Relationship of ankle blood pressures to cardiovascular events in older adults.

BACKGROUND AND PURPOSE Low values of ankle-arm systolic blood pressure ratio predict mortality and cardiovascular events. High values, associated with arterial calcification, also carry risk for mortality. We focus on the extent to which low and high ankle-arm index values as well as noncompressible arteries are associated with mortality and cardiovascular events, including stroke in older adults. METHODS We followed 2886 adults aged 70 to 79 for a mean of 6.7 years for vital status and cardiovascular events (coronary heart disease, stroke, and congestive heart failure). RESULTS Normal ankle-arm index values of 0.91 to 1.3 were found in 80%, low values of 1.3 were obtained in 5%, and noncompressible arteries were found in 2% of the group. Increased mortality was associated with both low and high ankle-arm index values beginning at levels of <1.0 or >or=1.4. Subjects with low ankle-arm index values or noncompressible arteries had significantly higher event rates than those with normal ankle blood pressures for all end points. For coronary heart disease, hazard ratios associated with a low ankle-arm index, high ankle-arm index, and noncompressible arteries were 1.4, 1.5, and 1.7 (P<0.05 for all) after controlling for age, gender, race, prevalent cardiovascular disease, diabetes, and major cardiovascular risk factors. Noncompressible arteries carried a particularly high risk of stroke and congestive heart failure (hazard ratio=2.1 and 2.4, respectively). CONCLUSIONS Among older adults, low and high ankle-arm index values carry elevated risk for cardiovascular events. Noncompressible leg arteries carry elevated risk for stroke and congestive heart failure specifically.