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

Abstract

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.