospital mortality after open repair of ruptured abdominal aortic aneurysms

      Saratzis, Athanasios (2023-06-28)
      Background: Several models and scores have been released to predict early mortality in patients undergoing surgery for a ruptured abdominal aortic aneurysm (rAAA). These scores included above all preoperative factors and they could be useful to deny surgical repair. The aim of the study was to evaluate intraoperative predictors of in-hospital mortality in patients undergoing open surgical repair (OSR) for a rAAA. Methods: Between January 2007 and December 2020, 265 patients were admitted at our tertiary referral hospital for a rAAA. Two-hundred-twenty-two patients underwent OSR. Intra-operative factors were analyzed by means of univariate analysis (step 1). Associations of procedure variables with in-hospital mortality rates were sought based on a multivariate Cox regression analysis (step 2). Results: Overall, in-hospital mortality rate was 28.8% (64 cases). Multivariate Cox regression analysis reported that operation time >240 minutes (P=0.032, OR 2.155, CI 95% 1.068-4.349), and hemoperitoneum (P<0.001, OR 3.582, CI 95% 1.749-7.335) were negative predictive factors for in-hospital mortality. Patency of at least one hypogastric artery (P=0.010; OR 0.128, CI 95% 0.271-0.609), and infrarenal clamping (P=0.001; OR 0.157, CI 95% 0.052-0.483) had a protective role in reducing in-hospital mortality rate. Conclusions: Operation time >240 minutes, and hemoperitoneum affected in-hospital mortality in patients undergoing OSR for rAAA. Patency of at least one hypogastric artery, and infrarenal clamping had a protective role. Further studies are needed to validate these outcomes. A validated predictive model could be useful to help the physicians in communication with patients' relatives.
    • Endovascular versus surgical treatment for all-comer patients with prosthetic bypass graft occlusion: the multicentre ENSUPRO study

      Saratzis, Athanasios (2023-08-03)
      Objective: Bypass surgery plays a key role in complex lower limb lesions. However, there is a lack of evidence regarding the management of symptomatic prosthetic bypass graft (PBG) occlusion. This study aimed to report outcomes following open, hybrid, or endovascular management of patients presenting with symptomatic PBG occlusion. Methods: A multicentre, retrospective cohort study was conducted, including patients presenting with PBG occlusion between January 2014 and December 2021 from 18 centres. It assessed the comparative value of treatment strategies, including (1) recanalisation of native vessels, (2) endovascular treatment of the failed PBG, (3) hybrid treatment, and (4) open surgery. The primary outcome measure was amputation free survival (AFS, time to major amputation and/or death), whereas all-cause mortality, major amputation, PBG re-occlusion, target lesion revascularisation (TLR), and Rutherford category (RC) improvement during follow up were deemed as secondary endpoints. Results: Of 260 patients with occluded PBGs, 108 (41.5%) were treated endovascularly (24 [22.2%] by recanalisation of native vessels and 84 [77.7%] by PBG reopening), 57 (21.9%) underwent hybrid revascularisation, and 58 (22.3%) had surgery. In addition, 27 (10.4%) were treated conservatively and 10 (3.8%) received systemic thrombolysis. With a median follow up of 1.4 (0.6 - 3.0) years, AFS was 95.5%, 76.4%, 45.5%, and 37.1%, respectively in Groups 1 - 4 (p = .007). Older age and non-endovascular treatment (HR 1.05 and 1.70; p < .01 for both) were independent predictors of poor AFS. Endovascular treatment was associated with lower rates of major amputation (p = .04), PBG re-occlusion (p < .001), and TLR (p = .04), and higher RC improvements (p < .001), whereas all-cause mortality was comparable between treatment groups (p = .21). Conclusion: Endovascular treatment is associated with higher rates of AFS and RC improvement and lower rates of PBG re-occlusion and TLR in patients with PBG occlusion.
    • Are portable ankle brachial pressure index measurement devices suitable for hypertension screening?

      Janus, Justyna; Nicholls, Jennifer; Pallett, Edward; Bown, Matthew; Chung, Emma (2023-03-21)
      Objective: In a large-scale population cardiovascular screening programme, peripheral artery disease (PAD) and hypertension would ideally be rapidly assessed using a single device. The ankle-brachial pressure index (ABPI) is calculated by comparing the ankle and brachial blood pressure (BP). However, it is currently unclear whether brachial BP measurements provided by automated PAD screening systems are sufficiently accurate for simultaneous hypertension screening. Methods: Two portable PAD screening devices, the MESI ABPI MD and Huntleigh's Dopplex ABIlity, were evaluated following the European Society of Hypertension International Protocol (ESH-IP) Revision 2010 using a mercury-free sphygmomanometer as a reference device. Results: On average, the MESI slightly underestimated brachial systolic blood pressure (BP) with a bias and standard deviation (SD) of -3.5 (SD: 3.3) mmHg and diastolic BP with a bias of -1.5 (SD: 2.3) mmHg. For systolic BP estimates, the Dopplex was more accurate than the MESI with a lower bias of -0.5 (SD: 4.2) mmHg but less precise. The MESI successfully fulfilled all the requirements of the ESH-IP for hypertension screening. The Dopplex device failed the ESH-IP due to the absence of DBP measurements. Conclusions: The MESI device appears to be suitable for simultaneous PAD and hypertension screening as part of a preventative care programme. Huntleigh's Dopplex ABIlity failed to pass the ESH-IP validation test. Further clinical trials are underway to assess the use of the MESI for simultaneous screening for hypertension and PAD in a population screening setting.
    • Clinimetrics of performance-based functional outcome measures for vascular amputees: A systematic review

      Daynes, Enya; Houghton, John; Sayers, Robert; Pepper, Coral; Singh, Sally (2023-06-03)
      Background: Objective physical performance-based outcome measures (PerBOMs) are essential tools for the holistic management of people who have had an amputation due to vascular disease. These people are often non-ambulatory, however it is currently unclear which PerBOMs are high quality and appropriate for those who are either ambulatory or non-ambulatory. Research question: Which PerBOMs have appropriate clinimetric properties to be recommended for those who have had amputations due to vascular disease ('vascular amputee')? Data sources: MEDLINE, CINAHL, EMBASE, EMCARE, the Cochrane Library, Cochrane Central Register of Controlled Trials (CENTRAL) and Scopus databases were searched for the terms: "physical performance" or "function", "clinimetric properties", "reliability", "validity", "amputee" and "peripheral vascular disease" or "diabetes". Review methods: A systematic review of PerBOMs for vascular amputees was performed following COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) methodology and PRISMA guidelines. The quality of studies and individual PerBOMs was assessed using COSMIN risk of bias and good measurement properties. Overall PerBOM quality was evaluated with a modified GRADE rating. Key clinimetric properties evaluated were reliability, validity, predictive validity and responsiveness. Results: A total of 15,259 records were screened. Forty-eight studies (2650 participants) were included: 7 exclusively included vascular amputees only, 35 investigated validity, 20 studied predictive validity, 23 investigated reliability or internal consistency and 7 assessed responsiveness. Meta-analysis was neither possible nor appropriate for this systematic review in accordance with COSMIN guidelines, due to heterogeneity of the data. Thirty-four different PerBOMs were identified of which only 4 are suitable for non-ambulatory vascular amputees. The Amputee Mobility Predictor no Prosthesis (AMPnoPro) and Transfemoral Fitting Predictor (TFP) predict prosthesis use only. PerBOMs available for assessing physical performance are the One-Leg Balance Test (OLBT) and Basic Amputee Mobility Score (BAMS). Conclusion: At present, few PerBOMs can be recommended for vascular amputees. Only 4 are available for non-ambulatory individuals: AMPnoPro, TFP, OLBT and BAMS.
    • Defining quality assessment in vascular surgery training: an expert Delphi process

      McCarthy, Mark (2023-02-13)
      Introduction: A robust and reproducible way of assessing training should optimise and standardise vascular surgical training. This study describes the methodology supporting the Vascular Surgery Specialty Advisory Committee regional quality assurance reports for vascular surgery training programmes in the UK. Methods: A Delphi consensus exercise was performed to establish the domains of training that most appropriately assess the quality of a vascular surgery training programme. A total of 54 stakeholders were invited to participate, including trainees, training programme directors and members of the vascular speciality advisory committee (SAC), vascular society executive and education committees. Results: A total of 39 stakeholders successfully completed the three-stage Delphi process over 15 weeks. The domains identified as most appropriate to assess the quality of a vascular training programme were: Joint Committee on Surgical Training (JCST) survey results, clinical experience, regional education programmes, radiology support, timetable, regional support for trainees, trainer support for trainees, opportunities for professional development, trainee-rated quality of consultant teaching and training, and trainee recommendation of the post. Conclusions: This study describes a method to identify and prioritise domains that are appropriate to assess the quality of a vascular training programme. The domains that were identified as appropriate to assess quality are transferable internationally and the Delphi methodology could be used by other training schemes to 'fine-tune' their own domains to review and optimise the quality of their own training programmes.
    • Genetic risk score for intracranial aneurysms: Prediction of subarachnoid hemorrhage and role in clinical heterogeneity

      Bown, Matthew (2023-03)
      Background: Recently, common genetic risk factors for intracranial aneurysm (IA) and aneurysmal subarachnoid hemorrhage (ASAH) were found to explain a large amount of disease heritability and therefore have potential to be used for genetic risk prediction. We constructed a genetic risk score to (1) predict ASAH incidence and IA presence (combined set of unruptured IA and ASAH) and (2) assess its association with patient characteristics. Methods: A genetic risk score incorporating genetic association data for IA and 17 traits related to IA (so-called metaGRS) was created using 1161 IA cases and 407 392 controls from the UK Biobank population study. The metaGRS was validated in combination with risk factors blood pressure, sex, and smoking in 828 IA cases and 68 568 controls from the Nordic HUNT population study. Furthermore, we assessed association between the metaGRS and patient characteristics in a cohort of 5560 IA patients. Results: Per SD increase of metaGRS, the hazard ratio for ASAH incidence was 1.34 (95% CI, 1.20-1.51) and the odds ratio for IA presence 1.09 (95% CI, 1.01-1.18). Upon including the metaGRS on top of clinical risk factors, the concordance index to predict ASAH hazard increased from 0.63 (95% CI, 0.59-0.67) to 0.65 (95% CI, 0.62-0.69), while prediction of IA presence did not improve. The metaGRS was statistically significantly associated with age at ASAH (β=-4.82×10-3 per year [95% CI, -6.49×10-3 to -3.14×10-3]; P=1.82×10-8), and location of IA at the internal carotid artery (odds ratio=0.92 [95% CI, 0.86-0.98]; P=0.0041). Conclusions: The metaGRS was predictive of ASAH incidence, although with limited added value over clinical risk factors. The metaGRS was not predictive of IA presence. Therefore, we do not recommend using this metaGRS in daily clinical care. Genetic risk does partly explain the clinical heterogeneity of IA warranting prioritization of clinical heterogeneity in future genetic prediction studies of IA and ASAH.
    • Acute kidney injury in patients with acute type B aortic dissection

      Katsogridakis, Emmanuel; Saratzis, Athanasios (2022-10-20)
      Objective: Acute kidney injury (AKI) is common in patients with aortic diseases; however, it has not been extensively studied in acute type B aortic dissection (TBAD). AKI is known to be associated with adverse kidney outcomes and premature death. This study investigated the incidence and impact of AKI in patients with acute TBAD. Methods: This was a retrospective study including data from two tertiary vascular centres in the UK. Case notes and electronic records were reviewed for consecutive patients presenting with acute symptomatic TBAD. Patients were managed according to a uniform clinical protocol; both patients who underwent surgery and those managed conservatively were included in this analysis. Serum creatinine values were used to calculate the number of patients who developed AKI, based on validated Kidney Disease Improving Global Outcomes definitions. Associations between incidence of AKI, death, and Major Adverse Kidney Events (MAKE; defined as death, dialysis and/or drop in estimated glomerular filtration rate > 25%) were explored. Results: Overall, 66 (42.6%) of 155 patients developed AKI within one week of presenting with TBAD. Of these, 23 patients (34.8%) had stage 1, 26 patients (39.4%) stage 2, and 17 patients (25.8%) stage 3 AKI. MAKE at 30 and 90 days occurred in 17 (11.0%) and 12 patients (7.7%), respectively. AKI was associated with significantly worse outcomes, with a 24.2% mortality rate in the AKI group compared with 7.8% among those with no AKI (p <.001); this association was also significant in adjusted analyses, both in patients who did and did not undergo surgery. Conclusion: AKI is very common among patients presenting with acute TBAD, even in clinically uncomplicated disease. There was a significant association with mortality and MAKE, whether patients underwent surgery or not. This warrants further investigation to better understand the underlying causes of the AKI and investigate management strategies which may improve outcomes.
    • 50 Shades of 'Groundhog Day'

      Naylor, Ross (2022-08-23)
      Introduction: The 2017 European Society for Vascular Surgery (ESVS) guidelines on carotid and vertebral artery disease concluded that the evidence did not support a role for carotid endarterectomy (CEA) or carotid artery stenting (CAS) in patients with asymptomatic carotid stenosis (ACS) in preventing cognitive impairment or dementia. What new data have emerged since 2017, and have they influenced the 2023 ESVS guidelines? Report: In a systematic review, 33/35 studies (94%) reported a "significant association" between ACS and cognitive impairment; 20 studies had 1-3 tests with significant cognitive impairment; 10 reported 4-6 tests with cognitive impairment; and three studies reported ≥7 tests with significant cognitive impairment. Baseline data from 1 000 patients with ACS in the second Carotid Revascularisation Endarterectomy versus Stenting Trial (CREST-2) reported that the overall Z score for cognition in patients with ACS was significantly lower than expected, especially for word list recall and word list learning. Another systematic review reported that (in the long term) 69% of patients with ACS undergoing CEA/CAS had no change in cognitive function. However, in another 25%, cognitive scores/domains were mostly unchanged, but 1-2 individual tests were significantly improved. In addition, 1 601 UK and Swedish patients with ACS were randomised in the first Asymptomatic Carotid Surgery Trial (ACST-1) to CEA or best medical therapy (BMT). There was no difference in 10 year rates of dementia (CEA 6.7% vs. 6.6% with BMT) or at 20 years (14.3% [CEA] vs. 15.5% [BMT]), suggesting that CEA did not prevent dementia vs. BMT (hazard ratio 0.98, 95% confidence interval 0.75-1.28; p = .89). Discussion: ACS is associated with significant cognitive impairment, but whether this supports a direct aetiological role, or a marker for something else, remains unknown. There is no evidence that CEA/CAS prevents late dementia. The 2023 ESVS guidelines have not changed its recommendation compared with the 2017 version.
    • Different endovascular modalities of treatment for isolated atherosclerotic popliteal artery lesions (EMO-POP) registry

      Saratzis, Athanasios; Katsogridakis, Emmanuel (2022-08-04)
      Background: The mid-term results after treatment of isolated popliteal lesions have been limited. The aim of the present study was to report the mid-term outcomes after endovascular treatment of isolated atherosclerotic popliteal artery lesions. Methods: A multicenter (15 hospitals in five countries) retrospective cohort study was performed. Between June 2016 and June 2021, 651 consecutive patients who had been treated for isolated popliteal lesions using endovascular methods exclusively were included in the present study. Six techniques were identified, including plain balloon angioplasty (PTA; n = 286; 43.9%), drug-coated balloon angioplasty (n = 98; 15.1%), stenting with low-chronic outward force (COF) stents (n = 84; 12.9%), stenting with high-COF stents (n = 76; 11.7%), atherectomy alone (n = 17; 2.6%), and directional atherectomy with drug-coated balloons (n = 90; 13.8%). The primary outcomes measures were primary and secondary patency and freedom from clinically driven target lesion revascularization (F-CDTLR). Results: The mean patient age was 74.5 years. Most of the patients (n = 409; 62.9%) had had chronic limb-threatening ischemia. Popliteal occlusion was found in 400 cases (61.4%). High-grade calcification was present in 36.7% of cases. Immediate technical success was 94.8%. The median follow-up was 26 months (range, 6-42 months). The actuarial rate for all patients at 26 months (per outcome measure) was as follows: primary patency, 73.9%; secondary patency, 88%; and F-CDTLR, 76.5%. When comparing PTA vs all other treatments in an adjusted regression analysis, the F-CDTLR was 75.2% for PTA vs 76.5% for all other treatment (hazard ratio, 1.06; 95% confidence interval, 0.75-1.48; P = .46, adjusted regression). The difference in secondary patency also was not statistically significant (85.7% for PTA vs 88%; P = .20). Adjusted Kaplan-Meier analysis revealed that the estimated primary patency was inferior for PTA in pairwise comparisons vs other treatments (P < .001 vs atherectomy; P = .002 vs directional atherectomy with drug-coated balloons; and P = .002 vs low-COF stenting). Conclusions: The results from our study have shown that endovascular treatment of isolated popliteal lesions is safe and associated with acceptable patency and F-CDTLR in the mid-term.
    • PHACTR1 modulates vascular compliance but not endothelial function: a translational study

      Wood, Alice; Marsh, Anna-Marie; Sian, Manjit; Meisuria, Mitul; McCann, Gerry; Adlam, David (2022-06-02)
      Introduction: The non-coding locus at 6p24 located in intron 3 of PHACTR1 has consistently been implicated as a risk allele in myocardial infarction and multiple other vascular diseases. Recent murine studies have identified a role for Phactr1 in the development of atherosclerosis. However, the role of PHACTR1 in vascular tone and in vivo vascular remodelling has yet to be established. The aim of this study was to investigate the role of PHACTR1 in vascular function. Methods and results: Prospectively recruited coronary artery disease (CAD) patients undergoing bypass surgery and retrospectively recruited spontaneous coronary artery dissection (SCAD) patients and matched healthy volunteers were genotyped at the PHACTR1 rs9349379 locus. We observed a significant association between the PHACTR1 loci and changes in distensibility in both the ascending aorta (AA = 0.0053 ± 0.0004, AG = 0.0041 ± 0.003, GG = 0.0034 ± 0.0009, P < 0.05, n = 58, 54 and 7 respectively) and carotid artery (AA = 12.83 ± 0.51, AG = 11.14 ± 0.38, GG = 11.69 ± 0.66, P < 0.05, n = 70, 65 and 18 respectively). This association was not observed in the descending aorta or in SCAD patients. In contrast, the PHACTR1 locus was not associated with changes in endothelial cell function with no association between the rs9349379 locus and in vivo or ex vivo vascular function observed in CAD patients. This finding was confirmed in our murine model where loss of Phactr1 on the pro-atherosclerosis ApoE-/- background did not alter ex vivo vascular function. Conclusion: In conclusion, we have shown a role for PHACTR1 in arterial compliance across multiple vascular beds. Our study suggests that PHACTR1 has a key structural role within the vasculature.
    • Effect of COVID-19 on outpatient services in patients with aortovascular disease: a UK multicentre study

      Roman, Marius (2022-05-31)
      Introduction: The SARS-CoV-2 coronavirus disease 2019 (COVID-19) pandemic has disrupted healthcare services worldwide. Outpatient services have necessarily been restructured to accommodate COVID-19 patients and to maintain social distancing measures. The aim of our study was to investigate how the COVID-19 pandemic has affected outpatient healthcare provision for patients with aortovascular disease. Methods: In this prospective study, a standardised proforma was circulated to seven aortic centres in the UK. Data on outpatient encounters were collected from March to July 2020. Captured data included demographic details, disease pattern, type of encounter (face-to-face, video or telephone), clinic outcome and availability of imaging. Results: A total of 632 patients were included in the study, including 164 (25.9%) new referrals. In this cohort, clinic settings have shifted towards remote consultations, with 424 (67.1%) patients undergoing telephone appointments. Over a third of new patients (34.8%) had a delay in diagnostic tests, which might be attributable to the indirect effects of COVID-19. A total of 102 (16.1%) patients were added to a surgical waiting list following clinic. Conclusions: To the best of our knowledge, this is the largest study of outpatient activity during the COVID-19 pandemic in patients with aortovascular disease. We demonstrate how the speciality has adapted to accommodate government-endorsed changes in healthcare provision, and question how COVID-19 may have affected access to diagnostics. Finally, we discuss how COVID-19 will affect patients added to surgical waiting lists.
    • Multimodal structural analysis of the human aorta: From valve to bifurcation

      Musto, Liam; Saratzis, Athanasios; Bown, Matthew (2022-03-25)
      Objective: The aims of the present study were to assess the relative proportion of collagen and elastin in the arterial wall and to evaluate the collagen microstructure from the aortic root to the external iliac artery. Methods: Arterial wall tissue samples sampled during post-mortem examination from 16 sites in 14 individuals without aneurysm disease were fixed and stained for collagen and elastin. Stained sections were imaged and analysed to calculate collagen and elastin content as a percentage of overall tissue area. Scanning electron microscopy was used to quantify the collagen microstructure at six specific arterial regions. Results: From the aortic root to the level of the suprarenal aorta, the percentages (area fractions) of collagen (ascending, descending, and suprarenal aorta respectively with 95% confidence interval [CI] 37.5%, 31.7 - 43.2; 38.9%, 33.1 - 44.7; 44.8%, 37.4 - 52.1) and elastin (43.0%, 37.3 - 48.8; 40.3%, 34.8 - 46.1; 32.4%, 25.2 - 39.6) in the aortic wall were similar. From the suprarenal aorta to the internal iliac arteries, the percentage of collagen increased (abdominal aorta, common and internal iliac arteries and external iliac artery respectively with 95% CI 50.6%, 42.7 - 58.7; 51.2%, 45.5 - 56.9; 49.2%, 42.0 - 56.4) reaching a double percentage for elastin (23.6%, 15.7 - 31.6; 20.8%, 15.1 - 26.5; 22.2%, 14.9 - 29.5). Mean collagen fibre diameter (MFD) and average segment length (ASL) were significantly larger in the external iliac artery (MFD 6.03, 95% CI 5.95 - 6.11; ASL 22.21, 95% CI 20.80 - 23.61) than in the ascending aorta (MFD 5.81, 5.72 - 5.89; ASL 19.47, 18.07 - 20.88) and the abdominal aorta (MFD 5.92, 5.84 - 6.00; ASL 21.10, 19.69 - 22.50). Conclusion: In subjects lacking aneurysmal disease, the aorta and iliac arteries are not structurally uniform along their length. There is an increase in collagen percentage and decrease in elastin percentage progressing distally along the aorta. Mean collagen fibre diameter and average segment length are larger in the external iliac artery, compared with the ascending and the abdominal aorta.
    • Effect of high-pain versus low-pain structured exercise on walking ability in people with intermittent claudication: meta-analysis

      Zaccardi, Francesco; Houghton, John; Pepper, Coral; Rayt, Harjeet; Sayers, Robert (2022-05-12)
      Background: The aim was to determine the comparative benefits of structured high-pain exercise, structured low-pain exercise, and usual-care control, to identify which has the largest effect on walking ability in people with intermittent claudication (IC). Methods: A network meta-analysis was undertaken to assess two outcomes: pain-free walking ability (PFWA) and maximal walking ability (MWA). Nine electronic databases were searched. Trials were included if they were: RCTS; involved adults with IC; had at least two of the following arms-structured low-pain exercise, structured high--pain exercise or usual-care control; and a maximal or pain-free treadmill walking outcome. Results: Some 14 trials were included; results were pooled using the standardized mean difference (MD). Structured low-pain exercise had a significant large positive effect on MWA (MD 2.23, 95 percent c.i. 1.11 to 3.35) and PFWA (MD 2.26, 1.26 to 3.26) compared with usual-care control. Structured high-pain exercise had a significant large positive effect on MWA (MD 0.95, 0.20 to 1.70) and a moderate positive effect on PFWA (0.77, 0.01 to 1.53) compared with usual-care control. In an analysis of structured low- versus high pain exercise, there was a large positive effect in favour of low-pain exercise on MWA (MD 1.28, -0.07 to 2.62) and PFWA (1.50, 0.24 to 2.75); however, this was significant only for PFWA. Conclusion: There is strong evidence in support of use of structured high-pain exercise, and some evidence in support of structured low-pain exercise, to improve walking ability in people with IC compared with usual-care control (unstructured exercise advice).
    • Vascular thrombosis in severe COVID-19 requiring extracorporeal membrane oxygenation: A multicenter study

      Brozik, Jan; Machin, Ruth; Das, Indrajeet (2022-04-01)
      Objectives: Coronavirus disease 2019 has been reported to be a prothrombotic condition; however, multicenter data comparing this with other viral pneumonias in those requiring extracorporeal membrane oxygenation are lacking. We conducted a multicenter study using whole-body CT to examine the prevalence, severity, and nature of vascular complications in coronavirus disease 2019 in comparison with patients with other viral pneumonias. Design: We analyzed whole-body CT scans for the presence of vascular thrombosis (defined as pulmonary artery thrombus, venous thrombus, systemic arterial thrombus, or end-organ infarct). The severity, distribution, and morphology of pulmonary artery thrombus were characterized. Competing risk cumulative incidence analysis was used to compare survival with discharge. Setting: Three centers of the English national extracorporeal membrane oxygenation service. Patients: Consecutive patients admitted with either coronavirus disease 2019 or noncoronavirus disease 2019 viral pneumonia admitted from January 2019. Interventions: None. Measurements and main results: One-hundred thirty-six patients (45.2 ± 10.6 yr old, 39/146 [27%] female) requiring extracorporeal membrane oxygenation support underwent whole-body CT scans at admission. Of these, 86 had coronavirus disease 2019 pneumonia, and 50 had noncoronavirus disease 2019 viral pneumonia. Vascular thrombosis was seen more often in patients with coronavirus disease 2019 (odds ratio, 12.9 [95% CI 4.5-36.8]). In those with coronavirus disease 2019, 57 (73%) demonstrated pulmonary artery thrombus or pulmonary perfusion defects. Eighty-two percent of thrombus exhibited emboli-like morphology. The location of pulmonary artery thrombus and parenchymal perfusion defects was only concordant in 30% of cases. The risk of mortality was higher in those with coronavirus disease 2019 compared with noncoronavirus disease 2019 pneumonia (χ2 = 3.94; p = 0.047). Mortality was no different in coronavirus disease 2019 patients with or without vascular thrombosis (χ2 = 0.44; p = 0.51). Conclusions: In patients who received extracorporeal membrane oxygenation, coronavirus disease 2019 is associated with a higher prevalence of vascular thrombosis compared with noncoronavirus disease viral pneumonias. The pattern of pulmonary vascular changes suggests concurrent embolic disease and small vessel disease. Despite this, vascular thrombosis was not linked to poorer short-term prognosis in those with coronavirus disease 2019.
    • Covered vs. bare metal stents in the reconstruction of the aortic bifurcation: Early and midterm outcomes from the COBRA European multicentre registry

      Saratzis, Athanasios; Davies, Robert (2022-03-22)
      Objective: To report outcomes following endovascular revascularisation for severe aorto-iliac occlusive disease (AIOD) using covered (CS) or bare metal (BMS) stent(s). Methods: This was a retrospective cohort study including patients who underwent treatment with CS or BMS for AIOD between November 2012 and March 2020 in 12 European centres. Outcome measures included death, freedom from target lesion revascularisation (TLR), major amputation, and major adverse cardiac and cerebrovascular events (MACCE). Results: Overall, 252 patients (53% males; mean age 65 ± 10 years) were included (102 with a bare metal and 150 with a covered aortic stent); 122 (48%) presented with chronic limb threatening ischaemia (CLTI). Severe arterial calcification was noted in > 65% of patients, 70% presented with Trans-Atlantic Societies Consensus (TASC) D lesions, 32% and 46% had aortic or iliac chronic total occlusion (CTO), respectively. Median follow up was 17 months (range 6 - 40; none lost to follow up). Median inpatient stay was two days (range two to four). During the first 30 days, two patients died (both with covered aortic stents, because of cardiovascular events), none required TLR, two (1%) patients had a major amputation (all presented with CLTI), and three (1%) had a MACCE. At 17 months, mortality (BMS 14% vs. CS 7%, hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.42 - 2.26, p = .94, log rank test) and TLR (11% vs. 10%, HR 1.98, 95% CI 0.89 - 4.43, p = .095) did not differ statistically significantly between the two groups; only three patients had a major limb amputation during late follow up (all with a covered stent). In a multivariable model, the use of an aortic CS did not influence TLR. In a conditional Cox regression, however, the concomitant use of aortic and iliac CSs was associated with improved freedom from TLR. Conclusion: Endovascular reconstruction with aortic CSs or BMSs for severe AIOD showed comparable midterm performance. The use of both aortic and iliac CSs seems to be associated with reduced TLR.
    • Comorbidities and outcomes in South Asian individuals with chronic kidney disease: an observational primary care cohort

      Major, Rupert; Medcalf, James; Xu, Gang; Brunskill, Nigel (2021-01-13)
      Background: South Asian (SA) individuals are more likely to develop end-stage renal disease (ESRD), but how chronic kidney disease (CKD) differs in relation to demographics, comorbidities and outcomes has not been studied. We aimed to study differences in SA individuals with CKD compared with White individuals. Methods: This was an observational CKD cohort comparing SA with White individuals. Inclusion criteria were ≥18 years of age and two or more Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFRs <60 mL/min/1.73 m2 >3 months apart. Individuals with ESRD at baseline were excluded. Baseline characteristics, including eGFR formulae [CKD-EPI and CKD-EPI-Pakistan (CKD-EPI-PK)], were compared. Analysis using competing risk regression for cardiovascular (CV) and ESRD events and Cox proportional hazard model for mortality was performed. Results: From an adult population of 277 248 individuals, 17 248 individuals had CKD, of whom 1990 (11.5%) were of SA ethnicity. Age-adjusted prevalence of CKD was similar between ethnicities. SA individuals were more likely to be male, younger and socioeconomically deprived, and to have diabetes mellitus, CV disease and advanced CKD. Mean CKD-EPI-PK eGFR was 6.5 mL/min/1.73 m2 lower (41.1 versus 47.6, 95% confidence interval for difference 6.47-6.56) than for CKD-EPI. During 5 years of follow-up, 5109 (29.6%) individuals died, 2072 (12.0%) had a CV and 156 (0.90%) an ESRD event. Risk for SA individuals was higher for ESRD, similar to CV events and lower for mortality. Each 1 mL/min/1.73 m2 decrease in CKD-EPI-PK was associated with a 13.1% increased ESRD risk (adjusted subdistribution hazard ratio 0.869, 95% confidence interval 0.841-0.898). Conclusions: SA individuals with CKD were younger and had more advanced disease than White individuals. Risk of ESRD was higher and CKD-EPI-PK was associated with ESRD risk in SA individuals. Specific CKD interventions, including the use of CKD-EPI-PK, should be considered in SA populations.
    • Selecting portable ankle/toe brachial pressure index systems for a peripheral arterial disease population screening programme: a systematic review, clinical evaluation exercise, and consensus process

      Patel, Bhavisha; Katsogridakis, Emmanuel; Pepper, Coral; Messeder, Sarah; Saratzis, Athanasios; Nicholls, Jennifer; Bown, Matthew (2022-08-12)
      Objective: To provide an overview of systems available for peripheral arterial disease (PAD) screening, together with respective accuracies and a clinical evaluation to identify a system suitable for use in a community screening programme. Methods: A systematic review of the diagnostic accuracy of six ankle brachial pressure index (ABPI) and toe brachial pressure index (TBPI) devices deemed to be portable, which were Conformité Européenne (CE) marked, and were automated or semi-automated was carried out compared with gold standard handheld Doppler and duplex ultrasound. The devices were MESI-ABPI-MD, Huntleigh Dopplex Ability, Huntleigh ABPI and TBPI systems, Systoe TBPI system, and BlueDop. Seven databases (MEDLINE, EMBASE, Scopus, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Register of Controlled Trials (CENTRAL), and Cumulative Index to Nursing and Allied Health Literature (CINAHL)) were searched, and 11 studies were identified as eligible for review. This was followed by hands on clinical evaluation by abdominal aortic aneurysm (AAA) screening staff (n = 39). During this, devices were demonstrated to staff which they then tested on volunteers and gave feedback using pre-designed questionnaires on their suitability for use in a screening programme. Finally, accuracy data and staff preferences were combined during a consensus conference that was held between study and screening staff to determine the most appropriate device to use in a community screening programme. Results: Generally, the evaluated systems have a moderate level of sensitivity and a high level of specificity: Dopplex ability sensitivity 20% - 70%, specificity 86% - 96%; MESI sensitivity 57% - 74%, specificity 85% - 99%; BlueDop sensitivity 95%, specificity 89%; and Systoe sensitivity 71%, specificity 77%. Clinical evaluation by screening staff identified a preference for the MESI system. The consensus conference concluded that the MESI device was a good candidate for use in a community PAD screening programme. Conclusion: The MESI system is a good candidate to consider for community PAD screening.