Longitudinal Associations between Changes in Inter-Ankle SBP Difference and Cardiovascular Events and Mortality in the ARIC Study.

Background: Large inter-ankle systolic blood pressure (IASBP) differences (≥10 or ≥15 mmHg) have been linked to cardiovascular events and mortality. This longitudinal study evaluated the association of changes in IASBP differences with incident cardiovascular events and mortality.

Methods: In the Atherosclerosis Risk in Communities study, bilateral ankle blood pressure was measured at Visit 5 and at Visit 6/7 (n = 2051; mean age 73.7 ± 4.3 years). Participants were categorized into four groups by IASBP differences: small at both visits (<10 mmHg); decreasing (≥10 mmHg at Visit 5 but <10 mmHg in Visit 6/7); increasing (<10 mmHg at Visit 5 but ≥10 mmHg in Visit 6/7); and large at both visits (≥10 mmHg). Categories were repeated using a ≥15 mmHg cutoff value. Cox proportional hazards regression models were used to calculate hazard ratios (HRs).

Results: In adjusted analyses, individuals with increasing differences (≥10 mmHg) had higher risks of heart failure (HR: 1.31; 95% confidence intervals [CI], 1.00-1.76) and stroke (HR: 1.57; 95% CI, 1.16-2.11), compared to those with small differences at both visits. Similarly, those with persistently large differences showed elevated risks of coronary heart disease (HR: 2.25; 95% CI, 1.46-3.47) and stroke (HR: 1.68; 95% CI, 1.17-2.41). Analyses using a ≥15 mmHg cutoff value demonstrated even stronger associations with all three cardiovascular events. No significant associations were observed with all-cause or cardiovascular mortality for these categories.

Conclusions: Increasing and persistently large IASBP differences are associated with elevated risk of incident cardiovascular events. Monitoring IASBP differences may help identify individuals at higher risk for adverse outcomes.