Arterial stiffness and left ventricular diastolic dysfunction: insights from the cardio-ankle vascular index

BACKGROUND: Arterial stiffness is a contributor to cardiovascular morbidity, but its role in elevated left ventricular (LV) filling pressure and heart failure with preserved ejection fraction (HFpEF) remains incompletely understood. OBJECTIVES: This study aimed to evaluate the relationship between arterial stiffness and the ratio of early diastolic transmitral flow velocity (E) to early diastolic mitral annulus velocity (e'), as well as its association with LV diastolic dysfunction. METHODS: This study cross-sectionally analyzed 335 patients with cardiovascular disease and an ejection fraction ≥50% who underwent the Cardio-Ankle Vascular Index (CAVI) measurement. Multivariable logistic regression was used to identify independent associated factors of elevated LV filling pressure, defined as E/e' >14. Smoothing spline analysis was used to assess the dose-response relationship between CAVI, age, and elevated E/e'. Mediation analysis was used to assess the direct and indirect effects of CAVI, age, and hypertension on elevated filling pressure. RESULTS: CAVI was independently associated with E/e' >14 (odds ratio (OR) 1.43; 95% confidence interval (CI): 1.17-1.74, p< 0.001) and diastolic dysfunction (OR 1.25; 95% CI 1.03-1.52, p = 0.024). CAVI enhanced risk stratification for elevated filling pressure (net reclassification index = 0.588, p < 0.001; integrated discrimination improvement = 0.035, p= 0.008). Smoothing spline analysis revealed a near-exponential increase in E/e' >14 risk above a CAVI threshold of 9.275. Mediated analysis indicated that CAVI accounted for 18.7% of the effect of age on elevated E/e' (p = 0.006). CONCLUSION: Arterial stiffness, as quantified by CAVI, independently increases the LV filling pressure and mediates age-related effects.