Improved Prediction of Fatal Myocardial Infarction Using the Ankle Brachial Index in Addition to Conventional Risk Factors

Abstract

Background-Prediction of major cardiovascular and cerebrovascular events using conventional risk factor models is limited. Noninvasive measures of subclinical atherosclerosis such as the ankle brachial index (ABI) could improve risk prediction and provide more focused primary prevention strategies. We wished to determine the added value of a low ABI in the prediction of long-term risk of cardiovascular and cerebrovascular events and death. Methods and Results-In 1988, 1592 men and women 55 to 74 years of age were randomly selected from the age-sex registers of 11 general practices in Edinburgh, Scotland, and followed up over a period of 12 years for incident events. After adjustment for age and sex, an ABI Յ0.9 was predictive of an increased risk of fatal myocardial infarction (MI), cardiovascular death, all-cause death, combined fatal and nonfatal MI, and total cardiovascular events. After further adjustment for prevalent cardiovascular disease, diabetes, and conventional risk factors, a low ABI was independently predictive of the risk of fatal MI. Addition of the ABI significantly (PՅ0.01) increased the predictive value of the model for fatal MI compared with a model containing risk factors alone. Comparison of areas under receiver operator characteristic curves confirmed that a model including the ABI discriminated marginally better than one without. Conclusions-Addition of the ABI significantly improved prediction of fatal MI over and above that of conventional risk factors. We recommend that the ABI be incorporated into routine cardiovascular screening and that the potential of its inclusion into cardiovascular scoring systems (with a view to improving their accuracy) now be examined.

Aortic augmentation index is associated with the ankle-brachial index: A community-based study

“…An ankle-brachial index (ABI) <1.00 is therefore abnormal, although a cut off <0.90 or <0.95 has greater specificity and is used to make the diagnosis of peripheral arterial disease (PAD) in the clinical setting. ABI is a simple, noninvasive method used to assess the presence and extent of PAD [2], and prospective studies have shown that a low ABI predicts fatal and non fatal coronary heart disease (CHD) and all cause mortality [3][4][5][6][7][8][9].…”

Implications of routinely measuring Ankle-Brachial Index (ABI) among patients attending at a Lipid Clinic

“…Although some have recently proposed to screen non invasively in a systematic way men aged 45-75 and women aged 55-75 for subclinical atherosclerosis [28], screening of subclinical atherosclerosis on a population-wide basis should be discouraged [18]. As expected, prevalence of PAD in this selected sample of asymptomatic subjects referred to a Lipid Clinic for CV risk stratification is slightly higher than that reported in population-based surveys [15], [29] and [30], but in keeping with that reported in individuals with diabetes within population-based studies [31]. Although the sample investigated was derived from a single Lipid Clinic in northern Italy, use of the SCORE model should allow an easy comparison with other primary prevention settings of care within and outside our country.…”

“…Low ABI values were originally used to identify PAD; however they have subsequently been shown to be an accurate and reliable marker of generalized atherosclerosis and increased risk of CV morbidity and mortality [10], [11] and [12]. Moreover, it has been shown that a low ABI is better at predicting risk of future cardiovascular and cerebrovascular events than conventional risk factors alone [26], and that addition of the ABI significantly improves prediction of CHD mortality over and above conventional risk factors [15]. Although there is yet no evidence that better risk prediction through ABI measurement may translate into reduced incidence of CV events or longer survival, it is reasonable to infer that aggressive treatment for higher risk patients identified by low ABI values irrespective of conventional risk prediction might provide additional benefit in primary prevention of CV events.…”

“…Moreover, a 50% 10-year mortality risk in these patients, mainly for CV fatal events, has been reported in several studies [11] and [12]. Therefore, recent CV prevention guidelines have included PAD as a CHD risk equivalent and suggest measurement of ABI as a simple way to identify high-risk subjects, irrespective of conventional risk prediction models, for whom aggressive medical treatment is strongly recommended [13], [14] and [15]. However, ABI measurement is not routinely performed in most primary prevention setting, and there remains a widespread lack of awareness of these recommendations among healthcare professionals [16] and [17], even in selected primary prevention settings caring for moderate to high risk patients (such as Lipid, Hypertension or Diabetes Clinics) wherein ABI determination, accordingly with some clinical recommendations [18], is mostly performed as a second-line test in patients at intermediate risk.…”

Ankle and exercise blood pressures as predictors of coronary morbidity and mortality in a prospective follow-up study

“…Low values of ABI (o0.95) signal advanced peripheral artery disease and significantly elevated risk of a major cardiovascular disease (CVD) event. [1][2][3][4][5][6][7] Stenotic changes leading to abnormally low ABI are, however, relatively rare in middle-aged persons. 4,5 Furthermore, also elevated ABI (41.40) or high ABP may be associated with increased risk, although the literature is somewhat conflicting.…”