The prevalence of symptomatic leg ischaemia (SLI) was studied using a standardised postal questionnaire and by measuring ankle systolic blood pressure among those with leg pain. All individuals, aged 50–89 years, of both sexes (n = 2748) in a community of 7524 inhabitants were included. The overall questionnaire response rate was 92%, of whom 441 (17%) reported any form of leg pain. Ankle systolic blood pressure (ASBP) was measured in 353 (80%) of those. Ankle/brachial index (ABI) ⩽0.8 was chosen as the criterion for verified SLI. One hundred and seven (30%) had a verified SLI (ABI ⩽0.8).Hospital records could be reviewed in 83% of the non-responders, and revealed corresponding distributions of risk factors among the non-responders and the questionnaire-responders. Risk factor frequencies among ASBP-examined and not examined individuals were also comparable. The overall prevalence of SLI in the age 50–89 years was 4.1%, ranging from 1.5% in the age decade of 50–59 years, to maximum 7.1% in the decade 70–79 years. A slight but not significant male predominance was recorded, except for the age decade 70–79 years. The prevalence of SLI in the whole community population was approximately 2000/100 000 of which 5% were possible candidates for vascular intervention.

Objective:

To quantify cardiovascular morbidity and mortality including the incidence of vascular surgery and amputations, among individuals with symptomatic leg ischaemia.

Design:

Prospective cohort study.

Material:

Inhabitants 50–89 years of age (n = 2784) of Vadstena community, Östergötland, Sweden, with 4 years of follow-up. 107 subjects with symptomatic leg ischaemia (SLI), selected by a postal questionnaire and ankle pressure measurements, and an age and sex matched control group of 214 individuals.

Chief outcome measures:

Cardiovascular morbidity and mortality, all cause mortality, surgical procedures for leg ischaemia, major amputations, ankle brachial pressure index.

Main results:

Age and sex adjusted all-cause mortality risk in the SLI-group was increased by 1.9. This was most prominent among men in their sixties and women in their seventies. Cardiovascular mortality was increased by 1.9 (95% confidence interval 1.1–3.3). Relative risks for acute myocardial infarction and cerebrovascular events were 2.4 (1.1–5.1) and 1.7 (0.9–3.2), respectively. The increase in age and sex adjusted incidence of primary reconstructive surgery during the first year after initial examination was 67-fold compared to the total population of Vadstena 50–89 years old, and 18-fold for the whole observation period, while the increase in risk for major amputation during the observation period was 12-fold. Median ankle brachial index improved significantly during follow-up among the individuals alive and not subjected to vascular surgery.

Conclusions:

Among the SLI-subjects identified in a general population, the overall risk for cardiovascular morbidity and mortality over 4 years was significantly increased compared to normals.

Objective: to study the association between the ankle–brachial pressure index (ABPI), premature death and the need for surgical treatment for lower limb ischaemia.

Design: population based cohort study.

Subjects: three hundred and fifty-three men and women, 50–89 years old, underwent a leg pain questionnaire and measurement of ABPI and was then followed for 10 years.

Outcome Measures: all cause mortality, vascular procedures and major amputations.

Results: a low ABPI was independently associated with premature all cause mortality in the multiple regression analysis, carrying a relative risk of 3.4 (95% confidence interval 2.0–5.9) and 2.1 (1.3–3.3) for ABPIs ≤0.50 and 0.51–0.80, respectively, compared to those with ABPI ≥1.0. Individuals with an ABPI in the interval 0.81–0.99 suffered only a slight, not statistically significant risk increase compared to normals. A low ABPI at baseline implied a continuous constant increased risk of death throughout the study period. The same risk was observed among elderly (70–89, median 77 years), and in the middle aged (50–69, median 63 years) individuals. The vast majority of those subjected to vascular intervention or major amputation during follow-up had an ABPI≤0.8 at baseline (83 and 89%, respectively). However, within that group, the individual ABPI was not predictive for surgical intervention.

Conclusion: the association found between an ABPI ≤0.8 and premature mortality in this cohort of symptomatic subjects implies that the ABPI is a powerful, independent predictor for premature death. The prognostic information carried by an ABPI in the interval 0.81–0.99 remains uncertain. Septuagenarians and octogenarians carry the same risk increase associated with a low ABPI as those in the middle ages.

The objective of the study was to evaluate the validity of oscillometric systolic ankle pressure in symptomatic leg arterial occlusive disease. Ankle pressure measurements using oscillometric curves obtained using a standard 12-cm cuff with a specially designed device for signal processing were validated against the continuous wave (CW) Doppler technique. Thirty-four subjects without signs or symptoms of peripheral vascular disease (68 legs) and 47 patients with leg ischaemia (85 legs) varying from moderate claudication to critical ischaemia were examined. The oscillometric curves were analysed using several algorithms reported in the literature, based on the assumption that maximum oscillations are recorded near mean arterial pressure. In normals, reasonable agreement between CW Doppler and oscillometric methods was seen. When an algorithm that determined the lowest cuff pressure at which maximum oscillations occurred, and a characteristic ratio for systolic pressure of 0·52 was used, the mean difference between CW Doppler and oscillometry was 1·7 mmHg [range −19 to +27, limits of agreement (2 SD) 21·1 mmHg]. In ischaemic legs, oscillometry overestimated systolic ankle pressure by a mean of 28·8 mmHg [range –126 to +65, limits of agreement 82·8 mmHg]. The difference was more pronounced among patients with critical ischaemia compared with claudicants, and also more evident among diabetics. The error of oscillometric pressure determination in subjects with leg arterial disease inversely increased with CW Doppler ankle pressure. In 39% of the recordings in legs with a CW Doppler systolic pressure below 100 mmHg, the oscillometric mean arterial pressure was higher than the recorded CW Doppler systolic pressure. In conclusion, the oscillometric method to determine systolic ankle pressure, based on the concept of maximum cuff oscillations occurring near mean arterial pressure, is not reliable in leg arterial disease, usually overestimating ankle pressure.

An automated method for ankle systolic pressure measurement, less operator dependent than the standard continuous wave (CW) Doppler technique, would imply an advantage both in patient measurements and in epidemiological studies. We present a new photoplethysmographic (PPG) probe that uses near-infrared light (880 nm) to detect pulsatory blood flow underneath the distal end of a standard pneumatic cuff. The probe is adapted to the anatomical conditions at the ankle, permitting recording of pressures in both ankle arteries separately. The validity of the equipment was tested with CW Doppler-derived systolic pressures and invasive blood pressure measurements for reference. In 20 healthy subjects, visual analysis of the PPG curves revealed a mean difference between CW Doppler and PPG measurements of –0.5 mmHg (SD 6.9). Corresponding results for the anterior and posterior tibial arteries separately were –1.8 mmHg (SD 6.2) and 0.9 mmHg (SD 7.3), respectively. A correct probe position was essential for the results. In direct recordings from the dorsalis pedis artery in 10 intensive care patients, PPG underestimated systolic pressure in the anterior tibial artery by 4.5 mmHg (SD 12.1). With further development, the PPG probe, integrated in the pneumatic cuff, may simplify measurements of ankle systolic pressures.

Objective

To evaluate a new technique using a photoplethysmographic (PPG) probe for automatic ankle pressure measurements.

Design

Comparative study on two techniques for ankle pressure measurement.

Setting

University hospital.

Material

Thirty-five patients with leg arterial disease and eight healthy volunteers. Ankle-brachial indices (ABPI) were measured using conventional CW Doppler technique and PPG-based prototype equipment for the ankle pressure recordings.

Chief outcome measures

ABPIs calculated from CW Doppler and PPG ankle pressure measurements. The PPG signals were analysed both by visual judgement and by a software based, automatic algorithm.

Main results

The mean difference between ABPIs calculated from CW Doppler recordings and PPG (visual analysis) was −0.01 (limits of agreement (±two standard deviations) +0.16 to −0.19). The correlation coefficient was 0.93. When the algorithm was used, the mean difference (CW Doppler−PPG) was 0.05 (limits of agreement 0.28 to −0.18, r=0.89).

Conclusions

The PPG method is a promising technique with an inherent potential for automatisation of the ankle pressure measurements, thereby reducing the observer-dependency in ABPI recordings.