Ankle-Brachial Index and Risk of Sudden Cardiac Death in the Community: The ARIC Study.

BACKGROUND: Sudden cardiac death (SCD) is a significant global public health problem accounting for 15% to 20% of all deaths. A great majority of SCD is associated with coronary heart disease, which may first be detected at autopsy. The ankle-brachial index (ABI) is a simple, noninvasive measure of subclinical atherosclerosis. The purpose of this study was to examine the relationship between ABI and SCD in a middle-aged biracial general population. METHODS AND RESULTS: Participants of the ARIC (Atherosclerosis Risk in Communities) study with an ABI measurement between 1987 and 1989 were included. ABI was categorized as low (≤0.90), borderline (0.90-1.00), normal (1.00-1.40), and noncompressible (>1.40). SCD was defined as a sudden pulseless condition presumed to be caused by a ventricular tachyarrhythmia in a previously stable individual and was adjudicated by a committee of cardiac electrophysiologists, cardiologists, and internists. Cox proportional hazards models were used to evaluate the associations between baseline ABI and incident SCD. Of the 15 081 participants followed for a median of 23.5 years, 556 (3.7%) developed SCD (1.96 cases per 1000 person-years). Low and borderline ABIs were associated with an increased risk of SCD (demographically adjusted hazard ratios [HRs], 2.27 [95% CI, 1.64-3.14] and 1.52 [95% CI, 1.17-1.96], respectively) compared with normal ABI. The association between low ABI and SCD remained significant after adjustment for traditional cardiovascular risk factors (HR, 1.63 [95% CI, 1.15-2.32]). CONCLUSIONS: Low ABI is independently associated with an increased risk of SCD in a middle-aged biracial general population. ABI could be incorporated into future SCD risk prediction models.

Association of Segment-Specific Pulse Wave Velocity With Vascular Calcification: The ARIC (Atherosclerosis Risk in Communities) Study.

BACKGROUND: Pulse wave velocity (PWV) is a noninvasive measure of arterial stiffness and predictor of cardiovascular disease. However, the association between PWV and vascular calcification across different vascular beds has not been fully investigated. This study aimed to quantify the association between PWV and multiterritory calcification and to explore whether PWV can identify individuals with vascular calcification beyond traditional risk factors. METHODS AND RESULTS: Among 1351 older adults (mean age, 79.2 years [SD, 4.1]) from the ARIC (Atherosclerosis Risk in Communities) study, we measured segment-specific PWVs: heart-carotid, heart-femoral, carotid-femoral, heart-ankle, brachial-ankle, and femoral-ankle. Dependent variables were high calcium score (≥75th percentile of Agatston score) across different vascular beds: coronary arteries, aortic valve ring, aortic valve, mitral valve, ascending aorta, and descending aorta. Quartiles of carotid-femoral, heart-femoral, heart-ankle, and brachial-ankle PWV were significantly associated with coronary artery calcium (eg, adjusted odds ratio [OR] for the highest versus lowest quartile of carotid-femoral PWV, 1.84 [95% CI, 1.24-2.74]). Overall, PWVs were most strongly associated with descending aorta calcification, with significant results for carotid-femoral, heart-femoral, heart-ankle, and brachial-ankle PWV (eg, adjusted OR for the highest versus lowest quartile of carotid-femoral PWV, 3.99 [95% CI, 2.61-6.17]). In contrast, femoral-ankle PWV was inversely associated with descending aorta calcification. Some PWVs improved the discrimination of coronary artery calcium and descending aorta calcification beyond traditional risk factors. CONCLUSIONS: The associations of PWV with vascular calcification varied substantially across segments, with descending aorta calcification most closely linked to PWVs. Our study suggests that some PWVs, especially carotid-femoral PWV, are helpful to identify individuals with coronary artery calcium and descending aorta calcification.

Blood Pressure, Hypertension, and Antihypertensive Medication Use and Risk of Total and Fatal Prostate Cancer in Black and White Men in the Atherosclerosis Risk in Communities (ARIC) Study.

Black men are disproportionately burdened by hypertension and prostate cancer (PCa), and some cohorts suggest hypertension is associated with increased PCa risk. We investigated the association of hypertension and antihypertensive use with total (N = 889; 290 Black, 599 White) and fatal (N = 127; 42 Black, 85 White) PCa risk in 6658 (1578 Black, 5080 White) men in the Atherosclerosis Risk in Communities study. In adjusted Cox models, time-updated untreated stage 1 hypertension (systolic/diastolic blood pressure 130-139/80-89 mmHg) was associated with a higher risk of fatal PCa compared to untreated normal blood pressure (hazard ratio (HR) = 1.95; 95% confidence interval (CI) = 1.03-3.70). Compared to untreated normal/elevated blood pressure (combined given few events in those with untreated normal blood pressure), the association was significant in Black (HR = 3.35; 95% CI = 1.27-8.83), but not White (HR = 1.21; 95% CI = 0.58-2.55) men. Ever antihypertensive use was associated with a lower risk of fatal PCa compared to never use (HR = 0.52; 95% CI = 0.31-0.87), including short-term (< 10 years) and long-term (310 years) use (p-trend = 0.02) with similar inverse associations in Black and White men. Hypertension and antihypertensive use were not significantly associated with total PCa. The positive association of untreated stage 1 hypertension and fatal PCa warrants additional confirmation, especially in Black men, and characterization of the underlying mechanism.