Mediation effect of arterial stiffness on ideal cardiovascular health and stroke

Ideal cardiovascular health (CVH) metrics was associated with stroke, but the causal pathway was poorly investigated. Arterial stiffness was a major factor associated with both ideal CVH metrics and stroke. This study aimed to investigate whether the effect of ideal CVH metrics on stroke was mediated and enhanced by arterial stiffness.

A total of 15,297 participants were included in current study. Arterial stiffness was measured by brachial-ankle pulse wave velocity (baPWV). Causal mediation analyses were used to separate the overall effects of ideal CVH metrics on stroke into indirect effects (mediated by arterial stiffness) and direct effects (mediated through pathways other than arterial stiffness). After a median follow-up of 5.88 years, 324 total stroke events (292 ischemic stroke and 31 hemorrhagic stroke) occurred. Mediation analysis showed 23.94% of the relation between ideal CVH and total stroke was mediated by baPWV (95% confidence interval [CI] of the indirect effect: 0.93-0.95). Further analysis showed the ideal CVH < median combined with baPWV ≥1400 cm/s was associated with the highest risk of total stroke (hazard ratio: 5.62; 95% CI, 3.53-8.96), compared with CVH ≥ median combined with baPWV < 1400 cm/s. Similar results were observed for ischemic stroke, but not for hemorrhagic stroke.

Arterial stiffness played a mediating role in the associations between ideal CVH metrics and risk of total and ischemic stroke. Combined ideal CVH metrics and baPWV is a reasonable and useful tool for the assessment and prevention of stroke.