Prevalence of peripheral artery disease varies significantly depending upon the method of calculating ankle brachial index.

OBJECTIVE

Peripheral artery disease (PAD) identifies individuals at high risk for future cardiovascular disease (CVD) warranting aggressive risk reduction therapies. PAD can be diagnosed noninvasively by calculating the ankle brachial index (ABI), a ratio of ankle and arm blood pressures. We examined the existing various methods of calculating ABI and the resulting estimates of PAD prevalence.

METHODS

We analyzed data from three National Health and Nutrition Examination Surveys. PAD prevalence using three different methods of calculating ABI was determined in 5,376 participants, aged > or =40 years without prior history of CVD. ABI was defined as an ankle brachial index of less than 0.9. Statistical analysis was performed using SPSS V15.0.

RESULTS

PAD prevalence among asymptomatic adults without CVD increased significantly during the 6-year time period (1999-2004), regardless of the method used for determining ABI. However, across the National Health and Nutrition Examination Survey assessments, ABI method significantly affected calculated PAD prevalence. Differences in calculated PAD prevalence correspond to approximately 2.2 million persons who would be reclassified as having or not having PAD.

CONCLUSION

The calculated prevalence of asymptomatic PAD varies significantly by the ABI method used. Further study is required to determine the most accurate method of performing ABI.