Objectives:This cross-sectional study aimed to individually and cumulatively compare sensitivity and specificity of the (1) ankle brachial index and (2) pulse volume waveform analysis recorded by the same automated device, with the presence or absence of peripheral arterial disease being verified by ultrasound duplex scan.Methods:Patients (n=205) referred for lower limb arterial assessment underwent ankle brachial index measurement and pulse volume waveform recording using volume plethysmography, followed by ultrasound duplex scan. The presence of peripheral arterial disease was recorded if ankle brachial index <0.9; pulse volume waveform was graded as 2, 3 or 4; or if haemodynamically significant stenosis >50% was evident with ultrasound duplex scan. Outcome measure was agreement between the measured ankle brachial index and interpretation of pulse volume waveform for peripheral arterial disease diagnosis, using ultrasound duplex scan as the reference standard.Results:Sensitivity of ankle brachial index was 79%, specificity 91% and overall accuracy 88%. Pulse volume waveform sensitivity was 97%, specificity 81% and overall accuracy 85%. The combined sensitivity of ankle brachial index and pulse volume waveform was 100%, specificity 76% and overall accuracy 85%.Conclusion:Combining these two diagnostic modalities within one device provided a highly accurate method of ruling out peripheral arterial disease, which could be utilised in primary care to safely reduce unnecessary secondary care referrals.

BackgroundPeripheral arterial disease (PAD) is a marker of systemic atherosclerosis and associated with a three to six fold increased risk of death from cardiovascular causes. Furthermore, it is typically asymptomatic and under-diagnosed; this has resulted in escalating calls for the instigation of Primary Care PAD screening via Ankle Brachial Index (ABI) measurement. However, there is limited evidence regarding the feasibility of this and if the requisite core skills and knowledge for such a task already exist within primary care. This study aimed to determine the current utility of ABI measurement in general practices across Wales, with consideration of the implications for its use as a cardiovascular risk screening tool.MethodA self-reporting questionnaire was distributed to all 478 General Practices within Wales, sent via their responsible Health Boards.ResultsThe survey response rate was 20%. ABI measurement is primarily performed by nurses (93%) for the purpose of wound management (90%). It is infrequently (73% < 4 times per month) and often incorrectly used (42% out of compliance with current ABI guidance). Only 52% of general practitioners and 16% of nurses reported that patients with an ABI of ≤ 0.9 require aggressive cardiovascular disease risk factor modification (as recommended by current national and international guidelines).ConclusionABI measurement is an under-utilised and often incorrectly performed procedure in the surveyed general practices. Prior to its potential adoption as a formalised screening tool for cardiovascular disease, there is a need for a robust training programme with standardised methodology in order to optimise accuracy and consistency of results. The significance of a diagnosis of PAD, in terms of associated increased cardiovascular risk and the necessary risk factor modification, needs to be highlighted.

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BackgroundEarly identification of peripheral arterial disease (PAD) and subsequent instigation of risk modification strategies could minimise disease progression and reduce overall risk of cardiovascular (CV) mortality. However, the feasibility and value of primary care PAD screening is uncertain.AimThis study (the PIPETTE study — Peripheral arterial disease In Primary carE: Targeted screening and subsequenT managEment) aimed to determine the value of a proposed primary care PAD screening strategy. Outcomes assessed were: prevalence of PAD and agreement of ankle– brachial index (ABI)-defined PAD (ABI ≤0.9) with QRISK®2-defined high CV risk (≥20).Design and settingA cross-sectional observational study was undertaken in a large general practice in Merthyr Tydfil, Wales.MethodIn total, 1101 individuals with ≥2 pre-identified CV risk factors but no known CV disease or diabetes were invited to participate. Participants underwent ABI measurement and QRISK2 assessment, and completed Edinburgh Claudication Questionnaires.ResultsA total of 368 people participated in the study (participation rate: 33%). Prevalence of PAD was 3% (n = 12). The number needed to screen (NNS) to detect one new case of PAD was 31. Refining the study population to those aged ≥50 years with a smoking history reduced the NNS to 14, while still identifying 100% of PAD cases. Of participants with PAD, 33% reported severe lifestyle-limiting symptoms of intermittent claudication that warranted subsequent endovascular intervention, yet had not previously presented to their GP. The QRISK2 score predicted high CV risk in 92% of participants with PAD.ConclusionThe low PAD yield and the fact that QRISK2 was largely comparable to the ABI in predicting high CV risk suggests that routine PAD screening may be unwarranted. Instead, strategies to improve public awareness of PAD are needed.

The ankle-brachial index is widely regarded as a pivotal tool for the diagnosis and quantification of peripheral arterial disease. It is, however, plagued by issues relating to its time consuming nature and the skills required to undertake its measurement using the gold standard Doppler ultrasound method. Automated ankle-brachial index measurement devices aim to address such issues; this study aimed to compare the performance of such a device with the Doppler method. Three hundred and eighty participants, with risk factors for cardiovascular disease (mean age: 64, 57% male), underwent ankle-brachial index measurement firstly with a plethysmographic device followed by the Doppler method. The mean difference between the two methods was 0.016±0.1, 95% limits of agreement:±0.2. Sensitivity for detection of peripheral arterial disease, as defined by Doppler ankle-brachial index⩽0.9, was 70%, specificity 96%, accuracy 94%. A receiver operating curve revealed an area under the curve of.96, with a 1.04 plethysmographic ankle-brachial index cutoff for optimal sensitivity (98%) and specificity (75%). Automated measurements were significantly faster than Doppler measurements (7 min 55 s vs. 17 min 45 s, respectively, P <0.01). Although is it unclear if the plethysmographic device has sufficient diagnostic accuracy to be used as a stand alone test for the diagnosis of peripheral arterial disease, it is concluded that it can be used as a fast and amenable method of identifying people who require further arterial assessment; the higher cutoff point of 1.04 should be used for this purpose.