Objective/BackgroundBiomarker(s) for prediction of the future progression rate of abdominal aortic aneurysms (AAA) may be useful to stratify the management of individual patients. AAAs are associated with features of systemic inflammation and endothelial dysfunction. Flow mediated dilatation (FMD) of the brachial artery is a recognised non-invasive measurement for endothelial function. We hypothesised that FMD is a potential biomarker of AAA progression and reflects the temporal changes of endothelial function during AAA progression.MethodsIn a prospectively recruited cohort of patients with AAAs (Oxford Abdominal Aortic Aneurysm Study), AAA size was recorded by antero-posterior diameter (APD) (outer to outer) on ultrasound. Annual AAA progression was calculated by (ΔAPD/APD at baseline)/(number of days lapsed/365 days). FMD was assessed at the same time as AAA size measurement. Analyses of data were performed in the overall cohort, and further in subgroups of AAA by size (small: 30–39 mm; moderate: 40–55 mm; large: > 55 mm).ResultsFMD is inversely correlated with the diameter of AAAs in all patients (n = 162, Spearman’s r = −.28, p < .001). FMD is inversely correlated with AAA diameter progression in the future 12 months (Spearman’s r = −.35, p = .001), particularly in the moderate size group. Furthermore, FMD deteriorates during the course of AAA surveillance (from a median of 2.0% at baseline to 1.2% at follow-up; p = .004), while surgical repair of AAAs (n = 50 [open repair n = 22, endovascular repair n = 28)] leads to an improvement in FMD (from 1.1% pre-operatively to 3.8% post-operatively; p < .001), irrespective of the type of surgery.ConclusionFMD is inversely correlated with future AAA progression in humans. FMD deteriorates during the natural history of AAA, and is improved by surgery. The utility of FMD as a potential biomarker in the context of AAA warrants further investigation.
ObjectiveAccurate prediction of abdominal aortic aneurysm (AAA) growth in an individual can allow personalised stratification of surveillance intervals and better inform the timing for surgery. The authors recently described the novel significant association between flow mediated dilatation (FMD) and future AAA growth. The feasibility of predicting future AAA growth was explored in individual patients using a set of benchmark machine learning techniques.MethodsThe Oxford Abdominal Aortic Aneurysm Study (OxAAA) prospectively recruited AAA patients undergoing the routine NHS management pathway. In addition to the AAA diameter, FMD was systemically measured in these patients. A benchmark machine learning technique (non-linear Kernel support vector regression) was applied to predict future AAA growth in individual patients, using their baseline FMD and AAA diameter as input variables.ResultsProspective growth data were recorded at 12 months (360 ± 49 days) in 94 patients. Of these, growth data were further recorded at 24 months (718 ± 81 days) in 79 patients. The average growth in AAA diameter was 3.4% at 12 months, and 2.8% per year at 24 months. The algorithm predicted the individual's AAA diameter to within 2 mm error in 85% and 71% of patients at 12 and 24 months.ConclusionsThe data highlight the utility of FMD as a biomarker for AAA and the value of machine learning techniques for AAA research in the new era of precision medicine.
Objectives Our centre offers a fast-track assessment service for patients with suspected giant cell arteritis (GCA) and this service continued to operate during the Covid-19 pandemic. During and immediately following the peak of the Covid-19 pandemic in the UK we observed an increase the number of patients diagnosed with GCA plus an increased number of patients with visual complications. Our aim was to investigate this further. Methods The electronic medical records of all patients referred for GCA fast-track assessment from January 2019 were reviewed. A complete list of patients undergoing temporal artery ultrasound and temporal artery biopsy for investigation of GCA, dating back to 2015, was also available. Results In the 12-week period between April and June 2020 24 patients were diagnosed with GCA. Six (25%) had associated visual impairment. In contrast during 2019, 28 new diagnoses of GCA were made in total, and just 10% of patients suffered visual involvement. The number of patients diagnosed with GCA in April-June 2020 was nearly 5-fold that of the same time period the previous year. GCA diagnoses between April and June 2020 were supported by imaging (temporal artery ultrasound or CT-PET) in 72% of cases. We noted a higher proportion of male patients and a lower median age but no clear difference in duration of symptom onset prior to assessment. Conclusions The reasons behind our observations remain unclear however our findings support the viral aetiopathogenesis hypothesis for GCA and demonstrate the importance of maintaining access to urgent rheumatology services during periods of healthcare disruption.
BackgroundThe epidemiology of abdominal aortic aneurysm (AAA) is changing. Outcomes for aortic surgery have improved. However, the accepted guideline for the management of AAAs has remained unchanged over the last 2 decades. We aimed to gain insight into the patients’ experience while they are managed under the traditional clinical pathway.MethodWith the help of a patient focus group, we designed a survey to assess the patients’ perception of the disease and their experience during different stages of the AAA clinical care pathway (surveillance, perioperative care, postoperative follow-up). An invitation to participate in the survey was sent to all patients with AAA who were receiving care at the Oxford Regional Vascular Services Unit, part of the Oxford University Hospitals NHS Trust.ResultsWe received 194 responses from patients with AAA. One hundred seventy-seven were male, with a median age of 75 to 79 years. Just over a third had undergone surgery already, and the remaining 63% were either in surveillance or awaiting surgery. Their experience during the AAA management pathway was mostly positive. Of the issues that were most important to them in terms of their medical care, the provision of explanation and regularity of monitoring stood out as the most common considerations.ConclusionPatients are generally satisfied with the care they received, but there is room for improvement. They have also highlighted key areas that are most important to them in terms of their medical care. These should guide the future direction for quality improvement and research.
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